 |
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
| Datasheet File OCR Text: |
| 19-2618; Rev 1; 4/03 80mW, Fixed-Gain, DirectDrive, Stereo Headphone Amplifier with Shutdown General Description The MAX4411 fixed-gain, stereo headphone amplifier is designed for portable equipment where board space is at a premium. The MAX4411 uses a unique, patented DirectDrive architecture to produce a ground-referenced output from a single supply, eliminating the need for large DC-blocking capacitors, saving cost, board space, and component height. Additionally, the gain of the amplifier is set internally (-1.5V/V, MAX4411 and -2V/V, MAX4411B), further reducing component count. The MAX4411 delivers up to 80mW per channel into a 16 load and has low 0.003% THD+N. An 86dB at 217Hz power-supply rejection ratio (PSRR) allows this device to operate from noisy digital supplies without an additional linear regulator. The MAX4411 includes 8kV ESD protection on the headphone outputs. Comprehensive click-and-pop circuitry suppresses audible clicks and pops on startup and shutdown. Independent left/right, low-power shutdown controls make it possible to optimize power savings in mixed-mode, mono/stereo applications. The MAX4411 operates from a single 1.8V to 3.6V supply, consumes only 5mA of supply current, has short-circuit and thermal-overload protection, and is specified over the extended -40C to +85C temperature range. The MAX4411 is available in a tiny (2mm 2mm 0.6mm), 16-bump chip-scale package (UCSPTM) and a 20-pin thin QFN package (4mm 4mm 0.8mm). Features o No Bulky DC-Blocking Capacitors Required o Fixed -1.5V/V Gain Eliminates External Feedback Network MAX4411: -1.5V/V MAX4411B: -2V/V o Ground-Referenced Outputs Eliminate DC-Bias Voltages on Headphone Ground Pin o No Degradation of Low-Frequency Response Due to Output Capacitors o 80mW per Channel into 16 o Low 0.003% THD+N o High PSRR (86dB at 217Hz) o Integrated Click-and-Pop Suppression o 1.8V to 3.6V Single-Supply Operation o Low Quiescent Current (5mA) o Independent Left/Right, Low-Power Shutdown Controls o Short-Circuit and Thermal-Overload Protection o 8kV ESD-Protected Amplifier Outputs o Available in Space-Saving Packages 16-Bump UCSP (2mm 2mm 0.6mm) 20-Pin Thin QFN (4mm 4mm 0.8mm) MAX4411 Ordering Information PART MAX4411EBE-T MAX4411ETP MAX4411BEBE-T MAX4411BETP TEMP RANGE -40C to +85C -40C to +85C -40C to +85C -40C to +85C PIN/BUMPPACKAGE 16 UCSP-16 20 Thin QFN 16 UCSP-16 20 Thin QFN GAIN (V/V) -1.5 -1.5 -2 -2 Applications Notebook PCs Cellular Phones PDAs MP3 Players Smart Phones Portable Audio Equipment UCSP is a trademark of Maxim Integrated Products, Inc. Functional Diagram LEFT AUDIO INPUT DirectDrive OUTPUTS ELIMINATE DC-BLOCKING CAPACITORS SHDNL SHDNR MAX4411 RIGHT AUDIO INPUT FIXED GAIN ELIMINATES EXTERNAL RESISTOR NETWORK Pin Configurations and Typical Application Circuit appear at end of data sheet. ________________________________________________________________ Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com. 80mW, Fixed-Gain, DirectDrive, Stereo Headphone Amplifier with Shutdown MAX4411 ABSOLUTE MAXIMUM RATINGS PGND to SGND .....................................................-0.3V to +0.3V PVDD to SVDD .................................................................-0.3V to +0.3V PVSS to SVSS .........................................................-0.3V to +0.3V PVDD and SVDD to PGND or SGND .........................-0.3V to +4V PVSS and SVSS to PGND or SGND ..........................-4V to +0.3V IN_ to SGND ................................(SVSS - 0.3V) to (SVDD + 0.3V) SHDN_ to SGND........................(SGND - 0.3V) to (SVDD + 0.3V) OUT_ to SGND .............................(SVSS - 0.3V) to (SVDD +0.3V) C1P to PGND.............................(PGND - 0.3V) to (PVDD + 0.3V) C1N to PGND .............................(PVSS - 0.3V) to (PGND + 0.3V) Output Short Circuit to GND or VDD ...........................Continuous Continuous Power Dissipation (TA = +70C) 16-Bump UCSP (derate 7.4mW/C above +70C)........589mW 20-Pin Thin QFN (derate 16.9mW/C above +70C) ..1349mW Junction Temperature ......................................................+150C Operating Temperature Range ...........................-40C to +85C Storage Temperature Range .............................-65C to +150C Bump Temperature (soldering) Reflow ..........................................................................+230C Lead Temperature (soldering, 10s) .................................