AD AD7992BRMZ-0REEL 2-channel, 12-bit adc with i2c-compatible Datasheet

2-Channel, 12-Bit ADC with I2C-Compatible
Interface in 10-Lead MSOP
AD7992
FUNCTIONAL BLOCK DIAGRAM
FEATURES
GND
CONVST
AD7992
VIN1
I/P
MUX
VIN2/REFIN
VDD
12-BIT SUCCESSIVE
APPROXIMATION
ADC
T/H
CONTROL
LOGIC
VIN2/REFIN
SOFTWARE
CONTROL
HYSTERESIS
REGISTER CH0
DATAHIGH LIMIT
REGISTER CH1
DATALOW LIMIT
REGISTER CH1
DATAHIGH LIMIT
REGISTER CH2
HYSTERESIS
REGISTER CH1
DATALOW LIMIT
REGISTER CH2
CONVERSION
RESULT
REGISTER
CONFIGURATION
REGISTER
ALERT
ALERT STATUS
REGISTER
CYCLE TIMER
REGISTER
AS
SCL
I2C INTERFACE
SDA
03263-0-001
12-bit ADC with fast conversion time: 2 µs typ
2 single-ended analog input channels
Specified for VDD of 2.7 V to 5.5 V
Low power consumption
Fast throughput rate: up to 188 kSPS
Sequencer operation
Temperature range: −40 °C to 125 °C
Automatic cycle mode
I2C®-compatible serial interface supports standard, fast,
and high speed modes
Out-of-range indicator/alert function
Pin-selectable addressing via AS
2 versions allow 5 I2C addresses
Shutdown mode: 1 µA max
10-lead MSOP package
GND
GENERAL DESCRIPTION
The AD7992 is a 12-bit, low power, successive approximation
ADC with an I2C-compatible interface. The part operates from
a single 2.7 V to 5.5 V power supply and features a 2 µs conversion time. The part contains a 2-channel multiplexer and trackand-hold amplifier that can handle input frequencies up to
11 MHz.
The AD7992 provides a 2-wire serial interface compatible with
I2C interfaces. The part comes in two versions, the AD7992-0
and the AD7992-1, and each version allows for at least two
different I2C addresses. The AD7992-0 supports standard and
fast I2C interface modes, and the AD7992-1 supports standard,
fast, and high speed I2C interface modes.
The AD7992 normally remains in a shutdown state while not
converting, and powers up only for conversions. The conversion
process can be controlled using the CONVST pin, by a
command mode where conversions occur across I2C write
operations, or an automatic conversion interval mode selected
through software control.
The AD7992 requires an external reference in the range of 1.2 V
to VDD. This allows the widest dynamic input range to the ADC.
On-chip limit registers can be programmed with high and low
limits for the conversion result, and an open-drain, out-ofrange indicator output (ALERT) becomes active when the
conversion result violates the programmed high or low limits.
This output can be used as an interrupt.
Figure 1.
PRODUCT HIGHLIGHTS
1.
2 µs conversion time and low power consumption.
2.
I2C-compatible serial interface with pin-selectable
addresses. Two AD7992 versions allow five AD7992
devices to be connected to the same serial bus.
3.
The part features automatic shutdown while not converting
to maximize power efficiency. Current consumption is
1 µA max when in shutdown mode at 3 V.
4.
Reference can be driven up to the power supply.
5.
Out-of-range indicator that can be software disabled or
enabled.
6.
One-shot and automatic conversion rates.
7.
Registers store minimum and maximum conversion
results.
Table 1. Related Products
Part Number
AD7998
AD7994
AD7997
AD7993
No. of Bits
12
12
10
10
No. of Channels
8
4
8
4
Package
20-TSSOP
16-TSSOP
20-TSSOP
16-TSSOP
Rev. 0
Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.326.8703
© 2005 Analog Devices, Inc. All rights reserved.
AD7992
TABLE OF CONTENTS
Specifications..................................................................................... 3
Serial Interface ................................................................................ 20
I2C Timing Specifications ................................................................ 5
Serial Bus Address...................................................................... 20
Absolute Maximum Ratings............................................................ 7
Writing to the AD7992 .................................................................. 21
ESD Caution.................................................................................. 7
Writing to the Address Pointer Register for a Subsequent
Read.............................................................................................. 21
Pin Configuration and Pin Function Descriptions...................... 8
Terminology ...................................................................................... 9
Typical Performance Characteristics ........................................... 10
Writing a Single Byte of Data to the Alert Status Register,
Cycle Register, or Configuration Register............................... 21
Circuit Information ........................................................................ 13
Writing Two Bytes of Data to a Limit Register or Hysteresis
Register ........................................................................................ 22
Converter Operation.................................................................. 13
Reading Data from the AD7992................................................... 23
Typical Connection Diagram ................................................... 14
ALERT/BUSY Pin .......................................................................... 24
Analog Input ............................................................................... 14
SMBus ALERT............................................................................ 24
Internal Register Structure ............................................................ 16
Placing the AD7992-1 into High Speed Mode....................... 24
Address Pointer Register ........................................................... 16
The Address Select (AS) Pin ..................................................... 24
Configuration Register .............................................................. 17
Modes of Operation ....................................................................... 25
Conversion Result Register ....................................................... 18
Mode 1—Using the CONVST Pin ........................................... 25
Limit Registers ............................................................................ 18
Mode 2 – Command mode....................................................... 26
Alert Status Register................................................................... 19
Mode 3—Automatic Cycle Mode............................................. 27
Cycle Timer Register.................................................................. 19
Outline Dimensions ....................................................................... 28
Sample Delay and Bit Trial Delay............................................. 19
Ordering Guide .......................................................................... 28
REVISION HISTORY
1/05—Revision 0: Initial Version
Rev. 0 | Page 2 of 28
AD7992
SPECIFICATIONS
Temperature range for B version is −40°C to +125°C. Unless otherwise noted, VDD = 2.7 V to 5.5 V; REFIN = 2.5 V to VDD. For the
AD7992-0, all specifications apply for fSCL up to 400 kHz; for the AD7992-1 all specifications apply for fSCL up to 3.4 MHz. All
specifications are for both single-channel mode and dual-channel mode, Unless otherwise noted; TA = TMIN to TMAX.
Table 2.
Parameter
DYNAMIC PERFORMANCE1
B Version
Unit
Signal-to-Noise + Distortion (SINAD)2
Signal-to-Noise Ratio (SNR)2
Total Harmonic Distortion (THD)2
Peak Harmonic or Spurious Noise (SFDR)2
Intermodulation Distortion (IMD)2
70.5
71
–78
–79
dB min
dB min
dB max
dB max
Second-Order Terms
Third-Order Terms
Aperture Delay2
Aperture Jitter2
Channel-to-Channel Isolation2
Full Power Bandwidth2
–90
–90
10
50
−90
11
2
dB typ
dB typ
ns max
ps typ
dB typ
MHz typ
MHz typ
12
±1
±0.2
+1/–0.9
±0.2
±4
±6
±1
±2
±1
Bits
LSB max
LSB typ
LSB max
LSB typ
LSB max
LSB max
LSB max
LSB max
LSB max
0 to REFIN
±1
30
V
µA max
pF typ
1.2 to VDD
±1
69
V min/V max
µA max
kΩ typ
0.7 (VDD)
0.3 (VDD)
±1
10
0.1 (VDD)
V min
V max
µA max
pF max
V min
DC ACCURACY
Resolution
Integral Nonlinearity1, 2
Differential Nonlinearity1, 2
Offset Error2
Offset Error Match2
Gain Error2
Gain Error Match2
ANALOG INPUT
Input Voltage Range
DC Leakage Current
Input Capacitance
REFERENCE INPUT
REFIN Input Voltage Range
DC Leakage Current
Input Impedance
LOGIC INPUTS (SDA, SCL)
Input High Voltage, VINH
Input Low Voltage, VINL
Input Leakage Current, IIN
Input Capacitance, CIN3
Input Hysteresis, VHYST
Test Conditions/Comments
FIN = 10 kHz sine wave for fSCL from 1.7 MHz to
3.4 MHz
FIN = 1 kHz sine wave for fSCL up to 400 kHz
fa = 10.1 kHz, fb = 9.9 kHz for fSCL from 1.7 MHz
to 3.4 MHz
fa = 1.1 kHz, fb = 0.9 kHz for fSCL up to 400 kHz
Rev. 0 | Page 3 of 28
FIN = 108 Hz; see the Terminology section
@ 3 dB
@ 0.1 dB
Guaranteed no missed codes to 12 bits
Mode 1 (CONVST mode)
Mode 2 (command mode)
Dual-channel mode
Dual-channel mode
VIN = 0 V or VDD
AD7992
Parameter
LOGIC INPUTS (CONVST)
Input High Voltage, VINH
Input Low Voltage, VINL
Input Leakage Current, IIN
Input Capacitance, CIN3
LOGIC OUTPUTS (OPEN DRAIN)
Output Low Voltage, VOL
Floating-State Leakage Current
Floating-State Output Capacitance3
Output Coding
CONVERSION RATE
Conversion Time
Throughput Rate
Mode 1 (Reading after the Conversion)
Mode 2
POWER REQUIREMENTS
VDD
IDD
Power-Down Mode, Interface Inactive
Power-Down Mode, Interface Active
Operating, Interface Inactive
Operating, Interface Active
Mode 3 (I2C Inactive, TCONVERT × 32)
POWER DISSIPATION
Fully Operational
Operating, Interface Active
Power Down, Interface Inactive
B Version
Unit
Test Conditions/Comments
2.4
2.0
0.8
0.4
±1
10
V min
V min
V max
V max
µA max
pF max
VDD = 5 V
VDD = 3 V
VDD = 5 V
VDD = 3 V
VIN = 0 V or VDD
0.4
0.6
±1
10
V max
V max
µA max
pF max
Straight (Natural) Binary
ISINK = 3 mA
ISINK = 6 mA
See the Serial Interface section
2
µs typ
5
21
121
5.5
22
147
kSPS typ
kSPS typ
kSPS typ
kSPS typ
kSPS typ
kSPS typ
2.7/5.5
V min/max
fSCL = 100 kHz
fSCL = 400 kHz
fSCL = 3.4 MHz
fSCL = 100 kHz
fSCL = 400 kHz
fSCL = 3.4 MHz , 188 kSPS typ @ 5 V
1/2
0.07/0.3
0.3/0.6
0.06/0.1
0.3/0.6
0.15/0.4
0.6/1.1
0.7/1.4
0.7/1.5
µA max
mA max
mA max
mA max
mA max
mA max
mA max
mA typ
mA max
Digital inputs = 0 V or VDD
VDD = 3.3 V/5.5 V
VDD = 3.3 V/5.5 V, 400 kHz fSCL
VDD = 3.3 V/5.5 V, 3.4 MHz fSCL
VDD = 3.3 V/5.5 V, 400 kHz fSCL
VDD = 3.3 V/5.5 V, 3.4 MHz fSCL
VDD = 3.3 V/5.5 V, 400 kHz fSCL
VDD = 3.3 V/5.5 V, 3.4 MHz fSCL Mode1
VDD = 3.3 V/5.5 V, 3.4 MHz fSCL Mode 2
VDD = 3.3 V/5.5 V
0.495/2.2
1.98/6.05
2.31/7.7
3.3/11
mW max
mW max
mW typ
µW max
VDD = 3.3 V/5.5 V, 400 kHz fSCL
VDD = 3.3 V/5.5 V, 3.4 MHz fSCL Mode 1
VDD = 3.3 V/5.5 V, 3.4 MHz fSCL Mode 2
VDD = 3.3 V/5.5 V
1
Maximum/minimum ac dynamic performance, INL and DNL specifications are typical specifications when operating in Mode 2 with I2C high speed mode SCL
frequencies. Specifications outlined for Mode 2 apply to Mode 3 also. Sample delay and bit trial delay enabled.
