SC2463 Datasheet, PDF (1/23 Pages) Semtech Corporation – High Performance Quad Output Switching Regulator

POWER MANAGEMENT
Description
The SC2463 is a high performance controller for multi-
output converters that can be configured for a wide vari-
ety of applications. The SC2463 utilizes PWM synchro-
nous buck topologies where efficiency is most important.
It also provides two dedicated programmable positive
linear regulators using external transistors. Each of the
four outputs is adjustable down to 0.5V. The two PWM
switchers are synchronized 180° out of phase reducing
input ripple, allowing for fewer input capacitors. Power
up sequencing prevents converter latch-up.
The SC2463 can be synchronized to other converters to
prevent beat frequencies. The wide range programmable
operating frequency allows users to optimize a converter
design. The PWM switchers sense the voltage across the
low-side MOSFETs on-resistance to efficiently provide
adjustable current-limit, eliminating costly current-sense
resistors. A POK signal is issued when soft-start is com-
plete on both PWM switchers and their outputs are within
10% of the set point.
Typical Application Circuit
SC2463
High Performance Quad Output
Switching Regulator
Features
‹ Two synchronized converters for low noise
‹ Power up sequencing to prevent latch-up
‹ Out of phase operation for low input ripple
‹ Over current protection
‹ Wide input range, 4.5 to 30V
‹ Programmable frequency up to 700kHz
‹ Low shutdown current 100uA
‹ Two synchronous bucks for high efficiency at high
current
‹ Two programmable positive linear regulators
‹ Output voltage as low as 0.5V
‹ Small package TSSOP-28. This product is fully
WEEE and RoHS compliant
Applications
‹ DSL applications with multiple input voltage
requirements
‹ Mixed-Signal applications requiring 4 positive
output voltages
‹ Cable modem power management
‹ Base station power management
+4.5-30V
Q1
R1
C2
C1
C3
R3
C4
U1
D1
D2
C6
6 _SS/SHDN
BST2 ¹⁷
C7
Q2
+3.3V
9 _OSC
R4
7 _{SY NC}
8 _POK
GD2H ¹⁸
PH2 ¹⁹
GD2L ²⁰
L1
Q3
+2.5V
C10
R7
Q4
4 _BD4
C14
5 _FB4
R9
R10
11 _BD3
SC2463
FB2 ¹³
EO2 ¹²
BST1 ²⁶
GD1H ²⁵
PH1 ²⁴
GD1L ²³
R8
C11
C12
C13
Q5
L2
Q6
FB1 ²
C17
+1.2V
Q7
R11
10 _FB3
EO1 ³
C19
C20
R15
R16 R17
C18
C16 ^R14
R18
+3.3V
C8 ^{R5 (as low as 0.5V)}
R6
+1.5V
C15
(as low as 0.5V)
R12
R13
Revision: May 16, 2007
1
www.semtech.com