BB ADS1100A0IDBVT

ADS1100
AD0
SBAS239B – MAY 2002 – REVISED NOVEMBER 2003
Self-Calibrating, 16-Bit
ANALOG-TO-DIGITAL CONVERTER
FEATURES
DESCRIPTION
● COMPLETE DATA ACQUISITION SYSTEM IN A
TINY SOT23-6 PACKAGE
The ADS1100 is a precision, continuously self-calibrating
Analog-to-Digital (A/D) converter with differential inputs and
up to 16 bits of resolution in a small SOT23-6 package.
Conversions are performed ratiometrically, using the power
supply as the reference voltage. The ADS1100 uses an
I2C-compatible serial interface and operates from a single
power supply ranging from 2.7V to 5.5V.
● 16-BITS NO MISSING CODES
● INL: 0.0125% of FSR MAX
● CONTINUOUS SELF-CALIBRATION
● SINGLE-CYCLE CONVERSION
● PROGRAMMABLE GAIN AMPLIFIER
GAIN = 1, 2, 4, OR 8
● LOW NOISE: 4µVp-p
● PROGRAMMABLE DATA RATE: 8SPS to 128SPS
● INTERNAL SYSTEM CLOCK
● I2CTM INTERFACE
● POWER SUPPLY: 2.7V to 5.5V
● LOW CURRENT CONSUMPTION: 90µA
● AVAILABLE IN EIGHT DIFFERENT ADDRESSES
The ADS1100 can perform conversions at rates of 8, 16, 32,
or 128 samples per second. The onboard Programmable
Gain Amplifier (PGA), which offers gains of up to 8, allows
smaller signals to be measured with high resolution. In
single-conversion mode, the ADS1100 automatically powers
down after a conversion, greatly reducing current consumption during idle periods.
The ADS1100 is designed for applications requiring highresolution measurement, where space and power consumption are major considerations. Typical applications include
portable instrumentation, industrial process control, and smart
transmitters.
APPLICATIONS
● PORTABLE INSTRUMENTATION
● INDUSTRIAL PROCESS CONTROL
● SMART TRANSMITTERS
A = 1, 2, 4, or 8
VIN+
PGA
VIN–
∆Σ A/D
Converter
I2 C
Interface
SCL
SDA
VDD
● CONSUMER GOODS
● FACTORY AUTOMATION
Clock
Oscillator
● TEMPERATURE MEASUREMENT
GND
I2C is a registered trademark of Philips Incorporated.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
Copyright © 2002-2003, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
www.ti.com
ELECTROSTATIC
DISCHARGE SENSITIVITY
ABSOLUTE MAXIMUM RATINGS
VDD to GND ........................................................................... –0.3V to +6V
Input Current ............................................................... 100mA, Momentary
Input Current ................................................................. 10mA, Continuous
Voltage to GND, VIN+, VIN– .......................................................... –0.3V to VDD + 0.3V
Voltage to GND, SDA, SCL ..................................................... –0.5V to 6V
Maximum Junction Temperature ................................................... +150°C
Operating Temperature .................................................. –40°C to +125°C
Storage Temperature ...................................................... –60°C to +150°C
Lead Temperature (soldering, 10s) ............................................... +300°C
NOTE: (1) Stresses above those listed under “Absolute Maximum Ratings” may
cause permanent damage to the device. Exposure to absolute maximum
conditions for extended periods may affect device reliability.
This integrated circuit can be damaged by ESD. Texas
Instruments recommends that all integrated circuits be handled
with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits
may be more susceptible to damage because very small
parametric changes could cause the device not to meet its
published specifications.
PACKAGE/ORDERING INFORMATION
SPECIFIED
TEMPERATURE
RANGE
PACKAGE
MARKING
ORDERING
NUMBER
TRANSPORT
MEDIA, QUANTITY
ADS1100A0IDBVT
ADS1100A0IDBVR
Tape and Reel, 250
Tape and Reel, 3000
ADS1100A1IDBVT
ADS1100A1IDBVR
Tape and Reel, 250
Tape and Reel, 3000
ADS1100A2IDBVT
ADS1100A2IDBVR
Tape and Reel, 250
Tape and Reel, 3000
ADS1100A3IDBVT
ADS1100A3IDBVR
Tape and Reel, 250
Tape and Reel, 3000
ADS1100A4IDBVT
ADS1100A4IDBVR
Tape and Reel, 250
Tape and Reel, 3000
ADS1100A5IDBVT
ADS1100A5IDBVR
Tape and Reel, 250
Tape and Reel, 3000
ADS1100A6IDBVT
ADS1100A6IDBVR
Tape and Reel, 250
Tape and Reel, 3000
ADS1100A7IDBVT
ADS1100A7IDBVR
Tape and Reel, 250
Tape and Reel, 3000
PRODUCT
I2C ADDRESS
PACKAGE-LEAD
PACKAGE
DESIGNATOR(1)
ADS1100
1001 000
SOT23-6
DBV
–40°C to +85°C
AD0
"
"
"
"
"
"
ADS1100
1001 001
SOT23-6
DBV
–40°C to +85°C
AD1
"
"
"
"
"
"
ADS1100
1001 010
SOT23-6
DBV
–40°C to +85°C
AD2
"
"
"
"
"
"
ADS1100
1001 011
SOT23-6
DBV
–40°C to +85°C
AD3
"
"
"
"
"
"
ADS1100
1001 100
SOT23-6
DBV
–40°C to +85°C
AD4
"
"
"
"
"
"
ADS1100
1001 101
SOT23-6
DBV
–40°C to +85°C
AD5
"
"
"
"
"
"
ADS1100
1001 110
SOT23-6
DBV
–40°C to +85°C
AD6
"
"
"
"
"
"
ADS1100
1001 111
SOT23-6
DBV
–40°C to +85°C
AD7
"
"
"
"
"
"
NOTE: (1) For the most current specifications and package information, refer to our web site at www.ti.com.
PIN CONFIGURATION
Top View
SOT23
VIN– VDD SDA
6
5
4
AD0
1
2
3
VIN+ GND SCL
NOTE: Marking text direction indicates pin 1. Marking text depends on I2C
address; see ordering table. Marking for I2C address 1001000 shown.
