4-Channel, 10- and 12-Bit ADCs with I2C-
Compatible Interface in 16-Lead TSSOP
AD7993/AD7994
FEATURES
FUNCTIONAL BLOCK DIAGRAM
10- and 12-bit ADC with fast conversion time: 2 µs typ
4 single-ended analog input channels
Specified for VDD of 2.7 V to 5.5 V
Low power consumption
Fast throughput rate: 188 kSPS
Temperature range:−40°C to +125°C
Sequencer operation
V
AGND
REF
CONVST
DD
IN
AD7993/AD7994
10-/12-BIT
SUCCESSIVE
APPROXIMATION
ADC
V
1
IN
CONTROL
LOGIC
T/H
V
V
V
2
3
4
IN
IN
IN
I/P
MUX
OSCILLATOR
Automatic cycle interval mode
I2C®-compatible serial interface
I2C interface supports standard, fast, and high speed modes
Out-of-range indicator/alert function
Pin-selectable addressing via AS
Shutdown mode: 1 µA max
CONVERSION
RESULT
REGISTER
DATA
LIMIT
REGISTER CH1–CH4
LOW
CONFIGURATION
REGISTER
ALERT/
BUSY
DATA
LIMIT
HIGH
REGISTER CH1–CH4
ALERT STATUS
REGISTER
16-lead TSSOP package
See AD7998 and AD7992 for 8-channel and 2-channel
equivalent devices, respectively.
HYSTERESIS
CYCLE TIMER
REGISTER
REGISTER CH1–CH4
AS
SCL
SDA
2
I C INTERFACE
GENERAL DESCRIPTION
AGND
The AD7993/AD7994 are 4-channel, 10- and 12-bit, low power,
successive approximation ADCs with an I2C-compatible inter-
face. The parts operate from a single 2.7 V to 5.5 V power
supply and feature a 2 µs conversion time. The parts contain a
4-channel multiplexer and track-and-hold amplifier that can
handle input frequencies up to 11 MHz.
Figure 1.
On-chip limit registers can be programmed with high and low
limits for the conversion result, and an open-drain, out-of-
range indicator output (ALERT) becomes active when the
programmed high or low limits are violated by the conversion
result. This output can be used as an interrupt.
The AD7993/AD7994 provide a 2-wire serial interface that is
compatible with I2C interfaces. Each part comes in two versions,
AD7993-0/AD7994-0 and AD7993-1/AD7994-1, and each
version allows for at least two different I2C addresses. The I2C
interface on the AD7993-0/AD7994-0 supports standard and
fast I2C interface modes. The I2C interface on the AD7993-1/
AD7994-1 supports standard, fast, and high speed I2C interface
modes.
PRODUCT HIGHLIGHTS
1. 2 µs conversion time with low power consumption.
2. I2C-compatible serial interface with pin-selectable
addresses. Two AD7993/AD7994 versions allow five
AD7993/AD7994 devices to be connected to the same
serial bus.
The AD7993/AD7994 normally remain in a shutdown state
while not converting, and power up only for conversions. The
3. The parts feature automatic shutdown while not converting
to maximize power efficiency. Current consumption is
1 µA max when in shutdown mode.
conversion process can be controlled using the
pin,
CONVST
by a command mode where conversions occur across I2C write
operations, or an automatic conversion interval mode selected
through software control.
4. Reference can be driven up to the power supply.
5. Out-of-range indicator that can be software disabled or
enabled.
The AD7993/AD7994 require an external reference that should
be applied to the REFIN pin and can be in the range of 1.2 V to
VDD. This allows the widest dynamic input range to the ADC.
6. One-shot and automatic conversion rates.
7. Registers can store minimum and maximum conversion
results.
Rev. 0
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