SC195_10 Datasheet, PDF (1/20 Pages) Semtech Corporation – 3.5MHz, 500mA Synchronous Step Down DC-DC Regulator

POWER MANAGEMENT
Features
 Input Voltage — 2.9V to 5.5V
 Output Voltage — 0.8V to 3.3V
 Output current capability — 500mA
 Efficiency up to 94%
 15 Programmable output voltages
 High light-load efficiency via automatic PSAVE mode
 Fast transient response
 Temperature range — -40 to +85°C
 Oscillator frequency — 3.5MHz
 100% duty cycle capability
 Quiescent current — 38µA typ
 Shutdown Current — 0.1µA typ
 Internal soft-start
 Over-voltage protection
 Current limit and short circuit protection
 Over-temperature protection
 Under-voltage lockout
 Floating control pin protection
 MLPQ-UT8 1.5 x 1.5 x 0.6 (mm) package
 Pb free, halogen free, and RoHS/WEEE compliant
Applications
 Smart phones and cellular phones
 MP3/Personal media players
 Personal navigation devices
 Digital cameras
 Single Li-ion cell or 3 NiMH/NiCd cell devices
 Devices with 3.3V or 5V internal power rails
SC195
3.5MHz, 500mA Synchronous
Step Down DC-DC Regulator
Description
The SC195 is a high efficiency, 500mA step down regula-
tor designed to operate with an input voltage range of
2.9V to 5.5 V. The input voltage range makes it ideal for
battery operated applications with space limitations. The
SC195 also includes fifteen programmable output voltage
settings that can be selected using the four control pins,
eliminating the need for external feedback resistors. The
output voltage can be fixed to a single setting or dynami-
cally switched between different levels. Pulling all four
control pins low disables the output.
The SC195 operates at a fixed 3.5MHz switching frequency
in normal PWM (Pulse-Width Modulation) mode. A vari-
able frequency PSAVE (power-save) mode is used to
optimize efficiency at light loads for each output setting.
Built-in hysteresis prevents chattering between the two
modes.
The SC195 provides several protection features to safe-
guard the device under stressed conditions. These
include short circuit protection, over-temperature protec-
tion, under-voltage lockout, and soft-start to control
in-rush current. These features, coupled with the small
1.5 x 1.5 x 0.6 (mm) package make the SC195 a versatile
device ideal for step-down regulation in products needing
high efficiency and a small PCB footprint.
Typical Application Circuit
V_IN
2.9V to 5.5V
Control Logic
Lines
C_IN
4.7µF
SC195
IN
LX
OUT
CTL3
CTL2
CTL1
CTL0
GND
L_X
1.0µH
V_OUT
0.8V to 3.3V
C_OUT
10µF
June 29, 2010
© 2010 Semtech Corporation