2
ADS1100
www.ti.com
SBAS239B
ELECTRICAL CHARACTERISTICS
All specifications at –40°C to +85°C, VDD = 5V, GND = 0V, and all PGAs, unless otherwise noted.
ADS1100
PARAMETER
ANALOG INPUT
Full-Scale Input Voltage
Analog Input Voltage
Differential Input Impedance
Common-Mode Input Impedance
SYSTEM PERFORMANCE
Resolution and No Missing Codes
Conversion Rate
Output Noise
Integral Nonlinearity
Offset Error
Offset Drift
Gain Error
Gain Error Drift
Common-Mode Rejection
DIGITAL INPUT/OUTPUT
Logic Level
VIH
VIL
VOL
Input Leakage
IIH
IIL
POWER-SUPPLY REQUIREMENTS
Power-Supply Voltage
Supply Current
CONDITIONS
MIN
(VIN+) – (VIN–)
VIN+, VIN– to GND
GND – 0.2
TYP
MAX
±VDD/PGA
VDD + 0.2
2.4/PGA
8
DR
DR
DR
DR
DR
DR
DR
DR
=
=
=
=
=
=
=
=
00
01
10
11
00
01
10
11
12
14
15
16
104
26
13
6.5
See Typical Characteristic Curves
DR = 11, PGA = 1, End Point Fit(1)
PGA
PGA
PGA
PGA
=
=
=
=
1
2
4
8
At DC, PGA = 8
At DC, PGA = 1
94
IOL = 3mA
0.7 • VDD
GND – 0.5
GND
VIH = 5.5V
VIL = GND
–10
VDD
Power Down
Active Mode
128
32
16
8
±0.003
±2.5/PGA
1.5
1.0
0.7
0.6
0.01
2
100
85
2.7
0.05
90
UNITS
V
V
MΩ
MΩ
12
14
15
16
184
46
23
11.5
Bits
Bits
Bits
Bits
SPS
SPS
SPS
SPS
±0.0125
±5/PGA
8
4
2
2
0.1
% of FSR(2)
mV
µV/°C
µV/°C
µV/°C
µV/°C
%
ppm/°C
dB
dB
6
0.3 • VDD
0.4
V
V
V
10
µA
µA
5.5
2
150
V
µA
µA
750
µW
µW
Power Dissipation
VDD = 5.0V
VDD = 3.0V
450
210
NOTES: (1) 99% of full-scale. (2) FSR = Full-Scale Range = 2 • VDD/PGA.
ADS1100
SBAS239B
www.ti.com
3
TYPICAL CHARACTERISTICS
At TA = 25°C and VDD = 5V, unless otherwise noted.
SUPPLY CURRENT vs I2C BUS FREQUENCY
SUPPLY CURRENT vs TEMPERATURE
250
120
225
VDD = 5V
200
IVDD (µA)
IVDD (µA)
100
80
25°C
175
125°C
150
125
100
60
VDD = 2.7V
–40°C
75
50
40
–60 –40 –20
0
20
40
60
80
100 120
10
140
100
OFFSET ERROR vs TEMPERATURE
2.0
VDD = 2.7V
VDD = 5V
1.0
PGA = 8
PGA = 4
PGA = 2
Offset Error (mV)
Offset Error (mV)
1.0
PGA = 1
0.0
–1.0
PGA = 8
PGA = 4
PGA = 2
PGA = 1
0
40
80
0.0
–1.0
–2.0
–2.0
–60 –40 –20
0
20
40
60
80
100 120
140
–60 –40 –20
Temperature (°C)
20
60
100 120
140
Temperature (°C)
GAIN ERROR vs TEMPERATURE
GAIN ERROR vs TEMPERATURE
0.010
0.04
VDD = 5V
VDD = 2.7V
0.03
0.005
PGA = 4
PGA = 1
0.01
0.00
–0.01
Gain Error (%)
PGA = 8
0.02
PGA = 4
PGA = 8
0.000
–0.005
PGA = 1
–0.010
PGA = 2
–0.02
PGA = 2
–0.015
–0.03
–0.020
–0.04
–60 –40
–20
0
20
40
60
80
–60 –40 –20
100 120 140
0
20
40
60
80
100 120
140
Temperature (°C)
Temperature (°C)
4
10k
OFFSET ERROR vs TEMPERATURE
2.0
Gain Error (%)
1k
I2C Bus Frequency (kHz)
Temperature (°C)
ADS1100
www.ti.com
SBAS239B
TYPICAL CHARACTERISTICS (Cont.)
At TA = 25°C and VDD = 5V, unless otherwise noted.
TOTAL ERROR vs INPUT SIGNAL
INTEGRAL NONLINEARITY vs SUPPLY VOLTAGE
0.016
0.0
–0.5
Total Error (mV)
PGA = 4
–1.0
PGA = 2
–1.5
–2.0
–2.5
–100
0.012
0.010
0.008
0.006
0.004
0.002
Data Rate = 8SPS
PGA = 1
PGA = 8
PGA = 4
PGA = 2
PGA = 1
0.014
Integral Nonlinearity (% of FSR)
PGA = 8
0.000
–75
–50
–25
0
25
50
75
2.5
100
3.0
3.5
4.0
5.0
5.5
NOISE vs INPUT SIGNAL
INTEGRAL NONLINEARITY vs TEMPERATURE
0.05
20
PGA =1
Data Rate = 8SPS
PGA = 8
0.04
0.03
Noise (p-p, % of LSB)
Integral Nonlinearity (% of FSR)
4.5
VDD (V)
Input Signal (% of Full-Scale)
VDD = 2.7V
0.02
VDD = 3.5V
VDD = 5V
15
PGA = 4
PGA = 2
10
PGA = 1
5
0.01
0
0.00
–60 –40 –20
0
20
40
60
80
100 120
0
140
20
60
80
100
NOISE vs TEMPERATURE
NOISE vs SUPPLY VOLTAGE
25
30
Data Rate = 8SPS
PGA = 8
PGA = 8
20
PGA = 4
15
PGA = 2
10
Noise (p-p, % of LSB)
25
Noise (p-p, % of LSB)
40
Input Signal (% of Full-Scale)
Temperature (°C)
20
15
10
5
PGA = 1
Data Rate = 8SPS
5
0
2.5
3.0
3.5
4.0
4.5
5.0
–60
5.5
ADS1100
SBAS239B
–40
–20
0
20
40
60
80
100
120 140
Temperature (°C)
VDD (V)
www.ti.com
5
TYPICAL CHARACTERISTICS (Cont.)