2
See the Terminology section.
3
Guaranteed by initial characterization.
Rev. 0 | Page 4 of 28
AD7992
I2C TIMING SPECIFICATIONS
Guaranteed by initial characterization. All values measured with the input filtering enabled. CB refers to the capacitive load on the bus
line. tr and tf measured between 0.3 VDD and 0.7 VDD.
High speed mode timing specifications apply to the AD7992-1 only. Standard and fast mode timing specifications apply to both the
AD7992-0 and the AD7992-1. See Figure 2. Unless otherwise noted, VDD = 2.7 V to 5.5 V; REFIN = 2.5 V to VDD; TA =TMIN to TMAX.
Table 3.
Parameter
fSCL
t1
t2
t3
t41
t5
t6
t7
t8
t9
Conditions
Standard mode
Fast mode
High speed mode
CB = 100 pF max
CB = 400 pF max
Standard mode
Fast mode
High speed mode
CB = 100 pF max
CB = 400 pF max
Standard mode
Fast mode
High speed mode
CB = 100 pF max
CB = 400 pF max
Standard mode
Fast mode
High speed mode
Standard mode
Fast mode
High Speed mode
CB = 100 pF max
CB = 400 pF max
Standard mode
Fast mode
High Speed mode
Standard mode
Fast mode
High speed mode
Standard mode
Fast mode
Standard mode
Fast mode
High speed mode
Standard mode
Fast mode
High speed mode
CB = 100 pF max
CB = 400 pF max
Min
Limit at TMIN, TMAX
Max
100
400
3.4
1.7
Unit
kHz
kHz
4
0.6
MHz
MHz
µs
µs
60
120
4.7
1.3
ns
ns
µs
µs
160
320
250
100
10
0
0
ns
ns
ns
ns
ns
µs
µs
0
0
4.7
0.6
160
4
0.6
160
4.7
1.3
4
0.6
160
3.45
0.9
702
150
20 + 0.1 CB
1000
300
ns
ns
µs
µs
ns
µs
µs
ns
µs
µs
µs
µs
ns
ns
ns
10
20
80
160
ns
ns
Rev. 0 | Page 5 of 28
Description
Serial clock frequency
tHIGH, SCL high time
tLOW, SCL low time
tSU;DAT, data setup time
tHD;DAT, data hold time
tSU;STA, setup time for a repeated START condition
tHD;STA, hold time for a repeated START condition
tBUF, bus free time between a STOP and a START condition
tSU;STO, setup time for STOP condition
tRDA, rise time of SDA signal
AD7992
Parameter
t10
Limit at TMIN, TMAX
Max
300
20 + 0.1 CB
300
Conditions
Standard mode
Fast mode
High speed mode
CB = 100 pF max
CB = 400 pF max
Standard mode
Fast mode
High speed mode
CB = 100 pF max
CB = 400 pF max
Standard mode
t11
t11A
Min
10
20
t12
tSP
40
80
1000
ns
ns
ns
20 + 0.1 CB
300
ns
10
20
80
160
300
300
ns
ns
ns
ns
40
80
50
10
ns
ns
ns
ns
µs typ
20 + 0.1 CB
10
20
0
0
1
Description
tFDA, fall time of SDA signal
tRCL, rise time of SCL signal
tRCL1, rise time of SCL signal after a repeated START
condition and after an acknowledge bit
tFCL, fall time of SCL signal
Pulse width of suppressed spike
Power-up time
A device must provide a data hold time for SDA in order to bridge the undefined region of the SCL falling edge.
For 3 V supplies, the maximum hold time with CB = 100 pF max is 100 ns max.
t11
t12
t6
t2
SCL
t6
t5
t3
t4
t8
t1
t9
t10
SDA
t7
P
S
S
P
03623-0-019
2
ns
ns
ns
ns
10
20
tPOWER-UP
1
80
160
1000
300
20 + 0.1 CB
Fast mode
High speed mode
CB = 100 pF max
CB = 400 pF max
Standard mode
Fast mode
High speed mode
CB = 100 pF max
CB = 400 pF max
Fast mode
High speed mode
Unit
ns
ns
S = START CONDITION
P = STOP CONDITION
Figure 2. Two-Wire Serial Interface Timing Diagram
Rev. 0 | Page 6 of 28
AD7992
ABSOLUTE MAXIMUM RATINGS
TA = 25°C, unless otherwise noted.
Table 4.
Parameter
VDD to GND
Analog Input Voltage to GND
Reference Input Voltage to GND
Digital Input Voltage to GND
Digital Output Voltage to GND
Input Current to Any Pin Except Supplies1
Operating Temperature Range
Commercial (B Version)
Storage Temperature Range
Junction Temperature
10-Lead MSOP Package
θJA Thermal Impedance
θJC Thermal Impedance
Pb/SN Temperature,
Soldering Reflow (10 sec to 30 sec)
Pb-Free Temperature, Soldering Reflow
ESD
1
Rating
−0.3 V to 7 V
−0.3 V to VDD + 0.3 V
−0.3 V to VDD + 0.3 V
−0.3 V to +7 V
−0.3 V to VDD + 0.3 V
±10 mA
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those listed in the operational sections
of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
−40°C to +125°C
−65°C to +150°
150°C
200°C/W (MSOP)
44°C/W (MSOP)
240 (+0/−5)°C
260 (+0)°C
1.5 kV
Transient currents of up to 100 mA do not cause SCR latch-up.
ESD CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on
the human body and test equipment and can discharge without detection. Although this product features
proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy
electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance
degradation or loss of functionality.
Rev. 0 | Page 7 of 28
AD7992
PIN CONFIGURATION AND PIN FUNCTION DESCRIPTIONS
CONVST
1
10
SCL
AGND
2
9
SDA
VDD
3
VIN2/REFIN
4
8
TOP VIEW 7
5 (Not to Scale) 6
ALERT
AGND
AS
03263-0-002
VIN1
AD7992
Figure 3. AD7992 Pin Configuration
Table 5. Pin Function Descriptions
Pin No.
2, 7
Mnemonic
AGND
3
4
VDD
VIN2/REFIN
5
6
1
VIN1
AS
CONVST
8
ALERT/BUSY
9
10
SDA
SCL
Function
Analog Ground. Ground reference point for all circuitry on the AD7992. All analog input signals should be
referred to this GND voltage.
Power Supply Input. The VDD range for the AD7992 is from 2.7 V to 5.5 V.
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 VDD. 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.
Analog Input 1. Single-ended analog input channel. The input range is 0 V to REFIN.
Logic Input. Address select input that selects one of three I2C addresses for the AD7992, as shown in Table 6.
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-andhold 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).
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 DATAHIGH or
DATALOW 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.
