Datasheet

MAX1954A
Low-Cost, Current-Mode PWM Buck
Controller with Foldback Current Limit
_______________________________________________________________________________________ 5
Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
EFFICIENCY
vs. LOAD CURRENT
MAX1954A toc01
LOAD CURRENT (A)
EFFICIENCY (%)
100
40
50
60
70
80
90
0.1 1 10
V
OUT
= 2.5V
V
IN
= V
HSD
= 5V
V
OUT
= 1.5V
2.60
2.55
2.50
2.45
2.40
021 345
OUTPUT VOLTAGE
vs. LOAD CURRENT
MAX1954A toc02
LOAD CURRENT (A)
OUTPUT VOLTAGE (V)
V
IN
= V
HSD
= 5V
-70
-30
-50
10
-10
50
30
70
3.0 4.03.5 4.5 5.0 5.5
OUTPUT VOLTAGE CHANGE
vs. INPUT VOLTAGE
MAX1954A toc03
INPUT VOLTAGE (V)
CHANGE IN OUTPUT VOLTAGE (mV)
V
OUT
= 2.5V
V
OUT
= 0.8V
V
IN
= V
HSD
I
OUT
= 5A
0.81
0.81
0.80
0.80
0.79
10.8 12.011.4 12.6 13.2
OUTPUT VOLTAGE
vs. INPUT VOLTAGE
MAX1954A toc04
INPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
V
IN
= V
HSD
I
OUT
= 5A
250
270
310
290
330
350
3.0 4.03.5 4.5 5.0 5.5
OSCILLATOR FREQUENCY
vs. INPUT VOLTAGE
MAX1954A toc05
INPUT VOLTAGE (V)
OSCILLATOR FREQUENCY (kHz)
T
A
= -40
°
C
T
A
= +85
°
C
T
A
= +25
°
C
V
IN
= V
HSD
LOAD TRANSIENT
MAX1954A toc06
40µs/div
100mV/div
V
OUT
AC-COUPLED
I
OUT
5A/µs
5A
500mA