SC403 Datasheet, PDF (1/32 Pages) Semtech Corporation – 6A EcoSpeedTM Integrated FET Regulator with Programmable LDO

SC403
6A EcoSpeed^TM Integrated FET
Regulator with Programmable LDO
POWER MANAGEMENT
Features
 Power System:
• Input voltage — 3V to 28V
• Internal or external bias voltage — 3V to 5V
• Integrated bootstrap switch
• Programmable LDO output — 200mA
• 1% reference tolerance -40 to +85 °C
• EcoSpeed^TM architecture with pseudo-fixed
frequency adaptive on-time control
 Logic Input/Output Control:
• Independent control EN for LDO and switcher
• Programmable V_IN UVLO threshold
• Power good output
• Selectable ultrasonic power save mode
• Programmable soft start time
 Protections:
• Over-voltage and under-voltage
• TC compensated R_DS(ON) sensed current limit
• Thermal shutdown
 Any ESR — SP, POSCAP, OSCON, and ceramic capacitors
 Package:
• Lead-free package — 5x5mm, 32-pin MLPQ
• Fully RoHS/WEEE compliant and halogen free
Description
The SC403 is a stand-alone synchronous EcoSpeed^TM buck
power supply which incorporates Semtech’s advanced
patent-pending adaptive on-time control architecture to
provide excellent light-load efficiency and fast transient
response. It features integrated power MOSFETs, a boot-
strap switch, and a programmable LDO in a 5x5mm
package. The device is highly efficient and uses minimal
PCB area.
The SC403 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 selectable power-
save provide high efficiency operation over a wide load
range.
Additional features include a programmable soft-start,
programmable cycle-by-cycle over-current limit protec-
tion, under and over-voltage protections, soft shutdown,
and selectable power-save. The device also provides sep-
arate enable inputs for the PWM controller and LDO as
well as a power good output for the PWM controller.
Applications
 Office automation and computing
 Networking and telecommunication equipment
 Point of load power supplies and module replacement
The wide input and bias voltage ranges, programmable
frequency, and programmable LDO make the device
extremely flexible and easy to use in a broad range of
applications. The SC402 can be used in server computers
and single cell or multi-cell battery systems in addition to
traditional DC power supply applications.
Typical Application Circuit
ENABLE/PSAVE
ENABLE LDO
VEXT/LDO
VIN
RTON
10Ω
1µF
CSOFT
ENL
TON
VDD
SS
BST
VIN
CIN
CBST
SC403
LXS
PGOOD
VOUT
RILIM
LX
L1
COUT
RFB1
+
FB
RFB2
PGOOD
VOUT
June 30, 2010
© 2010 Semtech Corporation