AD7416/AD7417/AD7418
Rev. I | Page 9 of 24
SDA
1
SCL
2
OTI
3
GND
4
V
DD
8
A0
7
A1
6
A2
5
AD7416
TOP VIEW
(Not to Scale)
1126-006
SDA
1
SCL
2
OTI
3
GND
4
CONVST
8
V
DD
7
REF
IN
6
A
IN
5
AD7418
TOP VIEW
(Not to Scale)
01126-007
Figure 7. AD7416 Pin Configuration (SOIC/MSOP) Figure 8. AD7418 Pin Configuration (SOIC/MSOP)
Table 5. AD7416 Pin Function Descriptions
Pin No. Mnemonic Description
1 SDA Digital I/O. Serial bus bidirectional data. Push-pull output.
2 SCL Digital Input. Serial bus clock.
3 OTI
This pin is a logic output. The OTI is set if the result of a conversion on Channel 0 (temperature sensor) is greater
than an 8-bit word in the T
OTI
setpoint register. The signal is reset at the end of a serial read operation. Open-drain
output.
4 GND Ground reference for track-and-hold, comparator and capacitor DAC, and digital circuitry.
5 A2 Digital Input. This is the highest programmable bit of the serial bus address.
6 A1 Digital Input. This is the middle programmable bit of the serial bus address.
7 A0 Digital Input. This is the lowest programmable bit of the serial bus address.
8 V
DD
Positive Supply Voltage, 2.7 V to 5.5 V.
Table 6. AD7418 Pin Function Descriptions
Pin No. Mnemonic Description
1 SDA Digital I/O. Serial bus bidirectional data. Push-pull output.
2 SCL Digital Input. Serial bus clock.
3 OTI
This is a logic output. The OTI is set if the result of a conversion on Channel 0 (temperature sensor) is greater than
an 8-bit word in the T
OTI
setpoint register. The signal is reset at the end of a serial read operation. Open-drain
output.
4 GND Ground reference for track-and-hold, comparator and capacitor DAC, and digital circuitry.
5 A
IN
Analog Input Channel. The input channel is single-ended with respect to GND. The input channel can convert
voltage signals in the range of 0 V to VREF. The analog input channel is selected by writing to the configuration
register of the AD7418 and choosing Channel 4.
6 REF
IN
Reference Input. An external 2.5 V reference can be connected to the AD7418 at this pin. To enable the on-chip
reference, the REF
IN
pin should be tied to GND. If an external reference is connected to the AD7418, the internal
reference shuts down.
7 V
DD
Positive Supply Voltage, 2.7 V to 5.5 V.
8
CONVST
Logic Input Signal. Convert start signal. The rising edge of this signal fully powers up the part. The power-up time
for the part is 4 s. If the
CONVST
pulse is greater than 4 s, the falling edge of
CONVST
places the track-and-hold
mode into hold mode and initiates a conversion. If the pulse is less than 4 s, an internal timer ensures that the
track-and-hold does not go into hold, and conversion is not initiated until the power-up time has elapsed. The
track-and-hold goes into track mode again at the end of conversion (see the section). Operating Modes