+300C Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (PVDD = SVDD = 3V, PGND = SGND = 0V, SHDNL = SHDNR = SVDD, C1 = C2 = 2.2F, CIN = 1F, RL = , TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 1) PARAMETER Supply Voltage Range Quiescent Supply Current Shutdown Supply Current SYMBOL VDD IDD I SHDN CONDITIONS Guaranteed by PSRR test One channel enabled Two channels enabled SHDNL = SHDNR = GND VIH SHDN_ Thresholds VIL SHDN_ Input Leakage Current SHDN_ to Full Operation CHARGE PUMP Oscillator Frequency AMPLIFIERS Voltage Gain Gain Match Total Output Offset Voltage Input Resistance AV AV VOS RIN 1.8V VDD 3.6V, MAX4411 Power-Supply Rejection Ratio PSRR VDD = 3.0V, 200mVP-P ripple, MAX4411 (Note 3) DC (Note 2) fRIPPLE = 217Hz fRIPPLE = 1kHz fRIPPLE = 20kHz Input AC-coupled MAX4411 MAX4411B 10 72 MAX4411 MAX4411B -1.55 -2.1 -1.5 -2 1 0.7 0.75 14 86 86 75 53 dB 2.8 3.0 19 -1.45 -1.9 V/V % mV k fOSC 272 320 368 kHz tSON -1 175 0.7 x SVDD 0.3 x SVDD +1 A s MIN 1.8 3.2 5 6 8.4 10 TYP MAX 3.6 UNITS V mA A V 2 _______________________________________________________________________________________ 80mW, Fixed-Gain, DirectDrive, Stereo Headphone Amplifier with Shutdown ELECTRICAL CHARACTERISTICS (continued) (PVDD = SVDD = 3V, PGND = SGND = 0V, SHDNL = SHDNR = SVDD, C1 = C2 = 2.2F, CIN = 1F, RL = , TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 1) PARAMETER SYMBOL CONDITIONS 1.8V VDD 3.6V, MAX4411B Power-Supply Rejection Ratio PSRR VDD = 3.0V, 200mVP-P ripple, MAX4411B (Note 3) THD+N 1% TA = +25C DC (Note 2) fRIPPLE = 217Hz fRIPPLE = 1kHz fRIPPLE = 20kHz RL = 32 RL = 16 RL = 32, POUT = 50mW THD+N fIN = 1kHz RL = 16, POUT = 60mW MAX4411 MAX4411B 55 MIN 69 TYP 86 86 73 51 65 80 0.003 % 0.004 94 dB 95 0.8 No sustained oscillations RL = 16, POUT = 1.6mW, fIN = 10kHz 150 90 140 15 Human Body Model (OUTR, OUTL) 8 V/s pF dB C C kV mW dB MAX UNITS MAX4411 Output Power POUT Total Harmonic Distortion Plus Noise Signal-to-Noise Ratio Slew Rate Maximum Capacitive Load Crosstalk Thermal Shutdown Threshold Thermal Shutdown Hysteresis ESD Protection SNR SR CL RL = 32, POUT = 20mW, fIN = 1kHz, BW = 22Hz to 22kHz Note 1: All specifications are 100% tested at TA = +25C; temperature limits are guaranteed by design. Note 2: Inputs are connected directly to GND. Note 3: Inputs are AC-coupled to ground. Typical Operating Characteristics (C1 = C2 = 2.2F, THD+N measurement bandwidth = 22Hz to 22kHz, TA = +25C, unless otherwise noted.) TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY MAX4411 toc01 TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY MAX4411 toc02 TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY VDD = 1.8V RL = 16 MAX4411 toc03 1 VDD = 3V RL = 16 1 VDD = 3V RL = 32 1 THD+N (%) THD+N (%) THD+N (%) 0.1 POUT = 10mW POUT = 25mW 0.01 0.1 0.1 POUT = 5mW POUT = 10mW 0.01 POUT = 5mW 0.01 POUT = 10mW POUT = 50mW 0.001 10 100 1k FREQUENCY (Hz) 10k 100k 0.001 10 100 POUT = 25mW 0.001 1k FREQUENCY (Hz) 10k 100k 10 POUT = 20mW 100 1k FREQUENCY (Hz) 10k 100k _______________________________________________________________________________________ 3 80mW, Fixed-Gain, DirectDrive, Stereo Headphone Amplifier with Shutdown MAX4411 Typical Operating Characteristics (continued) (C1 = C2 = 2.2F, THD+N measurement bandwidth = 22Hz to 22kHz, TA = +25C, unless otherwise noted.) TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY MAX4411 toc04 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER MAX4411 toc05 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER VDD = 3V RL = 16 fIN = 1kHz OUTPUTS IN PHASE MAX4411 toc06 1 VDD = 1.8V RL = 32 100 10 VDD = 3V RL = 16 fIN = 20Hz OUTPUTS 180 OUT OF PHASE OUTPUTS IN PHASE 100 10 0.1 THD+N (%) THD+N (%) 1 POUT = 5mW 0.01 POUT = 10mW THD+N (%) 1 OUTPUTS 180 OUT OF PHASE 0.1 0.1 0.01 POUT = 20mW 0.001 10 100 1k FREQUENCY (Hz) 10k 100k 0.001 0 50 100 ONE CHANNEL DRIVEN 150 200 0.01 ONE CHANNEL DRIVEN 0.001 0 50 100 150 200 OUTPUT POWER (mW) OUTPUT POWER (mW) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER MAX4411 toc07 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER MAX4411 toc08 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER VDD = 3V RL = 32 fIN = 1kHz OUTPUTS IN PHASE MAX4411 toc09 100 VDD = 3V RL = 16 fIN = 10kHz OUTPUTS IN PHASE 100 10 10 VDD = 3V RL = 32 fIN = 20Hz 100 OUTPUTS IN PHASE 10 THD+N (%) THD+N (%) 1 OUTPUTS 180 OUT OF PHASE 0.1 1 THD+N (%) 1 0.1 OUTPUTS 180 OUT OF PHASE ONE CHANNEL DRIVEN 0 25 50 75 100 125 0.1 OUTPUTS 180 OUT OF PHASE 0.01 ONE CHANNEL DRIVEN 0 50 100 150 200 0.01 0.01 ONE CHANNEL DRIVEN 0 25 50 75 100 125 0.001 OUTPUT POWER (mW) 0.001 0.001 OUTPUT POWER (mW) OUTPUT POWER (mW) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER MAX4411 toc10 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER MAX4411 toc11 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER VDD = 1.8V RL = 16 fIN = 1kHz OUTPUTS IN PHASE MAX4411 toc12 100 100 10 VDD = 3V RL = 32 fIN = 10kHz OUTPUTS IN PHASE 10 VDD = 1.8V RL = 16 fIN = 20Hz OUTPUTS IN PHASE 100 10 THD+N (%) THD+N (%) 1 OUTPUTS 180 OUT OF PHASE 1 OUTPUTS 180 OUT OF PHASE 0.1 THD+N (%) 1 OUTPUTS 180 OUT OF PHASE 0.1 0.1 0.01 ONE CHANNEL DRIVEN 0.001 0 25 50 75 100 125 OUTPUT POWER (mW) 0.01 ONE CHANNEL DRIVEN 0 10 20 30 40 50 60 0.01 ONE CHANNEL DRIVEN 0 10 20 30 40 50 60 0.001 0.001 OUTPUT POWER (mW) OUTPUT POWER (mW) 4 _______________________________________________________________________________________ 80mW, Fixed-Gain, DirectDrive, Stereo Headphone Amplifier with Shutdown Typical Operating Characteristics (continued) (C1 = C2 = 2.2F, THD+N measurement bandwidth = 22Hz to 22kHz, TA = +25C, unless otherwise noted.) