SC286 Datasheet, PDF (1/20 Pages) Semtech Corporation – Dual Channel 4A Synchronous Step-Down Regulator

POWER MANAGEMENT
Features
 Input Voltage Range — 2.9 to 5.5V
 Output Voltage Range — 0.8V to 3.3V
 Output Current — up to 4A for each channel
 Ultra-Small Footprint — <1mm Height Solution
 Switching Frequency — 1.6MHz
 Automatic Power Save Mode
 Efficiency Up to 95%
 Low Output Noise Across Load Range
 Excellent Transient Response
 Start Up into Pre-Bias Output
 Duty-Cycle Low Dropout Operation — 100%
 Shutdown Current — <1µA
 Externally Programmable Soft Start Time
 Power Good indicator
 Input Under-Voltage Lockout
 Output Over-Voltage, Current Limit Protection
 Over-Temperature Protection
 Thermally Enhanced 4 x 4 x 0.6 (mm)
MLPQ-UT28 package
 Lead-free, Halogen free, and RoHS/WEEE compliant
Applications
 Routers and Network Cards
 LCD TV
 Office Automation
 Printers
SC286
Dual Channel 4A Synchronous
Step-Down Regulator
Description
The SC286 is a dual channel 4A synchronous step-down
regulator designed to operate with an input voltage
range of 2.9V to 5.5V. Each channel offers fifteen pre-
determined output voltages via separate control pins
programmable from 0.8 to 3.3 Volts. The control pins
allow for on-the-fly voltage changes, enabling system
designers to implement dynamic power savings. The
device is also capable of adjusting output voltage via an
external resistor divider.
The SC286 is optimized for maximum efficiency over a
wide range of load currents. During full load operation,
the device operates in PWM mode with fixed 1.6MHz
oscillator frequency, allowing the use of small surface
mount external components. As the load decreases, the
regulator will transition into Power Save mode maintain-
ing high efficiency.
Connecting the control pins to logic low forces the device
into shutdown mode reducing the supply current to less
than 1μA. Connecting any of the control pins to logic high
enables the converter and sets the output voltage accord-
ing to Table 1. Other features include under-voltage
lockout, programmable soft-start to limit in-rush current,
power good indicator, over-temperature protection, and
output short circuit protection.
The SC286 is available in a thermally-enhanced, 4 x 4 x 0.6
(mm) MLPQ-UT28 package and has a rated temperature
range of -40 to +85°C.
Typical Application Circuit
VINA
C_INA
22µF
R_PGOODA
100kΩ
VINB
CINB
22µF
RPGOODB
100kΩ
CTL0A
CTL1A
CTL2A
CTL3A
R_AVINA 1Ω
C_AVINA0.1µF
R_AVINB 1Ω
CAVINB0.1µF
PVINA
LXA
AVINA ^{SC286 VOUTA}
AGNDA
PGOODA
PVINB
LXB
VOUTB
SSA
PGNDA
AVINB
AGNDB
PGOODB
CTL0A
CTL1A
CTL2A
CTL3A
SSB
PGNDB
CTL0B
CTL1B
CTL2B
CTL3B
LA 1.0µH
L_B 1.0µH
C_SSA
1nF
C_SSB
1nF
C_OUTA
47µF
C_OUTB
47µF
VOUTA
V_OUTB
CTL0B
CTL1B
CTL2B
CTL3B
Revision 2.0
© 2011 Semtech Corporation