SC632AULTRT Datasheet, PDF (1/15 Pages) Semtech Corporation – 1MHz Fixed 5.0V Output Charge Pump Regulator

POWER MANAGEMENT
Features
 Input voltage range — 2.95V to 5.5V
 V_OUT tolerance — 5.0V ±3%
 Continuous output current — 275mA
 Peak output current — 400mA
 Three charge pump modes — 1x, 1.5x and 2x
 Output ripple voltage — 50mV_PP , typical
 Short circuit, over-voltage, and over-temperature
protection
 Soft-start functionality
 Shutdown current — 0.1µA, typical
 Ultra thin package — 2 x 2 x 0.6 (mm)
 Lead-free and halogen-free
 WEEE and RoHS compliant
Applications
 Mobile phones
 Tablets
 USB On-The-Go
 Multi-LED backlit LCDs
 Compact flash/CF+ products
 Digital video cameras
 DVI/HDMI ports
 Wi-Fi base stations
 Modems
 Set-top boxes
SC632A
1MHz Fixed 5.0V Output
Charge Pump Regulator
Description
The SC632A is a high-current voltage regulator using
Semtech’s proprietary low-noise charge pump technol-
ogy. The charge pump provides a low EMI solution
compared to inductive boost regulators. Performance is
optimized for use in single Li-Ion battery cell applications.
The regulator provides the performance of a linear, low
drop-out (LDO) voltage regulator when the input is greater
than 5.0V. Unlike an LDO, drop-out is avoided when the
input is less than 5.0V. Instead, a charge pump is activated
to provide voltage boost and the head-room needed for
voltage regulation.
The SC632A’s charge pump has three modes of operation:
2x, 1.5x, and 1x modes. 2x and 1.5x are voltage boost
modes that deliver current to the load in each of two
phases. The 1x mode turns off the charge pump, deliver-
ing current through an LDO. Hysteresis is provided to
prevent chatter between charge pump modes. When
active, the charge pump provides low-ripple operation at
1MHz. Typically the output ripple is 50mVpp at the
maximum continuous current rating of 275mA.
A small 2.2µF capacitor is recommended for all four capaci-
tors. The full rated output current is provided when 2.2µF
is used for both bucket capacitors. At the output, a 2.2µF
capacitor decouples the load and provides smoothing for
mode transitions, while another 2.2µF is used to decouple
the input.
Typical Application Circuit
V_BAT
C_IN
IN
2.2µF
OUT
V_OUT = 5.0V @ 275mA
C_OUT
2.2µF
SC632A
Chip
enable
EN
C1+
C1-
C2+
GND
C2-
C₁
2.2µF
C₂
2.2µF
Revision 1.0
© 2011 Semtech Corporation
US Patent: 7,808,220