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER MAX4411 toc13 MAX4411 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER MAX4411 toc14 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER VDD = 1.8V RL = 32 fIN = 1kHz OUTPUTS IN PHASE MAX4411 toc15 100 10 VDD = 1.8V RL = 16 fIN = 10kHz 100 100 OUTPUTS IN PHASE 10 VDD = 1.8V RL = 32 fIN = 20Hz OUTPUTS IN PHASE 10 THD+N (%) THD+N (%) THD+N (%) 1 OUTPUTS 180 OUT OF PHASE 1 1 0.1 0.1 OUTPUTS 180 OUT OF PHASE 0.1 OUTPUTS 180 OUT OF PHASE ONE CHANNEL DRIVEN 0.01 ONE CHANNEL DRIVEN 0 10 20 30 40 50 60 0.01 ONE CHANNEL DRIVEN 0.001 0 10 20 30 40 50 0.01 0.001 OUTPUT POWER (mW) 0.001 0 10 20 30 40 50 OUTPUT POWER (mW) OUTPUT POWER (mW) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER VDD = 1.8V RL = 32 fIN = 10kHz MAX4411 toc16 POWER-SUPPLY REJECTION RATIO vs. FREQUENCY MAX4411 toc17 POWER-SUPPLY REJECTION RATIO vs. FREQUENCY -10 -20 -30 PSRR (dB) -40 -50 -60 -70 -80 -90 -100 VDD = 1.8V RL = 16 MAX4411 toc18 100 OUTPUTS IN PHASE 0 -10 -20 -30 VDD = 3V RL = 16 0 10 THD+N (%) 1 OUTPUTS 180 OUT OF PHASE ONE CHANNEL DRIVEN PSRR (dB) -40 -50 -60 -70 0.1 0.01 -80 -90 -100 50 10 100 1k FREQUENCY (Hz) 10k 100k 0.001 0 10 20 30 40 OUTPUT POWER (mW) 10 100 1k FREQUENCY (Hz) 10k 100k POWER-SUPPLY REJECTION RATIO vs. FREQUENCY MAX4411 toc19 POWER-SUPPLY REJECTION RATIO vs. FREQUENCY MAX4411 toc20 CROSSTALK vs. FREQUENCY VDD = 3V POUT = 1.6mW RL = 16 MAX4411 toc21 0 -10 -20 -30 PSRR (dB) VDD = 3V RL = 32 0 -10 -20 -30 PSRR (dB) 0 -20 -40 CROSSTALK (dB) -60 -80 -100 -120 -140 VDD = 1.8V RL = 32 -40 -50 -60 -70 -80 -90 -100 10 100 1k FREQUENCY (Hz) 10k 100k -40 -50 -60 -70 -80 -90 -100 10 100 1k FREQUENCY (Hz) 10k 100k LEFT TO RIGHT RIGHT TO LEFT 10 100 1k FREQUENCY (Hz) 10k 100k _______________________________________________________________________________________ 5 80mW, Fixed-Gain, DirectDrive, Stereo Headphone Amplifier with Shutdown MAX4411 Typical Operating Characteristics (continued) (C1 = C2 = 2.2F, THD+N measurement bandwidth = 22Hz to 22kHz, TA = +25C, unless otherwise noted.) OUTPUT POWER vs. SUPPLY VOLTAGE MAX4411 toc22 OUTPUT POWER vs. SUPPLY VOLTAGE MAX4411 toc23 OUTPUT POWER vs. SUPPLY VOLTAGE fIN = 1kHz RL = 32 THD+N = 1% MAX4411 toc24 200 180 160 OUTPUT POWER (mW) 140 120 100 80 60 40 20 0 1.8 2.1 2.4 2.7 3.0 3.3 INPUTS IN PHASE fIN = 1kHz RL = 16 THD+N = 1% INPUTS 180 OUT OF PHASE 300 250 OUTPUT POWER (mW) 200 150 100 50 0 INPUTS IN PHASE fIN = 1kHz RL = 16 THD+N = 10% INPUTS 180 OUT OF PHASE 140 120 OUTPUT POWER (mW) 100 80 60 40 20 0 INPUTS IN PHASE INPUTS 180 OUT OF PHASE 3.6 1.8 2.1 2.4 2.7 3.0 3.3 3.6 1.8 2.1 2.4 2.7 3.0 3.3 3.6 SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) OUTPUT POWER vs. SUPPLY VOLTAGE MAX4411 toc25 OUTPUT POWER vs. LOAD RESISTANCE MAX4411 toc26 OUTPUT POWER vs. LOAD RESISTANCE VDD = 3V fIN = 1kHz THD+N = 10% MAX4411 toc27 180 160 140 OUTPUT POWER (mW) 120 100 80 60 40 20 0 1.8 2.1 2.4 2.7 3.0 3.3 INPUTS IN PHASE fIN = 1kHz RL = 32 THD+N = 10% INPUTS 180 OUT OF PHASE 160 140 OUTPUT POWER (mW) 120 100 80 60 40 20 0 10 INPUTS IN PHASE 100 1k 10k INPUTS 180 OUT OF PHASE VDD = 3V fIN = 1kHz THD+N = 1% 250 200 OUTPUT POWER (mW) 150 INPUTS 180 OUT OF PHASE 100 50 INPUTS IN PHASE 100k 0 10 100 1k 10k 100k LOAD RESISTANCE () LOAD RESISTANCE () 3.6 SUPPLY VOLTAGE (V) OUTPUT POWER vs. LOAD RESISTANCE MAX4411 toc28 OUTPUT POWER vs. LOAD RESISTANCE MAX4411 toc29 POWER DISSIPATION vs. OUTPUT POWER 350 POWER DISSIPATION (mW) 300 250 200 150 100 50 0 INPUTS 180 OUT OF PHASE fIN = 1kHz RL = 16 VDD = 3V POUT = POUTL + POUTR INPUTS IN PHASE MAX4411 toc30 45 40 35 OUTPUT POWER (mW) 30 25 20 15 10 5 0 10 100 1k 10k INPUTS IN PHASE INPUTS 180 OUT OF PHASE VDD = 1.8V fIN = 1kHz THD+N = 1% 70 60 OUTPUT POWER (mW) 50 40 30 20 10 0 INPUTS IN PHASE INPUTS 180 OUT OF PHASE VDD = 1.8V fIN = 1kHz THD+N = 10% 400 100k 10 100 1k 10k 100k 0 40 80 120 160 200 LOAD RESISTANCE () LOAD RESISTANCE () OUTPUT POWER (mW) 6 _______________________________________________________________________________________ 80mW, Fixed-Gain, DirectDrive, Stereo Headphone Amplifier with Shutdown MAX4411 Typical Operating Characteristics (continued) (C1 = C2 = 2.2F, THD+N measurement bandwidth = 22Hz to 22kHz, TA = +25C, unless