At TA = 25°C and VDD = 5V, unless otherwise noted.
DATA RATE vs TEMPERATURE
FREQUENCY RESPONSE
0
10
Data Rate = 8SPS
VDD = 2.7V
–20
Gain (dB)
Data Rate (SPS)
9
8
VDD = 5V
–40
–60
7
–80
Data Rate = 8SPS
6
–60
–100
–40
–20
0
20
40
60
80
100
120
0.1
140
1
Temperature (°C)
THEORY OF OPERATION
The ADS1100 is a fully differential, 16-bit, self-calibrating,
delta-sigma A/D converter. Extremely easy to design with
and configure, the ADS1100 allows you to obtain precise
measurements with a minimum of effort.
The ADS1100 consists of a delta-sigma A/D converter core with
adjustable gain, a clock generator, and an I2C interface. Each of
these blocks are described in detail in the sections that follow.
ANALOG-TO-DIGITAL CONVERTER
The ADS1100 A/D converter core consists of a differential
switched-capacitor delta-sigma modulator followed by a digital
filter. The modulator measures the voltage difference between
the positive and negative analog inputs and compares it to a
reference voltage, which, in the ADS1100, is the power
supply. The digital filter receives a high-speed bitstream from
the modulator and outputs a code, which is a number
proportional to the input voltage.
OUTPUT CODE CALCULATION
The output code is a scalar value that is (except for clipping)
proportional to the voltage difference between the two analog
inputs. The output code is confined to a finite range of numbers;
this range depends on the number of bits needed to represent the
code. The number of bits needed to represent the output code for
the ADS1100 depends on the data rate, as shown in Table I.
DATA RATE
NUMBER OF BITS
8SPS
16SPS
32SPS
128SPS
16
15
14
12
MINIMUM CODE MAXIMUM CODE
–32,768
–16,384
–8192
–2048
TABLE I. Minimum and Maximum Codes.
6
32,767
16,383
8191
2047
10
Input Frequency (Hz)
100
1k
For a minimum output code of Min Code, gain setting of
PGA, positive and negative input voltages of VIN+ and VIN–,
and power supply of VDD, the output code is given by the
expression:
Output Code = –1• Min Code • PGA •
(V ) – (V )
IN+
IN –
VDD
In the previous expression, it is important to note that the negated
minimum output code is used. The ADS1100 outputs codes in
binary two’s complement format, so the absolute values of the
minima and maxima are not the same; the maximum n-bit code
is 2n-1 – 1, while the minimum n-bit code is –1 • 2n-1.
For example, the ideal expression for output codes with a
data rate of 16SPS and PGA = 2 is:
Output Code = 16384 • 2 •
(V ) – (V )
IN+
IN –
VDD
The ADS1100 outputs all codes right-justified and signextended. This makes it possible to perform averaging on the
higher data rate codes using only a 16-bit accumulator.
See Table II for output codes for various input levels.
SELF-CALIBRATION
The previous expressions for the ADS1100’s output code do
not account for the gain and offset errors in the modulator. To
compensate for these, the ADS1100 incorporates self-calibration circuitry.
The self-calibration system operates continuously, and requires no user intervention. No adjustments can be made to
the self-calibration system, and none need to be made. The
self-calibration system cannot be deactivated.
The offset and gain error figures shown in the Electrical
Characteristics include the effects of calibration.
ADS1100
www.ti.com
SBAS239B
INPUT SIGNAL
DATA RATE
NEGATIVE FULL-SCALE
–1LSB
ZERO
+1LSB
POSITIVE FULL-SCALE
8SPS
16SPS
32SPS
128SPS
8000H
C000H
E000H
F800H
FFFFH
FFFFH
FFFFH
FFFFH
0000H
0000H
0000H
0000H
0001H
0001H
0001H
0001H
7FFFH
3FFFH
1FFFH
07FFH
TABLE II. Output Codes for Different Input Signals.
CLOCK GENERATOR
The ADS1100 features an onboard clock generator, which
drives the operation of the modulator and digital filter. The
Typical Characteristics show varieties in data rate over
supply voltage and temperature.
It is not possible to operate the ADS1100 with an external
modulator clock.
When designing an input filter circuit, remember to take into
account the interaction between the filter network and the
input impedance of the ADS1100.
USING THE ADS1100
OPERATING MODES
The ADS1100 operates in one of two modes: continuous
conversion and single conversion.
INPUT IMPEDANCE
The ADS1100 uses a switched-capacitor input stage. To
external circuitry, it looks roughly like a resistance. The
resistance value depends on the capacitor values and the
rate at which they are switched. The switching frequency is
the same as the modulator frequency; the capacitor values
depend on the PGA setting. The switching clock is generated
by the onboard clock generator, so its frequency, nominally
275kHz, is dependent on supply voltage and temperature.
The common-mode and differential input impedances are
different. For a gain setting of PGA, the differential input
impedance is typically:
2.4MΩ/PGA
The common-mode impedance is typically 8MΩ.
The typical value of the input impedance often cannot be
neglected. Unless the input source has a low impedance, the
ADS1100’s input impedance may affect the measurement accuracy. For sources with high output impedance, buffering may be
necessary. Bear in mind, however, that active buffers introduce
noise, and also introduce offset and gain errors. All of these
factors should be considered in high-accuracy applications.
Because the clock generator frequency drifts slightly with
temperature, the input impedances will also drift. For many
applications, this input impedance drift can be neglected, and
the typical impedance values above can be used.