Digital I/O. Serial bus bidirectional data. Open-drain output. An external pull-up resistor is required.
Digital Input. Serial bus clock. Open-drain output. An external pull-up resistor is required.
Table 6. I2C Address Selection
Part Number
AD7992-0
AD7992-0
AD7992-1
AD7992-1
AD7992-x1
1
I2C Address
010 0001
010 0010
010 0011
010 0100
010 0000
AS Pin
GND
VDD
GND
VDD
Float
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.
Rev. 0 | Page 8 of 28
AD7992
TERMINOLOGY
Signal-to-Noise and Distortion Ratio (SINAD)
The measured ratio of signal-to-noise and distortion at the
output of the A/D converter. The signal is the rms amplitude of
the fundamental. Noise is the sum of all nonfundamental signals
up to half the sampling frequency (fS/2), excluding dc. The ratio
is dependent on the number of quantization levels in the digitization process; the more levels, the smaller the quantization
noise. The theoretical signal-to-noise and distortion ratio for
an ideal N-bit converter with a sine wave input is given by
Signal-to-(Noise + Distortion) = (6.02 N + 1.76) dB
Aperture Delay
The measured interval between the sampling clock’s leading
edge and the point at which the ADC takes the sample.
Thus, the SINAD is 74 dB for a 12-bit converter.
Total Harmonic Distortion (THD)
The ratio of the rms sum of harmonics to the fundamental. For
the AD7992, it is defined as
2
THD (dB) = 20 log
2
2
2
V2 + V3 + V4 + V5 + V6
Channel-to-Channel Isolation
A measure of the level of crosstalk between channels, taken
by applying a full-scale sine wave signal to the unselected input
channels, and determining how much the 108 Hz signal is
attenuated in the selected channel. The sine wave signal applied
to the unselected channels is then varied from 1 kHz up to
2 MHz, each time determining how much the 108 Hz signal in
the selected channel is attenuated. This figure represents the
worst-case level across all channels.
2
V1
where V1 is the rms amplitude of the fundamental, and V2, V3,
V4, V5, and V6 are the rms amplitudes of the second through
sixth harmonics.
Peak Harmonic or Spurious Noise
The ratio of the rms value of the next largest component in the
ADC output spectrum (up to fS/2 and excluding dc) to the rms
value of the fundamental. Typically, the value of this specification
is determined by the largest harmonic in the spectrum, but for
ADCs where the harmonics are buried in the noise floor, it is a
noise peak.
Intermodulation Distortion
With inputs consisting of sine waves at two frequencies, fa
and fb, any active device with nonlinearities creates distortion
products at sum and difference frequencies of mfa ± nfb, where
m, n = 0, 1, 2, 3, and so on. Intermodulation distortion terms
are those for which neither m nor n equal zero. For example,
second-order terms include (fa + fb) and (fa − fb), while
third-order terms include (2fa + fb), (2fa − fb),(fa + 2fb), and
(fa − 2fb).
The AD7992 is tested using the CCIF standard where two input
frequencies near the top end of the input bandwidth are used.
In this case, the second-order terms are usually distanced in
frequency from the original sine waves while the third-order
terms are usually at a frequency close to the input frequencies.
As a result, the second- and third-order terms are specified
separately. The calculation of intermodulation distortion is,
like the THD specification, the ratio of the rms sum of the
individual distortion products to the rms amplitude of the sum
of the fundamentals, expressed in dB.
Aperture Jitter
The sample-to-sample variation in the effective point in time
when the sample is taken.
Full-Power Bandwidth
The input frequency at which the amplitude of the reconstructed
fundamental is reduced by 0.1 dB or 3 dB for a full-scale input.
Power Supply Rejection Ratio (PSRR)
The ratio of the power in the ADC output at the full-scale
frequency, f, to the power of a 200 mV p-p sine wave applied
to the ADC VDD supply of frequency fS:
PSRR (dB) = 10 log (Pf/PfS)
where Pf is the power at frequency f in the ADC output; PfS is
the power at frequency fS coupled onto the ADC VDD supply.
Integral Nonlinearity
The maximum deviation from a straight line passing through
the endpoints of the ADC transfer function. The endpoints are
zero scale, a point 1 LSB below the first code transition, and full
scale, a point 1 LSB above the last code transition.
Differential Nonlinearity
The difference between the measured and the ideal 1 LSB
change between any two adjacent codes in the ADC.
Offset Error
The deviation of the first code transition (00…000) to
(00…001) from the ideal—that is, AGND + 1 LSB.
Offset Error Match
The difference in offset error between any two channels.
Gain Error
The deviation of the last code transition (111…110) to
(111…111) from the ideal (that is, REFIN − 1 LSB) after the
offset error has been adjusted out.
Gain Error Match
The difference in gain error between any two channels.
Rev. 0 | Page 9 of 28
AD7992
TYPICAL PERFORMANCE CHARACTERISTICS
0
76
FS = 121kSPS
FSCL = 3.4MHz
FIN = 10kHz
SNR = 71.84dB
SINAD = 71.68dB
THD = –86.18dB
SFDR = –88.70dB
–20
VDD = 4.5V
VDD = 5.5V
72
VDD = 2.7V
70
SINAD (dB)
SINAD (dB)
–40
VDD = 5.0V
74
–60
VDD = 3.0V
VDD = 3.3V
68
66
–80
64
–100
VREF = VDD
0
20
40
60
03263-0-024
–120
60
FREQUENCY (kHz)
1
10
INPUT FREQUENCY kHz
100
03263-0-020
62
Figure 7. SINAD vs. Analog Input Frequency for Various Supply Voltages at
136 kSPS with 3.4 MHz fSCL
Figure 4. Dynamic Performance with 5 V Supply and 2.5 V Reference,
121 kSPS, Mode 1, Single-Channel Mode
1.0
0
SNR = 73.23dB
SINAD = 73.10dB
THD = –88.59dB
SFDR = –90.46dB
FS = 121kSPS
FSCL = 3.4MHz
FIN = 10kHz
SINAD (dB)
–40
0.8
0.6
0.4
INL ERROR (LSB)
–20
–60
0.2
0
–0.2
–0.4
–80
–0.6
–100
0
10
20
30
40
FREQUENCY (kHz)
50
–1.0
03263-0-021
–120
60
0
1000
1500
2000
2500
3000
3500
4000
CODE
Figure 8. Typical INL, VDD = 5.5 V, Reference = 2.5 V, Mode 1,
3.4 MHz fSCL , 121 kSPS
Figure 5. Dynamic Performance with 5.5 V Supply and 5.5 V Reference,
121 KSPS, Mode 1, Dual-Channel Mode
1.0
100
VDD = 5V
90
500
03263-0-026
–0.8
0.8
VDD = 3V
0.6
DNL ERROR (LSB)
PSRR (dB)
80
70
60
50
0.4
0.2
0
–0.2
–0.4
40
1000
SUPPLY-RIPPLE FREQUENCY (kHz)
Figure 6. PSRR vs. Supply-Ripple Frequency, Single-Channel Mode Only
Rev. 0 | Page 10 of 28
–1.0
0
500
1000
1500
2000
2500
3000
3500
4000
CODE
Figure 9. Typical DNL, VDD = 5.5 V, Reference = 2.5 V Mode 1,
3.4 MHz fSCL , 121 kSPS
03263-0-027
100
–0.8
03263-0-025
20
10
–0.6
VDD = 3V/5V
200mV p-p SINE WAVE ON VDD
2nF CAPACITOR ON VDD
30
1.0
1.0
0.8
0.8
0.6
0.6
0.4
0.4
DNL ERROR (LSB)
0.2
0
–0.2
–0.4
0.2
0
–0.2
-0.6
–0.8
–0.8
500
1000
1500
2000
2500
3000
3500
4000
CODE
–1.0
1.2
03263-0-016
0
NEGATIVE DNL
–0.4
–0.6
–1.0
POSITIVE DNL
1.7
2.2
2.7
3.2
3.7
4.2
4.7
REFERENCE VOLTAGE (V)
03263-0-031
INL ERROR (LSB)
AD7992
Figure 13. Change in DNL vs. Reference Voltage, VDD = 5 V, Mode 1, 121 kSPS
Figure 10. Typical INL, VDD = 2.7 V, Reference = 2.5 V, Mode1,
3.4 MHz fSCL , 121 kSPS
0.0007
1.0
0.8
0.0006
SUPPLY CURRENT (mA)
DNL ERROR (LSB)
0.6
0.4
0.2
0
–0.2
–0.4
0.0005
–40°C
0.0004
+25°C
0.0003
+85°C
0.0002
–0.6
0.0001
500
1000
1500
2000
2500
3000
3500
4000
CODE
Figure 11. Typical DNL, VDD = 2.7 V, Reference = 2.5 V, Mode 1,
3.4 MHz fSCL, 121 kSPS
1.8
0.6
1.6
SUPPLY CURRENT (mA)
0.8
POSITIVE INL
0.2
0
NEGATIVE INL
–0.4
3.7
REFERENCE VOLTAGE (V)
4.2
4.7
Figure 12. Change in INL vs. Reference Voltage, VDD = 5 V, Mode 1, 121 kSPS
MODE 2
VDD = 3V
MODE 1
VDD = 5V
0.6
0
100
03263-0-030
3.2
MODE 2
VDD = 5V
0.8
0.2
2.7
5.2
1.0
–0.8
2.2
4.7
1.2
0.4
1.7
4.2
1.4
-0.6
–1.0
1.2
3.7
Figure 14. Shutdown Current vs. Supply Voltage, –40°C, +25°C, and +85°C
2.0
–0.2
3.2
SUPPLY VOLTAGE (V)
1.0
0.4
INL ERROR (LSB)
0
2.7
MODE 1
VDD = 3V
600
1100
1600
2100
2600
3100
SCL FREQUENCY (kHz)
Figure 15. Average Supply Current vs. I2C Bus Rate for VDD = 3 V and 5 V
Rev. 0 | Page 11 of 28
03263-0-033
0
03263-0-017
–1.0
03263-0-032
–0.8
AD7992
12.0
74
ENOB VDD = 5V
11.8
ENOB VDD = 3V
11.6
73
SINAD VDD = 5V
71
SINAD VDD = 3V
11.0
SINAD (dB)
11.2
70
10.8
69
10.6
10.4
68
1.200 2.048 2.500 2.700 3.000 3.300 4.096 4.500 5.000
REFERENCE VOLTAGE (V)
03263-0-034
ENOB (BITS)
72
11.4
Figure 16. ENOB/SINAD vs. Reference Voltage, Mode 1, 121 kSPS
Rev. 0 | Page 12 of 28
AD7992
CIRCUIT INFORMATION
CONVERTER OPERATION
The AD7992 is a successive approximation, analog-to-digital
converter based around a capacitive DAC. Figure 17 and
Figure 18 show simplified schematics of the ADC during its
acquisition and conversion phases, respectively. Figure 17 shows
the ADC during its acquisition phase. SW2 is closed and SW1 is
in position A, the comparator is held in a balanced condition,
and the sampling capacitor acquires the signal on VIN.