otherwise noted.) POWER DISSIPATION vs. OUTPUT POWER MAX4411 toc31 POWER DISSIPATION vs. OUTPUT POWER MAX4411 toc32 POWER DISSIPATION vs. OUTPUT POWER INPUTS IN PHASE MAX4411 toc33 180 160 POWER DISSIPATION (mW) 140 120 100 80 60 40 20 0 0 INPUTS IN PHASE 140 120 POWER DISSIPATION (mW) 100 80 60 40 20 0 fIN = 1kHz RL = 16 VDD = 1.8V POUT = POUTL + POUTR INPUTS IN PHASE 70 60 POWER DISSIPATION (mW) 50 40 30 20 10 0 fIN = 1kHz RL = 32 VDD = 1.8V POUT = POUTL + POUTR 0 10 20 30 40 50 INPUTS 180 OUT OF PHASE INPUTS 180 OUT OF PHASE INPUTS 180 OUT OF PHASE fIN = 1kHz RL = 32 VDD = 3V POUT = POUTL + POUTR 40 80 120 160 200 0 10 20 30 40 50 60 60 OUTPUT POWER (mW) OUTPUT POWER (mW) OUTPUT POWER (mW) GAIN FLATNESS vs. FREQUENCY MAX4411 toc34 CHARGE-PUMP OUTPUT RESISTANCE vs. SUPPLY VOLTAGE MAX4411 toc35 OUTPUT POWER vs. CHARGE-PUMP CAPACITANCE AND LOAD RESISTANCE C1 = C2 = 2.2F 80 C1 = C2 = 1F 70 OUTPUT POWER (mW) 60 50 40 30 20 10 C1 = C2 = 0.47F fIN = 1kHz THD+N = 1% INPUTS IN PHASE 10 20 30 40 50 C1 = C2 = 0.68F MAX4411 toc36 10 5 0 AV = -1.5V/V GAIN (dB) -5 -10 -15 -20 -25 -30 10 VDD = 3V RL = 16 100 1k 10k 100k AV = -2V/V 10 VIN_ = GND IPVSS = 10mA NO LOAD 90 OUTPUT RESISTANCE () 8 6 4 2 0 1M 1.8 2.1 2.4 2.7 3.0 3.3 3.6 FREQUENCY (Hz) SUPPLY VOLTAGE (V) 0 LOAD RESISTANCE () OUTPUT SPECTRUM vs. FREQUENCY MAX4411 toc37 SUPPLY CURRENT vs. SUPPLY VOLTAGE MAX4411 toc38 SHUTDOWN SUPPLY CURRENT vs. SUPPLY VOLTAGE SHDNL = SHDNR = GND 8 SUPPLY CURRENT (A) MAX4411 toc39 0 -20 OUTPUT SPECTRUM (dB) -40 -60 -80 -100 -120 0.1 1 10 VOUT = 1VP-P fIN = 1kHz RL = 32 10 10 8 SUPPLY CURRENT (mA) 6 6 4 4 2 2 0 100 0 0.9 1.8 2.7 3.6 FREQUENCY (kHz) SUPPLY VOLTAGE (V) 0 0 0.9 1.8 2.7 3.6 SUPPLY VOLTAGE (V) _______________________________________________________________________________________ 7 80mW, Fixed-Gain, DirectDrive, Stereo Headphone Amplifier with Shutdown MAX4411 Typical Operating Characteristics (continued) (C1 = C2 = 2.2F, THD+N measurement bandwidth = 22Hz to 22kHz, TA = +25C, unless otherwise noted.) EXITING SHUTDOWN MAX4411 toc40 POWER-UP/DOWN WAVEFORM MAX4411 toc41 3V 2V/div VDD SHDNR OUT_ OUTR 500mV/div -100dB 0V 10mV/div OUT_FFT 20dB/div fIN = 1kHz RL = 32 SHDNL = GND 200s/div RL = 32 VIN_ = GND 200ms/div FFT: 25Hz/div Pin Description PIN QFN 1 2 3 4, 6, 8, 12, 16, 20 5 7 9 10 11 13 14 15 17 18 19 -- BUMP UCSP A4 B4 C4 -- D4 D3 D2 D1 C2 C1 B1 A1 A2 B2 A3 -- NAME C1P PGND C1N N.C. PVSS SVSS OUTL SVDD OUTR INL SHDNR INR SGND SHDNL PVDD EP Flying Capacitor Positive Terminal Power Ground. Connect to ground (0V). Flying Capacitor Negative Terminal No Connection. Not internally connected. Charge-Pump Output Amplifier Negative Power Supply. Connect to PVSS. Left-Channel Output Amplifier Positive Power Supply. Connect to positive supply (1.8V to 3.6V). Right-Channel Output Left-Channel Audio Input Active-Low Right-Channel Shutdown. Connect to VDD for normal operation. Right-Channel Audio Input Signal Ground. Connect to ground (0V). Active-Low Left-Channel Shutdown. Connect to VDD for normal operation. Charge-Pump Power Supply. Powers charge-pump inverter, charge-pump logic, and oscillator. Connect to positive supply (1.8V to 3.6V). Exposed Paddle. Leave this connection floating. Do not tie to either GND or VDD. FUNCTION 8 _______________________________________________________________________________________ 80mW, Fixed-Gain, DirectDrive, Stereo Headphone Amplifier with Shutdown Detailed Description The MAX4411 fixed-gain, stereo headphone driver features Maxim's patented DirectDrive architecture, eliminating the large output-coupling capacitors required by conventional single-supply headphone drivers. The device consists of two 80mW Class AB headphone drivers, internal feedback network, undervoltage lockout (UVLO)/shutdown control, charge pump, and comprehensive click-and-pop suppression circuitry (see Typical Application Circuit). The charge pump inverts the positive supply (PVDD), creating a negative supply (PVSS). The headphone drivers operate from these bipolar supplies with their outputs biased about GND (Figure 1). The drivers have almost twice the supply range compared to other 3V single-supply drivers, increasing the available output power. The benefit of this GND bias is that the driver outputs do not have a DC component typically VDD/2. The large DC-blocking capacitors required with conventional headphone drivers are unnecessary, thus conserving board space, system cost, and improving frequency response. Each channel has independent left/right, active-low shutdown controls, optimizing power savings in mixedmode, mono/stereo operation. The device features an undervoltage lockout that prevents operation from an insufficient power supply and click-and-pop suppression that eliminates audible transients on startup and