ALIASING
In continuous conversion mode, the ADS1100 continuously
performs conversions. Once a conversion has been completed, the ADS1100 places the result in the output register,
and immediately begins another conversion. When the
ADS1100 is in continuous conversion mode, the ST/BSY bit
in the configuration register always reads 1.
In single conversion mode, the ADS1100 waits until the
ST/BSY bit in the conversion register is set to 1. When this
happens, the ADS1100 powers up and performs a single
conversion. After the conversion completes, the ADS1100
places the result in the output register, resets the ST/BSY bit
to 0 and powers down. Writing a 1 to ST/BSY while a
conversion is in progress has no effect.
When switching from continuous conversion mode to single
conversion mode, the ADS1100 will complete the current
conversion, reset the ST/BSY bit to 0 and power down.
RESET AND POWER-UP
When the ADS1100 powers up, it automatically performs a
reset. As part of the reset, the ADS1100 sets all of the bits
in the configuration register to their default setting.
The ADS1100 responds to the I2C General Call Reset
command. When the ADS1100 receives a General Call
Reset, it performs an internal reset, exactly as though it had
just been powered on.
I2C INTERFACE
If frequencies are input to the ADS1100 that exceed half the
data rate, aliasing will occur. To prevent aliasing, the input
signal must be bandlimited. Some signals are inherently
bandlimited. For example, a thermocouple’s output, which
has a limited rate of change, may nevertheless contain noise
and interference components. These can fold back into the
sampling band just as any other signal can.
The ADS1100’s digital filter provides some attenuation of
high-frequency noise, but the filter’s sinc1 frequency response cannot completely replace an anti-aliasing filter;
some external filtering may still be needed. For many applications, a simple RC filter will suffice.
The ADS1100 communicates through an I2C (Inter-Integrated Circuit) interface. The I2C interface is a 2-wire opendrain interface supporting multiple devices and masters on a
single bus. Devices on the I2C bus only drive the bus lines
LOW, by connecting them to ground; they never drive the
bus lines HIGH. Instead, the bus wires are pulled HIGH by
pull-up resistors, so the bus wires are HIGH when no device
is driving them LOW. This way, two devices cannot conflict;
if two devices drive the bus simultaneously, there is no driver
contention.
ADS1100
SBAS239B
www.ti.com
7
Communication on the I2C bus always takes place between
two devices, one acting as the master and the other acting
as the slave. Both masters and slaves can read and write,
but slaves can only do so under the direction of the master.
Some I2C devices can act as masters or slaves, but the
ADS1100 can only act as a slave device.
An I2C bus consists of two lines, SDA and SCL. SDA carries
data; SCL provides the clock. All data is transmitted across
the I2C bus in groups of eight bits. To send a bit on the I2C
bus, the SDA line is driven to the bit’s level while SCL is LOW
(a LOW on SDA indicates the bit is zero; a HIGH indicates
the bit is one). Once the SDA line has settled, the SCL line
is brought HIGH, then LOW. This pulse on SCL clocks the
SDA bit into the receiver’s shift register.
The I2C bus is bidirectional: the SDA line is used both for
transmitting and receiving data. When a master reads from
a slave, the slave drives the data line; when a master sends
to a slave, the master drives the data line. The master always
drives the clock line. The ADS1100 never drives SCL,
because it cannot act as a master. On the ADS1100, SCL is
an input only.
Most of the time the bus is idle, no communication is taking
place, and both lines are HIGH. When communication is
taking place, the bus is active. Only master devices can start
a communication. They do this by causing a start condition
on the bus. Normally, the data line is only allowed to change
state while the clock line is LOW. If the data line changes
state while the clock line is HIGH, it is either a start condition
or its counterpart, a stop condition. A start condition is when
the clock line is HIGH and the data line goes from HIGH to
LOW. A stop condition is when the clock line is HIGH and the
data line goes from LOW to HIGH.
After the master issues a start condition, it sends a byte that
indicates which slave device it wants to communicate with.
This byte is called the address byte. Each device on an I2C
bus has a unique 7-bit address to which it responds. (Slaves
can also have 10-bit addresses; see the I2C specification for
details.) The master sends an address in the address byte,
together with a bit that indicates whether it wishes to read
from or write to the slave device.
t(LOW)
Every byte transmitted on the I2C bus, whether it be address
or data, is acknowledged with an acknowledge bit. When a
master has finished sending a byte, eight data bits, to a
slave, it stops driving SDA and waits for the slave to acknowledge the byte. The slave acknowledges the byte by pulling
SDA LOW. The master then sends a clock pulse to clock the
acknowledge bit. Similarly, when a master has finished
reading a byte, it pulls SDA LOW to acknowledge this to the
slave. It then sends a clock pulse to clock the bit. (Remember
that the master always drives the clock line.)
A not-acknowledge is performed by simply leaving SDA
HIGH during an acknowledge cycle. If a device is not present
on the bus, and the master attempts to address it, it will
receive a not-acknowledge because no device is present at
that address to pull the line LOW.
When a master has finished communicating with a slave, it
may issue a stop condition. When a stop condition is issued,
the bus becomes idle again. A master may also issue
another start condition. When a start condition is issued while
the bus is active, it is called a repeated start condition.
A timing diagram for an ADS1100 I2C transaction is shown in
Figure 1. Table III gives the parameters for this diagram.
ADS1100 I2C ADDRESSES
The ADS1100 I2C address is 1001aaa, where “aaa” are bits
set at the factory. The ADS1100 is available in eight different
verisons, each having a different I2C address. For example,
the ADS1100A0 has address 1001000, and the ADS1100A3
has address 1001011. See the Package/Ordering Information table for a complete listing.
The I2C address is the only difference between the eight
variants. In all other repsects, they operate identically.
Each variant of the ADS1100 is marked with “ADx,” where x
identifies the address variant. For example, the ADS1100A0 is
marked “AD0”, and the ADS1100A3 is marked “AD3”. See the
Package/Ordering Information table for a complete listing.
When the ADS1100 was first introduced, it was shipped with
only one address, 1001000, and was marked “BAAI.” That
device is identical to the currently shipping ADS1100A0
variant marked “AD0”.
tF
tR
t(HDSTA)
SCL
t(HDSTA)
t(HIGH)
t(HDDAT)
t(SUSTO)
t(SUSTA)
t(SUDAT)
SDA
t(BUF)
P
S
S
P
FIGURE 1. I2C Timing Diagram.
