Technical Specification
5
6
ENABLE_A
ENABLE_B
Input:
Outputs:
Current:
Package:
36-75 V
5.0 V/ 3.3 V
10 A
Quarter-brick
HU_CAP
18
VRTN_A
3
Enable Logic
Temp
sense
FET
control
VRTN_B
Hold-up
connect control
circuits
E
A
F
dV/dt
sense
VRTN_OUT
17
4
FET
control
-48_A
1
E
B
F
EMI Filter
Hot Swap
Control Logic
Current-
controlled hold-
up charging
converter
HU_TRIM
16
C
FET
control
-48_B
2
-48V_OUT
15
D
FET
control
A
B
Management
Power
converter
LOGIC_GND
I
2
C Clock
Dis-
charge
Isolation barrier
3.3V
8
9
5.0 V
E
F
I
2
C Add.
I
2
C Data
10
11
12
14
ALARM
13
7
SHELF_GND
C
D
Monitoring
circuits
Figure A:
Internal Block Diagram
FEATURE DESCRIPTIONS
Input ORing MOSFETs:
ORing of dual -48V feeds is provided
by four MOSFETs, which are individually controlled so as to oper-
ate as an ideal diode (see Figure A). If there is an input feed short
of any kind, a control circuit will detect reverse current and turn
off the MOSFET in 250ns (typ.), to avoid disturbing the other feed
voltage. At zero current, the MOSFET is guaranteed to be off. In
the case of a fuse failure, this triggers the ALARM output, due to an
apparent input feed loss. Current hysteresis prevents limit cycling
around the transition point between body diode and MOSFET
conduction.
ALARM Output:
The ALARM pin gives an external indication
of a fault condition. It is an isolated and buffered open-collector
output, which is normally pulled low. In the presence of an input
feed loss (which can be caused by a fuse failure), the ALARM out-
put will be tri-stated.
Product # IQ65033QMA10
Phone 1-888-567-9596
External Input Fuse Failure Detection:
At zero current, the
input ORing MOSFETs are guaranteed to be off. In the case of a
fuse failure, an on-board bleed resistor pulls the input feed voltage
down. This triggers the ALARM output due to an apparent input
feed loss. There are two main down-sides to this approach. First,
there is no way to distinguish between a feed loss and a fuse fail-
ure. Second, an enable fuse loss is not detected, since the enables
are diode OR’d.
The full featured version of the iQor offers additional data report-
ing that makes full fuse detection possible. Among other data,
each feed voltage and each enable voltage is reported through
the I
2
C port. These voltages can be compared with the voltages
reported by the shelf manager to determine whether any board
fuse is blown.
www.synqor.com
Doc.# 005-IQ5033S Rev. G
05/04/09
Page 8
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