SC197 Просмотр технического описания (PDF) - Semtech Corporation
Номер в каталоге
Компоненты Описание
производитель
SC197 Datasheet PDF : 20 Pages
| |||
SC197
POWER MANAGEMENT
3.5MHz, 500mA Synchronous
Dual Step-Down DC-DC Regulator
Features
Description
Input Voltage — 2.9V to 5.5V
Output Voltage — 0.8V to 3.3V
Output current capability — 500mA per regulator
Efficiency up to 94%
Programmable output voltages — 15
High light-load efficiency via automatic PSAVE mode
Fast transient response
Oscillator frequency — 3.5MHz
100% duty cycle capability
Quiescent current — 38µA typical per regulator
Shutdown current — 0.1µA typical per regulator
Internal soft-start
Over-voltage protection
Current limit and short circuit protection
Over-temperature protection
Under-voltage lockout
Floating control pin protection
MLPQ-UT18 2.0 x 3.0 x 0.6 (mm) package
Lead-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
The SC197 contains two identical high efficiency 500mA
step-down regulators designed for use in battery-
powered applications. Each regulator includes 15
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 dynamically switched between
different levels. Pulling all four control pins low disables
the output.
The SC197 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 SC197 provides several protection features to safe-
guard the device under stressed conditions. These include
short circuit protection, over-temperature protection,
under-voltage lockout, and soft-start to control in-rush
current. These features, coupled with the small 2.0 x 3.0 x
0.6 (mm) package make the SC197 a versatile device ideal
for step-down regulation in products needing high effi-
ciency and a small PCB footprint.
Typical Application Circuit
VIN
2.9V to 5.5V
Control Logic
For Output A
VIN
2.9V to 5.5V
Control Logic
For Output B
CINA
4.7µF
SC197
INA
LXA
OUTA
CTL3A
CTL2A
CTL1A
CTL0A
GNDA
INB
CINB
4.7µF
CTL3B
CTL2B
CTL1B
CTL0B
LXB
OUTB
GNDB
LXA
1.0µH
LXB
1.0µH
VOUTA
0.8V to 3.3V
COUTA
10µF
VOUTB
0.8V to 3.3V
COUTB
10µF
January 17, 2011
© 2011 Semtech Corporation
Share Link: 