CAPACITIVE
DAC
A
VIN
CONTROL
LOGIC
SW1
B
SW2
COMPARATOR
AGND
Figure 18. ADC Conversion Phase
ADC Transfer Function
The output coding of the AD7992 is straight binary. The
designed code transitions occur at successive integer LSB values
(i.e., 1 LSB, 2 LSB, and so on). The LSB size for the AD7992 is
REFIN/4096. Figure 19 shows the ideal transfer characteristic for
the AD7992.
111...111
111...110
111...000
011...111
AD7992 1LSB = REFIN/4096
000...010
000...001
000...000
CAPACITIVE
DAC
AGND + 1LSB
A
VIN
B
COMPARATOR
03473-0-018
SW2
AGND
+REFIN – 1LSB
ANALOG INPUT
0V TO REFIN
CONTROL
LOGIC
SW1
03473-0-019
The AD7992 normally remains in a power-down state while not
converting. When supplies are first applied, the part comes up
in a power-down state. Power-up is initiated prior to a conversion, and the device returns to power-down upon
completion of the conversion. Conversions can be initiated on
the AD7992 by pulsing the CONVST signal, using an automatic
cycle interval mode or a command mode where wake-up and a
conversion occur during a write address function (see the
Modes of Operation section). On completion of a conversion,
the AD7992 again enters power-down mode. This automatic
power-down feature allows power saving between conversions.
This means any read or write operations across the I2C interface
can occur while the device is in power-down.
Figure 17. ADC Acquisition Phase
Rev. 0 | Page 13 of 28
Figure 19. AD7992 Transfer Characteristic
03263-0-003
The AD7992 provides the user with a 2-channel multiplexer,
an on-chip track-and-hold, an ADC, an on-chip oscillator,
internal data registers, and an I2C-compatible serial interface,
all housed in a 10-lead MSOP package that offers the user
considerable space-saving advantages over alternative solutions.
The AD7992 requires an external reference in the range of 1.2 V
to VDD.
When the ADC starts a conversion, as shown in Figure 18,
SW2 opens and SW1 moves to position B, causing the
comparator to become unbalanced. The input is disconnected
once the conversion begins. The control logic and the capacitive
DAC are used to add and subtract fixed amounts of charge from
the sampling capacitor to bring the comparator back into a
balanced condition. When the comparator is rebalanced, the
conversion is complete. The control logic generates the ADC
output code. Figure 19 shows the ADC transfer function.
ADC CODE
The AD7992 is a low power, 12-bit, single-supply, 2-channel
analog-to-digital converter (ADC). The part can be operated
from a 2.7 V to 5.5 V supply.
AD7992
TYPICAL CONNECTION DIAGRAM
ANALOG INPUT
Figure 21 shows the typical connection diagram for the
AD7992. In Figure 21, the address select pin (AS) is tied to VDD;
however AS can also be tied to AGND or left floating, allowing
the user to select up to five AD7992 devices on the same serial
bus. An external reference must be applied to the AD7992.
This reference can be in the range of 1.2 V to VDD. A precision
reference like the REF 19x family, ADR03, or ADR381 can be
used to supply the reference voltage to the ADC. The AD7992
can be configured to be a single-channel device with the
reference voltage applied to the VIN2/REFIN pin. The AD7992
can also be configured as a dual-channel device where the
reference voltage is taken from the supply voltage VDD, and the
VIN2/REFIN takes on its analog input function,VIN2.
Figure 20 shows an equivalent circuit of the AD7992 analog
input structure. The two diodes, D1 and D2, provide ESD
protection for the analog inputs. Care must be taken to ensure
that the analog input signal does not exceed the supply rails
by more than 300 mV. This causes these diodes to become
forward-biased and start conducting current into the substrate.
These diodes can conduct a maximum current of 10 mA
without causing irreversible damage to the part.
VDD
D1
C2
30pF
R1
C1
4pF
03473-0-022
VIN
SDA and SCL form the 2-wire I2C/SMBus-compatible interface.
External pull-up resisters are required for both SDA and SCL
lines.
D2
CONVERSION PHASE - SWITCH OPEN
TRACK PHASE - SWITCH CLOSED
2
The AD7992-0 supports standard and fast I C interface modes.
The AD7992-1 supports standard, fast, and high speed I2C
interface modes. Therefore, if operating the AD7992 in either
standard or fast mode, up to five AD7992 devices can be
connected to the bus (3 × AD7992-0 and 2 × AD7992-1 or
3 × AD7992-1 and 2 × AD7992-0). In high speed mode, up to
three AD7992-1 devices can be connected to the bus.
Figure 20. Equivalent Analog Input Circuit
Capacitor C1 in Figure 20 is typically about 4 pF and can
primarily be attributed to pin capacitance. Resistor R1 is a
lumped component made up of the on resistance (RON) of
a track-and-hold switch, and also the RON of the input multiplexer. The total resistor is typically about 400 Ω. C2, the ADC
sampling capacitor, has a typical capacitance of 30 pF.
Wake up from power-down prior to a conversion is approximately 1 µs, and conversion time is approximately 2 µs. The
AD7992 enters shutdown mode again after each conversion,
which is useful in applications where power consumption is a
concern.
5V SUPPLY
10µF
0.1µF
RP
VDD
VIN1
0V to REFIN
INPUT
AD7992
RP
RP
2-WIRE SERIAL
INTERFACE
SDA
µC/µP
SCL
ALERT
VIN2/REFIN GND
REF 19x
0.1µF
AS
SET TO REQUIRED
ADDRESS
1µF
Figure 21. AD7992 Typical Connection Diagram, Single-Channel Mode, Mode 1
Rev. 0 | Page 14 of 28
03263-0-004
CONVST
AD7992
–50
VREF = 2.5V
–55
–60
–65
VDD = 2.7V
–70
THD (dB)
VDD = 3.0V
–75
VDD = 3.3V
–80
–85
–90
When no amplifier is used to drive the analog input, the source
impedance should be limited to low values. The maximum
source impedance depends on the amount of total harmonic
distortion (THD) that can be tolerated. THD increases as the
source impedance increases, and performance degrades.
Figure 22 shows the THD vs. the analog input signal frequency
when using supply voltages of 3 V ± 10% and 5 V ± 10%.
Figure 23 shows the THD vs. the analog input signal frequency
for different source impedances.
VDD = 5.5V
VDD = 4.5V
–95
–100
VDD = 5.0V
1
10
INPUT FREQUENCY (kHz)
100
03263-0-022
For ac applications, removing high frequency components from
the analog input signal is recommended by use of an RC bandpass filter on the relevant analog input pin. In applications
where harmonic distortion and signal-to-noise ratio are critical,
the analog input should be driven from a low impedance
source. Large source impedances significantly affect the ac
performance of the ADC. This may necessitate the use of an
input buffer amplifier. The choice of the op amp is a function
of the particular application.
Figure 22. THD vs. Analog Input Frequency for Various
Supply Voltages, FS = 136 kSPS, Mode 1
–40
VDD = 5.5V
VREF = 2.5V
–50
RSOURCE = 1kΩ
–70
RSOURCE = 100Ω
–80
–90
RSOURCE = 10Ω
RSOURCE = 50Ω
–100
1
10
INPUT FREQUENCY (kHz)
RSOURCE = 0Ω
100
Figure 23. THD vs. Analog Input Frequency for Various
Source Impedances for VDD = 5.5 V, 136 kSPS, Mode 1
Rev. 0 | Page 15 of 28
03263-0-023
THD (dB)
–60
AD7992
INTERNAL REGISTER STRUCTURE
ADDRESS POINTER REGISTER
The AD7992 contains 11 internal registers (see Figure 24) that
are used to store conversion results, high and low conversion
limits, and information to configure and control the device.
