View KB3408B-33_4126770.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

Kingbor Technology Co.,Ltd
TEL:(86)0755-26508846 FAX:(86)0755-26509052
KB3408
1.5MHz, 350mA Synchronous Step-Down Regulator in SOT23-5
FEATURES

DESCRIPTION
The KB3408 is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode architecture. The device is available in an adjustable version and fixed output voltages of 1.8V and 3.3V. Supply current during operation is only 20A and drops to 1A in shutdown. The 2.5V to 7.4V input voltage range makes the KB3408 ideally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems. Automatic Burst Mode operation increases efficiency at light loads, further extending battery life. Switching frequency is internally set at 1.5MHz, allowing the use of small surface mount inductors and capacitors. The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. Low output voltages are easily supported with the 0.6V feedback reference voltage. The KB3408 is available in a low profile (1mm) SOT23-5 package.
High Efficiency: Up to 96% Very Low Quiescent Current: Only 20A During Operation 350mA Output Current 2.5V to 7.4V Input Voltage Range 1.5MHz Constant Frequency Operation No Schottky Diode Required Low Dropout Operation: 100% Duty Cycle 0.6V Reference Allows Low Output Voltages Shutdown Mode Draws 1A Supply Current Current Mode Operation for Excellent Line and Load Transient Response Overtemperature Protected Low Profile (1mm) SOT23-5 Package
APPLICATIONS

Cellular Telephones Personal Information Appliances Wireless and DSL Modems Digital Still Cameras MP3 Players Portable Instruments
TYPICAL APPLICATION
95 90
VIN 2.7V TO 7.4V 4.7H COUT 10F CER 5 VOUT 1.8V 350mA
VIN = 2.7V
85
EFFICIENCY (%)
4
+
CIN 4.7F Tan 1
VIN
SW
3
VIN = 3.6V 80 VIN = 4.2V 75 70 65 60 0.1 VOUT = 1.8V 1 10 100 OUTPUT CURRENT (mA) 500
KB3408-1.8 RUN VOUT 2
GND
Figure 1a. High Efficiency Step-Down Converter
Figure 1b. Efficiency vs Load Current
March 2007
1
KB3408
Kingbor Technology Co.,Ltd
TEL:(86)0755-26508846 FAX:(86)0755-26509052
KB3408
Peak SW Sink and Source Current .................... 350mA Operating Temperature Range (Note 2) .. - 40C to 85C Junction Temperature (Note 3) ............................ 125C Storage Temperature Range ................ - 65C to 150C Lead Temperature (Soldering, 10 sec)................. 300C
ABSOLUTE MAXIMUM RATINGS (Note 1)
Input Supply Voltage .................................. - 0.3V to 7.5V RUN, VFB Voltages ..................................... - 0.3V to VIN SW Voltage .................................. - 0.3V to (VIN + 0.3V) P-Channel Switch Source Current (DC) ............. 400mA N-Channel Switch Sink Current (DC) ................. 400mA
PACkAGE/ORDER INFORMATION
TOP VIEW
ORDER PART NUMBER
5 VFB 4 VIN
TOP VIEW
RUN 1 GND 2 SW 3
KB3408-ADJ
Top Marking
RUN 1 GND 2 SW 3
5 VOUT 4 VIN
ORDER PART NUMBER KB3408B-1.8
Top Marking
Marking
S5 PACKAGE 5-LEAD PLASTIC TSOT-23
Marking
JA
xxxx KB3408B-3.3
Top Marking
A19x x: DateCode
S5 PACKAGE 5-LEAD PLASTIC TSOT-23
TJMAX = 125C,
JA = 250C/ W, JC = 90C/ W
TJMAX = 125C,
= 250C/ W,
JC
= 90C/ W
xxxx
ELECTRICAL CHARACTERISTICS
The denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25C. VIN = 3.6V unless otherwise specified.
SYMBOL IVFB VFB PARAMETER Feedback Current Regulated Feedback Voltage KB3408 (Note 4) T A = 25C KB3408 (Note 4) 0 C TA 85C KB3408 (Note 4) -40 C TA 85C VIN = 2.5V to 7.4V (Note 4) KB3408-1.8, I OUT = 100mA KB3408-3.3, I OUT = 100mA VIN = 2.5V to 7.4V VIN = 3V, VFB = 0.5V or VOUT = 90%, Duty Cycle < 35%
CONDITIONS
MIN 0.5880 0.5865 0.5850 1.755 3.246 0.40
TYP 0.6 0.6 0.6 0.4 1.800 3.300 0.4 0.45 0.5
MAX 30 0.6120 0.6135 0.6150 1 1.845 3.354 1 0.5
UNITS nA V V V %/V V V %/V A %

