Datasheet

AD7992
Rev. 0 | Page 8 of 28
PIN CONFIGURATION AND PIN FUNCTION DESCRIPTIONS
AD7992
TOP VIEW
1
2
3
4
7
8
9
10
SDA
SCL
V
DD
AGND
AGND
5
(Not to Scale)
ALERT
6
AS
V
IN
1
V
IN
2/REF
IN
03263-0-002
CONVST
Figure 3. AD7992 Pin Configuration
Table 5. Pin Function Descriptions
Pin No. Mnemonic Function
2, 7 AGND
Analog Ground. Ground reference point for all circuitry on the AD7992. All analog input signals should be
referred to this GND voltage.
3 V
DD
Power Supply Input. The V
DD
range for the AD7992 is from 2.7 V to 5.5 V.
4 V
IN
2/REF
IN
Analog Input 2/Voltage Reference Input. In single-channel mode, this pin becomes the reference voltage input;
an external reference should be applied at this pin. The external reference input range is 1.2 V to V
DD
. A 0.1 µF
and 1µF capacitor should be tied between this pin and AGND. If Bit D6 is set to 1 in the configuration register,
the AD7992 operates in single-channel mode. In dual-channel mode, D6 in the configuration register is 0; in
this case, this pin provides the second analog input channel. The reference voltage for the AD7992 is taken
from the power supply voltage in dual-channel mode. See the Configuration Register section and Table 10.
5 V
IN
1 Analog Input 1. Single-ended analog input channel. The input range is 0 V to REF
IN
.
6 AS Logic Input. Address select input that selects one of three I
2
C addresses for the AD7992, as shown in Table 6.
1
CONVST Logic Input Signal. Convert start signal. This is an edge-triggered logic input. The rising edge of this signal
powers up the part. The power up time for the part is 1 µs. The falling edge of
CONVST places the track-and-
hold into hold mode and initiates a conversion. A power-up time of at least 1 µs must be allowed for the
CONVST high pulse; otherwise, the conversion result is invalid (see the Modes of Operation section).
8 ALERT/BUSY
Digital Output. Selectable as an ALERT or BUSY output function. When configured as an ALERT, this pin acts as
an out-of-range indicator and, if enabled, becomes active when the conversion result violates the DATA
HIGH
or
DATA
LOW
register values. See the Limit Registers section. When configured as a BUSY output, this pin becomes
active when a conversion is in progress. Open-drain output. An external pull-up resistor is required.
9 SDA Digital I/O. Serial bus bidirectional data. Open-drain output. An external pull-up resistor is required.
10 SCL Digital Input. Serial bus clock. Open-drain output. An external pull-up resistor is required.
Table 6. I
2
C Address Selection
Part Number AS Pin I
2
C Address
AD7992-0 GND 010 0001
AD7992-0 V
DD
010 0010
AD7992-1 GND 010 0011
AD7992-1 V
DD
010 0100
AD7992-x
1
Float 010 0000
1
If the AS pin is left floating on any of the AD7992 parts, the device address is 010 0000. This gives each AD7992 device three different address options.