SC4612 Datasheet, PDF (1/24 Pages) Semtech Corporation – Wide Input Range High Performance Synchronous Buck Switching Controller

SC4612
Wide Input Range High Performance
Synchronous Buck Switching Controller
POWER MANAGEMENT
Description
SC4612 is a high performance synchronous buck controller
that can be configured for a wide range of applications.
The SC4612 utilizes synchronous rectified buck topology
where high efficiency is the primary consideration. SC4612
is optimized for applications requiring wide input supply
range and low output voltages down to 500mV.
SC4612 implements an asynchronous soft-start mode,
which keeps the lower side MOSFET off during soft-start, a
desired feature when a converter turns on into a preset
external voltage or pre-biased output voltage. With the lower
MOSFET off, the external bus is not discharged, preventing
any disturbances in the start up slope and any latch-up of
modern day ASIC circuits.
SC4612 comes with a rich set of features such as regulated
DRV supply, programmable soft-start, high current gate
drivers, internal bootstrapping for driving high side
N-channel MOSFET, shoot through protection, R sensing
DS-ON
with hiccup over current protection, and asynchronous start
up with over current protection.
Features
‹ Wide voltage range, V_DD = 28V, V_PWRIN = 40V
‹ Internally regulated DRV
‹ Output voltage as low as 0.5V
‹ 1.7A gate drive capability
‹ Asynchronous start up mode
‹ Low side R_DS-ON sensing with hiccup mode current
limit
‹ Programmable current limit
‹ Programmable frequency up to 1.2 MHz
‹ Available in MLPD-12 and SOIC-14 Lead-free
packages. This product is fully WEEE and RoHS
compliant
Applications
‹ Distributed power architectures
‹ Telecommunication equipment
‹ Servers/work stations
‹ Mixed signal applications
‹ Base station power management
‹ Point of use low voltage high current applications
Typical Application Circuit
R1 R2
U1
S C4 61 2M LP
1 _ILIM
PHASE ¹²
C1
2 _OSC
DH ¹¹
D1
C2
3 _SS/EN
BST ¹⁰
R3
4 _EAO
C3
C4
5 _FB
DRV ⁹
Q1
C7
DL ⁸
6 _VDD
GND ⁷
Q2
C5
R5
R4
C6
R6
C8
L1
+
C9 _Vin
_
+
C10 _Vout
_
Revision: January 31, 2007
1
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