LTC1530_15 Datasheet, PDF (1/24 Pages) Linear Technology – High Power Synchronous Switching Regulator Controller

LTC1530
High Power Synchronous
Switching Regulator Controller
FEATURES
s _{High Power Buck Converter from 5V or 3.3V Input}
s _{Adjustable Current Limit in S0-8 with}
Topside FET R_DS(ON) Sensing
s _{No External Sense Resistor Required}
s _{Hiccup Mode Current Limit Protection}
s _{Adjustable, Fixed 1.9V, 2.5V, 2.8V and 3.3V Output}
s _{All N-Channel MOSFET Synchronous Driver}
s _{Excellent Output Regulation: ±2% over Line, Load}
and Temperature Variations
s _{High Efficiency: Over 95% Possible}
s _{Fast Transient Response}
s _{Fixed 300kHz Frequency Operation}
s _{Internal Soft-Start Circuit}
s _{Quiescent Current: 1mA; 45µA in Shutdown}
U
APPLICATIO S
s _{Power Supply for Pentium}^® _{II, AMD-K6}^®_{-2, SPARC,}
ALPHA and PA-RISC Microprocessors
s _{High Power 5V to 1.3V-3.5V Regulators}
DESCRIPTIO
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.
TYPICAL APPLICATIO
V_IN
5V
MBR0530T1 MBR0530T1
0.1µF +
2.7k
10µF
+ C_IN1200µF
×4
0.22µF
I_MAX PVCC
G1
20Ω
COMP
I_FB
150pF _10k
LTC1530-3.3
G2
0.022µF
GND ^VOUT
Q1 ^L1
2µH
+
Q2
C_OUT
330µF
×7
V_OUT
3.3V
14A
1530 F01a
C_IN: SANYO 10MV1200GX
C_OUT: AVX TPSE337M006R0100
L1: COILTRONICS CTX02-13198
OR PANASONIC ETQP6F2R5HA
Q1, Q2: SILICONIX SUD50N03-10
Figure 1. Single 5V to 3.3V Supply
Efficiency vs Load Current
100
90
80
70
60
50
40
30
20
10
0
02
0.3
T_A = 25°C
4 6 8 10 12 14
LOAD CURRENT (A)
1530 F01b
1530fa
1