MIC2591B
Micrel
Typical Application
+12V
System
Power +3.3V
Supply
VSTBY
0.1µF
0.1µF
11
26
PCI Express Connector
PCI
Express
Bus
33
23.2k
1%
20
VSTBYA VSTBYB
IREF
RFILTER[A&B]
VAUXA
12VINA
15
0.1F
110k
1%
2
5
12VSENSEA
CFILTERA
CFILTERB
12VGATEA
12VOUTA
8
V
STBY
C1
C2
100k
35
3
#
C
GS
22nF
#
*R
12VGATEA
15
R
SENSE
0.020
3.3AUX
375mA
100k
/FORCE_ONA
/FORCE_ONB
GPI_A0
GPI_B0
100k
100k
10
12
C
MILLER
6800pF
Si4435DY
12V
2.1A (x4/x8)
R
SENSE
0.013
9
28
4
38
/FORCE_ONA
/FORCE_ONB
GPI_A0
GPI_B0
3VINA
0.1F
13
3VSENSEA
3VGATEA
3VOUTA
MIC2591B
V
STBY
14
16
#
*R
3VGATEA
15
C
GATE
22nF
0.1F
Si4420DY
3.3V
3.0A
10k x 4
AUXENA
AUXENB
ONA
ONB
V
STBY
Hot-Plug
Controller
10k x 4
/PWRGDA
/PWRGDB
/FAULTA
/FAULTB
6
31
1
36
45
42
44
43
12VINB
AUXENA
AUXENB
ONA
ONB
12VSENSEB
32
29
C
GS
22nF
12VGATEB
12VOUTB
34
#
R
SENSE
0.020
*R
12VGATEB
15
#
27
C
MILLER
6800pF
0.1F
Si4435DY
12V
2.1A (x4/x8)
R
SENSE
0.013
/PWRGDA
/PWRGDB
/FAULTA
/FAULTB
3VINB
3VSENSEB
3VGATEB
25
24
23
21
22
17
#
*R
3VGATEB
15
Si4420DY
3.3V
3.0A
41
SMBus
Base
Address
V
STBY
A0
A1
A2
/INT
SCL
SDA
40
39
37
47
48
3VOUTB
VAUXB
GND
C
GATE
22nF
3.3AUX
375mA
PCI
Express
Bus
PCI Express Connector
GND
46
10k x 3
SDA
SMBus I/O
SCL
/INT
SDA
SCL
/INT
Management
Controller
* Values for R
12VGATE[A/B]
and R
3VGATE[A/B]
may vary
#
depending upon the CGS of the external MOSFETs.
These components are not required for MIC2591B
operation but can be implemented for GATE output
slew rate control (application specific)
¥ Bold lines indicate high current paths
March 2005
2
M9999-033105
MICREL [ MICREL SEMICONDUCTOR ]
