Datasheet

MAX8543/MAX8544
Step-Down Controllers with Prebias Startup,
Lossless Sensing, Synchronization, and OVP
_______________________________________________________________________________________ 7
EFFICIENCY vs. LOAD CURRENT
WITH 12V INPUT
MAX8543 toc01
LOAD CURRENT (A)
EFFICIENCY (%)
101
10
20
30
40
50
60
70
80
90
100
0
0.1 100
V
OUT
= 3.3V
V
OUT
= 2.5V
V
OUT
= 1.8V
f
S
= 600kHz
EFFICIENCY vs. LOAD CURRENT
WITH 3.3V INPUT
MAX8543 toc02
LOAD CURRENT (A)
EFFICIENCY (%)
101
10
20
30
40
50
60
70
80
90
100
0
0.1 100
V
OUT
= 2.5V
V
OUT
= 1.8V
f
S
= 500kHz
V
OUT
= 1.5V
LOAD REGULATION WITH 12V INPUT
MAX8543 toc03
LOAD CURRENT (A)
OUTPUT VOLTAGE (V)
12963
2.46
2.47
2.48
2.49
2.50
2.51
2.52
2.53
2.54
2.55
2.45
015
LINE REGULATION WITH 12V INPUT
AND 2.5V OUTPUT
MAX8543 toc04
INPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
12.612.011.4
2.492
2.494
2.496
2.498
2.500
2.502
2.504
2.506
2.508
2.510
2.490
10.8 13.2
NO LOAD
15A LOAD
LINE REGULATION
3.0V TO 3.6V INPUT
MAX8543 toc05
INPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
3.53.43.33.23.1
2.44
2.46
2.48
2.50
2.52
2.54
2.42
3.0 3.6
NO LOAD
15A LOAD
f
S
= 350kHz
15A LOAD
f
S
= 500kHz
OSCILLATOR FREQUENCY
vs. INPUT VOLTAGE
MAX8543 toc06
INPUT VOLTAGE (V)
OSCILLATOR FREQUENCY (kHz)
5.04.54.03.5
420
440
460
480
500
520
540
560
580
600
400
3.0 5.5
T
A
= +85
°
C
T
A
= +25
°
C
T
A
= -40
°
C
R6 = 53.6k
Ω
OSCILLATOR FREQUENCY
vs. INPUT VOLTAGE
MAX8543 toc07
INPUT VOLTAGE (V)
OSCILLATOR FREQUENCY (kHz)
11.59.57.5
520
540
560
580
600
620
640
660
680
700
500
5.5 13.5
R6 = 42.2kΩ
T
A
= +85
°
C
T
A
= -40
°
C
T
A
= +25
°
C
Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)