SC419
EcoSpeedTM DC-DC Converter
with Integrated Boost Diode
POWER MANAGEMENT
Features
Description
Power system
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.
• Input voltage — 3V to 28V
• Integrated bootstrap switch
• 1% reference tolerance -40 to +85 °C
• EcoSpeedTM architecture with pseudo-fixed fre-
quency adaptive on-time control
• Internal soft-start and soft-shutdown at output
• SmartDriveTM
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.
Logic input/output control
• Independent control EN for LDO and switcher
• Programmable VIN UVLO threshold
• Power good output
• Selectable power save mode
• Programmable ultrasonic power save mode
Protections
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.
• Over-voltage/under-voltage
• TC compensated RDS(ON) sensed current limit
• Thermal shutdown
• Smart power save
Output capacitor types
• High ESR — SP, POSCAP, OSCON
• Ceramic capacitors
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.
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
Typical Application Circuit
VIN
VIN
VIN
VIN
5V
CIN
PGOOD
EN
PGOOD
ENABLE
DH
LX
VOUT
L1
+
RTON
COUT
BST
ILIM
TON
SC419
RILIM
VDDA
VDDP
5V
DL
0.1µF
1µF
VOUT
PSV
PSV
FB
AGND
PGND
© 2010 Semtech Corporation
July 27, 2010
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