LTC1430 Datasheet, PDF (1/16 Pages) Linear Technology – High Power Step-Down Switching Regulator Controller

LTC1430
High Power Step-Down
Switching Regulator Controller
FEATURES
s _{High Power 5V to 3.xV Switching Controller:}
Can Exceed 10A Output
s _{All N-Channel External MOSFETs}
s _{Constant Frequency Operation—Small Inductor}
s _{Excellent Output Regulation: ±1% Over Line, Load}
and Temperature Variations
s _{High Efficiency: Over 95% Possible}
s _{Fixed Frequency Operation}
s _{No Low Value Sense Resistor Needed}
s _{Outputs Can Drive External FETs with Up to}
10,000pF Gate Capacitance
s _{Quiescent Current: 350µA Typ, 1µA in Shutdown}
s _{Fast Transient Response}
s _{Adjustable or Fixed 3.3V Output}
s _{Available in 8- and 16-Lead PDIP and SO Packages}
U
APPLICATIO S
s _{Power Supply for P6 and Pentium}^®
Microprocessors
s _{High Power 5V to 3.xV Regulators}
s _{Local Regulation for Dual Voltage Logic Boards}
s _{Low Voltage, High Current Battery Regulation}
DESCRIPTIO
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.
TYPICAL APPLICATIO
+
4.7µF
Typical 5V to 3.3V, 10A Application
V_IN 5V
+
100Ω
1µF
1N4148
+ C_IN
220µF
×4
0.1µF
0.01µF
PV_CC2 PV_CC1
V_CC
G1
SS
I_MAX
LTC1430 I_FB
NC
FREQSET G2
SHUTDOWN
SHDN PGND
16k
0.1µF
M1A, M1B
2 IN PARALLEL
0.1µF
L1, 2.8µH
1k
3.3V
+ C_OUT
10A
M2
330µF
×6
COMP
GND
C1
220pF ^RC
SENSE⁺
7.5k
FB NC
C_C
SENSE^–
4700pF
LTC1430 • TA01
C_IN: AVX-TPSE227M010R0100
C_OUT: AVX-TPSE337M006R0100
L1: ETQP6F1R6SFA
M1A, M1B, M2: MOTOROLA MTD20N03HL
Efficiency
100
T_A = 25°C
90
V_IN = 5V
V_OUT = 3.3V
80
70
60
50
40
0.1
1
LOAD CURRENT (A)
10
LTC1430 • TA02
1