8
ADS1100
www.ti.com
SBAS239B
FAST MODE
PARAMETER
MIN
SCLK Operating Frequency
HIGH-SPEED MODE
MAX
f(SCLK)
Bus Free Time Between STOP and START Condition
MIN
0.4
MAX
UNITS
3.4
MHz
t(BUF)
600
160
ns
t(HDSTA)
600
160
ns
Repeated START Condition Setup Time
t(SUSTA)
600
160
ns
STOP Condition Setup Time
t(SUSTO)
600
160
ns
Data Hold Time
t (HDDAT)
0
0
ns
Data Setup Time
t(SUDAT)
100
10
ns
SCLK Clock LOW Period
t(LOW)
1300
160
ns
SCLK Clock HIGH Period
t(HIGH)
600
Hold Time After Repeated START Condition.
After this period, the first clock is generated.
60
ns
Clock/Data Fall Time
tF
300
160
ns
Clock/Data Rise Time
tR
300
160
ns
TABLE III. Timing Diagram Definitions.
I2C GENERAL CALL
REGISTERS
The ADS1100 responds to General Call Reset, which is an
address byte of 00H followed by a data byte of 06H. The
ADS1100 acknowledges both bytes.
The ADS1100 has two registers that are accessible via its I2C
port. The output register contains the result of the last conversion; the configuration register allows you to change the
ADS1100’s operating mode and query the status of the device.
On receiving a General Call Reset, the ADS1100 performs a
full internal reset, just as though it had been powered off and
then on. If a conversion is in process, it is interrupted; the
output register is set to zero, and the configuration register is
set to its default setting.
OUTPUT REGISTER
The 16-bit output register contains the result of the last
conversion in binary two’s complement format. Following
reset or power-up, the output register is cleared to zero; it
remains zero until the first conversion is completed. Therefore, if you read the ADS1100 just after reset or power-up,
you will read zero from the output register.
The ADS1100 always acknowledges the General Call address byte of 00H, but it does not acknowledge any General
Call data bytes other than 04H or 06H.
I2C DATA RATES
The output register’s format is shown in Table IV.
The I2C bus operates in one of three speed modes: Standard, which allows a clock frequency of up to 100kHz; Fast,
which allows a clock frequency of up to 400kHz; and Highspeed mode (also called Hs mode), which allows a clock
frequency of up to 3.4MHz. The ADS1100 is fully compatible
with all three modes.
CONFIGURATION REGISTER
You can use the 8-bit configuration register to control the
ADS1100’s operating mode, data rate, and PGA settings.
The configuration register’s format is shown in Table V. The
default setting is 8CH.
No special action needs to be taken to use the ADS1100 in
Standard or Fast modes, but High-speed mode must be
activated. To activate High-speed mode, send a special
address byte of 00001XXX following the start condition,
where the XXX bits are unique to the Hs-capable master.
This byte is called the Hs master code. (Note that this is
different from normal address bytes: the low bit does not
indicate read/write status.) The ADS1100 will not acknowledge this byte; the I2C specification prohibits acknowledgment of the Hs master code. On receiving a master code, the
ADS1100 will switch on its High-speed mode filters, and will
communicate at up to 3.4MHz. The ADS1100 switches out of
Hs mode with the next stop condition.
BIT
7
6
5
4
3
NAME
ST/BSY
0
0
SC
2
DR1 DR0
1
0
PGA1
PGA0
TABLE V. Configuration Register.
Bit 7: ST/BSY
The meaning of the ST/BSY bit depends on whether it is
being written to or read from.
In single conversion mode, writing a 1 to the ST/BSY bit
causes a conversion to start, and writing a 0 has no effect.
In continuous conversion mode, the ADS1100 ignores the
value written to ST/BSY.
For more information on High-speed mode, consult the I2C
specification.
BIT
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
NAME
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
TABLE IV. Output Register.
ADS1100
SBAS239B
www.ti.com
9
When read in single conversion mode, ST/BSY indicates whether
the A/D converter is busy taking a conversion. If ST/BSY is read
as 1, the A/D converter is busy, and a conversion is taking
place; if 0, no conversion is taking place, and the result of the
last conversion is available in the output register.
In continuous mode, ST/BSY is always read as 1.
READING FROM THE ADS1100
You can read the output register and the contents of the
configuration register from the ADS1100. To do this, address
the ADS1100 for reading, and read three bytes from the
device. The first two bytes are the output register’s contents;
the third byte is the configuration register’s contents.
You do not always have to read three bytes from the
ADS1100. If you want only the contents of the output register, read only two bytes.
Bits 6-5: Reserved
Bits 6 and 5 must be set to zero.
Bit 4: SC
SC controls whether the ADS1100 is in continuous conversion or single conversion mode. When SC is 1, the ADS1100
is in single conversion mode; when SC is 0, the ADS1100 is
in continuous conversion mode. The default setting is 0.
Reading more than three bytes from the ADS1100 has no
effect. All of the bytes beginning with the fourth will be FFH.
See Figure 2 for a timing diagram of an ADS1100 read
operation.
Bits 3-2: DR
Bits 3 and 2 control the ADS1100’s data rate, as shown in
Table VI.
DR1
DR0
DATA RATE
0
0
0
1
1
0
1(1)
1(1)
NOTE: (1) Default Setting.
128SPS
32SPS
16SPS
8SPS(1)
WRITING TO THE ADS1100
You can write new contents into the configuration register
(you cannot change the contents of the output register). To
do this, address the ADS1100 for writing, and write one byte
to it. This byte is written into the configuration register.
Writing more than one byte to the ADS1100 has no effect.
The ADS1100 will ignore any bytes sent to it after the first
one, and it will only acknowledge the first byte.
See Figure 3 for a timing diagram of an ADS1100 write
operation.
TABLE VI. DR Bits.
Bits 1-0: PGA
Bits 1 and 0 control the ADS1100’s gain setting, as shown in
Table VII.