shutdown. Additionally, the MAX4411 features thermaloverload and short-circuit protection and can withstand 8kV ESD strikes on the output pins. MAX4411 VDD VOUT VDD/2 GND CONVENTIONAL DRIVER-BIASING SCHEME +VDD VOUT GND -VDD DirectDrive BIASING SCHEME Fixed Gain The MAX4411 utilizes an internally fixed gain configuration of either -1.5V/V (MAX4411) or -2V/V (MAX4411B). All gain-setting resistors are integrated into the device, reducing external component count. The internally set gain, in combination with DirectDrive, results in a headphone amplifier that requires only five tiny 1F capacitors to complete the amplifier circuit: two for the charge pump, two for audio input coupling, and one for powersupply bypassing (see Typical Application Circuit). Figure 1. Conventional Driver Output Waveform vs. MAX4411 Output Waveform DirectDrive Conventional single-supply headphone drivers have their outputs biased about a nominal DC voltage (typically half the supply) for maximum dynamic range. Large coupling capacitors are needed to block this DC bias from the headphone. Without these capacitors, a significant amount of DC current flows to the headphone, resulting in unnecessary power dissipation and possible damage to both headphone and headphone driver. Maxim's patented DirectDrive architecture uses a charge pump to create an internal negative supply volt- age. This allows the MAX4411 outputs to be biased about GND, almost doubling dynamic range while operating from a single supply. With no DC component, there is no need for the large DC-blocking capacitors. Instead of two large (220F, typ) tantalum capacitors, the MAX4411 charge pump requires two small ceramic capacitors, conserving board space, reducing cost, and improving the frequency response of the headphone driver. See the Output Power vs. Charge-Pump Capacitance and Load Resistance graph in the Typical Operating Characteristics for details of the possible capacitor sizes. There is a low DC voltage on the driver outputs due to amplifier offset. However, the offset of the MAX4411 is typically 0.7mV, which, when combined with a 32 load, results in less than 23A of DC current flow to the headphones. Previous attempts to eliminate the output-coupling capacitors involved biasing the headphone return (sleeve) to the DC-bias voltage of the headphone amplifiers. This 9 _______________________________________________________________________________________ 80mW, Fixed-Gain, DirectDrive, Stereo Headphone Amplifier with Shutdown MAX4411 MICROPHONE BIAS MICROPHONE AMPLIFIER MICROPHONE AMPLIFIER OUTPUT LOW-FREQUENCY ROLLOFF (RL = 16) 0 -3 -6 ATTENUATION (dB) -9 -12 -15 -18 -21 -24 33F DirectDrive 330F 220F 100F AUDIO INPUT AUDIO INPUT MAX4411 -27 -30 10 100 1k FREQUENCY (Hz) 10k 100k HEADPHONE DRIVER Figure 2. Earbud Speaker/Microphone Combination Headset Configuration Figure 3. Low-Frequency Attenuation for Common DC-Blocking Capacitor Values method raises some issues: * The sleeve is typically grounded to the chassis. Using this biasing approach, the sleeve must be isolated from system ground, complicating product design. * During an ESD strike, the driver's ESD structures are the only path to system ground. Thus, the driver must be able to withstand the full ESD strike. * When using the headphone jack as a line out to other equipment, the bias voltage on the sleeve may conflict with the ground potential from other equipment, resulting in possible damage to the drivers. * When using a combination microphone and speaker headset, the microphone typically requires a GND reference. The driver DC bias on the sleeve conflicts with the microphone requirements (Figure 2). f-3dB = 1 2RLCOUT Low-Frequency Response In addition to the cost and size disadvantages of the DCblocking capacitors required by conventional headphone amplifiers, these capacitors limit the amplifier's low-frequency response and can distort the audio signal: 1) The impedance of the headphone load and the DCblocking capacitor forms a highpass filter with the -3dB point set by: where RL is the impedance of the headphone and COUT is the value of the DC-blocking capacitor. The highpass filter is required by conventional single-ended, single power-supply headphone drivers to block the midrail DC-bias component of the audio signal from the headphones. The drawback to the filter is that it can attenuate low-frequency signals. Larger values of COUT reduce this effect but result in physically larger, more expensive capacitors. Figure 3 shows the relationship between the size of COUT and the resulting low-frequency attenuation. Note that the -3dB point for a 16 headphone with a 100F blocking capacitor is 100Hz, well within the normal audio band, resulting in low-frequency attenuation of the reproduced signal. 