VFB VOUT VOUT IPK VLOADREG VIN IS
Reference Voltage Line Regulation Regulated Output Voltage Output Voltage Line Regulation Peak Inductor Current Output Voltage Load Regulation Input Voltage Range Input DC Bias Current Active Mode Sleep Mode Shutdown Oscillator Frequency RDS(ON) of P-Channel FET RDS(ON) of N-Channel FET SW Leakage
2.5 250 20 0.1
7.4 400 35 1 1.8 0.5 0.45 1
V A A A MHz kHz
(Note 5) VFB = 0.5V or VOUT = 90%, ILOAD = 0A VFB = 0.62V or VOUT = 103%, ILOAD = 0A VRUN = 0V, VIN = 4.2V VFB = 0.6V or VOUT = 100% VFB = 0V or VOUT = 0V ISW = 100mA ISW = -100mA VRUN = 0V, VSW = 0V or 5V, VIN = 5V
fOSC RPFET RNFET ILSW
1.2
1.5 210 0.4 0.35 0.01
A
March 2007
2
KB3408
Kingbor Technology Co.,Ltd
TEL:(86)0755-26508846 FAX:(86)0755-26509052
KB3408
ELECTRICAL CHARACTERISTICS
The denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25C. VIN = 3.6V unless otherwise specified.
SYMBOL VRUN IRUN PARAMETER RUN Threshold RUN Leakage Current CONDITIONS