PGA1
PGA0
GAIN
0(1)
0(1)
1(1)
2
4
8
0
1
1
NOTE: (1) Default Setting.
1
0
1
TABLE VII. PGA Bits.
10
ADS1100
www.ti.com
SBAS239B
1
9
1
9
…
SCL
SDA
1
0
0
1
A2
A1
A0
D15
R/W
Start By
Master
D14
D13
ACK By
ADS1100
SDA
(Continued)
…
9
D7
D6
D5
D4
D3
D2
D9
…
D8
ACK By
Master
Frame 2: Output Register Upper Byte
1
…
D10
From
ADS1100
Frame 1: I2C Slave Address Byte
SCL
(Continued)
D12 D11
D1
1
ST/
BSY
D0
From
ADS1100
9
0
0
SC
ACK By
Master
DR1 DR0 PGA1 PGA0
ACK By
Master
From
ADS1100
Frame 3: Output Register Lower Byte
Stop By
Master
Frame 4: Configuration Register
(Optional)
FIGURE 2. Timing Diagram for Reading From the ADS1100.
1
9
1
9
SCL
SDA
1
0
0
1
A2
A1
A0
R/W
Start By
Master
ST/
BSY
0
0
SC
DR1 DR0 PGA1 PGA0
ACK By
ADS1100
Frame 1: I2C Slave Address Byte
ACK By
ADS1100
Stop By
Master
Frame 2: Configuration Register
FIGURE 3. Timing Diagram for Writing to the ADS1100.
ADS1100
SBAS239B
www.ti.com
11
APPLICATIONS INFORMATION
non-multiiple-master I2C peripherals, will work with the
ADS1100. The ADS1100 does not perform clock-stretching
(i.e., it never pulls the clock line low), so it is not necessary
to provide for this unless other devices are on the same I2C
bus.
The sections that follow give example circuits and tips for
using the ADS1100 in various situations.
An evaluation board, the ADS1100EVM, is available. This
small, simple board connects to an RS-232 serial port on
almost any PC. The supplied software simulates a digital
voltmeter, and also displays raw output codes in hex and
decimal. All features of the ADS1100 can be controlled from
the main window. For more information, contact TI or your
local TI representative, or visit the Texas Instruments website
at http://www.ti.com/.
Pull-up resistors are necessary on both the SDA and SCL
lines because I2C bus drivers are open-drain. The size of
these resistors depends on the bus operating speed and
capacitance of the bus lines. Higher-value resistors consume
less power, but increase the transition times on the bus,
limiting the bus speed. Lower-value resistors allow higher
speed at the expense of higher power consumption. Long
bus lines have higher capacitance and require smaller pullup resistors to compensate. The resistors should not be too
small; if they are, the bus drivers may not be able to pull the
bus lines low.
BASIC CONNECTIONS
For many applications, connecting the ADS1100 is extremely
simple. A basic connection diagram for the ADS1100 is
shown in Figure 4.
CONNECTING MULTIPLE DEVICES
The fully differential voltage input of the ADS1100 is ideal for
connection to differential sources with moderately low source
impedance, such as bridge sensors and thermistors. Although the ADS1100 can read bipolar differential signals, it
cannot accept negative voltages on either input. It may be
helpful to think of the ADS1100 positive voltage input as noninverting, and of the negative input as inverting.
Connecting multiple ADS1100s to a single bus is almost
trivial. The ADS1100 is available in eight different versions, each of which has a different I2C address. An
example showing three ADS1100s connected on a single
bus is shown in Figure 5. Up to eight ADS1100s (provided
their addresses are different) can be connected to a single
bus.
When the ADS1100 is converting, it draws current in short
spikes. The 0.1µF bypass capacitor supplies the momentary
bursts of extra current needed from the supply.
Note that only one set of pull-up resistors is needed per bus.
You might find that you need to lower the pull-up resistor
values slightly to compensate for the additional bus capacitance presented by multiple devices and increased line
length.
The ADS1100 interfaces directly to standard mode, fast
mode, and high-speed mode I 2 C controllers. Any
microcontroller’s I2C peripheral, including master-only and
Positive Input
(0V to 5V)
I2C Pull-Up Resistors
1kΩ to 10kΩ (typ.)
Negative Input
(0V to 5V)
VDD
ADS1100
Microcontroller or
Microprocessor
with I2C Port
SCL
VDD
1
VIN+
VIN–
6
2
GND
VDD
5
3
SCL
SDA
4
4.7µF (typ.)
SDA
FIGURE 4. Typical Connections of the ADS1100.
12
ADS1100
www.ti.com
SBAS239B
I2C Pull-Up Resistors
1kΩ to 10kΩ (typ.)
Note that no pull-up resistor is shown on the SCL line. In this
simple case, the resistor is not needed; the microcontroller
can simply leave the line on output, and set it to one or zero
as appropriate. It can do this because the ADS1100 never
drives its clock line low. This technique can also be used with
multiple devices, and has the advantage of lower current
consumption due to the absence of a resistive pull-up.
VDD
ADS1100A0
Microcontroller or
Microprocessor
with I2C Port
SCL
1
VIN+
VIN–
6
2
GND
VDD
5
3
SCL
SDA
4
If there are any devices on the bus that may drive their clock
lines low, the above method should not be used; the SCL line
should be high-Z or zero and a pull-up resistor provided as
usual. Note also that this cannot be done on the SDA line in
any case, because the ADS1100 does drive the SDA line low
from time to time, as all I2C devices do.
SDA
ADS1100A1
1
VIN+
VIN–
6
2
GND
VDD
5
3
SCL
SDA
4
Some microcontrollers have selectable strong pull-up circuits
built in to their GPIO ports. In some cases, these can be
switched on and used in place of an external pull-up resistor.
Weak pull-ups are also provided on some microcontrollers,
but usually these are too weak for I2C communication. If
there is any doubt about the matter, test the circuit before
committing it to production.
ADS1100A2
NOTE: ADS1100 power
and input connections
omitted for clarity.
1
VIN+
VIN–
6
2
GND
VDD
5
3
SCL
SDA
4
SINGLE-ENDED INPUTS
FIGURE 5. Connecting Multiple ADS1100s.
