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SC560
Dual Output Low Noise LDO Linear Regulator
POWER MANAGEMENT Features
Input voltage range -- 2.5V to 5.5V Output voltage ranges -- 1.2V to 3.3V (each LDO) Maximum output current -- 300mA (both LDOs) Dropout at 200mA load -- 200mV max. Quiescent supply current -- 100A (both LDOs enabled) Shutdown current -- 100nA (typ) Output noise < 50VRMS (SC560A and fixed output versions) PSRR < -65dB at 1kHz (SC560A and fixed output versions) Over-temperature protection Short-circuit protection Under-voltage lockout Power good monitor for output A (SC560C and fixed output versions) Independent enable/disable for LDOB (SC560C and fixed output versions) MLPQ-UT8, 1.5mm x 1.5mm x 0.6mm package
Description
The SC560 is a family of dual output, ultra-low dropout linear voltage regulators designed for use in battery powered wireless applications. The SC560A, SC560B, and SC560C provide adjustable output voltages that can be set using two external resistors. Fixed output voltages are also available (see ordering information for available combinations). Fixed output devices provide the powergood monitor, independent enable pins, and a bypass pin for low-noise operation All members of the SC560 family require an input voltage level between 2.5V and 5.5V. Output voltages for the adjustable versions can vary between 1.2V and 3.3V. Fixed output voltage options are also chosen from this range. The SC560A provides superior low-noise performance by using an external bypass capacitor connected to pin 7 to filter the bandgap reference. The SC560B uses pin 7 as a separate enable pin for the second regulator output so the two outputs can be controlled independently. The SC560C uses this pin to provide a PGOOD output to hold a processor in reset when the voltage on OUTA is not in regulation. All other versions provide all three functions with fixed output voltages (no feedback pins are provided). The device also provides protection circuitry such as current limiting, under-voltage lockout, and thermal protection to prevent device failures. Stability is maintained by using 1F capacitors on the output pins. The MLPQ-UT8 package and 0402 ceramic capacitors minimize the required PCB area.
Applications
PDAs and cellular phones GPS devices Palmtop computers and handheld instruments TFT/LCD applications Wireless handsets Digital cordless phones and PCS phones Personal communicators Wireless LAN
Typical Application Circuit
SC560D VIN EN ENB CIN 2.2F VIN EN ENB GND PGOOD OUTA OUTB BYP CBYP 22nF COUTA 1F COUTB 1F PGOOD OUTA OUTB
September 12, 2007
1
SC560
Pin Configuration Ordering Information
Device
SC560xULTRT(1)(2)(3) SC560xEVB(3)
8 1 TOP VIEW 2 6 7
Package
MLPQ-UT8 1.5x1.5 Evaluation Board
Notes: (1) Available in tape and reel only. A reel contains 3,000 devices. (2) Available in lead-free package only. Device is WEEE and RoHS compliant. (3) The device variant is denoted by the x.
3 4
5
MLPQ-UT-8; 1.5x1.5, 8 LEAD JA = 157C/W
Marking Information
Pinout and Voltage Options
Pin Options Device Pin 4 SC560A SC560B SC560C FBA FBA FBA ENB ENB ENB ENB ENB Pin7 BYP ENB PGOOD BYP BYP BYP BYP BYP Pin 8 FBB FBB FBB PGOOD PGOOD PGOOD PGOOD PGOOD Output Voltage Options VLDOA ADJ ADJ ADJ 2.8V 2.85V 2.5V 2.8V 3.3V VLDOB ADJ ADJ ADJ 1.8V 2.85V 1.8V 1.5V 3.3V Part No. Code 0A 0B 0C 0D 0K 0L 0U 0S
0n yw
0n = Part No. Code See Pinout and Voltage Options Table for details yw = Datecode
SC560D SC560E SC560F SC560G SC560H
2
SC560
Absolute Maximum Ratings
VIN (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +6.5 VEN, VENB (V) . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to (VIN + 0.3) VPGOOD (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to (VIN + 0.3) Pin Voltage -- All Other Pins (V) . . . . . . . . . -0.3 to (VIN + 0.3) VOUTA, VOUTB, Short Circuit Duration . . . . . . . . . . Continuous ESD Protection Level(1) (kV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Recommended Operating Conditions
Ambient Temperature Range (C) . . . . . . . . . -40 < TA < +85 VIN (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 < VIN < 5.5 OUTA, OUTB (V) . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 < VOUT < 3.3
Thermal Information
Thermal Resistance, Junction to Ambient(2) (C/W) . . . 157 Maximum Junction Temperature (C) . . . . . . . . . . . . . . +150 Storage Temperature Range (C) . . . . . . . . . . . . -65 to +150 Peak IR Reflow Temperature (10s to 30s) (C) . . . . . . . +260
Exceeding the above specifications may result in permanent damage to the device or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not recommended. NOTES: (1) Tested according to JEDEC standard JESD22-A114-B. (2) Calculated from package in still air, mounted to 3" x 4.5", 4 layer FR4 PCB with thermal vias under the exposed pad per JESD51 standards.
