MIC2591B
Micrel
Parameter
Auxiliary Output Current Limit
Threshold (Figure 4)
Maximum Transient Short Circuit
Current
Regulated Current after Transient
Output Discharge Resistance
12VOUT[A/B]
3VOUT[A/B]
3VAUX[A/B]
12V Current Limit Response Time
(Figure 2)
3.3V Current Limit Response Time
(Figure 3)
VAUX[A/B] Current Limit Response
Time (Figure 5)
Condition
Current which must be drawn from
V
AUX
to register as a fault
V
AUX
Enabled, then Grounded
Min
Typ
0.84
V
STBY[A/B]
R
DS(AUX)
1.35
Max
Units
A
Electrical Characteristics (continued)
(7)
Symbol
I
AUX(THRESH)
I
SC(TRAN)
I
LIM(AUX)
R
DIS(12V)
R
DIS(3V)
R
DIS(VAUX)
t
OFF(12V)
t
OFF(3V)
t
SC(TRAN)
I
MAX
=
0.375
A
A
Ω
Ω
Ω
From end of I
SC(TRAN)
to C
FILTER
time-out
12V
OUT[A/B]
= 6.0V
3V
OUT[A/B]
= 1.65V
3V
AUX[A/B]
= 1.65V
MIC2591B-2BTQ
C
GATE
= 25pF
V
IN
–V
SENSE
= 140mV
0.7
1600
150
430
1
2.0
µs
V
AUX[A/B]
= 0V, V
STBYA
= V
STBYB
= +3.3V
MIC2591B-2BTQ
C
FILTER
= 0
V
IN
–V
SENSE
= 140mV
(8)
MIC2591B-2BTQ
C
GATE
= 25pF
V
IN
–V
SENSE
= 140mV
(8)
1
2.0
µs
2.5
1
5
µs
µs
t
PROP(12VFAULT)
Delay from 12V[A/B] Overcurrent
Limit to /FAULT output
t
PROP(3VFAULT)
t
PROP(VAUXFAULT)
Delay from 3V[A/B] Overcurrent
Limit to /FAULT[A/B] Output
Delay from VAUX[A/B] Overcurrent
MIC2591B-2BTQ
C
FILTER
= 0
V
IN
–V
SENSE
= 140mV
(8)
1
µs
t
W
ON[A/B], AUXEN[A/B] Pulse Width
MIC2591B Power-On Reset Time
after VSTBY[A/B] becomes valid
SCL (clock) period
Data In setup time to SCL HIGH
Data Out stable after SCL LOW
Data LOW setup time to SCL LOW
MIC2591B-2BTQ
limit to /FAULT[A/B] output
C
FILTER
= 0
V
AUX
Output Grounded
(8)
Note 8
Note 8
1
µs
100
250
ns
µs
t
POR
SMBus Timing
t
1
t
2
t
3
t
4
t
5
Notes:
7.
8.
Specification for packaged product only.
Parameters guaranteed by design. Not 100% production tested.
Figure 1
Figure 1
Figure 1
Start condition, Figure 1
2.5
100
300
100
100
µs
ns
ns
ns
ns
Data HIGH hold time after SCL HIGH Stop condition, Figure 1
March 2005
9
M9999-033105
MICREL [ MICREL SEMICONDUCTOR ]
