SC402B Datasheet, PDF (1/32 Pages) Semtech Corporation – 10A EcoSpeed® Integrated FET Regulator with Programmable LDO

SC402B
POWER MANAGEMENT
10A EcoSpeed^® Integrated FET
Regulator with Programmable LDO
Features
 Power System
• Input voltage — 3V to 28V
• Bias voltage — 3V to 5.5V LDO or external
• Up to 96% peak efficiency
• Integrated bootstrap switch
• Programmable LDO output — 200mA
• Reference tolerance — 1% T_J= -40 to +125 °C
• Programmable soft start time
 Logic Input/Output Control
• Independent EN controls for LDO and switcher
• Programmable V_IN UVLO threshold
• Power good output
• Selectable PSAVE or FCM mode
 Protection
• Over-voltage and under-voltage
• TC compensated R_DS(ON) sensed current limit
• Thermal Shutdown
 Output Capacitor Types
• High ESR — SP, POSCAP, OSCON
• Ceramic capacitors
 Package
• Lead-free package — 5x5mm, 32-Pin MLPQ
• RoHS/WEEE compliant and Halogen free
Applications
 Networking and telecommunication equipment
 Printers, DSL, and STB applications
 Embedded systems and power supply modules
 Point of load power supplies
Description
The SC402B is a stand-alone synchronous EcoSpeed^® buck
power supply which incorporates Semtech’s advanced
patented adaptive on-time control architecture. This pro-
vides 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 SC402B has the same package and pin con-
figuration as the entire SC40x series for compatibility.
The SC402B supports using standard capacitor types such
as electrolytic or specialty 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-voltage and over-voltage protection, soft
shutdown, and selectable power-save operation. The
device also provides separate enable inputs for the PWM
controller and LDO as well as a power good output for the
PWM controller.
The wide input and programmable frequency make the
device extremely flexible and easy to use in a broad range
of applications.
Typical Application Circuit
ENABLE/PSAVE
ENABLE LDO
VEXT/LDO
VIN
RTON
EN/PSV
ENL
TON
10Ω
1µF
CIN
VDD
CSOFT
SS
BST
VIN
CBST
SC402B
ILIM
LXS
PGOOD
VOUT
LX
FB
RILIM
L1
COUT
RFB1
+
RFB2
PGOOD
VOUT
Rev. 2.1
© 2011 Semtech Corporation