SC419 Datasheet, PDF (1/24 Pages) Semtech Corporation – EcoSpeedTM DC-DC Converter with Integrated Boost Diode

SC419
POWER MANAGEMENT
Features
 Power system
• Input voltage — 3V to 28V
• Integrated bootstrap switch
• 1% reference tolerance -40 to +85 °C
• EcoSpeed^TM architecture with pseudo-fixed fre-
quency adaptive on-time control
• Internal soft-start and soft-shutdown at output
• SmartDrive^TM
 Logic input/output control
• Independent control EN for LDO and switcher
• Programmable V_IN UVLO threshold
• Power good output
• Selectable power save mode
• Programmable ultrasonic power save mode
 Protections
• Over-voltage/under-voltage
• TC compensated R_DS(ON) sensed current limit
• Thermal shutdown
• Smart power save
 Output capacitor types
• High ESR — SP, POSCAP, OSCON
• Ceramic capacitors
 Package — 3 x 3mm, 20-pin MLPQ
 Lead-free and halogen free
 RoHS and WEEE compliant
Applications
 Office automation and computing
 Networking and telecommunication equipment
 Point-of-load power supplies and module replacement
EcoSpeed^TM DC-DC Converter
with Integrated Boost Diode
Description
The SC419 is a synchronous buck power supply controller.
It features a bootstrap switch in a space-saving MLPQ-
3 x 3mm 20-pin package. The device is highly efficient
and uses minimal PCB area. It uses pseudo-fixed frequency
adaptive on-time operation to provide fast transient
response.
The SC419 supports using standard capacitor types such
as electrolytic or special polymer in addition to ceramic, at
switching frequencies up to 1MHz. The programmable
frequency, synchronous operation, and programmable
power-save provide high efficiency operation over a wide
load range.
Additional features include cycle-by-cycle current limit,
soft-start, under and over-voltage protection, program-
mable over-current protection, soft shutdown, selectable
power-save modes, and programmable ultra-sonic power-
save. The device also provides an enable input and a
power good output, useful for sequencing multiple
devices.
The input voltage can range from 3V to 28V. The wide
input voltage range and programmable frequency make
the device extremely flexible and easy to use in a broad
range of applications. Support is provided for single cell
or multi-cell battery systems in addition to traditional DC
power supply applications.
Typical Application Circuit
VIN
VIN
5V
PGOOD
ENABLE
RTON
5V
0.1µF
1µF
PSV
VIN
PGOOD
EN
TON
VDDA
VDDP
SC419
DH
LX
BST
ILIM _RILIM
DL
VOUT
PSV
AGND
PGND
FB
VIN
L1
CIN
+ _COUT
VOUT
July 27, 2010
© 2010 Semtech Corporation