Kontron AT8901M - Manual (Page 45)

AT8901M Hardware Description
Page 3 - 15 AT8901M User Guide
3.7.2 Power Distribution
The 48 Volts are supplied by the backplane via two independent rails, primary (A) and second-
ary (B). The rails are mixed using power Schottky rectifiers. A 7A fuse protects each -48V line
and a 10A fuse protects each RTN line. A hot swap controller enables the 48V power to the
board.
A quarter brick DC/DC converter transforms the 48 Volts to secondary 12 Volts, which are dis-
tributed on the board. The converter allows a maximum of 14A output current.
Two different management voltages (3.3V and 5V) and five payload voltages (3.3V, 2.5V, 1.8V,
1.25V and 1.2V) are generated by point of load converters. These are either switches or linear
regulators.
The management (or suspend) power is present once the board is connected to the backplane.
It supplies the IPMI part which in turn controls the payload power. The various payload voltages
are sequenced. The initial power up sequence is as follows (20ms delay between steps):
1. 3.3V, 1.8V and fabric mezzanine
2. 2.5V, 1.25V and 1.2V
The Power Down Sequence is performed in reversed order with a 1ms delay.
Table 3-14: Power Connector (P10)
Signal Pin Pin Signal
N.C. 1 2 N.C.
N.C. 3 4 N.C.
HA0 5 6 HA1
HA2 7 8 HA3
HA4 9 10 HA4
HA6 11 12 HA5
SCL_A 13 14 SDA_A
SCL_B 15 16 SDA_B
MT1_TIP(N.C.) 17 18 MT2_TIP(N.C.)
RING_A(N.C.) 19 20 RING_B(N.C.)
MT1_RING(N.
C.) 21 22 MT2_RING(N.
C.)
RRTN_A(N.C.) 23 24 RRTN_B(N.C.)
SHELF_GND 25 26 LOGIC_GND
ENABLE_B 27 28 VRTN_A
VRTN_B 29 30 EARLY_A
EARLY_B 31 32 ENABLE_A
-48V_A 33 34 -48V_B
4
16
20
24
26
28
32
31
34
1
13
25
29
27
30
33
17
21