CPFE1000FI SERIES
POWER SUPPLY
OPERATION MANUAL
29
19 August 2020
5.3 Analog Functions
Analog functions are provided by a 8-channel 10-bit resolution Analog-Digital Converter (ADC).When
this device is read by the I2C bus controller it provides a 2 bytes word information.
The ADC has to be scaled to obtain a correct value for the voltage, current and temperature readings.
The following scaling factor (SF) should be employed:
CPFE1000FI28
Range
SF
Accuracy
Voltage
0 – 34V
0.03973
+/-2%
Current
0-36A
0.0488
+/-5%
Temperature
0-100
o
C
Note 1
+/-3%
Note 1:
At ambient temperatures below -20C, a period of warm-up may be required before the current
readback meets these accuracy levels. The current readback accuracy may also be affected during fault (OTP,
OVP, OCP) condition.
Note 2:
Use the following formula for calculating temperature.
Tbase (C) = (DEC number – 610)/2.048 + 25
Where DEC Number is the decimal conversion of the HEX number read on address 6 (temp reading)
Example:
For 12 volts output @ 30C baseplate temperature
Get the HEX number: 26D
Convert the HEX to DEC number: 621
Apply formula: Temp = (DEC number – 610)/2.048 + 25
(621 – 610)/2.048 + 25 = 30.4C
Temp =~ 30.4C
Address
Bytes
Data
04
2
Output Voltage Readback
05
2
Output Current Readback
06
2
Baseplate Temperature Readback
CPFE1000FI12
Range
SF
Accuracy
Voltage
0 – 15V
0.01668
+/-2%
Current
0-60A
0.0815
+/-5%
Temperature
0-100
o
C
Note 1
+/-3%
CPFE1000FI48
Range
SF
Accuracy
Voltage
0 - 58V
0.06772
+/-2%
Current
0-21A
0.0282
+/-5%
Temperature
0-100
o
C
Note 1
+/-3%
02
6D
