TI ADS8344EB

ADS
ADS
834
ADS8344
¤
834
4
¤
4
SBAS139E – SEPTEMBER 2000 – REVISED SEPTEMBER 2006
16-Bit, 8-Channel Serial Output Sampling
ANALOG-TO-DIGITAL CONVERTER
FEATURES
DESCRIPTION
● PIN FOR PIN WITH ADS7844
The ADS8344 is an 8-channel, 16-bit, sampling
Analog-to-Digital (A/D) converter with a synchronous serial
interface. Typical power dissipation is 10mW at a 100kHz
throughput rate and a +5V supply. The reference voltage
(VREF) can be varied between 500mV and VCC, providing a
corresponding input voltage range of 0V to VREF. The
device includes a shutdown mode that reduces power dissipation to under 15µW. The ADS8344 is tested down to 2.7V
operation.
● SINGLE SUPPLY: 2.7V to 5V
● 8-CHANNEL SINGLE-ENDED OR
4-CHANNEL DIFFERENTIAL INPUT
● UP TO 100kHz CONVERSION RATE
● 84dB SINAD
● SERIAL INTERFACE
● QSOP-20 AND SSOP-20 PACKAGES
APPLICATIONS
●
●
●
●
●
DATA ACQUISITION
TEST AND MEASUREMENT EQUIPMENT
INDUSTRIAL PROCESS CONTROL
PERSONAL DIGITAL ASSISTANTS
BATTERY-POWERED SYSTEMS
ADS8341
ADS8343
CH2
ADS8344
ADS8345
CH0
CH0
CH1
Low power, high speed, and an on-board multiplexer make
the ADS8344 ideal for battery-operated systems such as
personal digital assistants, portable multi-channel data loggers, and measurement equipment. The serial interface also
provides low-cost isolation for remote data acquisition. The
ADS8344 is available in a QSOP-20 or SSOP-20 package
and is ensured over the –40°C to +85°C temperature range.
4-Channel
Multiplexer
SAR
CH1
DCLK
CH2
CH3
CH3
COM
CH4
CH5
8-Channel
Multiplexer
CS
Comparator
CDAC
CH6
CH7
COM
Serial
Interface
and
Control
SHDN
DIN
DOUT
BUSY
VREF
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 © 2000-2006, 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(1)
+VCC to GND ........................................................................ –0.3V to +6V
Analog Inputs to GND ............................................ –0.3V to +VCC + 0.3V
Digital Inputs to GND ........................................................... –0.3V to +6V
Power Dissipation .......................................................................... 250mW
Maximum Junction Temperature ................................................... +150°C
Operating Temperature Range ........................................ –40°C to +85°C
Storage Temperature Range ......................................... –65°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(1)
PRODUCT
MINIMUM
RELATIVE
MAXIMUM
SPECIFIED
ACCURACY GAIN ERROR TEMPERATURE
PACKAGE
(LSB)
(%)
RANGE
DESIGNATOR PACKAGE-LEAD
ADS8344E
"
ADS8344N
"
ADS8344EB
"
ADS8344NB
"
±0.05
"
"
"
±0.024
"
"
"
8
"
"
"
6
"
"
"
–40°C to +85°C
"
"
"
–40°C to +85°C
"
"
"
DBQ
"
DB
"
DBQ
"
DB
"
QSOP-20
"
SSOP-20
"
QSOP-20
"
SSOP-20
"
PACKAGE
DRAWING
NUMBER
ORDERING
NUMBER
DBQ
"
DB
"
DBQ
"
DB
"
ADS8344E
ADS8344E/2K5
ADS8344N
ADS8344N/1K
ADS8344EB
ADS8344EB/2K5
ADS8344NB
ADS8344NB/1K
TRANSPORT
MEDIA, QUANTITY
Rails, 56
Tape and Reel,
Rails, 68
Tape and Reel,
Rails, 56
Tape and Reel,
Rails, 68
Tape and Reel,
2500
1000
2500
1000
NOTE: (1) For the most current package and ordering information, see the Package Option Addendum at the end of this data sheet, or see the TI web site at
www.ti.com.
PIN CONFIGURATION
PIN DESCRIPTIONS
Top View
SSOP
NAME
DESCRIPTION
1
2
3
4
5
6
7
8
9
CH0
CH1
CH2
CH3
CH4
CH5
CH6
CH7
COM
Analog Input Channel 0
Analog Input Channel 1
Analog Input Channel 2
Analog Input Channel 3
Analog Input Channel 4
Analog Input Channel 5
Analog Input Channel 6
Analog Input Channel 7
Ground reference for analog inputs. Sets zero code
voltage in single–ended mode. Connect this pin to ground
or ground reference point.
Shutdown. When LOW, the device enters a very
low-power shutdown mode.
Voltage Reference Input. See Electrical Characteristics
Table for ranges.
Power Supply, 2.7V to 5V
Ground
Ground
Serial Data Output. Data is shifted on the falling edge of
DCLK. This output is high impedance when CS is HIGH.
Busy Output. Busy goes LOW when the DIN control bits
are being read and also when the device is converting.
The Output is high impedance when CS is HIGH.
Serial Data Input. If CS is LOW, data is latched on rising
edge of DCLK.
Chip Select Input. Active LOW. Data will not be clocked
into DIN unless CS is LOW. When CS is HIGH, DOUT is
high impedance.
External Clock Input. The clock speed determines the
conversion rate by the equation fDCLK = 24 • fSAMPLE.
Power Supply
CH0
1
20
+VCC
CH1
2
19
DCLK
CH2
3
18
CS
CH3
4
17
DIN
10
SHDN
CH4
5
16
BUSY
11
VREF
12
13
14
15
+VCC
GND
GND
DOUT
16
BUSY
17
DIN
18
CS
19
DCLK
20
+VCC
ADS8344
2
PIN
CH5
6
15
DOUT
CH6
7
14
GND
CH7
8
13
GND
COM
9
12
+VCC
SHDN 10
11
VREF
ADS8344
SBAS139E
ELECTRICAL CHARACTERISTICS: +5V
At TA = –40°C to +85°C, +VCC = +5V, VREF = +5V, fSAMPLE = 100kHz, and fCLK = 24 • fSAMPLE = 2.4MHz, unless otherwise noted.