Electrical Characteristics
Unless otherwise noted VIN = 3.6V, CIN = 2.2F, COUTA = COUTB = 1F, VEN = VENB = VIN, TA = -40 to +85C. Typical values are at TA = 25C. All specifications apply to both LDOs unless otherwise noted.
Parameter
Symbol
VIN VOUTx VOUTx IMAX VD ISD IQ VLOAD VLINE VFB ILIM
Conditions
Min
2.5 1.2
Typ
Max
5.5 3.3 3
Units
V V % mA
Input Supply Voltage Range Output Voltage Output Voltage Accuracy Maximum Output Current Dropout Voltage(1) Shutdown Current Quiescent Current Load Regulation Line Regulation Feedback Regulation Voltage(2) Current Limit
VIN = 2.5V to 5.5V, IOUTx = 0 to 300mA
-3 300
IOUTx = 200mA, VOUTx = 2.5V to 3.3V TA = 25C IOUTA = IOUTB = 0mA, TA = 25C IOUTx = 1mA to IMAX IOUTx = 1mA -6 0.985 350
100 0.1 100
200 1
mV A A
20 6 1 1.015 850
mV mV V mA
3
SC560
Electrical Characteristics (continued)
Parameter
Symbol
Conditions
VIN = 3.7V, IOUTx = 50mA , 10Hz < f < 100kHz, CBYP = 22nF
Min
Typ
50
Max
Units
VRMS
Noise
(3)
eN
VIN = 3.7V, IOUTx = 50mA , 10Hz < f < 100kHz VIN = 3.7V, IOUTx = 50mA, f = 1kHz, CBYP = 22nF
300
VRMS
65
dB
Power Supply Rejection Ratio (3)
PSRR VIN = 3.7V, IOUTx = 50mA, f = 1kHz 40 160 Percentage of nominal output, VOUTA falling From OFF to 87% VOUTx, IOUTx = 50mA, CBYP = 22nF(2) Delay between VOUTA and VOUTB start-ups VIN Rising 2.15 82 200 87 240 92 ms %
PGOOD Delay(4) PGOOD Threshold(4)
tDELAY V TH-PGOOD tSU tDELAY VUVLO VUVLO-HYS TOT TOT-HYS Temperature Rising
Start-Up Time Power Up Delay Between LDOA and LDOB(5) Under Voltage Lockout UVLO Hysteresis Over Temperature Protection Threshold Over Temperature Hysteresis Digital Inputs Logic Input High Threshold Logic Input Low Threshold Logic Input High Current Logic Input Low Current Digital Outputs PGOOD Output voltage Low
1
ms
128 2.25 100 160 20 2.35
s V mV C C
VIH VIL IIH IIL
VIN = 5.5V VIN = 2.5V VIN = 5.5V VIN = 5.5V
1.25 0.4 1 1
V V A A
VOL
ISINK = 500A,VIN=3.7V
7
20
mV
Notes: (1) Dropout voltage is defined as VIN - VOUTx , when VOUTx is 100mV below the value of VOUTx at VIN = VOUTx + 0.5V. (2) SC560A, SC560B and SC560C only (3) Except SC560B and fixed output versions (4) Except SC560A and SC560B (5) SC560A and SC560C only
4
SC560
Typical Characteristics
Load Regulation -- LDOA
6 VOUTA = 3.3V, VIN = 3.6V
8 7
Load Regulation -- LDOB
VOUTB = 2.8V, VIN = 3.6V
5
Output Voltage Variation (mV)
Output Voltage Variation (mV)
6 5 4 3 TA=25C 2 1
4 TA=85C 3 TA=25C 2 TA=-40C 1
TA=85C
TA=-40C
0 0 50 100 150 200 250
0
0
50
100
150
200
250
Output Current (mA)
Output Current (mA)
Line Regulation -- LDOA
2 VOUTA = 3.3V, IOUTA = 1mA
3
Line Regulation -- LDOB
VOUTB = 2.8V, IOUTB = 1mA
2.5
Output Voltage Variation (mV)
Output Voltage Variation (mV)
1.5
2
1
1.5
0.5 TA=85C 0 TA=-40C -0.5 3.3 TA=25C
1 TA=85C 0.5 TA=-40C
0
TA=25C
3.5
3.7
3.9
4.1
4.3
4.5
4.7
4.9
5.1
5.3
5.5
-0.5 2.9
3.1
3.3
3.5
3.7
3.9
4.1
4.3
4.5
4.7
4.9
5.1
5.3
5.5
Input Voltage (V)
Input Voltage (V)
Dropout Voltage LDOA
300 VOUTA = 3.3V, IOUTA = 200mA
Dropout Voltage LDOB
400 350 VOUTB = 2.8V, IOUTB = 200mA
250
300
VIN - VOUT (mV)
VIN - VOUT (mV)
200
250 200 150 100
150
TA=85C
TA=85C
100
50
TA=25C
TA=-40C
TA=25C 50 0 2.5
TA=-40C
0 2.95
3
3.05
3.1
3.15
3.2
3.25
3.3
3.35
3.4
3.45
3.5
3.55
3.6
2.55
2.6
2.65
2.7
2.75
2.8
2.85
2.9
2.95
3
3.05
3.1
Input Voltage (V)
Input Voltage (V)
5
SC560
Typical Characteristics (continued)
PSRR vs. Frequency (Both LDOs)
0 -10 -20
-20
PSRR vs. Frequency (Both LDOs)
0 VOUT = 2.8V, IO = 50mA
VOUT = 2.8V, Io=50mA, CBYP=22nF
