SC171_16 Datasheet, PDF (1/27 Pages) Semtech Corporation – Regulator with Optional Ultrasonic Power Save

SC171
POWER MANAGEMENT
1A EcoSpeed^TM Synchronous Step-Down
Regulator with Optional Ultrasonic Power Save
Features
 V_IN: 3V to 5.5V
 V_OUT: 0.75V to 95% x V_IN
 I_OUT: Up to 1A
 Low R_DS(ON) Switches
Up to 95% Peak Efficiency
 High Output Accuracy
 Small Ceramic Capacitors
 Power Good Pin (Open-Drain)
 Patented Adaptive On-Time Control:
Excellent Transient Response
Programmable Pseudo-fixed Frequency
 Fault Protection Features:
Cycle-by-Cycle Current Limit
Short Circuit Protection
Over and Under Output Voltage Protection
Over-Temperature
 Internal Soft start
 Ultrasonic Power Save
 Smart Power Save
 Ultra-Small Lead-Free 3x3mm, 10-Pin MLPD Package
 Fully WEEE and RoHS Compliant
Applications
 Networking Equipment, Embedded Systems
 Medical Equipment, Office Automation
 Instrumentation, Portable Systems
 Consumer Devices (DTV, Set-top Box, ... )
 5V POL Converters
Description
The SC171 is an integrated, synchronous 1A EcoSpeed^TM
step-down regulator, which incorporates Semtech’s
advanced, patented adaptive on-time architecture to
achieve best-in-class performance in dynamic point-of-
load applications. The input voltage range is 3V to 5.5V
with a programmable output voltage from 0.75V up to
95% x V_IN. The device features low-R_DS(ON) internal switch-
es and optional PSAVE mode for high efficiency across
the output load range.
Adaptive on-time control provides programmable pseu-
do-fixed frequency operation and excellent transient
performance. The switching frequency can be set from
200kHz to 1MHz - allowing the designer to reduce exter-
nal LC filtering and minimize light load (standby) losses.
Disabling PSAVE operation reduces output voltage ripple
at light load for ceramic output capacitors.
Additional features include cycle-by-cycle current limit,
soft start, input UVLO and output OV protection, and
over temperature protection. The open-drain PGOOD
pin provides output status. Standby current is less than
10μA when disabled.
The device is available in a low profile, thermally en-
hanced MLPD-3x3mm 10-pin package.
Typical Application Circuit
3 to 5.5V
VIN
BST
LX
SC 171
VOUT = 0.75 V to 95% VIN
VDD
FB
PGOOD
Power Good
Enable /
Power Save
EN/ PSV
PGND
TON
AGND
October 11 , 2010
© 2010 Semtech Corporation