Isolated, Digital Output, Power Monitoring IC
with Zero-Crossing Detection, Overcurrent and Overvoltage Flagging
ACS37800
If for any reason the external slave address setting feature is not
EEPROM Error Checking and Correction (ECC)
desired, the DIO polling can be disabled by setting the i2c_dis_
slv_addr. When this bit is set, the ACS37800 will automatically
use the number stored in i2c_slv_addr as the I2C slave address
regardless of the voltage on the DIO pins. Note that the device
must be repowered for these changes to take effect.
Hamming code methodology is implemented for EEPROM
checking and correction (ECC). ECC is enabled after power-up.
The ACS37800 analyzes message data sent by the controller and
the ECC bits are added. The first 6 bits sent from the device to
the controller are dedicated to ECC. The device always returns
32 bits.
Table 2: DIO Startup Voltage Addressing
Slave Address
DIO_1 DIO_2 A6 A5 A4 A3 A2 A1 A0
(decimal)
EEPROM ECC Errors
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
97
Bits
Name
Description
97
31:28
–
No meaning
98
00 = No Error
01 = Error detected and message corrected
10 = Uncorrectable error
11 = No meaning
99
27:26
25:0
ECC
100
101
102
103
104
105
106
107
108
109
110
D[25:0]
EEPROM data
I2C Slave Addressing
The ACS37800 supports I2C communication over the SCL and
SDA lines at speeds of up to 400 kHz. When the device first
powers on, it measures the voltage level on the two DIO pins. It
converts both voltage levels into a 4-bit code for a total of sixteen
slave addresses. Table 2 shows the sixteen possible I2C configu-
rations that can be set with externally applied voltage. If both
pins are pulled to VCC, then the internal slave address stored in
EEPROM is used. By default, the value of i2c_slv_addr is pro-
grammed at the Allegro factory to 127, but this can be changed
with programming by the customer.
EEPROM
value
1
1
1
1
EE EE EE EE EE EE EE
25
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
ALLEGRO [ ALLEGRO MICROSYSTEMS ]