ADS8344E, N
PARAMETER
CONDITIONS
MIN
RESOLUTION
ANALOG INPUT
Full-Scale Input Span
Absolute Input Range
Positive Input - Negative Input
Positive Input
Negative Input
0
–0.2
–0.2
POWER-SUPPLY REQUIREMENTS
+VCC
Quiescent Current
1.0
20
3
+4.75V < VCC < 5.25V
✻
✻
✻
8
±2
4
±0.05
4
✻
✻
✻
✻
=
=
=
=
5Vp-p
5Vp-p
5Vp-p
5Vp-p
at
at
at
at
0.024
0
2.4
2.4
0.5
✻
✻
+VCC
5
40
2.5
0.001
3.0
–0.3
3.5
✻
✻
✻
100
3
✻
✻
✻
Power Dissipation
7.5
–40
✻
✻
✻
✻
✻
0.4
1.5
300
CLK Cycles
CLK Cycles
kHz
ns
ns
ps
MHz
MHz
MHz
V
GΩ
µA
µA
µA
✻
5.5
+0.8
4.75
Bits
LSB
mV
LSB(1)
%
LSB
µVrms
LSB(1)
dB
dB
dB
dB
✻
✻
✻
✻
✻
V
V
V
V
✻
Straight Binary
Specified Performance
6
±1
✻
±0.024
✻
✻
✻
✻
✻
CMOS
| IIH | ≤ +5µA
| IIL | ≤ +5µA
IOH = –250µA
IOL = 250µA
V
V
V
pF
µA
✻
–90
86
92
100
DCLK Static
✻
✻
✻
✻
✻
✻
✻
500
30
100
2.4
10kHz
10kHz
10kHz
10kHz
BITS
✻
100
VIN
VIN
VIN
VIN
UNITS
✻
✻
16
SHDN = VDD
MAX
✻
✻
4.5
fSAMPLE = 100kHz
Power-Down Mode(3), CS = +VCC
TEMPERATURE RANGE
Specified Performance
TYP
15
1.2
fSAMPLE = 12.5kHz
DCLK Static
DIGITAL INPUT/OUTPUT
Logic Family
Logic Levels
VIH
VIL
VOH
VOL
Data Format
VREF
+VCC + 0.2
+1.25
14
Data Transfer Only
REFERENCE INPUT
Range
Resistance
Input Current
MIN
25
±1
SAMPLING DYNAMICS
Conversion Time
Acquisition Time
Throughput Rate
Multiplexer Settling Time
Aperture Delay
Aperture Jitter
Internal Clock Frequency
External Clock Frequency
DYNAMIC CHARACTERISTICS
Total Harmonic Distortion(2)
Signal-to-(Noise + Distortion)
Spurious–Free Dynamic Range
Channel-to-Channel Isolation
MAX
16
Capacitance
Leakage Current
SYSTEM PERFORMANCE
No Missing Codes
Integral Linearity Error
Offset Error
Offset Error Match
Gain Error
Gain Error Match
Noise
Power-Supply Rejection
TYP
ADS8344EB, NB
5.25
2.0
✻
✻
✻
✻
✻
V
mA
µA
µA
mW
✻
°C
✻
3
10
+85
✻
✻ Same specifications as ADS8344E, N.
NOTES: (1) LSB means Least Significant Bit. With VREF equal to +5.0V, one LSB is 76µV. (2) First nine harmonics of the test frequency. (3) Auto power-down mode
(PD1 = PD0 = 0) active or SHDN = GND.
ADS8344
SBAS139E
3
ELECTRICAL CHARACTERISTICS: +2.7V
At TA = –40°C to +85°C, +VCC = +2.7V, VREF = +2.7V, fSAMPLE = 100kHz, and fCLK = 24 • fSAMPLE = 2.4MHz, unless otherwise noted.
ADS8344E, N
PARAMETER
CONDITIONS
MIN
TYP
RESOLUTION
ANALOG INPUT
Full-Scale Input Span
Absolute Input Range
SAMPLING DYNAMICS
Conversion Time
Acquisition Time
Throughput Rate
Multiplexer Settling Time
Aperture Delay
Aperture Jitter
Internal Clock Frequency
External Clock Frequency
Positive Input - Negative Input
Positive Input
Negative Input
REFERENCE INPUT
Range
Resistance
Input Current
0
–0.2
–0.2
VREF
+VCC + 0.2
+0.2
POWER-SUPPLY REQUIREMENTS
+VCC
Quiescent Current
✻
✻
✻
1
20
3
+2.7 < VCC < +3.3V
12
±1
4
±0.05
4
✻
✻
✻
✻
SHDN = VDD
0.024
0.024
0
2.4
2.0
2.4
VIN = 2.5Vp-p at 1kHz
VIN = 2.5Vp-p at 1kHz
VIN = 2.5Vp-p at 1kHz
VIN = 2.5Vp-p at 10kHz
V
V
V
pF
µA
8
0.5
✻
±0.024
✻
✻
✻
✻
0.5
+VCC
DCLK Static
5
13
2.5
0.001
✻
40
3
✻
✻
✻
3.2
✻
✻
✻
✻
✻
0.4
V
GΩ
µA
µA
µA
V
V
V
V
✻
Straight Binary
1.2
220
CLK Cycles
CLK Cycles
kHz
ns
ns
ps
MHz
MHz
MHz
MHz
✻
5.5
+0.8
2.7
Bits
LSB
mV
LSB
% of FSR
LSB
µVrms
LSB(1)
dB
dB
dB
dB
✻
✻
✻
✻
✻
CMOS
+VCC • 0.7
–0.3
+VCC • 0.8
✻
✻
✻
✻
✻
✻
–90
86
92
100
–40
✻
✻
✻
✻
✻
✻
✻
500
30
100
2.4
Power Dissipation
BITS
✻
100
Specified Performance
UNITS
✻
✻
16
4.5
| IIH | ≤ +5µA
| IIL | ≤ +5µA
IOH = –250µA
IOL = 250µA
MAX
15
1.2
fSAMPLE = 100kHz
Power-Down Mode(3), CS = +VCC
TEMPERATURE RANGE
Specified Performance
TYP
✻
✻
14
fSAMPLE = 12.5kHz
DCLK Static
DIGITAL INPUT/OUTPUT
Logic Family
Logic Levels
VIH
VIL
VOH
VOL
Data Format
MIN
25
±1
When used with Internal Clock
Data Transfer Only
DYNAMIC CHARACTERISTICS
Total Harmonic Distortion(2)
Signal-to-(Noise + Distortion)
Spurious-Free Dynamic Range
Channel-to-Channel Isolation
MAX
16
Capacitance
Leakage Current
SYSTEM PERFORMANCE
No Missing Codes
Integral Linearity Error
Offset Error
Offset Error Match
Gain Error
Gain Error Match
Noise
Power-Supply Rejection
ADS8344EB, NB
3.6
1.85
✻
✻
✻
3
5
+85
✻
✻
✻
✻
✻
V
mA
µA
µA
mW
✻
°C
✻ Same specifications as ADS8344E, N.
