Product # IQ65033QGA12

Phone 1-888-567-9596

www.synqor.com

Doc.# 005-0006070 Rev. B

09/06/2012

Page 8

Outputs:

Current:

Package:

5.0V/ 3.3V

10A

Quarter-brick

Application Section

FEATURE DESCRIPTIONS

Input ORing MOSFETs: ORing of dual -48V feeds is provided by four

MOSFETs, which are individually controlled so as to operate 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. Due to the ‘Turn On Current’ feature, at fixed Input- Voltages

the Output Voltage will experience one or two Diode drops (0.6V or 1.2V)

for currents at or below ‘Turn On Current’ thresholds.

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 output will be tri-stated.

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 failure. 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 reporting that

makes full fuse detection possible. Among other data, each feed voltage

can be compared with the voltages reported by the shelf manager to

determine whether any board fuse is blown.

Input Enable: The ENABLE_A/B signals connect to VRTN_A/B on the

backplane via the shortest pins in the zone 1 connector. They are the last

pins to mate during board insertion, and the first to disconnect during board

extraction. The ENABLE_A and ENABLE_B signals are diode-ORed together

which lets either signal enable the module. Whenever both ENABLE pins

are open, the hot-swap switch is opened. This prevents -48V output power

from being drawn though the EARLY pre-charge resistors.

A

EMI Filter

Hot Swap

Control Logic

Current-

controlled hold-

up charging

converter

Hold-up

connect control

circuits

Management

Power

converter

FET

control

FET

control

FET

control

FET

control

Dis-

charge

Enable Logic

A

B

C

D

B

C

D

Temp

sense

-48_B

ENABLE_A

ENABLE_B

-48_A

VRTN_A

VRTN_B

SHELF_GND

3.3V

5.0 V

-48V_OUT

VRTN_OUT

HU_TRIM

HU_CAP

5

6

3

4

1

2

7

4

1

3

1

8

9

15

16

17

18

Isolation barrier

E

F

dV/dt

sense

F

E

E

F

10

11

12

Monitoring

circuits

Figure A: Internal Block Diagram