Low-Voltage, Dual Hot-Swap Controllers with
Independent On/Off Control
_______________________________________________________________________________________ 5
0.1
1
10
20
30 35
25
40
45 50 55 60 65 70 75 80
TURN-OFF TIME vs. SENSE VOLTAGE
(EXPANDED SCALE)
V
IN
- V
SENSE
(mV)
SLOW-COMP. THRESHOLD
0
40
20
80
60
100
120
0
200
100
300
400
SLOW-COMPARATOR THRESHOLD
vs. R
LIM
R
LIM
(k&)
0
20
10
40
30
50
60
STARTUP PERIOD vs. R
TIM
R
TIM
(k&)
0
200 300
100
400 500 600
0
0
0
V
PGOOD
5V/div
V
SENSE
- V
IN
100mV/div
V
GATE
5V/div
TURN-OFF TIME
SLOW-COMPARATOR FAULT
MAX5955/56 toc13
1ms/div
V
IN
= 5.0V
t
SCD
26mV STEP
0
0
0
V
PGOOD
5V/div
V
SENSE
- V
IN
100mV/div
V
GATE
5V/div
TURN-OFF TIME
FAST-COMPARATOR FAULT
MAX5955/56 toc14
400ns/div
V
IN
= 5.0V
t
FCD
125mV STEP
V
ON
2V/div
V
PGOOD
2V/div
I
OUT
5A/div
V
OUT
5V/div
V
GATE
5V/div
STARTUP WAVEFORMS
FAST TURN-ON
MAX5955/56 toc15
1ms/div
V
IN
= 5.0V, R
SENSE
= 10m&,
R
TIM
= 27k&, C
BOARD
= 1000礔
V
ON
2V/div
V
PGOOD
2V/div
I
OUT
5A/div
V
OUT
5V/div
V
GATE
5V/div
STARTUP WAVEFORMS
SLOW TURN-ON
MAX5955/56 toc16
1ms/div
V
IN
= 5.0V, R
SENSE
= 10m&, R
TIM
= 47k&,
C
BOARD
= 1000礔, C
GATE
= 22nF
I
OUT
5A/div
V
OUT
5V/div
V
GATE
5V/div
AUTORETRY DELAY
MAX5955/56 toc17
40ms/div
V
IN
= 5.0V, R
SENSE
= 10m&, R
TIM
= 47k&,
C
BOARD
= 1000礔, R
BOARD
= 1.4&
Typical Operating Characteristics (continued)
(Typical Operating Circuits, Q1 = Q2 = Fairchild FDB7090L, V
IN1
= +5V, V
IN2
= +3.3V, V
ON1
= V
ON2
= +2.7V, T
A
= +25癈, unless
otherwise noted. Channels 1 and 2 are identical in performance. Where characteristics are interchangeable, channels 1 and 2 are
referred to as X and Y.)