NOTES: (1) LSB means Least Significant Bit. With VREF equal to +2.5V, one LSB is 38µV. (2) First nine harmonics of the test frequency. (3) Auto power-down mode
(PD1 = PD0 = 0) active or SHDN = GND.
4
ADS8344
SBAS139E
TYPICAL CHARACTERISTICS: +5V
At TA = +25°C, +VCC = +5V, VREF = +5V, fSAMPLE = 100kHz, and fDCLK = 24 • fSAMPLE = 2.4MHz, unless otherwise noted.
FREQUENCY SPECTRUM
(4096 Point FFT; fIN = 9.985kHz, –0.2dB)
0
0
–20
–20
–40
–40
Amplitude (dB)
–60
–80
–100
–60
–80
–100
–120
–120
–140
–140
–160
–160
0
10
20
30
40
50
0
10
20
30
Frequency (kHz)
SIGNAL-TO-NOISE RATIO AND SIGNAL-TO(NOISE+DISTORTION) vs INPUT FREQUENCY
SPURIOUS-FREE DYNAMIC RANGE AND TOTAL
HARMONIC DISTORTION vs INPUT FREQUENCY
100
50
–100
100
SNR
SFDR
90
–90
90
SFDR (dB)
SNR and SINAD (dB)
40
Frequency (kHz)
80
SINAD
70
THD(1)
80
–80
THD (dB)
Amplitude (dB)
FREQUENCY SPECTRUM
(4096 Point FFT; fIN = 1.001kHz, –0.2dB)
–70
70
NOTE: (1) First Nine Harmonics
of the Input Frequency
60
10
100
1
10
Frequency (kHz)
Frequency (kHz)
EFFECTIVE NUMBER OF BITS
vs INPUT FREQUENCY
CHANGE IN SIGNAL-TO-(NOISE+DISTORTION)
vs TEMPERATURE
15.0
0.4
fIN = 9.985kHz, –0.2dB
14.5
0.2
14.0
Delta from +25°C (dB)
Effective Number of Bits
–60
100
60
1
13.5
13.0
12.5
12.0
0.0
–0.2
–0.4
–0.6
11.5
11.0
–0.8
1
10
Frequency (kHz)
ADS8344
SBAS139E
100
–40
–25
0
20
50
75
100
Temperature (°C)
5
TYPICAL CHARACTERISTICS: +5V
(Cont.)
At TA = +25°C, +VCC = +5V, VREF = +5V, fSAMPLE = 100kHz, and fDCLK = 24 • fSAMPLE = 2.4MHz, unless otherwise noted.
1
2
0
1
–1
0
–2
–1
–3
–2
–4
0000H
4000H
C000H
8000H
–3
0000H
FFFFH
C000H
8000H
Output Code
WORST CASE CHANNEL-TO-CHANNEL
OFFSET MATCH vs TEMPERATURE
WORST CASE CHANNEL-TO-CHANNEL
GAIN MATCH vs TEMPERATURE
3.0
2.0
2.5
1.5
2.0
1.5
1.0
–50
4000H
Output Code
Gain Match (LSB)
Offset Match (LSB)
DIFFERENTIAL LINEARITY ERROR vs CODE
3
DLE (LSB)
ILE (LSB)
INTEGRAL LINEARITY ERROR vs CODE
2
FFFFH
1.0
0.5
–25
0
25
50
Temperature (°C)
75
0.0
–50
100
CHANGE IN OFFSET vs TEMPERATURE
–25
0
25
50
Temperature (°C)
75
100
CHANGE IN GAIN vs TEMPERATURE
3
1.0
Delta from 25°C (LSB)
Delta from 25°C (LSB)
2
1
0
–1
0.5
0.0
–2
–3
–50
–25
0
25
Temperature (°C)
6
50
75
100
–0.5
–50
–25
0
25
50
75
100
Temperature (°C)
ADS8344
SBAS139E
TYPICAL CHARACTERISTICS: +5V
(Cont.)
At TA = +25°C, +VCC = +5V, VREF = +5V, fSAMPLE = 100kHz, and fDCLK = 24 • fSAMPLE = 2.4MHz, unless otherwise noted.
POWER DOWN SUPPLY CURRENT
vs TEMPERATURE
SUPPLY CURRENT vs TEMPERATURE
3.0
1.8
Supply Current (µA)
Supply Current (mA)
1.7
1.6
1.5
2.5
2.0
1.5
1.4
1.3
–50
–25
0
25
Temperature (°C)
ADS8344
SBAS139E
50
75
100
1.0
–50
–25
0
25
50
Temperature (°C)
75
100
7
TYPICAL CHARACTERISTICS: +2.7V
At TA = +25°C, +VCC = +2.7V, VREF = +2.7V, fSAMPLE = 100kHz, and fDCLK = 24 • fSAMPLE = 2.4MHz, unless otherwise noted.
