LTC1530
High Power Synchronous
Switching Regulator Controller
FEATURES
s
s
DESCRIPTIO
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s
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High Power Buck Converter from 5V or 3.3V
Main Power
Adjustable Current Limit in S0-8 with
Topside FET R
DS(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
Internal Soft-Start Circuit
Quiescent Current: 1mA, 45µA in Shutdown
The LTC
®
1530 is a high power synchronous switching
regulator controller optimized for 5V to 1.3V-3.5V output
applications. Its synchronous switching architecture drives
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.
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.
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.
APPLICATIO S
s
s
Power Supply for Pentium
®
II, AMD-K6
®
-2, SPARC,
ALPHA and PA-RISC Microprocessors
High Power 5V to 1.3V-3.5V Regulators
TYPICAL APPLICATIO
+
V
IN
5V
100
MBR0530T1 MBR0530T1
0.1µF
2.7k
+
10µF
0.22µF
L
O†
2µH
90
C
IN
**
1200µF
×
4
EFFICIENCY (%)
80
70
60
50
40
30
1530 F01a
I
MAX
PV
CC
C1
150pF
C
C
0.022µF
R
C
10k
G1
20Ω
Q1*
I
FB
COMP
LTC1530-3.3
G2
GND
V
OUT
†
COILTRONICS CTX02-13198
+
Q2*
C
O††
330µF
×
7
V
OUT
3.3V
14A
20
10
T
A
= 25°C
0
0.3
2
8
4
10
6
LOAD CURRENT (A)
12
14
OR PANASONIC ETQP6F2R5HA
††
AVX TPSE337M006R0100
* SILICONIX SUD50N03-10
** SANYO 10MV1200GX
COILTRONICS (561) 241-7876
Figure 1. Single 5V to 3.3V Supply
U
Efficiency vs Load Current
0
1530 F01b
U
U
1
LINER [ LINEAR TECHNOLOGY ]