There are ten data registers and one address pointer register.
CONVERSION
RESULT REGISTER
ALERT STATUS
REGISTER
CONFIGURATION
REGISTER
CYCLE TIMER
REGISTER
D
DATALOW
REGISTER CH1
ADDRESS
POINTER
REGISTER
DATAHIGH
REGISTER CH1
A
Because it is the register to which the first data byte of every
write operation is written automatically, the address pointer
register does not have and does not require an address. The
address pointer register is an 8-bit register in which the 4 LSBs
are used as pointer bits to store an address that points to one of
the AD7992’s data registers. The 4 MSBs are used as command
bits when operating in Mode 2 (see the Modes of Operation
section). The first byte following each write address is the
address of one of the data registers, which is stored in the
address pointer register and selects the data register to which
subsequent data bytes are written. Only the 4 LSBs of this
register are used to select a data register. On power-up, the
address pointer register contains all 0s, pointing to the
conversion result register.
T
A
Table 7. Address Pointer Register
HYSTERESIS
REGISTER CH1
C4
0
DATAHIGH
REGISTER CH2
C2
0
C1
0
P3
P2
P1
Register select
P0
Table 8. AD7992 Register Addresses
DATALOW
REGISTER CH2
SDA
SCL
03263-0-005
HYSTERESIS
REGISTER CH2
SERIAL BUS INTERFACE
C3
0
Figure 24. AD7992 Register Structure
Each data register has an address that the address pointer
register points to when communicating with it. The conversion
result register is the only data register that is read-only.
P3
0
0
0
0
0
0
0
0
1
1
Rev. 0 | Page 16 of 28
P2
0
0
0
0
1
1
1
1
0
0
P1
0
0
1
1
0
0
1
1
0
0
P0
0
1
0
1
0
1
0
1
0
1
Registers
Conversion result register (read)
Alert status register (read/write)
Configuration register (read/write)
Cycle Timer register (read/write)
DATALOW register CH1 (read/write)
DATAHIGH register CH1 (read/write)
Hysteresis register CH1 (read/write)
DATALOW register CH2 (read/write)
DATAHIGH register CH2 (read/write)
Hysteresis register CH2 (read/write)
AD7992
CONFIGURATION REGISTER
The configuration register is a 8-bit, read/write register that is used to set the operating modes of the AD7992. The MSB of the register is
unused and is a don’t care bit. The bit functions of the configuration register are outlined in Table 9. A single-byte write is necessary when
writing to the configuration register.
Table 9. Configuration Register Bit Function Descriptions and Default Settings at Power-Up
D7
DONTC
0
D6
Single/Dual
0
Bit
D7
D6
Mnemonic
DONTC
Single/Dual
D5, D4
CH2, CH1
D3
FLTR
D2
ALERT EN
D1
BUSY/ALERT
D0
BUSY/ALERT
POLARITY
D5
CH2
0
D4
CH1
0
D3
FLTR
1
D2
ALERT EN
0
D1
BUSY/ALERT
0
D0
ALERT/BUSY POLARITY
0
Comment
Don’t care bit.
The value written to this bit determines the functionality of the VIN2/REFIN pin and the reference source for the
conversions. When this bit is 1, the pin takes on its reference input function, REFIN, making the AD7992 a singlechannel part with the reference being taken from the REFIN pin. However, when only Channel 1 is selected for a
conversion, the reference can also be taken from the supply voltage by setting D6 to 0. When this bit is a 0, the
VIN2/REFIN pin becomes a second analog input pin, VIN2, making the AD7992 a dual-channel part with the
reference being taken from the supply voltage. See Table 10.
These two channel address bits select which analog input channel is to be converted. A 1 in any of Bits D5 or D4
selects a channel for conversion. If more than one channel bit is set (with D6 = 0), the alternating channel
sequence is used. Table 10 shows how these two channel address bits are decoded. If D5 is selected, the part
operates in dual-channel mode, with the reference for the ADC being taken from the supply voltage (D6 set to 0
for dual-channel mode).
The value written to this bit of the control register determines whether the filtering on SDA and SCL is enabled or
is bypassed. If this bit is a 1, the the filtering is enabled; if it is a 0, the filtering is bypassed.
The hardware ALERT function is enabled if this bit is set to 1 and disabled if this bit is set to 0. This bit is used in
conjunction with the BUSY/ALERT bit to determine if the ALERT/BUSY pin acts as an ALERT or a BUSY output
(see Table 11).
This bit is used in conjunction with the ALERT EN bit to determine if the ALERT/BUSY pin acts as an ALERT or
BUSY output (see Table 11), and if configured as an ALERT output pin, if it is to be reset.
This bit determines the active polarity of the ALERT/BUSY pin regardless of whether it is configured as an ALERT
or BUSY output. It is active low if this bit is set to 0 and active high if set to 1.
Table 10. Channel and Reference Selection
D6
Single/Dual
0
0
1
0
0
D5
CH2
0
0
0
1
1
D4
CH1
0
1
1
0
1
Analog Input Channel
No conversion
Convert on VIN1 (reference from VDD)
Convert on VIN1 (reference from REFIN)
Convert on VIN2 (reference from VDD)
Sequence between Channel 1 and Channel 2, beginning with Channel 1 (reference from VDD)
Table 11. ALERT/BUSY Function
D2
0
0
1
1
D1
0
1
0
1
ALERT/BUSY Pin Configuration
Pin does not provide any interrupt signal.
Pin configured as a BUSY output.
Pin configured as an ALERT output.
Resets the ALERT output pin, the Alert_Flag bit in the conversion result register, and the entire alert status
register (if any is active). If 1/1 is written to Bits D2/D1 in the configuration register to reset the ALERT pin, the
Alert_Flag bit, and the alert status register, the contents of the configuration register read 1/0 for D2/D1,
respectively, if read back.
Rev. 0 | Page 17 of 28
AD7992
CONVERSION RESULT REGISTER
The conversion result register is a 16-bit, read-only register that
stores the conversion result from the ADC in straight binary
format. A 2-byte read is needed to read data from this register.
reset. The value of N is taken from the 12-bit hysteresis register
associated with that channel. The ALERT pin can also be reset
by writing to Bits D2 and D1 in the configuration register.
Table 12 shows the contents of the first byte to be read from the
AD7992, and Table 13 shows the contents of the second byte.
Table 14. AD7992 DATAHIGH Register (First Read/Write)
Table 12. Conversion Value Register (First Read)
D15
Alert_Flag
D14
Zero
D13
Zero
D12
CHID0
D11
MSB
D10
B10
D9
B9
D8
B8
Table 13. Conversion Value Register (Second Read)
D7
B7
D6
B6
D5
B5
D4
B4
D3
B3
D2
B2
D1
B1
D0
B0
The AD7992 conversion result consists of an Alert_Flag bit, two
leading zeros, a channel identifier bit, and the 12-bit data result.
The Alert_Flag bit indicates whether the conversion result
being read or any other channel result has violated the limit
registers associated with it. If an ALERT occurs, the master may
wish to read the ALERT status register to obtain more information on where the ALERT occurred if the Alert_Flag bit is set.
The Alert_Flag bit is followed by two leading zeros and a
channel identifier bit that indicate to which channel the conversion result corresponds. When this bit is 0, the conversion
result corresponds to VIN1, and when it is 1, the conversion
result corresponds to VIN2. These, in turn, are followed by the
12-bit conversion result, MSB first.
D15
0
D14
0
D13
0
D12
0
D11
B11
D10
B10
D9
B9
D8
B8
Table 15. AD7992 DATAHIGH Register (Second Read/Write)
D7
B7
D6
B6
D5
B5
D4
B4
D3
B3
D2
B2
D1
B1
D0
B0
DATALOW Register CH1/CH2
The DATALOW register for each channel is a 16-bit read/write
register; only the 12 LSB of each register are used. The register
stores the lower limit that activates the ALERT output and/or
the Alert_Flag bit in the conversion result register. If the value
in the conversion result register is less than the value in the
DATALOW register, an ALERT occurs. When the conversion
result returns to a value at least N LSB above the DATALOW
register value, the ALERT output pin and Alert_Flag bit are
reset. The value of N is taken from the hysteresis register
associated with that channel. The ALERT output pin can also be
reset by writing to Bits D2 and D1 in the configuration register.
Table 16. DATALOW Register (First Read/Write)
D15
0
D14
0
D13
0
D12
0
D11
B11
D10
B10
D9
B9
D8
B8
Table 17. DATALOW Register (Second Read/Write)
LIMIT REGISTERS
The AD7992 has two pairs of limit registers. Each pair stores
high and low conversion limits for both analog input channels.
Each pair of limit registers has one associated hysteresis register.
All 6 registers are 16 bits wide; only the 12 LSBs of the registers
are used. On power-up, the contents of the DATAHIGH register
for each channel are full scale, while the contents of the
DATALOW registers are zero scale by default.
The limit registers can be used to monitor the conversion
results on one or both channels. The AD7992 signals an
ALERT (in either hardware or software or both, depending
on the configuration) if the result moves outside the upper or
lower limit set by the user.