FREQUENCY SPECTRUM
(4096 Point FFT; fIN = 9.985kHz, –0.2dB)
0
0
–20
–20
–40
–40
Amplitude (dB)
Amplitude (dB)
FREQUENCY SPECTRUM
(4096 Point FFT; fIN = 1.001kHz, –0.2dB)
–60
–80
–100
–60
–80
–100
–120
–120
–140
–140
–160
–160
0
10
20
30
40
0
50
10
20
30
40
50
Frequency (kHz)
Frequency (kHz)
SIGNAL-TO-NOISE RATIO AND SIGNAL-TO(NOISE+DISTORTION) vs INPUT FREQUENCY
SPURIOUS-FREE DYNAMIC RANGE AND TOTAL
HARMONIC DISTORTION vs INPUT FREQUENCY
100
100
–100
90
–90
SFDR (dB)
SNR and SINAD (dB)
80
70
SINAD
60
70
–70
–60
NOTE: (1) First Nine Harmonics
of the Input Frequency
50
1
10
100
1
–50
100
10
Frequency (kHz)
Frequency (kHz)
EFFECTIVE NUMBER OF BITS
vs INPUT FREQUENCY
CHANGE IN SIGNAL-TO-(NOISE+DISTORTION)
vs TEMPERATURE
15
2.0
14
1.5
Delta from +25°C (dB)
Effective Number of Bits
–80
THD(1)
60
50
13
12
11
10
9
fIN = 9.985kHz, –0.2dB
1.0
0.5
0.0
–0.5
–1.0
–1.5
8
–2.0
1
10
Frequency (kHz)
8
SFDR
80
THD (dB)
SNR
90
100
–40
–25
0
20
50
75
100
Temperature (°C)
ADS8344
SBAS139E
TYPICAL CHARACTERISTICS: +2.7V
(Cont.)
At TA = +25°C, +VCC = +2.7V, VREF = +2.7V, fSAMPLE = 100kHz, and fDCLK = 24 • fSAMPLE = 2.4MHz, unless otherwise noted.
DIFFERENTIAL LINEARITY ERROR vs CODE
3
2
2
1
1
DLE (LSB)
ILE (LSB)
INTEGRAL LINEARITY ERROR vs CODE
3
0
0
–1
–1
–2
–2
–3
0000H
4000H
C000H
8000H
–3
0000H
FFFFH
4000H
C000H
8000H
FFFFH
Output Code
Output Code
WORST CASE CHANNEL-TO-CHANNEL
OFFSET MATCH vs TEMPERATURE
WORST CASE CHANNEL-TO-CHANNEL
GAIN MATCH vs TEMPERATURE
1.2
1.2
Gain Match (LSBS)
Offset Match (LSBS)
1.0
0.8
0.6
0.4
1.0
0.8
0.6
0.2
0
–50
–25
0
25
50
75
0.4
–50
100
–25
0
Temperature (°C)
Delta from 25°C (LSB)
Delta from 25°C (LSB)
1
0
SBAS139E
100
0.3
2
ADS8344
75
CHANGE IN GAIN vs TEMPERATURE
CHANGE IN OFFSET vs TEMPERATURE
3
–1
–50
25
50
Temperature (°C)
0.2
0.1
0.0
–0.1
–25
0
25
50
Temperature (°C)
75
100
–0.2
–50
–25
0
25
50
75
100
Temperature (°C)
9
TYPICAL CHARACTERISTICS: +2.7V (Cont.)
At TA = +25°C, +VCC = +2.7V, VREF = +2.7V, fSAMPLE = 100kHz, and fDCLK = 24 • fSAMPLE = 2.4MHz, unless otherwise noted.
SUPPLY CURRENT vs TEMPERATURE
SUPPLY CURRENT vs +VSS
1.25
1.6
1.20
1.5
Supply Current (mA)
Supply Current (mA)
fSAMPLE = 100kHz, VREF = +VSS
1.15
1.10
1.05
1.00
–50
1.4
1.3
1.2
1.1
1.0
–25
0
25
50
75
100
2.5
3.0
Temperature (°C)
3.5
4.0
4.5
5.0
+VSS (V)
POWER DOWN SUPPLY CURRENT
vs TEMPERATURE
Supply Current (µA)
3.0
2.5
2.0
1.5
1.0
–50
10
–25
0
25
50
Temperature (°C)
75
100
ADS8344
SBAS139E
THEORY OF OPERATION
ANALOG INPUT
See Figure 2 for a block diagram of the input multiplexer on
the ADS8344. The differential input of the converter is
derived from one of the eight inputs in reference to the COM
pin, or four of the eight inputs. Table I and Table II show the
relationship between the A2, A1, A0, and SGL/DIF control
bits and the configuration of the analog multiplexer. The
control bits are provided serially via the DIN pin (see the
Digital Interface section of this data sheet for more details).
The ADS8344 is a classic Successive Approximation
Register (SAR) A/D converter. The architecture is based on
capacitive redistribution that inherently includes a sampleand-hold function. The converter is fabricated on a 0.6µs
CMOS process.
The basic operation of the ADS8344 is shown in Figure 1.
The device requires an external reference and an external
clock. It operates from a single supply of 2.7V to 5.25V. The
external reference can be any voltage between 500mV and
+VCC. The value of the reference voltage directly sets the
input range of the converter. The average reference input
current depends on the conversion rate of the ADS8344.
When the converter enters the hold mode, the voltage
difference between the +IN and –IN inputs is captured on
the internal capacitor array (see Figure 2). The voltage on
the –IN input is limited between –0.2V and 1.25V, allowing
the input to reject small signals that are common to both the
+IN and –IN input. The +IN input has a range of –0.2V to
+VCC + 0.2V.
The analog input to the converter is differential and is
provided via an 8-channel multiplexer. The input can be
provided in reference to a voltage on the COM pin (which
is generally ground) or differentially by using four of the
eight input channels (CH0 - CH7). The particular configuration is selectable via the digital interface.
A2
A1
A0
0
0
0
1
0
0
0
0
1
1
0
1
0
1
0
1
1
0
0
1
1
1
1
1
The input current on the analog inputs depends on the conversion rate of the device. During the sample period, the source
must charge the internal sampling capacitor (typically 25pF).
After the capacitor has been fully charged, there is no further
input current. The rate of charge transfer from the analog
source to the converter is a function of conversion rate.
CH0 CH1 CH2 CH3 CH4 CH5 CH6 CH7 COM
+IN
–IN
+IN
+IN
+IN
–IN
A2
A1
A0
CH0
CH1
–IN
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
+IN
–IN
–IN
+IN
–IN
+IN
–IN
+IN
–IN
+IN
–IN
–IN
CH2
CH3
+IN
–IN
CH4
CH5
+IN
–IN
CH6
CH7
+IN
–IN
–IN
+IN
+IN
–IN
+IN
–IN
+IN
TABLE II. Differential Channel Control (SGL/DIF LOW).
TABLE I. Single-Ended Channel Selection (SGL/DIF HIGH).