MIN 0.3
TYP 1 0.01
MAX 1.5 1
UNITS V A
Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The KB3408 is guaranteed to meet performance specifications from 0C to 70C. Specifications over the -40C to 85C operating temperature range are assured by design, characterization and correlation with statistical process controls.
Note 3: TJ is calculated from the ambient temperature TA and power dissipation PD according to the following formula: KB3408: T J = TA + (PD)(250C/W) Note 4: The KB3408 is tested in a proprietary test mode that connects VFB to the output of the error amplifier. Note 5: Dynamic supply current is higher due to the gate charge being delivered at the switching frequency.
TYPICAL PERFORMANCE CHARACTERISTICS
(From Figure1a Except for the Resistive Divider Resistor Values) Efficiency vs Input Voltage
100 95 90 IOUT = 100mA IOUT = 10mA
Efficiency vs Output Current
95 90 85
EFFICIENCY (%)
Efficiency vs Output Current
95 VOUT = 1.5V VIN = 2.7V VIN = 4.2V 80 VIN = 3.6V 75 70 65 60 0.1 90 85
VOUT = 1.2V VIN = 2.7V
EFFICIENCY (%)
85 IOUT = 1mA 80 75 70 65 60 55 50 VOUT = 1.8V 2 3 4 5 INPUT VOLTAGE (V) 6 IOUT = 0.1mA IOUT = 350mA
80 75 70 65 60 0.1
VIN = 4.2V VIN = 3.6V
1 10 100 OUTPUT CURRENT (mA)
500
EFFICIENCY (%)
1 10 100 OUTPUT CURRENT (mA)
500
Efficiency vs Output Current
100 95 90
EFFICIENCY (%)
Reference Voltage vs Temperature
0.614 VIN = 3.6V 0.609 1.65 1.60 0.604 0.599 0.594 0.589 0.584 -50 -25 1.70
Oscillator Frequency vs Temperature
VIN = 3.6V
VOUT = 2.5V VIN = 2.7V REFERENCE VOLTAGE (V) VIN = 3.6V
FREQUENCY (MHz)
50 25 75 0 TEMPERATURE (C) 100 125
85 80 75 70 65 60 0.1 1 10 100 OUTPUT CURRENT (mA) 500 VIN = 4.2V
1.55 1.50 1.45 1.40 1.35 1.30 -50 -25 50 25 75 0 TEMPERATURE (C) 100 125
March 2007
3
Kingbor Technology Co.,Ltd
TEL:(86)0755-26508846 FAX:(86)0755-26509052
KB3408
TYPICAL PERFORMANCE CHARACTERISTICS
(From Figure 1a Except for the Resistive Divider Resistor Values) Start-Up from Shutdown
RUN 2V/DIV VOUT 2V/DIV
VOUT 100mV/DIV AC COUPLED IL 500mA/DIV
Load Step
VOUT 100mV/DIV AC COUPLED
Load Step
IL 500mA/DIV ILOAD 500mA/DIV
VIN = 3.6V 20s/DIV VOUT = 1.8V ILOAD = 0mA TO 350mA
ILOAD 500mA/DIV
ILOAD 500mA/DIV
VIN = 3.6V VOUT = 1.8V ILOAD = 350mA
40s/DIV
VIN = 3.6V 20s/DIV VOUT = 1.8V ILOAD = 50mA TO 350mA
Load Step
VOUT 100mV/DIV AC COUPLED
Load Step
VOUT 100mV/DIV AC COUPLED
IL 500mA/DIV
IL 500mA/DIV
ILOAD 500mA/DIV VIN = 3.6V 20s/DIV VOUT = 1.8V ILOAD = 100mA TO 350mA
ILOAD 500mA/DIV VIN = 3.6V 20s/DIV VOUT = 1.8V ILOAD = 200mA TO 350mA
PIN FUNCTIONS
RUN (Pin 1): Run Control Input. Forcing this pin above 1.5V enables the part. Forcing this pin below 0.3V shuts down the device. In shutdown, all functions are disabled drawing <1A supply current. Do not leave RUN floating. GND (Pin 2): Ground Pin. SW (Pin 3): Switch Node Connection to Inductor. This pin connects to the drains of the internal main and synchronous power MOSFET switches. VIN (Pin 4): Main Supply Pin. Must be closely decoupled to GND, Pin 2, with a 2.2F or greater ceramic capacitor. VFB (Pin 5) (kB3408): Feedback Pin. Receives the feedback voltage from an external resistive divider across the output. VOUT (Pin 5) (kB3408-1.8/kB3408-3.3): Output Voltage Feedback Pin. An internal resistive divider divides the output voltage down for comparison to the internal reference voltage.
4
March 2007
Kingbor Technology Co.,Ltd
TEL:(86)0755-26508846 FAX:(86)0755-26509052
KB3408
SIMPLIFIED BLOC DIAGRAM
SLOPE COMP OSC OSC
0.65V
FREQ SHIFT VFB /VOUT 5 R1 FB R2 0.6V
4 VIN
- + - +
EA 0.4V
- +
BURST S R Q Q
SLEEP
-
ICOMP
+
5
RS LATCH VIN RUN 1 0.6V REF
SWITCHING LOGIC AND BLANKING CIRCUIT
ANTISHOOTTHRU
3 SW
SHUTDOWN
TYPICAL APPLICATION
Tiny 3.3V/350mA Buck Regulator
VIN 3.6V to 7.4V 4 VIN SW 3 4.7H 22pF KB3408 1 RUN GND 2 VFB 5 450k 100k ** TAIYO YUDEN JMK316BJ106ML VOUT 3.3V 350mA COUT** 10F CER
+
CIN 4.7F
100
VIN = 5V 95 VOUT = 3.3V 90
VOUT 100mV/DIV AC COUPLED IL 500mA/DIV
EFFICIENCY (%)
85 80 75 70 65 60 0.1 1 10 100 OUTPUT CURRENT (mA) 500
ILOAD 500mA/DIV VIN = 5V 20s/DIV VOUT = 3.3V ILOAD = 200mA TO 350mA
March 2007
5
-
IRCMP
+
2 GND
Kingbor Technology Co.,Ltd
TEL:(86)0755-26508846 FAX:(86)0755-26509052
KB3408
PACAGE DESCRIPTION
S5 Package 5-Lead Plastic TSOT-23(SOT23-5)
0.62 MAX
0.95 REF
2.90 BSC (NOTE 4)
1.22 REF
3.85 MAX 2.62 REF
1.4 MIN
2.80 BSC
1.50 - 1.75 (NOTE 4)
PIN ONE RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR 0.30 - 0.45 TYP 5 PLCS (NOTE 3)
0.95 BSC
0.80 - 0.90 0.20 BSC 1.00 MAX DATUM `A' 0.01 - 0.10
0.30 - 0.50 REF 0.09 - 0.20 (NOTE 3) NOTE: 1. DIMENSIONS ARE IN MILLIMETERS 2. DRAWING NOT TO SCALE 3. DIMENSIONS ARE INCLUSIVE OF PLATING 4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 5. MOLD FLASH SHALL NOT EXCEED 0.254mm 6. JEDEC PACKAGE REFERENCE IS MO-193
1.90 BSC
Kingbor Technology
TEL:(86)0755-26508846 FAX:(86)0755-26509052 www.kingbor.com
6
March 2007

▲Up To Search▲

Price & Availability of KB3408B-33

	To Download KB3408B-33 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .