20
PCF8574 slave address:
Table 7-2
7.3 Block diagram of the I2C option
Refer to Fig 7-1 for description of the I2C block diagram and for typical application.
A0
A1
A2
REGISTER
A0 Output voltage
A1
A2
ADC Temperature
A0 A0
A1 A1
A2 A2
EEPROM
Fig 7-1: I2C option bloack diagram
Output Fail
OTP
Temperature Alarm
Fan Fail
AC Input Fail
Serial CLOCK
Serial DATA
Output current
7.4 Operation and functions
7.4.1. Digital status
Digital status functions are provided by a PCF8574, 8-bit Register. It provides a single 8-bit word when read by the
I2C controller. Fault is indicated by "1" and Good level is indicated by "0".
Refer to Table 7-1 for the register information.
Bit 7 6 5 4 3 2 1 0
Value 0 1 0 0 A2 A1 A0 R/W
The slave EEPROM address is:
Bit 7 6 5 4 3 2 1 0
Value 1 0 10 A2 A1 A0 R/W
7.4.2 EEPROM functions
A 256 bytes EEPROM included in the I2C option. The EEPROM type is AT24C02 and it is programmed at the factory
with the data shown in Table 7-2.
BIT
0 Output Fail Output voltage is <80% +/- 5% of Vout rated
1 Over Temperature Protection Internal temperature is over 80°C. Supply turns off.
2 Temperature Alarm Internal temperature is over 70°C. Supply is on.
3 Fan Fail Failure of an internal fan.
4AC Input Fail AC Input <85Vac
5 Not Used Always "0".
6 Not Used Always "0".
7 Not Used Always "0".
Table 7-1
FUNCTION MEANING
ADDRESS BYTES DATA
0 4 Number of fields
4 16 Manufacturer
20 20 Serial number
40 16 Revision
56 16 Country of manufacture
72 16 Model name
88 16 Output voltage
104 16 Date of manufacture
254 2 Checksum