+2.7V to +5V
ADS8344
Single-ended
or differential
analog inputs
1µF to 10µF
0.1µF
1
CH0
+VCC 20
2
CH1
DCLK 19
3
CH2
CS 18
Chip Select
4
CH3
DIN 17
Serial Data In
5
CH4
BUSY 16
6
CH5
DOUT 15
7
CH6
GND 14
8
CH7
GND 13
9
COM
+VCC 12
10 SHDN
VREF 11
Serial/Conversion Clock
Serial Data Out
External
VREF
+
1µF
1µF to 10µF
FIGURE 1. Basic Operation of the ADS8344.
ADS8344
SBAS139E
11
(Least Significant Bit) size and is equal to the reference
voltage divided by 65536. Any offset or gain error inherent
in the A/D converter will appear to increase, in terms of LSB
size, as the reference voltage is reduced. For example, if the
offset of a given converter is 2LSBs with a 2.5V reference,
then it will typically be 10LSBs with a 0.5V reference. In
each case, the actual offset of the device is the same,
76.3µV.
A2-A0
(shown 00oB)(1)
CH0
CH1
CH2
CH3
CH4
Likewise, the noise or uncertainty of the digitized output
will increase with lower LSB size. With a reference voltage
of 500mV, the LSB size is 7.6µV. This level is below the
internal noise of the device. As a result, the digital output
code will not be stable and will vary around a mean value by
a number of LSBs. The distribution of output codes will be
gaussian and the noise can be reduced by simply averaging
consecutive conversion results or applying a digital filter.
CH5
CH6
+IN
Converter
CH7
–IN
With a lower reference voltage, care should be taken to
provide a clean layout including adequate bypassing, a clean
(low-noise, low-ripple) power supply, a low-noise reference,
and a low-noise input signal. Because the LSB size is lower,
the converter will also be more sensitive to nearby digital
signals and electromagnetic interference.
The voltage into the VREF input is not buffered and directly
drives the Capacitor Digital-to-Analog Converter (CDAC)
portion of the ADS8344. Typically, the input current is
13µA with a 2.5V reference. This value will vary by
microamps depending on the result of the conversion. The
reference current diminishes directly with both conversion
rate and reference voltage. As the current from the reference
is drawn on each bit decision, clocking the converter more
quickly during a given conversion period will not reduce
overall current drain from the reference.
COM
NOTE: (1) See Truth Tables, Table I
and Table II for address coding.
SGL/DIF
(shown HIGH)
FIGURE 2. Simplified Diagram of the Analog Input.
REFERENCE INPUT
The external reference sets the analog input range. The
ADS8344 will operate with a reference in the range of
100mV to +VCC. Keep in mind that the analog input is the
difference between the +IN input and the –IN input, as
shown in Figure 2. For example, in the single-ended mode,
a 1.25V reference with the COM pin grounded, the selected
input channel (CH0 - CH7) will properly digitize a signal in
the range of 0V to 1.25V. If the COM pin is connected to
0.5V, the input range on the selected channel is 0.5V to
1.75V.
DIGITAL INTERFACE
The ADS8344 has a four-wire serial interface compatible
with several microprocessor families (note that the digital
inputs are over-voltage tolerant up to +5.5V, regardless of
+VCC). Figure 3 shows the typical operation of the ADS8344
digital interface.
Most microprocessors communicate using 8-bit transfers;
the ADS8344 can complete a conversion with three such
transfers, for a total of 24 clock cycles on the DCLK input,
provided the timing is as shown in Figure 3.
There are several critical items concerning the reference
input and its wide-voltage range. As the reference voltage is
reduced, the analog voltage weight of each digital output
code is also reduced. This is often referred to as the LSB
CS
tACQ
DCLK
1
8
Idle
DIN
S
A2
8
1
Acquire
A1
A0
1
8
1
8
Conversion
Idle
SGL/ PD1 PD0
DIF
S
(START)
A2
Acquire
A1
A0
1
Conversion
SGL/ PD1 PD0
DIF
(START)
BUSY
DOUT
15
(MSB)
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
(LSB)
Zero Filled...
15
14
(MSB)
FIGURE 3. Conversion Timing, 24-Clocks per Conversion, 8-Bit Bus Interface. No DCLK Delay Required with Dedicated
Serial Port.
12
ADS8344
SBAS139E
The first eight clock cycles are used to provide the control
byte via the DIN pin. When the converter has enough
information about the following conversion to set the input
multiplexer appropriately, it enters the acquisition (sample)
mode. After four more clock cycles, the control byte is
complete and the converter enters the conversion mode. At
this point, the input sample-and-hold goes into the Hold
mode. The next sixteen clock cycles accomplish the actual
A/D conversion.
Control Byte
See Figure 3 for placement and order of the control bits
within the control byte. Tables III and IV give detailed
information about these bits. The first bit, the “S” bit, must
always be HIGH and indicates the start of the control byte.
The ADS8344 will ignore inputs on the DIN pin until the
START bit is detected. The next three bits (A2-A0) select
the active input channel or channels of the input multiplexer
(see Tables I and II and Figure 2).
BIT 7
(MSB)
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
(LSB)
S
A2
A1
A0
—
SGL/DIF
PD1
PD0
TABLE III. Order of the Control Bits in the Control Byte.
BIT
NAME
7
DESCRIPTION
S
Start Bit. Control byte starts with first HIGH bit on
DIN.
6-4
A2 - A0
Channel Select Bits. Along with the SGL/DIF bit,
these bits control the setting of the multiplexer input,
see Tables I and II.
2
SGL/DIF
Single-Ended/Differential Select Bit. Along with bits
A2 - A0, this bit controls the setting of the multiplexer
input, see Tables I and II.
PD1 - PD0
Power-Down Mode Select Bits. See Table V for
details.
1-0
TABLE IV. Descriptions of the Control Bits within the
Control Byte.
The SGL/DIF-bit controls the multiplexer input mode: either in single-ended mode, where the selected input channel
is referenced to the COM pin, or in differential mode, where
the two selected inputs provide a differential input.
See Tables I and II and Figure 2 for more information. The
last two bits (PD1 - PD0) select the power-down mode and
Clock mode, as shown in Table V. If both PD1 and PD0 are
HIGH, the device is always powered up. If both PD1 and
PD0 are LOW, the device enters a power-down mode
between conversions. When a new conversion is initiated,
the device will resume normal operation instantly—no delay
is needed to allow the device to power up and the very first
conversion will be valid.
