Datasheet

MAX1533A/MAX1537A
High-Efficiency, 5x Output, Main Power-Supply
Controllers for Notebook Computers
10 ______________________________________________________________________________________
Typical Operating Characteristics (continued)
(MAX1537A circuit of Figure 1, V
IN
= 12V, LDO5 = V
CC
= 5V, SKIP = GND, FSEL = REF, T
A
= +25°C, unless otherwise noted.)
IDLE-MODE CURRENT
vs. INPUT VOLTAGE
MAX1533/37 toc10
INPUT VOLTAGE (V)
PEAK CURRENT (A)
2515 2010
1.5
1.0
0.5
2.0
2.5
3.0
3.5
0
05 30
DUTY CYCLE
LIMITED
5V OUTPUT
2.0V REFERENCE LOAD REGULATION
MAX1533 toc11
REF LOAD CURRENT (μA)
REF VOLTAGE (V)
80600 20 40
1.99
2.00
2.01
2.02
1.98
-20 100
LINEAR-REGULATOR
LOAD REGULATION
MAX1533/37 toc12
LDO LOAD CURRENT (mA)
LDO DEVIATION VOLTAGE (mV)
12010080604020
-150
-100
-50
0
50
-200
0140
LDO3
LDO5
V
IN
= 6V
ON3 = ON5 = GND
AUXILIARY LINEAR-REGULATOR
LOAD REGULATION
MAX1533/37 toc13
LDOA LOAD CURRENT (mA)
AUX LDO VOLTAGE (V)
1601208040
11.8
11.9
12.0
12.1
11.7
0200
INTERLEAVED OPERATION
MAX1533/37 toc14
2.0μs/div
12V
0
A
B
C
D
E
F
5V
0
12V
0
3.3V
0
A. LX5, 10V/div
B. 5V OUTPUT, 100mV/div
C. PWM5 INDUCTOR CURRENT, 5A/div
D. LX3, 10V/div
E. 3.3V OUTPUT, 100mV/div
F. PWM3 INDUCTOR CURRENT, 5A/div
LINEAR-REGULATOR
STARTUP WAVEFORMS
MAX1533/37 toc15
400μs/div
5V
4V
0
A
B
C
D
2V
0
2V
0
2V
0
B. LDO5, 2V/div
C. LDO3, 2V/div
D. REF, 2V/div
100Ω LOAD ON LDO5 AND LDO3
A. SHDN, 5V/div