Datasheet

9Maxim Integrated
MAX5988A/MAX5988B
IEEE 802.3af-Compliant, High-Efficiency, Class 1/Class 2,
Powered Devices with Integrated DC-DC Converter
Typical Operating Characteristics (continued)
(T
A
= +25°C, unless otherwise noted.)
5V LOAD TRANSIENT
(0% TO 50%)
MAX5988A toc12
V
OUT
AC-COUPLED
50mV/div
I
OUT
500mA/div
0A
100µs/div
EFFICIENCY vs. LOAD CURRENT
(MAX5988A, V
OUT
= 5V)
MAX5988A toc10
LOAD CURRENT (A)
EFFICIENCY (%)
0.90.80.1 0.2 0.3 0.5 0.60.4 0.7
65
70
75
80
85
90
95
100
60
0 1.0
V
IN
= 57V
V
IN
= 48V
V
IN
= 12V
V
IN
= 36V
DC-DC CONVERTER STARTUP
I
OUT
= 0A
MAX5988A toc14
V
OUT
1V/div
V
GND
2ms/div
5V LOAD TRANSIENT
(50% TO 100%)
MAX5988A toc13
V
OUT
AC-COUPLED
50mV/div
I
OUT
500mA/div
0A
100µs/div
EFFICIENCY vs. LOAD CURRENT
(MAX5988B, V
OUT
= 12V)
MAX5988A toc11
LOAD CURRENT (A)
EFFICIENCY (%)
0.1 0.2 0.3 0.5 0.60.4
65
70
75
80
85
90
95
100
60
0 0.7
V
IN
= 57V
V
IN
= 36V
V
IN
= 48V
DC-DC CONVERTER STARTUP
R
OUT
= 6.67I
MAX5988A toc15
V
OUT
1V/div
V
GND
2ms/div