LTC1430
High Power Step-Down
Switching Regulator Controller
FEATURES
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DESCRIPTIO
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High Power 5V to 3.xV Switching Controller:
Can Exceed 10A Output
All N-Channel External MOSFETs
Constant Frequency Operation—Small Inductor
Excellent Output Regulation:
±1%
Over Line, Load
and Temperature Variations
High Efficiency: Over 95% Possible
Fixed Frequency Operation
No Low Value Sense Resistor Needed
Outputs Can Drive External FETs with Up to
10,000pF Gate Capacitance
Quiescent Current: 350µA Typ, 1µA in Shutdown
Fast Transient Response
Adjustable or Fixed 3.3V Output
Available in 8- and 16-Lead PDIP and SO Packages
The LTC
®
1430 is a high power, high efficiency switching
regulator controller optimized for 5V to 3.xV applications.
It includes a precision internal reference and an internal
feedback system that can provide output regulation of
±1%
over temperature, load current and line voltage shifts. The
LTC1430 uses a synchronous switching architecture with
two N-channel output devices, eliminating the need for a
high power, high cost P-channel device. Additionally, it
senses output current across the drain-source resistance
of the upper N-channel FET, providing an adjustable
current limit without an external low value sense resistor.
The LTC1430 includes a fixed frequency PWM oscillator for
low output ripple under virtually all operating conditions.
The 200kHz free-running clock frequency can be externally
adjusted from 100kHz to above 500kHz. The LTC1430
features low 350µA quiescent current, allowing greater
than 90% efficiency operation in converter designs from
1A to greater than 50A output current. Shutdown mode
drops the LTC1430 supply current to 1µA.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Pentium is a registered trademark of Intel Corporation.
APPLICATIO S
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Power Supply for P6 and Pentium
®
Microprocessors
High Power 5V to 3.xV Regulators
Local Regulation for Dual Voltage Logic Boards
Low Voltage, High Current Battery Regulation
TYPICAL APPLICATIO
V
IN
5V
Typical 5V to 3.3V, 10A Application
100
+
100Ω
1µF
PV
CC2
1N4148
PV
CC1
G1
I
MAX
LTC1430 I
FB
FREQSET
SHDN
COMP
G2
PGND
GND
SENSE
SENSE
–
+
+
16k
0.1µF
0.1µF
1k
C
IN
220µF
×4
EFFICIENCY (%)
+
4.7µF
0.1µF
0.01µF
NC
SHUTDOWN
C1
220pF
V
CC
SS
M1A, M1B
2 IN PARALLEL
L1, 2.8µH
+
M2
C
OUT
330µF
×6
3.3V
10A
R
C
7.5k
C
C
4700pF
LTC1430 • TA01
FB
NC
C
IN
: AVX-TPSE227M010R0100
C
OUT
: AVX-TPSE337M006R0100
L1: ETQP6F1R6SFA
M1A, M1B, M2: MOTOROLA MTD20N03HL
U
Efficiency
T
A
= 25°C
V
IN
= 5V
V
OUT
= 3.3V
90
80
70
60
50
40
0.1
1
LOAD CURRENT (A)
10
LTC1430 • TA02
U
U
1
LINER [ LINEAR TECHNOLOGY ]