PD1
PD0
0
0
Power-down between conversions. When each
conversion is finished, the converter enters a
low-power mode. At the start of the next conversion, the device instantly powers up to full power.
There is no need for additional delays to assure full
operation and the very first conversion is valid.
DESCRIPTION
1
0
Selects Internal Clock Mode.
0
1
Reserved for Future Use.
1
1
No power-down between conversions, device always powered. Selects external clock mode.
TABLE V. Power-Down Selection.
Clock Modes
The ADS8344 can be used with an external serial clock or an
internal clock to perform the successive-approximation conversion. In both clock modes, the external clock shifts data in
and out of the device. Internal clock mode is selected when
PD1 is HIGH and PD0 is LOW.
If the user decides to switch from one clock mode to the other,
an extra conversion cycle will be required before the
ADS8344 can switch to the new mode. The extra cycle is
required because the PD0 and PD1 control bits need to be
written to the ADS8344 prior to the change in clock modes.
When power is first applied to the ADS8344, the user must
set the desired clock mode. It can be set by writing PD1
= 1 and PD0 = 0 for internal clock mode or PD1 = 1 and PD0
= 1 for external clock mode. After enabling the required
clock mode, only then should the ADS8344 be set to powerdown between conversions (i.e., PD1 = PD0 = 0). The
ADS8344 maintains the clock mode it was in prior to
entering the power-down modes.
External Clock Mode
In external clock mode, the external clock not only shifts data
in and out of the ADS8344, it also controls the A/D conversion
steps. BUSY will go HIGH for one clock period after the last
bit of the control byte is shifted in. Successive-approximation
bit decisions are made and appear at DOUT on each of the next
16 DCLK falling edges (see Figure 3). Figure 4 shows the
BUSY timing in external clock mode.
CS
tCSS
tCL
tCH
tBD
tBD
tD0
tCSH
DCLK
tDS
DIN
tDH
PD0
tBDV
tBTR
BUSY
tDV
DOUT
tTR
15
14
FIGURE 4. Detailed Timing Diagram.
ADS8344
SBAS139E
13
Since one clock cycle of the serial clock is consumed with
BUSY going HIGH (while the MSB decision is being
made), 16 additional clocks must be given to clock out all 16
bits of data; thus, one conversion takes a minimum of 25
clock cycles to fully read the data. Since most microprocessors communicate in 8-bit transfers, this means that an
additional transfer must be made to capture the LSB.
If CS is LOW when BUSY goes LOW following a conversion, the next falling edge of the external serial clock will
write out the MSB on the DOUT line. The remaining bits
(D14-D0) will be clocked out on each successive clock cycle
following the MSB. If CS is HIGH when BUSY goes LOW
then the DOUT line will remain in tri-state until CS goes
LOW, as shown in Figure 6. CS does not need to remain
LOW once a conversion has started. Note that BUSY is not
tri-stated when CS goes HIGH in internal clock mode.
There are two ways of handling this requirement. One is
where the beginning of the next control byte appears at the
same time the LSB is being clocked out of the ADS8344
(see Figure 3). This method allows for maximum throughput
and 24 clock cycles per conversion.
Data can be shifted in and out of the ADS8344 at clock rates
exceeding 2.4MHz, provided that the minimum acquisition
time tACQ, is kept above 1.7µs.
The other method is shown in Figure 5, which uses 32 clock
cycles per conversion; the last seven clock cycles simply
shift out zeros on the DOUT line. BUSY and DOUT go into a
high-impedance state when CS goes HIGH; after the next
CS falling edge, BUSY will go LOW.
Digital Timing
Figure 4 and Tables VI and VII provide detailed timing for
the digital interface of the ADS8344.
Internal Clock Mode
In internal clock mode, the ADS8344 generates its own
conversion clock internally. This relieves the microprocessor from having to generate the SAR conversion clock and
allows the conversion result to be read back at the processor’s
convenience, at any clock rate from 0MHz to 2.0MHz.
BUSY goes LOW at the start of a conversion and then
returns HIGH when the conversion is complete. During the
conversion, BUSY will remain LOW for a maximum of 8µs.
Also, during the conversion, DCLK should remain LOW to
achieve the best noise performance. The conversion result is
stored in an internal register; the data may be clocked out of
this register any time after the conversion is complete.
SYMBOL
DESCRIPTION
MIN
tACQ
tDS
tDH
tDO
tDV
tTR
tCSS
tCSH
tCH
tCL
tBD
tBDV
tBTR
Acquisition Time
DIN Valid Prior to DCLK Rising
DIN Hold After DCLK HIGH
DCLK Falling to DOUT Valid
CS Falling to DOUT Enabled
CS Rising to DOUT Disabled
CS Falling to First DCLK Rising
CS Rising to DCLK Ignored
DCLK HIGH
DCLK LOW
DCLK Falling to BUSY Rising
CS Falling to BUSY Enabled
CS Rising to BUSY Disabled
1.5
100
10
TYP
MAX
UNITS
µs
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
200
200
200
100
0
200
200
200
200
200
TABLE VI. Timing Specifications (+VCC = +2.7V to 3.6V,
TA = –40°C to +85°C, CLOAD = 50pF).
CS
tACQ
DCLK
1
8
Idle
DIN
S
A2
1
8
Acquire
A1
A0
1
1
8
8
Conversion
Idle
SGL/
DIF PD1 PD0
(START)
BUSY
DOUT
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Zero Filled...
0
(MSB)
(LSB)
FIGURE 5. External Clock Mode, 32 Clocks Per Conversion.
CS
tACQ
DCLK
1
8
Idle
DIN
S
A2
Acquire
A1
A0
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
Conversion
SGL/ PD1 PD0
DIF
(START)
BUSY
DOUT
15
(MSB)
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Zero Filled...
(LSB)
FIGURE 6. Internal Clock Mode Timing.
14
ADS8344
SBAS139E
SYMBOL
DESCRIPTION
MIN
tACQ
tDS
tDH
tDO
tDV
tTR
tCSS
tCSH
tCH
tCL
tBD
tBDV
tBTR
Acquisition Time
DIN Valid Prior to DCLK Rising
DIN Hold After DCLK HIGH
DCLK Falling to DOUT Valid
CS Falling to DOUT Enabled
CS Rising to DOUT Disabled
CS Falling to First DCLK Rising
CS Rising to DCLK Ignored
DCLK HIGH
DCLK LOW
DCLK Falling to BUSY Rising
CS Falling to BUSY Enabled
CS Rising to BUSY Disabled
1.7
50
10
TYP
MAX
UNITS
100
70
70
50
0
150
150
100
70
70
µs
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
TABLE VII. Timing Specifications (+VCC = +4.75V to
+5.25V, TA = –40°C to +85°C, CLOAD = 50pF).
