E
NGINEERING
D
EPARTMENT
706679 Rev 09-26-18
3 of 9
Signal Descriptions and Connector/Pin Assignments
Signal
Description/Remarks
I
2
C Serial Clock
Provides PMBus control/status interface. Pulled-up to 3.3V by a
4.7K resistor. Maximum frequency is 100Khz.
I
2
C Serial Data
Provides PMBus control/status interface. Pulled-up to 3.3V by a
4.7K resistor.
Address 1
High-true address selection input (2 bits: 0, 1).
Address 0
High-true address selection input (2 bits: 0, 1).
DC Return (ground)
XL270 circuit return for all outputs and status/control signals. (RTN)
CAN HIGH
HIGH data line for CAN (Controller area Network)
communications (for current sharing and service use)
CAN LOW
LOW data line for CAN (Controller area Network)
communications (for current sharing and service use)
-RS
Remote sense for RTN
+RS
Remote sense for VOUT (compensates for load-cable drop)
PF/PG
A high-logic level (≈4.5V) indicates the output power is in
regulation for at least the next 2ms.
RE
Remote Enable Input
12V Auxiliary
(12VAUX) / FAN
Controlled Output
Provides 0.5A at 12V. Uses RTN for its return.
With the PMBUS command, this output can switch on and off with
a preprogrammed duty cycle to control fan speed.
5VSB
Provides 1A at 5V. Uses RTN for its return.
Tachometer Input
The tachometer output of a single fan may be connected to this
input. The loss of the tachometer signal is detected and can be
reported over the optional serial data interface.
Table 3 Signal Descriptions and Connector/Pin Assignments