USING GPIO PORTS FOR I2C
Most microcontrollers have programmable input/output pins
that can be set in software to act as inputs or outputs. If an
I2C controller is not available, the ADS1100 can be connected to GPIO pins, and the I2C bus protocol simulated, or
bit-banged, in software. An example of this for a single
ADS1100 is shown in Figure 6.
Although the ADS1100 has a fully differential input, it can
easily measure single-ended signals. A simple single-ended
connection scheme is shown in Figure 7. The ADS1100 is
configured for single-ended measurement by grounding either of its input pins, usually VIN–, and applying the input
signal to VIN+. The single-ended signal can range from –0.2V
to VDD + 0.3V. The ADS1100 loses no linearity anywhere in
its input range. Negative voltages cannot be applied to this
circuit because the ADS1100 inputs can only accept positive
voltages.
VDD
ADS1100
Microcontroller or
Microprocessor
with I2C Port
SCL
1
VIN+
VIN–
6
2
GND
VDD
5
3
SCL
SDA
4
VDD
0V - VDD
Single-Ended
SDA
Filter Capacitor
33pF to 100pF
(typ.)
NOTE: ADS1100 power
and input connections
omitted for clarity.
ADS1100
1
VIN+
VIN–
6
2
GND
VDD
5
3
SCL
SDA
4
Output
Codes
0-32767
FIGURE 6. Using GPIO with a Single ADS1100.
FIGURE 7. Measuring Single-Ended Inputs.
Bit-banging I2C with GPIO pins can be done by setting the
GPIO line to zero and toggling it between input and output
modes to apply the proper bus states. To drive the line low,
the pin is set to output a zero; to let the line go high, the pin
is set to input. When the pin is set to input, the state of the
pin can be read; if another device is pulling the line low, this
will read as a zero in the port’s input register.
The ADS1100 input range is bipolar differential with respect
to the reference, i.e. ±VDD. The single-ended circuit shown in
Figure 7 covers only half the ADS1100 input scale because
it does not produce differentially negative inputs; therefore,
one bit of resolution is lost. The Burr-Brown DRV134 balanced line driver from Texas Instruments can be employed
to regain this bit for single-ended signals.
ADS1100
SBAS239B
www.ti.com
13
Negative input voltages must be level-shifted. A good candidate for this function is the Texas Instruments THS4130
differential amplifier, which can output fully differential signals. This device can also help recover the lost bit noted
previously for single-ended positive signals. Level shifting
can also be performed using the DRV134.
WHEATSTONE BRIDGE SENSOR
The ADS1100 has a fully differential high-impedance input
stage and internal gain circuitry, which makes it a good
candidate for bridge-sensor measurement. An example is
shown in Figure 9.
LOW-SIDE CURRENT MONITOR
VDD
Figure 8 shows a circuit for a low-side shunt-type current
monitor. The circuit reads the voltage across a shunt resistor,
which is sized as small as possible while still giving a readable
output voltage. This voltage is amplified by an OPA335 lowdrift op-amp, and the result is read by the ADS1100.
Bridge
Sensor
E+
V–
V+
E–
11.5kΩ
5V
V
ADS1100
5V
FS = 0.63V
Load
OPA335
R3(1)
49.9kΩ
RS(2)
ADS1100
I2C
1
VIN+
VIN–
6
2
GND
VDD
5
3
SCL
SDA
4
VDD
4.7µF
1kΩ
G = 12.5
–5V
(PGA Gain = 8)
5V FS
NOTE: (1) Pull-down resistor to allow accurate swing to 0V.
(2) RS is sized for a 50mV drop at full-scale current.
I2C I/O
FIGURE 9. Measuring a Wheatstone Bridge Sensor.
FIGURE 8. Low-Side Current Measurement.
It is suggested that the ADS1100 be operated at a gain of 8. The
gain of the OPA335 can then be set lower. For a gain of 8, the
op amp should be set up to give a maximum output voltage of
no greater than 0.75V. If the shunt resistor is sized to provide
a maximum voltage drop of 50mV at full-scale current, the
full-scale input to the ADS1100 is 0.63V.
14
The Wheatstone bridge sensor is connected directly to the
ADS1100 without intervening instrumentation amplifiers; a
single, small input capacitor provides rejection of high-frequency interference. The excitation voltage of the bridge is
the power supply, which is also the ADS1100 reference
voltage. The measurement is, therefore, ratiometric. In this
circuit, the ADS1100 would typically be operated at a gain of
8. The input range in this case is ±0.75 volts.
ADS1100
www.ti.com
SBAS239B
Many resistive bridge sensors, such as strain gauges, have
very small full-scale output ranges. For these sensors, the
measurement resolution obtainable without additional amplification can be low. For example, if the bridge sensor output
is ±20mV, the ADS1100 outputs codes from approximately
–873 to +873, resulting in a best-case resolution of around 11
bits. If higher resolution is required, it is best to supply an
external instrumentation amplifier to bring the signal to full
scale.
If the ADS1100 is driven by an op amp with high voltage
supplies, such as ±12V, protection should be provided, even
if the op amp is configured so that it will not output out-ofrange voltages. Many op amps seek to one of the supply rails
immediately when power is applied, usually before the input
has stabilized; this momentary spike can damage the ADS1100.
Sometimes this damage is incremental and results in slow,
long-term failure—which can be distastrous for permanently
installed, low-maintenance systems.
ADVICE
If you use an op amp or other front-end circuitry with the
ADS1100, be sure to take the performance characteristics of this
circuitry into account. A chain is only as strong as its weakest link.
The ADS1100 is fabricated in a small-geometry low-voltage
process. The analog inputs feature protection diodes to the
supply rails. However, the current-handling ability of these
diodes is limited, and the ADS1100 can be permanently
damaged by analog input voltages that remain more than
approximately 300mV beyond the rails for extended periods.
One way to protect against overvoltage is to place currentlimiting resistors on the input lines. The ADS1100 analog
inputs can withstand momentary currents of as large as
10mA.