DATAHIGH Register CH1/CH2
The DATAHIGH register for a channel is a 16-bit, read/write
register; only the 12 LSBs of each register are used. This register
stores the upper limit that activates the ALERT output and/or
the Alert_Flag bit in the conversion result register. If the value
in the conversion result register is greater than the value in the
DATAHIGH register, an ALERT occurs. When the conversion
result returns to a value at least N LSB below the DATAHIGH
register value, the ALERT output pin and Alert_Flag bit are
D7
B7
D6
B6
D5
B5
D4
B4
D3
B3
D2
B2
D1
B1
D0
B0
Hysteresis Register (CH1/CH2)
Each hysteresis register is a 16-bit read/write register; only
the 12 LSBs of the register are used. The hysteresis register
stores the hysteresis value, N, when using the limit registers.
Each pair of limit registers has a dedicated hysteresis register.
The hysteresis value determines the reset point for the ALERT
pin/Alert_Flag if a violation of the limits has occurred. For
example, if a hysteresis value of 8 LSB is required on the
upper and lower limits of Channel 1, the 16 bit word,
0000 0000 0000 1000, should be written to the hysteresis
register of CH1 (see Table 8 for the address of this register).
On power-up, the hysteresis registers contain a value of 8 LSB.
If a different hysteresis value is required, that value must be
written to the hysteresis register for the channel in question.
Table 18. Hysteresis Register (First Read/Write)
D15
0
D14
0
D13
0
D12
0
D11
B11
D10
B10
D9
B9
D8
B8
Table 19. Hysteresis Register (Second Read/Write)
D7
B7
Rev. 0 | Page 18 of 28
D6
B6
D5
B5
D4
B4
D3
B3
D2
B2
D1
B1
D0
B0
AD7992
Using the Limit Registers to Store Min/Max Conversion
Results
If full scale—that is, all 1s—is written to the hysteresis register
for a particular channel, the DATAHIGH and DATALOW registers
for that channel no longer act as limit registers as previously
described, but instead act as storage registers for the maximum
and minimum conversion results returned from conversions on
a channel over any given period of time. This function is useful
in applications where the widest span of actual conversion
results is required rather than using the ALERT to signal that an
intervention is necessary—for example, when monitoring
temperature extremes during refrigerated goods transportation.
Note that on power-up, the contents of the DATAHIGH register
for each channel are full scale, while the contents of the
DATALOW registers are zero scale by default. Therefore, minimum and maximum conversion values being stored in this
way are lost if power is removed or cycled.
ALERT STATUS REGISTER
The alert status register is an 8-bit read/write register that
provides information on an alert event. If a conversion results in
activating the ALERT pin or Alert_Flag bit in the conversion
result register (see the Limit Registers section) the alert status
register may be read to gain further information. It contains
two status bits per channel, one corresponding to each of the
DATAHIGH and DATALOW limits. The bit with a status of 1 shows
where the violation occurred—that is, on which channel—and
whether the violation occurred on the upper or lower limit.
If a second alert event occurs on the other channel between
receiving the first alert and interrogating the alert status
register, the corresponding bit for that alert event is also set.
The entire contents of the alert status register can be cleared by
writing 1,1 to Bits D2 and D1 in the configuration register, as
shown in Table 11. This can also be achieved by writing all 1s to
the alert status register itself. Thus, if the alert status register is
addressed for a write operation, which is all 1s, the contents of
the alert status register are cleared or reset to all 0s.
Table 20. Alert Status Register
D7
0
D6
0
D5
0
D4
0
D3
CH2HI
D2
CH2LO
D1
CH1HI
D0
CH1LO
Table 21. Alert Status Register Bit Function Descriptions
Bit
D0
Mnemonic
CH1LO
D1
CH1HI
D2
CH2LO
D3
CH2HI
Comment
Violation of DATALOW limit on Channel 1 if
bit is set to 1, no violation if bit is set to 0.
Violation of DATAHIGH limit on Channel 1 if
bit is set to 1, no violation if bit is set to 0.
Violation of DATALOW limit on Channel 2 if
bit is set to 1, no violation if bit is set to 0.
Violation of DATAHIGH limit on Channel 2 if
bit is set to 1, no violation if bit is set to 0.
CYCLE TIMER REGISTER
The cycle timer register is an 8-bit read/write register that stores
the conversion interval value for the automatic cycle mode of
the AD7992 (see the Modes of Operation section). The 5 MSBs
of the cycle timer register are unused and should contain 0s at
all times (see the Sample Delay and Bit Trial Delay section). On
power-up, the cycle timer register contains all 0s, thus disabling
automatic cycle operation of the AD7992. To enable automatic
cycle mode, the user must write to the cycle timer register,
selecting the required conversion interval. Table 22 shows the
structure of the cycle timer register, while Table 23 shows how
the bits in this register are decoded to provide various
automatic sampling intervals.
Table 22. Cycle Timer Register and Defaults at Power-Up
D7
Sample
Delay
0
D6
Bit Trial
Delay
0
D5
0
D4
0
D3
0
0
0
0
D2
Cyc
Bit 2
0
D1
Cyc
Bit 1
0
D0
Cyc
Bit 0
0
Table 23. Cycle Timer Intervals
D2
0
0
0
0
1
1
1
1
CYC Reg Value
D1
D0
0
0
0
1
1
0
1
1
0
0
0
1
1
0
1
1
Conversion Interval
(TCONVERT =conversion time of ADC)
Mode not selected
TCONVERT × 32
TCONVERT × 64
TCONVERT × 128
TCONVERT × 256
TCONVERT × 512
TCONVERT × 1024
TCONVERT × 2048
SAMPLE DELAY AND BIT TRIAL DELAY
It is recommended that no I2C bus activity occurs when a
conversion is taking place. However, this may not be possible,
for example, when operating in Mode 2 or the automatic cycle
mode. In order to maintain the performance of the ADC in
such cases, Bits D7 and D6 in the cycle timer register are used
to delay critical sample intervals and bit trials from occurring
while there is activity on the I2C bus. This may have the effect of
increasing the conversion time. When Bits D7 and D6 are both
0, the bit trial and sample interval delaying mechanism are
implemented. The default setting of D7 and D6 is 0. If bit trial
delays extend longer than 1 µs, the conversion terminates.
When D7 is 0, the sampling instant delay is implemented.
When D6 is 0, the bit trial delay is implemented. To turn off
both the sample delay and bit trial delay, set D7 and D6 to 1.
Rev. 0 | Page 19 of 28
AD7992
SERIAL INTERFACE
Control of the AD7992 is carried out via the I2C-compatible
serial bus. The AD7992 is connected to this bus as a slave device
under the control of a master device, such as the processor.
SERIAL BUS ADDRESS
Like all I2C-compatible devices, the AD7992 has a 7-bit serial
address. The 3 MSBs of this address for the AD7992 are set to
010. The device comes in two versions, the AD7992-0 and the
AD7992-1. The two versions have three different I2C addresses
available, which are selected by either tying the address select
pin, AS, to AGND or VDD, or by letting the pin float (refer to
Table 6). By giving different addresses for the two versions, up
to five AD7992 devices can be connected to a single serial bus,
or the addresses can be set to avoid conflicts with other devices
on the bus.
The serial bus protocol operates as follows.
The master initiates data transfer by establishing a START
condition, defined as a high-to-low transition on the serial
data line SDA, while the serial clock line, SCL, remains high.
This indicates that an address/data stream follows. All slave
peripherals connected to the serial bus respond to the START
condition and shift in the next eight bits, consisting of a 7-bit
address (MSB first) plus an R/W bit that determines the
direction of the data transfer—that is, whether data is written to
or read from the slave device.
Data is sent over the serial bus in sequences of nine clock
pulses, eight bits of data followed by an acknowledge bit from
the receiver of data. Transitions on the data line must occur
during the low period of the clock signal and remain stable
during the high period, because a low-to-high transition when
the clock is high may be interpreted as a STOP signal.
When all data bytes have been read or written, stop conditions
are established. In write mode, the master pulls the data line
high during the 10th clock pulse to assert a STOP condition. In
read mode, the master device pulls the data line high during the
low period before the ninth clock pulse. This is known as no
acknowledge. The master then takes the data line low during
the low period before the 10th clock pulse, then high during the
10th clock pulse to assert a STOP condition.
Any number of bytes of data may be transferred over the serial
bus in one operation, but it is not possible to mix read and write
in one operation because the type of operation is determined at
the beginning and cannot subsequently be changed without
starting a new operation.
The peripheral whose address corresponds to the transmitted
address responds by pulling the data line low during the low
period before the ninth clock pulse, known as the acknowledge
bit. All other devices on the bus remain idle while the selected
device waits for data to be read from or written to it. If the R/W
bit is a 0, the master writes to the slave device. If the R/W bit is
a 1, the master reads from the slave device.
Rev. 0 | Page 20 of 28
AD7992
WRITING TO THE AD7992
WRITING A SINGLE BYTE OF DATA TO THE ALERT
STATUS REGISTER, CYCLE REGISTER, OR
CONFIGURATION REGISTER
Depending on the register being written to, there are three
different writes for the AD7992.