2) The voltage coefficient of the DC-blocking capacitor contributes distortion to the reproduced audio signal as the capacitance value varies as the function of the voltage across the capacitor changes. At low frequencies, the reactance of the capacitor dominates at frequencies below the -3dB point and the voltage coefficient appears as frequency-dependent distortion. Figure 4 shows the THD+N intro- 10 ______________________________________________________________________________________ 80mW, Fixed-Gain, DirectDrive, Stereo Headphone Amplifier with Shutdown ADDITIONAL THD+N DUE TO DC-BLOCKING CAPACITORS MAX4411 fig04 6A. The charge pump is enabled once either SHDN_ input is driven high. MAX4411 10 Click-and-Pop Suppression In conventional single-supply audio drivers, the outputcoupling capacitor is a major contributor of audible clicks and pops. Upon startup, the driver charges the coupling capacitor to its bias voltage, typically half the supply. Likewise, on shutdown, the capacitor is discharged to GND. This results in a DC shift across the capacitor, which in turn, appears as an audible transient at the speaker. Since the MAX4411 does not require output-coupling capacitors, this does not arise. Additionally, the MAX4411 features extensive click-andpop suppression that eliminates any audible transient sources internal to the device. The Power-Up/Down Waveform in the Typical Operating Characteristics shows that there are minimal spectral components in the audible range at the output upon startup or shutdown. In most applications, the output of the preamplifier driving the MAX4411 has a DC bias of typically half the supply. At startup, the input-coupling capacitor is charged to the preamplifier's DC-bias voltage through the RF of the MAX4411, resulting in a DC shift across the capacitor and an audible click/pop. Delaying the rise of the SHDN_ signals 4 to 5 time constants (80ms to 100ms) based on RIN and CIN, relative to the startup of the preamplifier, eliminates this click/pop caused by the input filter. 1 THD+N (%) 0.1 TANTALUM 0.01 0.001 ALUM/ELEC 0.0001 10 100 1k FREQUENCY (Hz) 10k 100k Figure 4. Distortion Contributed by DC-Blocking Capacitors duced by two different capacitor dielectric types. Note that below 100Hz, THD+N increases rapidly. The combination of low-frequency attenuation and frequency-dependent distortion compromises audio reproduction in portable audio equipment that emphasizes low-frequency effects such as multimedia laptops, as well as MP3, CD, and DVD players. By eliminating the DC-blocking capacitors through DirectDrive technology, these capacitor-related deficiencies are eliminated. Charge Pump The MAX4411 features a low-noise charge pump. The 320kHz switching frequency is well beyond the audio range, and thus does not interfere with the audio signals. The switch drivers feature a controlled switching speed that minimizes noise generated by turn-on and turn-off transients. By limiting the switching speed of the charge pump, the di/dt noise caused by the parasitic bond wire and trace inductance is minimized. Although not typically required, additional high-frequency noise attenuation can be achieved by increasing the size of C2 (see Typical Application Circuit). Applications Information Power Dissipation Under normal operating conditions, linear power amplifiers can dissipate a significant amount of power. The maximum power dissipation for each package is given in the Absolute Maximum Ratings section under Continuous Power Dissipation or can be calculated by the following equation: PDISSPKG(MAX) = TJ(MAX) - TA JA Shutdown The MAX4411 features two shutdown controls allowing either channel to be shut down or muted independently. SHDNL controls the left channel while SHDNR controls the right channel. Driving either SHDN_ low disables the respective channel, sets the driver output impedance to 1k, and reduces the supply current. When both SHDN_ inputs are driven low, the charge pump is also disabled, further reducing supply current draw to where TJ(MAX) is +150C, TA is the ambient temperature, and JA is the reciprocal of the derating factor in C/W as specified in the Absolute Maximum Ratings section. For example, JA of the QFN package is +59.3C/W. The MAX4411 has two power dissipation sources, the charge pump and the two drivers. If the power dissipation for a given application exceeds the maximum allowed for a given package, either reduce V DD , increase load impedance, decrease the ambient temperature, or add heatsinking to the device. Large 11 ______________________________________________________________________________________ 80mW, Fixed-Gain, DirectDrive, Stereo Headphone Amplifier with Shutdown MAX4411 OUTPUT POWER vs. SUPPLY VOLTAGE fIN = 1kHz RL = 16 THD+N = 10% INPUTS 180 OUT OF PHASE MAX4411 fig05 300 250 OUTPUT POWER (mW) 200 150 100 50 0 1.8 2.1 2.4 2.7 3.0 3.3 INPUTS IN PHASE PVSS is roughly proportional to PVDD and is not a regulated voltage. The charge-pump output impedance must be taken into account when powering other devices from PVSS. The charge-pump output impedance plot appears in the Typical Operating Characteristics. For best results, use 2.2F chargepump capacitors. Component Selection Input Filtering The input capacitor (CIN), in conjunction with the internal RIN, forms a highpass filter that removes the DC bias from an incoming signal (see Typical Application Circuit). The AC-coupling capacitor allows the amplifier to bias the signal to an optimum DC level. Assuming zero-source impedance, the -3dB point of the highpass filter is given by: 1 f-3dB = 2RINCIN RIN is the amplifier's internal input resistance value given in the Electrical Characteristics. Choose the CIN such that f-3dB is well below the lowest frequency of interest. Setting f-3dB too high affects the amplifier's lowfrequency response. Use capacitors whose dielectrics have low-voltage coefficients, such as tantalum or aluminum electrolytic ones. Capacitors with high-voltage coefficients, such as ceramics, may result in increased distortion at low frequencies. Charge-Pump Capacitor Selection Use capacitors with an ESR less than 100m for optimum performance. Low-ESR ceramic capacitors minimize the output resistance of the charge pump. For best performance over the extended temperature range, select capacitors with an X7R dielectric. Table 1 lists suggested manufacturers. Flying Capacitor (C1) The value of the flying capacitor (C1) affects the charge pump's load regulation and output resistance. A C1 value that is too small degrades the device's ability to provide sufficient current drive, which leads to a loss of output voltage. Increasing the value of C1 improves load regulation and reduces the charge-pump output resistance to an extent. See the Output Power vs. Charge-Pump Capacitance and Load Resistance graph in the Typical Operating Characteristics. Above 2.2F, the on-resistance of the switches and the ESR of C1 and C2 dominate. Hold Capacitor (C2) The hold capacitor value and ESR directly affect the ripple at PV SS. Increasing the value of C2 reduces 3.6 SUPPLY VOLTAGE (V) Figure 5. Output Power vs. Supply Voltage with Inputs In/Out of Phase output, supply, and ground traces improve the maximum power dissipation in the package. Thermal-overload protection limits total power dissipation in the MAX4411. When the junction temperature exceeds +140C, the thermal protection circuitry disables the amplifier output stage. The amplifiers are enabled once the junction temperature cools by 15C. This results in a pulsing output under continuous thermaloverload conditions. Output Power The device has been specified for the worst-case scenario--when both inputs are in phase. Under this condition, the drivers simultaneously draw current from the charge pump, leading to a slight loss in headroom of VSS. In typical stereo audio applications, the left and right signals have differences in both magnitude and phase, subsequently leading to an increase in the maximum attainable output power. Figure 5 shows the two extreme cases for in and out of phase. In reality, the available power lies between these extremes. Powering Other Circuits from a Negative Supply An additional benefit of the MAX4411 is the internally generated, negative supply voltage (PVSS). This voltage provides the ground-referenced output level. PVSS can, however, also be used to power other devices within a design limit current drawn from PVSS to 5mA; exceeding this affects the headphone driver operation. A typical application is a negative supply to adjust the contrast of LCD modules. 12 ______________________________________________________________________________________ 80mW, Fixed-Gain, DirectDrive, Stereo Headphone Amplifier with Shutdown MAX4411 Table 1. Suggested Capacitor Manufacturers SUPPLIER Taiyo Yuden TDK PHONE 800-348-2496 847-803-6100 FAX 847-925-0899 847-390-4405 WEBSITE www.t-yuden.com www.component.tdk.com Note: Please indicate you are using the MAX4411 when contacting these component suppliers. output ripple. Likewise, decreasing the ESR of C2 reduces both ripple and output resistance. Lower capacitance values can be used in systems with low maximum output power levels. See the Output Power vs. Charge-Pump Capacitance and Load Resistance graph in the Typical Operating Characteristics. Power-Supply Bypass Capacitor The power-supply bypass capacitor (C3) lowers the output impedance of the power supply, and reduces the impact of the MAX4411's charge-pump switching transients. Bypass PVDD with C3, the same value as C1, and place it physically close to the PVDD and PGND pins. device. Connect PV