LTC1530
High Power Synchronous
Switching Regulator Controller
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FEATURES
DESCRIPTIO
The LTC®1530 is a high power synchronous switching
regulator controller optimized for 5V to 1.3V-3.5V output
applications.Itssynchronousswitchingarchitecturedrives
two external N-channel MOSFET devices to provide high
efficiency. The LTC1530 contains a precision trimmed
reference and feedback system that provides worst-case
output voltage regulation of ±2% over temperature, load
current and line voltage shifts. Current limit circuitry
senses the output current through the on-resistance of
the topside N-channel MOSFET, providing an adjustable
current limit without requiring an external low value sense
resistor.
■
High Power Buck Converter from 5V or 3.3V
Main Power
■
Adjustable Current Limit in S0-8 with
Topside FET RDS(ON) Sensing
■
No External Sense Resistor Required
■
Hiccup Mode Current Limit Protection
■
Adjustable, Fixed 1.9V, 2.5V, 2.8V and 3.3V Output
■
All N-Channel MOSFET Synchronous Driver
■
Excellent Output Regulation: ±2% over Line, Load
and Temperature Variations
■
High Efficiency: Over 95% Possible
■
Fast Transient Response
■
Fixed 300kHz Frequency Operation
The LTC1530 includes a fixed frequency PWM oscillator
that free runs at 300kHz, providing greater than 90%
efficiency in converter designs from 1A to 20A of output
current. Shutdown mode drops the LTC1530 supply cur-
rent to 45µA.
■
Internal Soft-Start Circuit
■
Quiescent Current: 1mA, 45µA in Shutdown
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APPLICATIO S
Power Supply for Pentium® II, AMD-K6®-2, SPARC,
■
The LTC1530 is specified for commercial and industrial
temperature ranges and is available in the S0-8 package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Pentium is a registered trademark of Intel Corp.
AMD-K6 is a registered trademark of Advanced Micro Devices, Inc.
ALPHA and PA-RISC Microprocessors
■
High Power 5V to 1.3V-3.5V Regulators
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TYPICAL APPLICATIO
V
IN
Efficiency vs Load Current
5V
100
MBR0530T1 MBR0530T1
90
+
C
**
IN
0.1µF
+
80
70
60
50
40
30
20
10
0
2.7k
1200µF
× 4
10µF
20Ω
0.22µF
†
L
O
PV
I
Q1*
Q2*
G1
CC
MAX
2µH
V
3.3V
14A
OUT
I
FB
COMP
††
+
C
O
330µF
× 7
C1
150pF
R
C
10k
LTC1530-3.3
G2
1530 F01a
C
C
0.022µF
V
OUT
GND
T
= 25°C
A
†
COILTRONICS CTX02-13198
OR PANASONIC ETQP6F2R5HA
AVX TPSE337M006R0100
* SILICONIX SUD50N03-10
** SANYO 10MV1200GX
COILTRONICS (561) 241-7876
0
0.3
2
4
6
8
10
12
14
††
LOAD CURRENT (A)
1530 F01b
Figure 1. Single 5V to 3.3V Supply
1