WRITING TO THE ADDRESS POINTER REGISTER
FOR A SUBSEQUENT READ
The alert status register, cycle register, and configuration
register are all 8-bit registers, so only one byte of data can be
written to each. Writing a single byte of data to one of these
registers consists of the serial bus write address, the chosen
data register address written to the address pointer register,
followed by the data byte written to the selected data register.
See Figure 26.
In order to read from a particular register, the address pointer
register must first contain the address of that register. If it does
not, the correct address must be written to the address pointer
register by performing a single-byte write operation, as shown
in Figure 25. The write operation consists of the serial bus
address followed by the address pointer byte. No data is
written to any of the data registers. A read operation can be
subsequently performed to read the register of interest.
1
9
1
9
SCL
0
1
0
A3
A2
A1
A0
C4
R/W
START BY
MASTER
C3
C2
P3
C1
P2
P1
P0
ACK. BY
AD7992
ACK. BY
AD7992
FRAME 1
SERIAL BUS ADDRESS BYTE
STOP BY
MASTER
03263-0-006
SDA
FRAME 2
ADDRESS POINTER REGISTER BYTE
Figure 25. Writing to the Address Pointer Register to Select a Register for a Subsequent Read Operation
1
9
1
9
SCL
0
1
0
A3
A2
A1
A0
START BY
MASTER
C4
R/W
C3
C2
C1
P3
P2
P1
P0
ACK. BY
AD7992
ACK. BY
AD7992
FRAME 2
ADDRESS POINTER REGISTER BYTE
FRAME 1
SERIAL BUS ADDRESS BYTE
9
1
9
SCL (CONTINUED)
SDA (CONTINUED)
D7
D6
D5
D4
D3
D2
D1
03263-0-007
SDA
D0
ACK. BY
AD7992
FRAME 3
DATA BYTE
Figure 26. Single-Byte Write Sequence
Rev. 0 | Page 21 of 28
STOP BY
MASTER
AD7992
WRITING TWO BYTES OF DATA TO A LIMIT
REGISTER OR HYSTERESIS REGISTER
Each of the limit registers and hysteresis registers are 12-bit
registers, so two bytes of data are required to write a value to
any one of them. Writing two bytes of data to one of these
registers consists of the serial bus write address, the chosen
limit register address written to the address pointer register,
followed by two data bytes written to the selected data register.
See Figure 27.
If the master is write-addressing the AD7992, it can write to
more than one register with out re-addressing the ADC. After
the first write operation has completed for the first data register,
during the next byte, the master writes to the address pointer
byte to select the next data register for a write operation. This
eliminates the need to re-address the device in order to write to
another data register.
1
9
1
9
SCL
0
SDA
1
0
A3
A2
A1
A0
C4
R/W
C3
C1
P3
P2
P1
P0
ACK. BY
AD7992
START BY
MASTER
ACK. BY
AD7992
FRAME 1
SERIAL BUS ADDRESS BYTE
9
C2
FRAME 2
ADDRESS POINTER REGISTER
1
9
1
9
SDA (CONTINUED)
0
0
0
0
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
ACK. BY
AD7992
MOST SIGNIFICANT DATA BYTE
D0/0
ACK. BY
AD7992
LEAST SIGNIFICANT DATA BYTE
Figure 27. Two-Byte Write Sequence
Rev. 0 | Page 22 of 28
D1/0
03263-0-008
SCL (CONTINUED)
STOP BY
MASTER
AD7992
READING DATA FROM THE AD7992
Reading data from the AD7992 is a 1- or 2-byte operation.
Reading back the contents of the alert status register, the configuration register, or the cycle timer register is a single-byte read
operation, as shown in Figure 28. This assumes the particular
register address has previously been set up by a single-byte write
operation to the address pointer register (see Figure 25). Once
the register address has been set up, any number of reads can
be performed from that particular register without having to
write to the address pointer register again. If a read from a
different register is required, the relevant register address has
to be written to the address pointer register, and again any
number of reads from this register may then be performed.
1
Reading data from the conversion result register, DATAHIGH
registers, DATALOW registers, or hysteresis registers is a 2-byte
operation, as shown in Figure 29. The same rules apply for a
2-byte read as a 1-byte read.
When reading data back from a register, such as the conversion
result register, if more than two read bytes are supplied, the
same or new data is read from the AD7992 without the need to
re-address the device. This allows the master to continuously
read from a data register without having to re-address the
AD7992.
9
1
9
SCL
0
1
0
A3
A2
A1
A0
D7
R/W
START BY
MASTER
D6
D5
D4
D3
D2
D1
D0
ACK. BY
AD7992
NO ACK. BY
MASTER
FRAME 1
SERIAL BUS ADDRESS BYTE
STOP BY
MASTER
03263-0-009
SDA
FRAME 2
SINGLE DATA BYTE FROM AD7992
Figure 28. Reading a Single Byte of Data from a Selected Register
1
9
1
9
SCL
0
1
0
A3
A2
A1
A0
START BY
MASTER
D11
R/W
ACK. BY
AD7992
ALERTFLAG
D10
D9
D8
ACK. BY
MASTER
ZERO ZERO CHID
FRAME 2
MOST SIGNIFICANT DATA BYTE FROM
AD7992
FRAME 1
SERIAL BUS ADDRESS BYTE
1
9
SCL (CONTINUED)
SDA (CONTINUED)
D7
D6
D5
D4
D3
D2
D1/0
D0/0
NO ACK. BY
MASTER
FRAME 2
MOST SIGNIFICANT DATA BYTE FROM
AD7992
Figure 29. Reading Two Bytes of Data from the Conversion Result Register
Rev. 0 | Page 23 of 28
STOP BY
MASTER
03263-0-010
SDA
AD7992
ALERT/BUSY PIN
The ALERT/BUSY pin may be configured as an ALERT output
or BUSY output, as shown in Table 11.
The ALERT output requires an external pull-up resistor that
can be connected to a voltage different from VDD provided the
maximum voltage rating of the ALERT output pin is not
exceeded. The value of the pull-up resistor depends on the
application, but should be as large as possible to avoid excessive
sink currents at the ALERT output.
SMBus ALERT
The AD7992 ALERT output is an SMBus interrupt line for
devices that want to trade their ability to master for an extra
pin. The AD7992 is a slave-only device and uses the SMBus
ALERT to signal the host device that it wants to talk. The
SMBus ALERT on the AD7992 is used as an out-of-conversionrange indicator (a limit violation indicator).
PLACING THE AD7992-1 INTO HIGH SPEED MODE
High speed mode communication commences after the master
addresses all devices connected to the bus with the master code,
00001XXX, to indicate that a high speed mode transfer is to
begin. No device connected to the bus is allowed to acknowledge the high speed master code; therefore, the code is followed
by a not acknowledge (see Figure 30). The master must then
issue a repeated start followed by the device address with a R/W
bit. The selected device then acknowledges its address.
The ALERT pin has an open-drain configuration that allows the
ALERT outputs of several AD7992s to be wire-AND’ed together
when the ALERT pin is active low. D0 of the configuration
register is used to set the active polarity of the ALERT output.
The power-up default is active low. The ALERT function can be
disabled or enabled by setting D2 of the configuration register
to 0 or 1, respectively.
All devices continue to operate in high speed mode until the
master issues a STOP condition. When the STOP condition is
issued, the devices all return to fast mode.
The host device can process the ALERT interrupt and simultaneously access all SMBus ALERT devices through the alert
response address. Only the device that pulled the ALERT low
acknowledges the ARA (alert response address). If more than
one device pulls the ALERT pin low, the highest priority (lowest
address) device wins communication rights via standard I2C
arbitration during the slave address transfer.
THE ADDRESS SELECT (AS) PIN
The address select pin on the AD7992 is used to set the I2C
address for the AD7992 device. The AS pin can be tied to VDD,
to AGND, or left floating. The selection should be made as close
as possible to the AS pin; avoid having long tracks introducing
extra capacitance onto the pin. This is important for the float
selection, because the AS pin has to charge to a midpoint after
the start bit during the first address byte. Extra capacitance on
the AS pin increases the time taken to charge to the midpoint
and may cause an incorrect decision on the device address.
When the AS pin is left floating, the AD7992 can work with a
capacitive load up to 40 pF.
The ALERT output becomes active when the value in the
conversion result register exceeds the value in the DATAHIGH
register or falls below the value in the DATALOW register for a
selected channel. It is reset when a write operation to the
configuration register sets D1 to a 1, or when the conversion
result returns N LSBs below or above the value stored in the
DATAHIGH register or DATALOW register, respectively. N is the
value in the hysteresis register (see the Limit Registers section).
HIGH SPEED MODE
FAST MODE
1
9
1
NACK
Sr
9
SCL
0
0
0
0
1
X
X
X
0
1
0
A3
A2
A1
ACK. BY
AD7992
START BY
MASTER
HS-MODE MASTER CODE
SERIAL BUS ADDRESS BYTE
Figure 30. Placing the Part into High Speed Mode
Rev. 0 | Page 24 of 28
A0
03263-0-011
SDA
AD7992
MODES OF OPERATION
When supplies are first applied to the AD7992, the ADC
powers up in sleep mode and normally remains in this
shutdown state while not converting. There are three different
methods of initiating a conversion on the AD7992.
