Bel Fuse Inc. 206 Van Vorst Street, Jersey City, NJ 07302
Tel 201-432-0463
Fax 201-432-9542
www.belfuse.com
NON-ISOLATED DC/DC CONVERTERS
12V Input / Programmable Output / 81A VRM 9.1 Compatible
High efficiency means less power dissipation
Remote on/off
2-Wire Remote sense
5 bit VID digital voltage programming.
Single wire current sharing
Description
The G7NB-81A Series is a non-isolated step down DC/DC
converters providing up to 81A of output current and designed
to be compatible to the Intel VRM 9.1 specification. Standard features include current share, remote on/off, over
current protection, remote sense and a power good signal. This product also makes use of adaptive
positioning to improve transient response performance. These products may be used almost anywhere low-
voltage silicon is being employed and a nominal 12V source is available. Typical applications include file
servers, work stations and other computing applications.
Input Specifications
Parameter
Min
Typ
Max
Notes
Input Voltage Range
10.8 VDC
13.2 VDC
Input Current (disabled)
17mA
Input Current (full load)
16A
Reflected Ripple Current
500mA rms
With 100uF, 25mOhm
capacitor and 200nH of input
inductance.
Output Specifications
Parameter
Min
Typ
Max
Notes
Output Current
0A
81A
Set Point Accuracy
1.81V
1.83
1.85
no load, excluding Adaptive
positioning, VID 00000
Adaptive Positioning
(Droop Impedance)
800 uOhm
Ripple and Noise
20mV
pk-pk, 0 to 20MHz Bandwidth
Full load with two external
560uF oscon capacitors on
output.
Turn on Time
8mS
16mS
Transient Response
Deviation
Settling Time
100mV
175uS
di/dt = 5A/uS
30A Load step
Remote Sense Compensation
0.3VDC
Output Capacitance
4400uF
9000uF
For applications requiring
higher or lower output
capacitance please consult
factory.
G7NB-81A180 PRELIMINARY
2003 Bel Fuse Inc. Specifications subject to change without notice. 011202
CORPORATE
FAR EAST
EUROPE
Bel Fuse Inc.
Bel Fuse Ltd.
Bel Fuse Europe Ltd.
206 Van Vorst Street
8F/ 8 Luk Hop Street
Preston Technology Management Centre
Jersey City, NJ 07302
San Po Kong
Marsh Lane, Suite G7, Preston
Tel 201-432-0463
Kowloon, Hong Kong
Lancashire, PR1 8UD, U.K.
Fax 201-432-9542
Tel 852-2328-5515
Tel 44-1772-556601
www.belfuse.com
Fax 852-2352-3706
Fax 44-1772-888366
www.belfuse.com
www.belfuse.com
NON-ISOLATED DC/DC CONVERTERS
12V Input / Programmable Output / 81A VRM 9.1 Compatible
General Specifications
Parameter
Specification
Switching Frequency
1 MHz typical (fixed)
Dimensions
inches
mm
3.8 x 1.35 x .59
96.5 x 34.3 x 15
Weight
TBD
Operating Temperature
0
C to 70
C
Non-Operating Temperature
-40
C to 100
C
Protection Features
Over current
Undervoltage
110% to 170% max Io
UVLO Vin < 10.8V
Remote On/Off
Active High
Efficiency (full load)
1.85V output
86%
Pin Connections
Row A
Row B
Pin
Function
Pin
Function
1 VIN+
62 VIN-
2 VIN+
61 VIN-
3 VIN+
60 VIN-
4 VIN+
59 VIN-
5 NC
58 VIN-
6 NC
57 VID4
7 VID3
56 VID2
8 VID1
55 VID0
9 Memory
54 Ishare
10 PWRGD
53 OUTEN
11 VO-sen-
52 VO-sen+
12 No Pin
51 No Pin
13 VO-
50 VO+
14 VO+
49 VO+
15 VO-
48 VO-
16 VO+
47 VO+
17 VO-
46 VO-
18 VO+
45 VO+
19 VO-
44 VO-
20 VO+
43 VO+
21 VO-
42 VO-
22 VO+
41 VO+
23 VO-
40 VO-
24 VO+
39 VO+
25 VO-
38 VO-
26 VO+
37 VO+
27 VO-
36 VO-
28 VO+
35 VO+
29 VO-
34 VO-
30 VO+
33 VO+
31 VO-
32 VO-
Notes:
1. Mechanical key between pins 11 & 12 and 51 & 52
2. Pin 6 is electrical key.
Voltage Identification (VID) Code
VID4
VID3
VID2
VID1
VID0
Vo (VDC)
1
1
1
1
1 Output Off
1
1
1
1
0
1.1
1
1
1
0
1
1.125
1
1
1
0
0
1.15
1
1
0
1
1
1.175
1
1
0
1
0
1.2
1
1
0
0
1
1.225
1
1
0
0
0
1.25
1
0
1
1
1
1.275
1
0
1
1
0
1.3
1
0
1
0
1
1.325
1
0
1
0
0
1.35
1
0
0
1
1
1.375
1
0
0
1
0
1.4
1
0
0
0
1
1.425
1
0
0
0
0
1.45
0
1
1
1
1
1.475
0
1
1
1
0
1.5
0
1
1
0
1
1.525
0
1
1
0
0
1.55
0
1
0
1
1
1.575
0
1
0
1
0
1.6
0
1
0
0
1
1.625
0
1
0
0
0
1.65
0
0
1
1
1
1.675
0
0
1
1
0
1.7
0
0
1
0
1
1.725
0
0
1
0
0
1.75
0
0
0
1
1
1.775
0
0
0
1
0
1.8
0
0
0
0
1
1.825
0
0
0
0
0
1.85
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