-10
-30
PSRR (dB)
PSRR (dB)
-40 -50 -60
-30
-40
-50
-70 -80 -90
-60
10
100
Frequency (Hz)
1000
10000
-70 10
100
1000
10000
Frequency (Hz)
Output Noise vs. Load Current (Both LDOs)
80 70 VOUT = 2.8V, VIN=3.7V, CBYP=22nF
Output Noise vs. Load Current (Both LDOs)
450 400 VOUT = 2.8V, VIN = 3.7V, no CBYP
TA=85C
Output Voltage Noise (V)
Output Voltage Noise (V)
60 50 40 30 20 10 0 0 50 100
T=85C
350 300 250 200 150 100 50 0 TA=25C TA=-40C
T=25C
T=-40C
150
200
250
0
50
100
150
200
250
Output Current (mA)
Output Current (mA)
Load Transient Response Rising Edge (Both LDOs)
VIN = 3.6V, VOUT = 2.8V IOUT=10mA to 200ma (100mA/div) IOUT=10mA to 200ma (100mA/div))
Load Transient Response Falling Edge (Both LDOs)
VIN = 3.6V, VOUT = 2.8V
VOUT (10mV/div) VOUT (10mV/div)
6
SC560
Pin Configurations and Descriptions
Pin # SC560A
1 2 3 4 5 6 7 7
SC560B
1 2 3 4 5 6
SC560C
1 2 3 4 5 6
SC560 Fixed Output
1 2 3
Pin Name
OUTB VIN OUTA FBA Output for LDOB
Pin Function
Input supply voltage terminal Output for LDOA Feedback sense pin for LDOA -- Connect this pin to an external resistor divider to set VOUTA Analog and digital ground Logic input -- active HIGH enables both LDOs for the SC560A and SC560C, or LDOA for all other variants. LDO bypass output -- Bypass with a 22nF capacitor Logic input -- active HIGH enables LDOB for SC560B and SC560D Power Good output -- monitors the level of LDOA, switches low when the output drops out of regulation. Feedback sense pin for LDOB -- Connect this pin to an external resistor divider to set VOUTB
5 6 7 4
GND EN BYP ENB
7
8
PGOOD
8
8
8
FBB
7
SC560
Block Diagrams
SC560A VIN 2
VIN
VREF UVLO
VIN
7
BYP
GND
5
3 O/T LDOA 4 PowerON Logic
VIN
OUTA FBA
EN
6
1 LDOB 8
OUTB FBB
SC560B VIN 2
VIN
VREF UVLO
VIN
GND
5
3 O/T LDOA 4
OUTA FBA
EN
6
ENB
7
PowerON Logic
VIN
1 LDOB 8
OUTB FBB
8
SC560
Block Diagrams (continued)
SC560C VIN 2
VIN
VREF UVLO
VIN
7 PGOOD Logic 3 O/T LDOA 4
PGOOD
GND
5
OUTA FBA
EN
6
PowerON Logic
VIN
1 LDOB 8
OUTB FBB
SC560 - Fixed Output Versions VIN 2
VIN
VREF
7 8 UVLO
VIN
BYP PGOOD
PGOOD Logic
GND
5
O/T
LDOA
3
OUTA
EN
6
ENB
4
PowerON Logic
VIN
LDOB
1
OUTB
9
SC560
Applications Information
General Description
The SC560 is a family of dual output linear regulator devices intended for applications where low dropout voltage, low supply current, and low output noise are critical. Each device provides a very simple, low cost solution for two separate regulated outputs. Very little PCB area is required due to the miniature package size and the need for only four external capacitors. The linear regulators LDOA and LDOB are powered from a single input supply rail, and each provides 300mA of output current. The SC560 can provide output voltages in the range 1.2V to 3.3V. The output voltages for the SC560A, SC560B and SC560C are set by connecting external resistor dividers to the feedback pins of each LDO. All other versions of the SC560 have fixed output voltage values shown in the Pinout and Voltage Options table. The SC560B and the fixed output variants provide a separate enable pin for LDOB which allows LDOA and LDOB to be enabled independently. The EN pin controls the LDOA output and the ENB provides the same functionality relative to the LDOB output. The table shown below lists the effect of the polarity of the EN and ENB signals on the outputs of LDOA and LDOB. Since LDOB can be enabled separately, there is no timing relationship between the two outputs at startup.