The previous paragraph does not apply to the I2C ports,
which can both be driven to 6V regardless of the supply.
LAYOUT TIPS
PCB layout for the ADS1100 is relatively undemanding.
16-bit performance is not difficult to achieve.
Any data converter is only as good as its reference. For the
ADS1100, the reference is the power supply, and the power
supply must be clean enough to achieve the desired performance. If a power-supply filter capacitor is used, it should be
placed close to the VDD pin, with no vias placed between the
capacitor and the pin. The trace leading to the pin should be as
wide as possible, even if it must be necked down at the device.
ADS1100
SBAS239B
www.ti.com
15
PACKAGE OPTION ADDENDUM
www.ti.com
18-Feb-2005
PACKAGING INFORMATION
Orderable Device
Status (1)
Package
Type
Package
Drawing
Pins Package Eco Plan (2)
Qty
ADS1100A0IDBVR
ACTIVE
SOT-23
DBV
6
3000
None
CU NIPDAU
Level-1-240C-UNLIM
ADS1100A0IDBVT
ACTIVE
SOT-23
DBV
6
250
None
CU NIPDAU
Level-1-240C-UNLIM
ADS1100A1IDBVR
ACTIVE
SOT-23
DBV
6
3000
None
CU NIPDAU
Level-1-240C-UNLIM
ADS1100A1IDBVT
ACTIVE
SOT-23
DBV
6
250
None
CU NIPDAU
Level-1-240C-UNLIM
ADS1100A1IDBVTG4
ACTIVE
SOT-23
DBV
6
250
Green (RoHS &
no Sb/Br)
CU NIPDAU
Level-1-260C-UNLIM
ADS1100A2IDBVR
ACTIVE
SOT-23
DBV
6
3000
None
CU NIPDAU
Level-1-240C-UNLIM
ADS1100A2IDBVT
ACTIVE
SOT-23
DBV
6
250
None
CU NIPDAU
Level-1-240C-UNLIM
ADS1100A3IDBVR
ACTIVE
SOT-23
DBV
6
3000
None
CU NIPDAU
Level-1-240C-UNLIM
ADS1100A3IDBVT
ACTIVE
SOT-23
DBV
6
250
None
CU NIPDAU
Level-1-240C-UNLIM
ADS1100A4IDBVR
ACTIVE
SOT-23
DBV
6
3000
None
CU NIPDAU
Level-1-240C-UNLIM
Lead/Ball Finish
MSL Peak Temp (3)
ADS1100A4IDBVT
ACTIVE
SOT-23
DBV
6
250
None
CU NIPDAU
Level-1-240C-UNLIM
ADS1100A5IDBVR
ACTIVE
SOT-23
DBV
6
3000
None
CU NIPDAU
Level-1-240C-UNLIM
ADS1100A5IDBVT
ACTIVE
SOT-23
DBV
6
250
None
CU NIPDAU
Level-1-240C-UNLIM
ADS1100A6IDBVR
ACTIVE
SOT-23
DBV
6
3000
None
CU NIPDAU
Level-1-240C-UNLIM
ADS1100A6IDBVT
ACTIVE
SOT-23
DBV
6
250
None
CU NIPDAU
Level-1-240C-UNLIM
ADS1100A7IDBVR
ACTIVE
SOT-23
DBV
6
3000
None
CU NIPDAU
Level-1-240C-UNLIM
ADS1100A7IDBVT
ACTIVE
SOT-23
DBV
6
250
None
CU NIPDAU
Level-1-240C-UNLIM
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in
a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan - May not be currently available - please check http://www.ti.com/productcontent for the latest availability information and additional
product content details.
None: Not yet available Lead (Pb-Free).
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements
for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Green (RoHS & no Sb/Br): TI defines "Green" to mean "Pb-Free" and in addition, uses package materials that do not contain halogens,
including bromine (Br) or antimony (Sb) above 0.1% of total product weight.
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDECindustry standard classifications, and peak solder
temperature.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is
provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the
accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take
reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on
incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited
information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI
to Customer on an annual basis.
Addendum-Page 1
IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications,
enhancements, improvements, and other changes to its products and services at any time and to discontinue
any product or service without notice. Customers should obtain the latest relevant information before placing
orders and should verify that such information is current and complete. All products are sold subject to TI’s terms
and conditions of sale supplied at the time of order acknowledgment.
TI warrants performance of its hardware products to the specifications applicable at the time of sale in
accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI
deems necessary to support this warranty. Except where mandated by government requirements, testing of all
parameters of each product is not necessarily performed.
TI assumes no liability for applications assistance or customer product design. Customers are responsible for
their products and applications using TI components. To minimize the risks associated with customer products
and applications, customers should provide adequate design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right,
copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process
in which TI products or services are used. Information published by TI regarding third-party products or services
does not constitute a license from TI to use such products or services or a warranty or endorsement thereof.
Use of such information may require a license from a third party under the patents or other intellectual property
of the third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of information in TI data books or data sheets is permissible only if reproduction is without
alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction
of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for
such altered documentation.
Resale of TI products or services with statements different from or beyond the parameters stated by TI for that
product or service voids all express and any implied warranties for the associated TI product or service and
is an unfair and deceptive business practice. TI is not responsible or liable for any such statements.
Following are URLs where you can obtain information on other Texas Instruments products and application
solutions:
Products
Applications
Amplifiers
amplifier.ti.com
Audio
www.ti.com/audio
Data Converters
dataconverter.ti.com
Automotive
www.ti.com/automotive
DSP
dsp.ti.com
Broadband
www.ti.com/broadband
Interface
interface.ti.com
Digital Control
www.ti.com/digitalcontrol
Logic
logic.ti.com
Military
www.ti.com/military
Power Mgmt
power.ti.com
Optical Networking
www.ti.com/opticalnetwork
Microcontrollers
microcontroller.ti.com
Security
www.ti.com/security
Telephony
www.ti.com/telephony
Video & Imaging
www.ti.com/video
Wireless
www.ti.com/wireless
Mailing Address:
Texas Instruments
Post Office Box 655303 Dallas, Texas 75265
Copyright  2005, Texas Instruments Incorporated