AD7294 Analog Devices, AD7294 Datasheet - Page 29

• Manufacturer Part Number: AD7294
• Description: 12-Bit Monitor and Control System with Multichannel ADC, DACs, Temperature Sensor, and Current Sense
• Manufacturer: Analog Devices

Specifications of AD7294

• Resolution (bits): 12bit
• # Chan: 9
• Sample Rate: 200kSPS
• Interface: I²C/Ser 2-Wire,Ser
• Analog Input Type: Diff-Uni,SE-Uni
• Ain Range: (Vref) p-p,2 V p-p,Uni (Vref),Uni (Vref) x 2
• Adc Architecture: SAR
• Pkg Type: CSP

Data Sheet
ADC Channel Allocation
The three channel address bits indicate which channel the result
in the result register represents. Table 13 details the channel ID bits
(S.E. indicates single-ended and DIFF indicates differential).
Table 13. ADC Channel Allocation
Function
V
V
V
V
V
V
V
V
I
I
T
T
T
Register T
The MSB, D15 is the alert_flag bit whereas Bit D14 to Bit D12
contain the three ADC channel allocation bits. D11 is reserved
for flagging diode open circuits. The temperature reading from
the ADC is stored in an 11-bit twos complement format, D10 to
D0 (see Table 14 and Table 15). Conversions take place approx-
imately every 5 ms.
Table 16. T
Input
Value (°C)
SENSE
SENSE
SENSE
SENSE
IN
IN
IN
IN
IN
IN
IN
IN
SENSE
0 (S.E.) or
0 − V
1 (S.E.) or
1 − V
2 (S.E.) or
2 − V
3 (S.E.) or
3 − V
1
2
1
2
1, T
IN
IN
IN
IN
1 (DIFF)
0 (DIFF)
3 (DIFF)
2 (DIFF)
SENSE
SENSE
SENSE
1 and Register T
2 RESULT REGISTERS (0x02 AND 0x03)
Data Format
D10 (MSB)
−256
CH
0
0
0
0
1
1
1
1
ID2
SENSE
2 are 16-bit read only registers.
CH
0
0
1
1
0
0
1
1
Channel ID
D9
+128
ID1
D8
+64
CH
0
1
0
1
0
1
0
1
ID0
D7
+32
Rev. H | Page 29 of 48
D6
+16
Table 14. T
MSB
D15
Alert_Flag
Table 15. Register (Second Read)
MSB
D7
B7
T
The T
store the ADC data generated from the internal temperature
sensor. Similar to the T
register stores the temperature readings from the ADC in an 11-
bit twos complement format, D10 to D0, and uses the MSB as a
general alert flag. Bits[ D14:D11] are not used and are set to
zero. Conversions take place approximately every 5 ms. The
temperature data format in Table 16 also applies to the internal
temperature sensor data.
Temperature Value Format
The temperature reading from the ADC is stored in an 11-bit
twos complement format, D10 to D0, to accommodate both
positive and negative temperature measurements. The temper-
ature data format is provided in Table 16.
SENSE
D5
+8
SENSE
INT RESULT REGISTER (0x04)
INT register is a 16-bit read-only register used to
D6
B6
SENSE
D14
CH
D4
+4
Register (First Read)
ID2
D5
B5
D13
CH
D3
+2
SENSE
ID1
D4
B4
1 and T
D12
CH
D2
+1
ID0
D3
B3
SENSE
D11
B11
2 result registers, this
D1
+0.5
D2
B2
D10
B10
D1
B1
D0 (LSB)
+0.25
AD7294
D9
B9
LSB
D0
B0
LSB
D8
B8