EN
Low Low High High
ENB
Low High Low High
LDOA
Off Off On On
LDOB
Off Off Off On
Power On Control
The SC560A and SC560C devices have a single enable pin (EN) that controls both LDO outputs. Pulling this pin low causes the device to enter a low power shutdown mode where it typically draws 100nA from the input supply. When EN transitions high, the output of LDOA is enabled. After a delay of 128s, the output of LDOB is enabled. In the SC560C, when the output voltage of LDOA reaches 87% of its regulation point, the delay timer starts and the PGOOD signal transitions high after a delay of 200ms. The power up/down sequence is shown in the timing diagram in Figure 1. The SC560C and the fixed output variants have a PGOOD signal which monitors the output of LDOA and transitions high 200ms after LDOA has reached 87% of its regulation point. This can be used to hold a processor in reset when the output voltage is out of regulation.
Output Voltage Selection
The output voltage of each LDO for the SC560A, SC560B, and SC560C version is set independently using external resistor dividers. Figure 2 illustrates the proper connection for LDOA.
OUTA FBA
EN
87% 87% 200ms
OUTA
R1 R2
PGOOD
128 s
OUTB
Figure 1 -- Timing Diagram
Figure 2 -- Output Voltage Feedback Circuit
10
SC560
Applications Information (continued)
The values of the resistors in the voltage divider network can be calculated using the equation:
VOUT VREF R1 R 2 R2
where VREF = 1V. Since the bias current into the feedback pins of each LDO is only a few A, the value of R2 can be as high as 100k without affecting accuracy. The value of R2 should be between 100k and 200k to maintain quiescent current of less than 100A.
Over-Temperature Protection An internal Over-Temperature (OT) protection circuit is provided that monitors the internal junction temperature. When the temperature exceeds the OT threshold as defined in the Electrical Characteristics section, the OT protection disables both LDO outputs and holds the PGOOD signal low. When the junction temperature drops below the hysteresis level, the LDOs are re-enabled into their previous states and PGOOD transitions high after a 200ms delay, provided EN has remained high (SC560C and fixed output variants only). Short-Circuit Protection Each output has short-circuit protection. If the output current exceeds the current limit, the output voltage will drop and the output current will be limited until the load current returns to a specified level. If a short-circuit occurs on the output of LDOA, the output of LDOB will also be disabled until the fault is removed and the load current returns to a specified level.
Protection Features
The SC560 family provides the following protection features to ensure that no damage is incurred in the event of a fault condition: Under-Voltage Lockout Over-Temperature Protection Short-Circuit Protection
* * *
Under-Voltage Lockout The Under-Voltage Lockout (UVLO) circuit protects the device from operating in an unknown state if the input voltage supply is too low. When the VIN drops below the UVLO threshold, the LDOs are disabled and PGOOD is held low (SC560C and fixed output variants only). When VIN is increased above the hysteresis level, the LDOs are re-enabled into their previous states, provided EN has remained high. When powering up with VIN below the UVLO threshold, the LDOs remain disabled and PGOOD is held low (SC560C and fixed output variants only).