If the CONVST pulse does not remain high for more than 1 µs,
the falling edge of CONVST still initiates a conversion, but the
result is invalid because the AD7992 is not fully powered up
when the conversion takes place. To maintain the performance
of the AD7992 in this mode, it is recommended that the I2C bus
is quiet when a conversion is taking place.
MODE 1—USING THE CONVST PIN
A conversion can be initiated on the AD7992 by pulsing the
CONVST signal. The conversion clock for the part is internally
generated so no external clock is required, except when reading
from or writing to the I2C serial port. On the rising edge of
CONVST, the AD7992 begins to power up (see point A in
Figure 31). The power-up time from shutdown mode for the
AD7992 is approximately 1 µs; the CONVST signal must
remain high for 1 µs for the part to power up fully. CONVST
can be brought low after this time. The falling edge of the
CONVST signal places the track-and-hold into hold mode; a
conversion is also initiated at this point (point B in Figure 31).
When the conversion is complete, approximately 2 µs later, the
part returns to shutdown (point C in Figure 31) and remains
there until the next rising edge of CONVST. The master can
then read the ADC to obtain the conversion result. The address
pointer register must be pointing to the conversion result
register in order to read back the conversion result.
A
The cycle timer register and Command Bits C4 to C1 in the
address pointer register should contain all 0s when operating
the AD7992 in this Mode 1. The CONVST pin should be tied
low for all other modes of operation. Prior to initiating a
conversion in this mode, a write to the configuration register is
needed to select the channel for conversion. To select both input
channels for conversion, set D5 and D4 in the configuration
register to 1. The ADC services each channel in the sequence
with each CONVST pulse.
Once the conversion is complete, the master can address the
AD7992 to read the conversion result. If further conversions are
required, the SCL line can be taken high while the CONVST
signal is pulsed; then an additional 18 SCL pulses are required
to read the next conversion result.
C
B
tPOWER-UP
CONVST
tCONVERT
9
1
9
1
9
SDA
S
7-BIT ADDRESS
R
A
FIRST DATA BYTE (MSBs)
Figure 31. Mode 1 Operation
Rev. 0 | Page 25 of 28
A
SECOND DATA BYTE (LSBs) A P
03473-0-032
SCA
AD7992
MODE 2 – COMMAND MODE
Mode 2 allows a conversion to be automatically initiated any
time a write operation occurs. In order to use this mode,
Command Bits C2 to C1 in the address pointer byte, shown in
Table 7, must be programmed. Command Bits C4 and C3 are
not used and should contain zeros at all times.
accesses the data from the conversion on VIN1. While this read
takes place, a conversion occurs on VIN2. The second read
accesses this data from VIN2. Figure 33 shows how this mode
operates.
After the conversion result has been read, and if further read
bytes are issued, the ADC continuously converts on the selected
input channel(s). This has the effect of increasing the overall
throughput rate of the ADC.
To select a channel for conversion in Mode 2, set the corresponding channel command bit in the address pointer byte
(see Table 24). To select both analog input channels for conversion, set both C1 and C2 to 1. When all four command
bits are 0, this mode is not used.
When operating the AD7992-1 in Mode 2 with high speed
mode, 3.4 MHz SCL, the conversion may not be complete
before the master tries to read the conversion result. In this
case, the AD7992-1 holds the SCL line low during the ACK
clock after the read address until the conversion is complete.
When the conversion is complete, the AD7992-1 releases the
SCL line and the master can then read the conversion result.
Figure 28 illustrates a 2-byte read operation from the conversion result register. Prior to the read operation, ensure that the
address pointer is pointing to the conversion result register.
When the contents of the address pointer register are being
loaded, if Command Bits C2 or C1 are set, the AD7992 begins
to power up and convert upon the selected channel(s). Powerup begins on the fifth SCL falling edge of the address point byte
(see point A in Figure 32). Table 24 shows the channel selection
in this mode via Command Bits C1 and C2 in the address
pointer register. The wake-up and conversion time together
should take approximately 3 µs, and the conversion begins
when the last Command Bit, C1, has been clocked in midway
through the write to the address pointer register. Following
this, the AD7992 must be addressed again to tell it that a read
operation is required. The read then takes place from the
conversion result register. This read accesses the result from
the conversion selected via the command bits. If Command Bits
C2, C1 are set to 1,1, a 4-byte read is necessary. The first read
1
8
9
W
A
1
After a conversion is initiated in this mode by setting the
command bits in the address pointer byte, if the AD7992
receives a STOP or NACK from the master, the AD7992 stops
converting.
Table 24. Address Pointer Byte—Command Bits
C2
0
0
1
1
C1
0
1
0
1
A
Analog Input Channel
No conversion
Conversion on VIN1
Conversion on VIN2
Conversion on VIN1 followed by conversion on VIN2
9
SCL
SDA
7-BIT ADDRESS
S
COMMAND/ADDRESS
POINT BYTE
ACK BY
AD7992
1
9
A
ACK BY
AD7992
1
9
9
SCL
Sr
7-BIT ADDRESS
R
FIRST DATA BYTE
(MSBs)
A
ACK BY
AD7992
Figure 32. Mode 2 Operation
Rev. 0 | Page 26 of 28
A
ACK BY
MASTER
SECOND DATA BYTE
(LSBs)
A
Sr/P
NACK BY
MASTER
03263-0-012
SDA
AD7992
1
8
9 1
9
SCL
SDA
7-BIT ADDRESS
S
1
COMMAND/ADDRESS
A
POINT BYTE
ACK BY
ACK BY
AD7992
AD7992
9
9 1
W A
9
9
9
SCL
Sr
7-BIT ADDRESS
R A
FIRST DATA BYTE
(MSBs)
ACK BY
AD7992
A
SECOND DATA BYTE
(LSBs)
ACK BY
MASTER
A
ACK BY
MASTER
RESULT FROM CH1
FIRST DATA BYTE
(MSBs)
A
SECOND DATA BYTE
(LSBs)
A/A
ACK BY
MASTER
RESULT FROM CH2
03263-0-013
SDA
Figure 33. Mode 2 Sequence Operation
MODE 3—AUTOMATIC CYCLE MODE
An automatic conversion cycle can be selected and enabled by
writing a value to the cycle timer register. A conversion cycle
interval can be set up on the AD7992 by programming the
relevant bits in the 8-bit cycle timer register, as decoded in
Table 23. Only the 3 LSBs are used; the 5 MSBs should contain
0s (see the Sample Delay and Bit Trial Delay section). When the
3 LSBs of the register are programmed with any configuration
other than all 0s, a conversion takes place every X ms; the cycle
interval, X, depends on the configuration of these three bits in
the cycle timer register. There are seven different cycle time
intervals to choose from, as shown in Table 23. Once the
conversion has taken place, the part powers down again until
the next conversion occurs. To exit this mode of operation, the
user must program the 3 LSBs of the cycle timer register to
contain all 0s. For cycle interval options, see Table 23.
To select a channel(s) for operation in cycle mode, set the
corresponding channel bit(s), D5 to D4, of the configuration
register. If more than one channel bit is set in the configuration
register, the ADC automatically cycles through the channel
sequence, starting with the lowest channel. Once the sequence
is complete, the ADC starts converting on the lowest channel
again, continuing to loop through the sequence until the cycle
timer register contents are set to all 0s. This mode is useful for
monitoring signals, such as battery voltage and temperature,
alerting only when the limits are violated.
Rev. 0 | Page 27 of 28
AD7992
OUTLINE DIMENSIONS
3.00 BSC
10
6
4.90 BSC
3.00 BSC
1
5
PIN 1
0.50 BSC
0.95
0.85
0.75
0.15
0.00
1.10 MAX
0.27
0.17
SEATING
PLANE
8°
0°
0.23
0.08
0.80
0.60
0.40
COPLANARITY
0.10
COMPLIANT TO JEDEC STANDARDS MO-187BA
Figure 34. 10-Lead Mini Small Outline Package [MSOP]
(RM-10)
Dimensions shown in millimeters
ORDERING GUIDE
Model1
AD7992BRM-0
AD7992BRM-0REEL
AD7992BRMZ-03
AD7992BRMZ-0REEL3
AD7992BRM-1
AD7992BRM-1REEL
AD7992BRMZ-13
AD7992BRMZ-1REEL3
EVAL-AD7992CB
Temperature Range
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
Linearity Error2 (Max)
±1 LSB
±1 LSB
±1 LSB
±1 LSB
±1 LSB
±1 LSB
±1 LSB
±1 LSB
Package Option
RM-10
RM-10
RM-10
RM-10
RM-10
RM-10
RM-10
RM-10
Package Description
10-Lead MSOP
10-Lead MSOP
10-Lead MSOP
10-Lead MSOP
10-Lead MSOP
10-Lead MSOP
10-Lead MSOP
10-Lead MSOP
Stand-Alone Evaluation Board
Branding
C10
C10
C2Q
C2Q
C11
C11
C2S
C2S
1
The AD7992-0 supports standard and fast I2C interface modes. The AD7992-1 supports standard, fast, and high speed I2C interface modes.
Linearity error here refers to integral nonlinearity.
3
Z = Pb-free part.
2
Purchase of licensed I2C components of Analog Devices or one of its sublicensed Associated Companies conveys a license for the purchaser under the Philips I2C Patent
Rights to use these components in an I2C system, provided that the system conforms to the I2C Standard Specification as defined by Philips.
© 2005 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
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