Datasheet

Data Sheet ADM1276
Rev. C | Page 5 of 48
Parameter Symbol Min Typ Max Unit Test Conditions/Comments
Foldback Active 3.5 4 4.5 mV V
FLB
= 0 V; V
GATE
= (SENSE+) + 3 V; I
GATE
= 0 μA; V
SS
≥ 1 V
9.6 10 10.4 mV
V
ISET
> 1.0 V; V
FLB
= 0.5 V; V
GATE
= (SENSE+) + 3 V; I
GAT E
= 0 μA;
V
SS
≥ 1 V
Circuit Breaker Offset V
CBOS
0.6 0.88 1.12 mV Circuit breaker trip voltage, V
CB
= V
SENSECL
− V
CBOS
SEVERE OVERCURRENT
Voltage Threshold V
SENSEOC
40 50 mV V
ISET
= 1.0 V; V
FLB
> 1.1 V; V
SS
≥ 2 V
9.5 13.0 mV V
ISET
= 0.25 V; V
FLB
> 1.1 V; V
SS
≥ 2 V
Short Glitch Filter Duration
90
200
ns
V
ISET
> 1.65 V; V
SENSE
driven from 18 mV to 52 mV; selectable via
PMBus
Long Glitch Filter Duration
(Default)
530 900 ns V
SENSE
driven from 18 mV to 52 mV
Response Time
With Short Glitch Filter 180 370 ns 2 mV overdrive maximum severe overcurrent threshold
With Long Glitch Filter
645
1020
ns
SOFT START (SS PIN)
SS Pull-Up Current I
SS
−12 −10 −8 µA V
SS
= 0 V
Default V
SENSECL
Limit 0.5 1.25 1.8 mV
When V
SENSE
reaches this level, I
SS
is enabled, ramping V
SENSECL
;
V
SS
= 0 V
SS Pull-Down Current 100 µA V
SS
= 1 V
TIMER PIN
Timer Pull-Up Current I
TIMERUP
Power-On Reset(POR) I
TIMERUPPOR
−2 −3 −4 µA Initial power-on reset; V
TIMER
= 0.5 V
Overcurrent (OC) Fault I
TIMERUPFLT
−57 −60 −63 µA Overcurrent fault; 0.2 V ≤ V
TIMER
≤ 1 V
Timer Pull-Down Current
Retry
I
TIMERDNRT
1.7
2
2.3
µA
After fault when GATE is off; V
TIMER
= 0.5 V
Hold I
TIMERDNHOLD
100 µA Holds TIMER at 0 V when inactive; V
TIMER
= 0.5 V
Timer Retry/OC Fault
Current Ratio
3.33 3.8 % Defines the limits of the autoretry duty cycle
Timer High Threshold V
TIMERH
0.98 1.0 1.02 V
Timer Low Threshold V
TIMERL
0.18 0.2 0.22 V
FOLDBACK (FLB PIN)
FLB and PWRGD Threshold V
FLBTH
1.08 1.1 1.12 V FLB rising; V
ISET
= 1.0 V
Input Current
I
FLB
100
nA
V
FLB
≤ 1.0 V; V
ISET
= 1.25 V
100 nA V
VCAP
≤ V
FLB
≤ 20 V
Hysteresis Current 1.7 2.3 μA
Internal Hysteresis Voltage 1.9 3.1 mV Voltage drop across the internal 1.3 kΩ resistor
Power-Good Glitch Filter PWRGD
GF
0.3 0.7 1 μs 50 mV overdrive
Minimum Foldback Clamp 200 mV Accuracies included in total sense voltage accuracies
VOUT PIN
Input Current 20 μA VOUT = 20 V
LATCH PIN
Output Low Voltage V
OL_LATCH
0.4 V I
LATCH
= 1 mA
1.5 V I
LATCH
= 5 mA
Leakage Current 100 nA
V
LATCH
≤ 2 V; LATCH output high-Z
1 µA
V
LATCH
= 20 V; LATCH output high-Z
ENABLE PIN No internal pull-up present on this pin
Leakage Current
100
nA
V
GPO2
≤ 2 V
1 µA V
GPO2
= 20 V
Input High Voltage V
IH
1.1 V
Input Low Voltage V
IL
0.8 V