Component Selection
A capacitance of 1F or larger on each output is recommended to ensure stability. Ceramic capacitors of type X5R or X7R should be used because of their low ESR and stable temperature coefficients. It is also recommended that the input be bypassed with a 2.2F, low ESR X5R or X7R capacitor to minimize noise and improve transient response. Note: Tantalum and Y5V capacitors are not recommended. The BYP pin on the SC560D and the fixed output versions must have a minimum of 22nF connected to ground to meet all noise-sensitive requirements. Increasing the capacitance to 100nF will further improve PSRR and output noise.
11
SC560
Applications Information (continued)
Thermal Considerations
Although each of the two LDOs in the SC560 can provide 300mA of output current, the maximum power dissipation in the device is restricted by the miniature package size. The graphs in Figure 3 and Figure 4 can be used as a guideline to determine whether the input voltage, output voltages, output currents, and ambient temperature of the system result in power dissipation within the operating limits are met or if further thermal relief is required.
0.7 0.6 0.5
Maximum Recommended Input Voltage
The following procedure can be followed to determine if the thermal design of the system is adequate. The junction temperature of the SC560 can be determined in known operating conditions using the following equation: TJ = TA +(PD x JA) where TJ = Junction Temperature (C) TA = Ambient Temperature (C) PD = Power Dissipation (W) JA = Thermal Resistance Junction to Ambient (C/W) Example An SC560D is used to provide outputs of 2.8V, 150mA from LDOA and 1.8V, 200mA from LDOB. The input voltage is 4.2V, and the ambient temperature of the system is 40C. PD= 0.15(4.2 - 2.8) + 0.2(4.2 - 1.8) = 0.69W
Maximum Total Output Current (A)
0.4 Vo=1.5V 0.3 0.2 0.1
______
Vo=3.3V
0 2.5
TA=+25C, PD(MAX)= 0.8W - - - - TA=+85C, PD(MAX)= 0.41W
3
3.5
4.5 4 Input Voltage (V)
5
5.5
6
and TJ = 40 + (0.69 x 157) = 148.3C Figures 3 and 4 show that the junction temperature would be within the maximum specification of 150C for this power dissipation. This means that operation of the SC560 under these conditions is within the specified limits and the device would not require further thermal relief measures.
Figure 3 -- Safe Operating Limit
1.6 1.4
Maximum Power Dissipation (W)
1.2 1 0.8 0.6
TJ(Max)=125C
TJ(Max)=150C
0.4 0.2 0 -40 -20 0
60 20 40 Ambient Temperature (oC)
80
100
Figure 4 -- Maximum PD vs. TA
12
SC560
Applications Information (continued)
Layout Considerations
While layout for linear devices is generally not as critical as for a switching application, careful attention to detail will ensure reliable operation. The diagram below illustrates proper layout of a circuit using the SC560A.
* *
Connect all ground connections directly to the ground plane whenever possible to minimize ground potential differences on the PCB. Ensure that the feedback resistors are placed as close as possible to the feedback pins.
* *
Attach the part to a large copper footprint, to enable better heat transfer from the device on PCBs where there are internal power and ground planes. Place the input, output, and bypass capacitors close to the device for optimal transient response and device behavior.
C3
1
R4 R3
C1
U1
C4
C2
R1 R2
U1 = SC560A
13
SC560
Outline Drawing -- MLPQ-UT8
A D
B
PIN 1 INDICATOR (LASER MARK)
E
DIMENSIONS INCHES MILLIMETERS DIM MIN NOM MAX MIN NOM MAX .018 .024 0.45 0.60 A .002 0.00 0.05 A1 .000 (.006) (0.1524) A2 b .006 .008 .010 0.15 0.20 0.25 .059 BSC 1.50 BSC D .059 BSC 1.50 BSC E e .016 BSC 0.40 BSC 0.12 .014 0.16 0.30 0.35 0.40 L 8 8 N aaa .004 0.10 .004 0.10 bbb A2
A aaa C A1 C LxN SEATING PLANE
e 2 0.20 0.25 0.17 1 N bxN bbb CAB
NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS THE TERMINALS.
14
SC560
Land Pattern -- MLPQ-UT8
Z G DIM C G 2X (C) P P (G) (Z) R X Y X R Y Z DIMENSIONS INCHES (.057) .028 .016 .004 .008 .030 .087 MILLIMETERS (1.45) 0.70 0.40 0.10 0.20 0.75 2.20
NOTES: 1. 2. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET.
Contact Information
Semtech Corporation Power Management Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805) 498-2111 Fax: (805) 498-3804 www.semtech.com
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