Data Format
The ADS8344 output data is in straight binary format, as
shown in Figure 7. This figure shows the ideal output code
for the given input voltage and does not include the effects
of offset, gain, or noise.
FS = Full-Scale Voltage = VREF
1LSB = VREF/65,536
1LSB
11...111
Output Code
11...110
11...101
00...010
00...001
00...000
FS – 1LSB
0V
Input Voltage(1) (V)
NOTE: (1) Voltage at converter input, after multiplexer: +IN – (–IN). (See Figure 2.)
FIGURE 7. Ideal Input Voltages and Output Codes.
remain approximately equal. However, if the DCLK frequency is kept at the maximum rate during a conversion, but
conversions are simply done less often, then the difference
between the two modes is dramatic. In the latter case, the
converter spends an increasing percentage of its time in
power-down mode (assuming the auto power-down mode is
active).
If DCLK is active and CS is LOW while the ADS8344 is in
auto power-down mode, the device will continue to dissipate
some power in the digital logic. The power can be reduced
to a minimum by keeping CS HIGH.
Operating the ADS8344 in auto power-down mode will
result in the lowest power dissipation, and there is no
conversion time “penalty” on power-up. The very first
conversion will be valid. SHDN can be used to force an
immediate power-down.
NOISE
The noise floor of the ADS8344 itself is extremely low, as
shown in Figures 8 thru 11, and is much lower than competing A/D converters. The ADS8344 was tested at both 5V
and 2.7V, and in both the internal and external clock modes.
A low-level DC input was applied to the analog-input pins
and the converter was put through 5,000 conversions. The
digital output of the A/D converter will vary in output code
due to the internal noise of the ADS8344. This is true for all
16-bit SAR-type A/D converters. Using a histogram to plot
the output codes, the distribution should appear bell-shaped
with the peak of the bell curve representing the nominal code
for the input value. The ±1σ, ±2σ, and ±3σ distributions will
represent the 68.3%, 95.5%, and 99.7%, respectively, of all
codes. The transition noise can be calculated by dividing the
number of codes measured by 6 and this will yield the ±3σ
distribution, or 99.7%, of all codes. Statistically, up to 3
codes could fall outside the distribution when executing
1,000 conversions. The ADS8344, with < 3 output codes for
the ±3σ distribution, will yield a < ±0.5LSB transition noise
at 5V operation. Remember, to achieve this low-noise performance, the peak-to-peak noise of the input signal and
reference must be < 50µV.
POWER DISSIPATION
There are three power modes for the ADS8344: full-power
(PD1 - PD0 = 11B), auto power-down (PD1 - PD0 = 00B),
and shutdown (SHDN LOW). The effects of these modes
varies depending on how the ADS8344 is being operated.
For example, at full conversion rate and 24-clocks per
conversion, there is very little difference between
full-power mode and auto power-down; a shutdown will not
lower power dissipation.
When operating at full-speed and 24-clocks per conversion
(see Figure 3), the ADS8344 spends most of its time
acquiring or converting. There is little time for auto
power-down, assuming that this mode is active. Thus, the
difference between full-power mode and auto power-down
is negligible. If the conversion rate is decreased by simply
slowing the frequency of the DCLK input, the two modes
ADS8344
SBAS139E
4561
0
242
7FFD
7FFE
7FFF
197
0
8000
8001
Code
FIGURE 8. Histogram of 5,000 Conversions of a DC Input at the
Code Transition, 5V operation external clock mode.
15
sion results will reduce the transition noise by 1/2 to
±0.25LSBs. Averaging should only be used for input signals
with frequencies near DC.
For AC signals, a digital filter can be used to low-pass filter
and decimate the output codes. This works in a similar
manner to averaging: for every decimation by 2, the
signal-to-noise ratio will improve 3dB.
4507
LAYOUT
0
251
7FFD
7FFE
7FFF
242
0
8000
8001
Code
FIGURE 9. Histogram of 5,000 Conversions of a DC Input at the
Code Center, 5V operation internal clock mode.
3511
666
721
50
7FFD
52
7FFE
7FFF
8000
8001
Code
FIGURE 10. Histogram of 5,000 Conversions of a DC Input at the
Code Transition, 2.7V operation external clock mode.
2868
1137
858
78
7FFD
59
7FFE
7FFF
8000
8001
Code
FIGURE 11. Histogram of 5,000 Conversions of a DC Input at the
Code Center, 2.7V operation internal clock mode.
AVERAGING
The noise of the A/D converter can be compensated by
averaging the digital codes. By averaging conversion results,
transition noise will be reduced by a factor of 1/√n, where n
is the number of averages. For example, averaging 4 conver-
16
For optimum performance, care should be taken with the
physical layout of the ADS8344 circuitry. This is particularly true if the reference voltage is LOW and/or the conversion rate is HIGH.
The basic SAR architecture is sensitive to glitches or sudden
changes on the power supply, reference, ground connections, and digital inputs that occur just prior to latching the
output of the analog comparator. Thus, during any single
conversion for an n-bit SAR converter, there are n “windows” in which large external transient voltages can easily
affect the conversion result. Such glitches might originate
from switching power supplies, nearby digital logic, and
high-power devices. The degree of error in the digital output
depends on the reference voltage, layout, and the exact
timing of the external event. The error can change if the
external event changes in time with respect to the DCLK
input.
With this in mind, power to the ADS8344 should be clean
and well bypassed. A 0.1µF ceramic bypass capacitor should
be placed as close to the device as possible. In addition, a
1µF to 10µF capacitor and a 5Ω or 10Ω series resistor may
be used to low-pass filter a noisy supply.
The reference should be similarly bypassed with a 0.1µF
capacitor. Again, a series resistor and large capacitor can be
used to low-pass filter the reference voltage. If the reference
voltage originates from an op amp, make sure that it can
drive the bypass capacitor without oscillation (the series
resistor can help in this case). The ADS8344 draws very
little current from the reference on average, but it does place
larger demands on the reference circuitry over short periods
of time (on each rising edge of DCLK during a conversion).