SS and SV SS together at the device. Bypassing of both supplies is accomplished by charge-pump capacitors C2 and C3 (see Typical Application Circuit). Place capacitors C2 and C3 as close to the device as possible. Route PGND and all traces that carry switching transients away from SGND and the traces and components in the audio signal path. The QFN package features an exposed paddle that improves thermal efficiency of the package. However, the MAX4411 does not require additional heatsinking. Ensure that the exposed paddle is isolated from GND or VDD. Do not connect the exposed paddle to GND or VDD. When using the MAX4411 in a UCSP package, make sure the traces to OUTR (bump C2) are wide enough to handle the maximum expected current flow. Multiple traces may be necessary. Adding Volume Control The addition of a digital potentiometer provides simple volume control. Figure 6 shows the MAX4411 with the MAX5408 dual log taper digital potentiometer used as an input attenuator. Connect the high terminal of the MAX5408 to the audio input, the low terminal to ground, and the wiper to CIN. Setting the wiper to the top position passes the audio signal unattenuated. Setting the wiper to the lowest position fully attenuates the input. UCSP Applications Information For the latest application details on UCSP construction, dimensions, tape carrier information, printed circuit board techniques, bump-pad layout, and recommended reflow temperature profile, as well as the latest information on reliability testing results, go to Maxim's website at www.maxim-ic.com/ucsp and look up the Application Note: UCSP-A Wafer-Level Chip-Scale Package. Layout and Grounding Proper layout and grounding are essential for optimum performance. Connect PGND and SGND together at a single point on the PC board. Connect all components associated with the charge pump (C2 and C3) to the PGND plane. Connect PVDD and SVDD together at the LEFT AUDIO INPUT 5 H0 CIN W0A 7 6 L0 13 INL OUTL 9 MAX5408 RIGHT AUDIO 12 H1 INPUT CIN W1A 10 11 L1 15 INR MAX4411 OUTR 11 Figure 6. MAX4411 and MAX5408 Volume Control Circuit ______________________________________________________________________________________ 13 80mW, Fixed-Gain, DirectDrive, Stereo Headphone Amplifier with Shutdown MAX4411 System Diagram VDD 0.1F 15k 0.1F 15k INR VDD PVDD 0.1F AUX_IN OUT 0.1F 15k OUTR+ OUTR- 1F 1F BIAS MAX9710 SHDN OUTLINL CODEC 15k VCC OUTL+ VCC 10k INQ Q VCC 10k 100k 100k IN+ 0.1F SHDNL SHDNR 1F INL VCC 1F INR PVDD SVDD C1P CIN OUTR PVSS SVSS 1F 1F MAX4060 BIAS 2.2k 0.1F IN+ IN0.1F MAX961 MAX4411 OUTL 1F 14 ______________________________________________________________________________________ 80mW, Fixed-Gain, DirectDrive, Stereo Headphone Amplifier with Shutdown Typical Application Circuit 1.8V TO 3.6V LEFT CHANNEL AUDIO IN 19 (A3) PVDD 10 (D1) SVDD 18 (B2) SHDNL CIN 1F MAX4411 C3 1F 14 (B1) SHDNR 13 (C1) INL RF* RIN 14k SVDD 9 OUTL (D2) 1 (A4) C1P UVLO/ SHUTDOWN CONTROL SVSS CHARGE PUMP HEADPHONE JACK C1 1F 3 (C4) C1N CLICK-AND-POP SUPPRESSION SGND SVDD SGND RIN 14k OUTR 11 (C2) MAX4411 SVSS RF PVSS 5 (D4) C2 1F SVSS PGND 2 7 (D3) (B4) SGND 17 (A2) RIGHT CHANNEL AUDIO IN CIN 1F INR 15 (A1) *MAX4411: 21k, MAX4411B: 28k ( ) UCSP BUMPS. ______________________________________________________________________________________ 15 80mW, Fixed-Gain, DirectDrive, Stereo Headphone Amplifier with Shutdown MAX4411 Pin Configurations N.C. 20 PVDD 19 SHDNL 18 SGND 17 1 A INR B SHDNR C INL 2 3 4 TOP VIEW SGND PVDD C1P 1 2 SHDNL PGND C1P PGND C1N N.C. PVSS OUTL 10 SVDD SVSS N.C. 16 TOP VIEW (BUMPS SIDE DOWN) MAX4411 INR 15 SHDNR 14 3 OUTR C1N MAX4411 INL 13 N.C. 12 OUTR 11 4 5 SVDD OUTL SVSS PVSS 6 N.C. 7 8 N.C. D UCSP (B16-2) QFN Chip Information TRANSISTOR COUNT: 4295 PROCESS: BiCMOS 16 ______________________________________________________________________________________ 9 80mW, Fixed-Gain, DirectDrive, Stereo Headphone Amplifier with Shutdown Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) MAX4411 ______________________________________________________________________________________ 16L,UCSP.EPS 17 80mW, Fixed-Gain, DirectDrive, Stereo Headphone Amplifier with Shutdown MAX4411 Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.) 24L QFN THIN.EPS PACKAGE OUTLINE 12,16,20,24L QFN THIN, 4x4x0.8 mm 21-0139 A PACKAGE OUTLINE 12,16,20,24L QFN THIN, 4x4x0.8 mm 21-0139 A Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 18 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. |
Price & Availability of MAX4411
 |
|
|
|
|
All Rights Reserved © IC-ON-LINE 2003 - 2022 |
| [Add Bookmark] [Contact Us] [Link exchange] [Privacy policy] |
|
Mirror Sites : [www.datasheet.hk]
[www.maxim4u.com] [www.ic-on-line.cn]
[www.ic-on-line.com] [www.ic-on-line.net]
[www.alldatasheet.com.cn]
[www.gdcy.com]
[www.gdcy.net] |