The ADS8344 architecture offers no inherent rejection of
noise or voltage variation in regards to the reference input.
This is of particular concern when the reference input is tied
to the power supply. Any noise and ripple from the supply
will appear directly in the digital results. While
high-frequency noise can be filtered out as discussed in the
previous paragraph, voltage variation due to line frequency
(50Hz or 60Hz) can be difficult to remove.
The GND pin should be connected to a clean ground point.
In many cases, this will be the “analog” ground. Avoid
connections that are too near the grounding point of a
microcontroller or digital signal processor. If needed, run a
ground trace directly from the converter to the power-supply
entry point. The ideal layout will include an analog ground
plane dedicated to the converter and associated analog
circuitry.
ADS8344
SBAS139E
Revision History
DATE
REVISION
9/06
E
PAGE
SECTION
2
Package/Ordering Info
4
Electrical Characteristics
DESCRIPTION
Added quantity to last column.
Fixed typo. Changed +2.7V Gain Error minimum value (for EB, NB grade)
from ±0.0024 to ±0.024.
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
ADS8344
SBAS139E
17
PACKAGE OPTION ADDENDUM
www.ti.com
11-Apr-2013
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
Lead/Ball Finish
(2)
MSL Peak Temp
Op Temp (°C)
Top-Side Markings
(3)
(4)
ADS8344E
ACTIVE
SSOP
DBQ
20
50
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
-40 to 85
ADS8344E
ADS8344E/2K5
ACTIVE
SSOP
DBQ
20
2500
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-3-260C-168 HR
-40 to 85
ADS8344E
ADS8344E/2K5G4
ACTIVE
SSOP
DBQ
20
2500
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-3-260C-168 HR
-40 to 85
ADS8344E
ADS8344EB
ACTIVE
SSOP
DBQ
20
50
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-3-260C-168 HR
-40 to 85
ADS8344E
B
ADS8344EB/2K5
ACTIVE
SSOP
DBQ
20
2500
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-3-260C-168 HR
-40 to 85
ADS8344E
B
ADS8344EB/2K5G4
ACTIVE
SSOP
DBQ
20
2500
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-3-260C-168 HR
-40 to 85
ADS8344E
B
ADS8344EBG4
ACTIVE
SSOP
DBQ
20
50
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-3-260C-168 HR
-40 to 85
ADS8344E
B
ADS8344EG4
ACTIVE
SSOP
DBQ
20
50
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
-40 to 85
ADS8344E
ADS8344N
ACTIVE
SSOP
DB
20
70
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
-40 to 85
ADS8344N
B
ADS8344N/1K
ACTIVE
SSOP
DB
20
1000
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
-40 to 85
ADS8344N
B
ADS8344N/1KG4
ACTIVE
SSOP
DB
20
1000
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
-40 to 85
ADS8344N
B
ADS8344NB
ACTIVE
SSOP
DB
20
70
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
-40 to 85
ADS8344N
B
ADS8344NB/1K
ACTIVE
SSOP
DB
20
1000
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
-40 to 85
ADS8344N
B
ADS8344NB/1KG4
ACTIVE
SSOP
DB
20
1000
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
-40 to 85
ADS8344N
B
ADS8344NBG4
ACTIVE
SSOP
DB
20
70
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
-40 to 85
ADS8344N
B
ADS8344NG4
ACTIVE
SSOP
DB
20
70
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
-40 to 85
ADS8344N
B
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
Addendum-Page 1
Samples
PACKAGE OPTION ADDENDUM
www.ti.com
11-Apr-2013
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 - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability
information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
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.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight
in homogeneous material)
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4)
Multiple Top-Side Markings will be inside parentheses. Only one Top-Side Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a
continuation of the previous line and the two combined represent the entire Top-Side Marking for that device.
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 2
PACKAGE MATERIALS INFORMATION
www.ti.com
24-Jul-2013
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device
Package Package Pins
Type Drawing
SPQ
Reel
Reel
A0
Diameter Width (mm)
(mm) W1 (mm)
B0
(mm)
K0
(mm)
P1
(mm)
W
Pin1
(mm) Quadrant
8.0
16.0
Q1
ADS8344E/2K5
SSOP
DBQ
20
2500
330.0
16.4
6.5
9.0
2.1
ADS8344EB/2K5
SSOP
DBQ
20
2500
330.0
16.4
6.5
9.0
2.1
8.0
16.0
Q1
ADS8344N/1K
SSOP
DB
20
1000
330.0
16.4
8.2
7.5
2.5
12.0
16.0
Q1
ADS8344NB/1K
SSOP
DB
20
1000
330.0
16.4
8.2
7.5
2.5
12.0
16.0
Q1
Pack Materials-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com
24-Jul-2013
*All dimensions are nominal
Device
Package Type
Package Drawing
Pins
SPQ
Length (mm)
Width (mm)
Height (mm)
ADS8344E/2K5
SSOP
DBQ
20
2500
367.0
367.0
38.0
ADS8344EB/2K5
SSOP
DBQ
20
2500
367.0
367.0
38.0
ADS8344N/1K
SSOP
DB
20
1000
367.0
367.0
38.0
ADS8344NB/1K
SSOP
DB
20
1000
367.0
367.0
38.0
Pack Materials-Page 2
MECHANICAL DATA
MSSO002E – JANUARY 1995 – REVISED DECEMBER 2001
DB (R-PDSO-G**)
PLASTIC SMALL-OUTLINE
28 PINS SHOWN
0,38
0,22
0,65
28
0,15 M
15
0,25
0,09
8,20
7,40
5,60
5,00
Gage Plane
1
14
0,25
A
0°–ā8°
0,95
0,55
Seating Plane
2,00 MAX
0,10
0,05 MIN
PINS **
14
16
20
24
28
30
38
A MAX
6,50
6,50
7,50
8,50
10,50
10,50
12,90
A MIN
5,90
5,90
6,90
7,90
9,90
9,90
12,30
DIM
4040065 /E 12/01
NOTES: A.
B.
C.
D.
All linear dimensions are in millimeters.
This drawing is subject to change without notice.
Body dimensions do not include mold flash or protrusion not to exceed 0,15.
Falls within JEDEC MO-150
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