ADS8345 [TI]
16-Bit, 8-Channel Serial Output Sampling ANALOG-TO-DIGITAL CONVERTER; 16位8通道串行输出采样模拟数字转换器型号: | ADS8345 |
厂家: | TEXAS INSTRUMENTS |
描述: | 16-Bit, 8-Channel Serial Output Sampling ANALOG-TO-DIGITAL CONVERTER |
文件: | 总20页 (文件大小:503K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
ADS8345
A
®
D
S
8
3
4
5
ADS8345
®
SBAS177C – FEBRUARY 2001 – REVISED APRIL 2003
16-Bit, 8-Channel Serial Output Sampling
ANALOG-TO-DIGITAL CONVERTER
DESCRIPTION
FEATURES
ꢀ BIPOLAR INPUT RANGE
The ADS8345 is an 8-channel, 16-bit, sampling
Analog-to-Digital (A/D) converter with a synchronous serial
interface. Typical power dissipation is 8mW at a 100kHz
throughput rate and a +5V supply. The reference voltage
(VREF) can be varied between 500mV and VCC/2, providing a
corresponding input voltage range of ±VREF. The device
includes a shutdown mode which reduces power dissipation
to under 15µW. The ADS8345 is ensured down to 2.7V
operation.
ꢀ PIN-FOR-PIN COMPATIBLE WITH THE
ADS7844 AND ADS8344
ꢀ SINGLE SUPPLY: 2.7V to 5V
ꢀ 8-CHANNEL SINGLE-ENDED OR
4-CHANNEL DIFFERENTIAL INPUT
ꢀ UP TO 100kHz CONVERSION RATE
ꢀ 85dB SINAD
Low-power, high-speed, and an onboard multiplexer make
the ADS8345 ideal for battery-operated systems such as
personal digital assistants, portable multi-channel data log-
gers, and measurement equipment. The serial interface also
provides low-cost isolation for remote data acquisition. The
ADS8345 is available in a QSOP-20 or SSOP-20 package
and is ensured over the –40°C to +85°C temperature range.
ꢀ SERIAL INTERFACE
ꢀ QSOP-20 AND SSOP-20 PACKAGES
APPLICATIONS
ꢀ DATA ACQUISITION
ꢀ TEST AND MEASUREMENT EQUIPMENT
ꢀ INDUSTRIAL PROCESS CONTROL
ꢀ PERSONAL DIGITAL ASSISTANTS
ꢀ BATTERY-POWERED SYSTEMS
CH0
CH1
CH2
SAR
DCLK
CH3
CH4
CH5
CH6
CH7
COM
VREF
8-Channel
Multiplexer
CS
Comparator
SHDN
DIN
Serial
Interface
and
CDAC
DOUT
Control
BUSY
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.
PRODUCTION DATA information is current as of publication date.
Copyright © 2001-2003, Texas Instruments Incorporated
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
ABSOLUTE MAXIMUM RATINGS(1)
+VCC to GND ........................................................................ –0.3V to +6V
Analog Inputs to GND .......................................... –0.3V to (+VCC) + 0.3V
ELECTROSTATIC
DISCHARGE SENSITIVITY
This integrated circuit can be damaged by ESD. Texas Instru-
ments recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling
and installation procedures can cause damage.
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
ESD damage can range from subtle performance degrada-
tion 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.
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.
PACKAGE/ORDERING INFORMATION
MAXIMUM
INTEGRAL
LINEARITY
ERROR (LSB)
MAXIMUM
GAIN
ERROR (%)
SPECIFIED
TEMPERATURE
RANGE
PACKAGE
DESIGNATOR(1)
ORDERING
NUMBER
TRANSPORT
MEDIA, QUANTITY
PRODUCT
PACKAGE-LEAD
ADS8345E
8
"
±0.05
QSOP-20
DBQ
"
–40°C to +85°C
ADS8345E
ADS8345E/2K5
ADS8345N
Rails, 100
Tape and Reel, 2500
Rails, 100
"
"
"
"
ADS8345N
8
±0.05
SSOP-20
DB
–40°C to +85°C
"
"
"
"
"
"
ADS8345N/1K
ADS8345EB
Tape and Reel, 1000
Rails, 100
ADS8345EB
6
"
±0.024
QSOP-20
DBQ
"
–40°C to +85°C
"
"
±0.024
"
"
"
ADS8345EB/2K5 Tape and Reel, 2500
ADS8345NB
6
SSOP-20
DB
–40°C to +85°C
ADS8345NB
Rails, 100
"
"
"
"
"
ADS8345NB/1K
Tape and Reel, 1000
NOTE: (1) For the most current specifications and package information, refer to our web site at www.ti.com.
PIN DESCRIPTIONS
PIN CONFIGURATION
PIN
NAME
DESCRIPTION
Top View
SSOP
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
CH0
CH1
CH2
CH3
CH4
CH5
CH6
CH7
COM
1
2
3
4
5
6
7
8
9
20 +VCC
19 DCLK
18 CS
Common reference for analog inputs. This pin is typically
connected to VREF
.
10
11
SHDN
VREF
Shutdown. When LOW, the device enters a very
low-power shutdown mode.
17 DIN
Voltage Reference Input. See the Electrical Character-
istics Table for ranges.
16 BUSY
15 DOUT
14 GND
13 GND
12 +VCC
11 VREF
ADS8345
12
13
14
15
+VCC
GND
GND
DOUT
Power Supply, 2.7V to 5.25V
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
16
BUSY
SHDN 10
17
18
DIN
CS
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.
19
20
DCLK
+VCC
External Clock Input. The clock speed determines the
conversion rate by the equation fDCLK = 24 • fSAMPLE
.
Power Supply
2
ADS8345
SBAS177C
www.ti.com
ELECTRICAL CHARACTERISTICS: +5V
At TA = –40°C to +85°C, +VCC = +5V, VREF = +2.5V, fSAMPLE = 100kHz, and fCLK = 24 • fSAMPLE = 2.4MHz, unless otherwise noted.
ADS8345E, N
ADS8345EB, NB
PARAMETER
RESOLUTION
CONDITIONS
MIN
TYP
MAX
MIN
TYP
MAX
UNITS
16
ꢀ
Bits
ANALOG INPUT
Full-Scale Input Span
Absolute Input Range
Positive Input-Negative Input
–VREF
–0.2
–0.2
+VREF
+VCC + 0.2
+VCC + 0.2
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
V
V
V
+IN
–IN
Capacitance
Leakage Current
25
±1
ꢀ
ꢀ
pF
µA
SYSTEM PERFORMANCE
No Missing Codes
Integral Linearity Error
Bipolar Error
Bipolar Error Match
Gain Error
Gain Error Match
Noise
Power-Supply Rejection
14
15
Bits
LSB
mV
LSB(1)
%
LSB
±8
±2
8
±0.05
4
±6
±1
ꢀ
±0.024
ꢀ
4
ꢀ
1.0
20
3
ꢀ
ꢀ
ꢀ
µVrms
LSB(1)
+4.75V < VCC < 5.25V
SAMPLING DYNAMICS
Conversion Time
Acquisition Time
16
ꢀ
ꢀ
CLK Cycles
CLK Cycles
kHz
4.5
ꢀ
Throughput Rate
100
Multiplexer Settling Time
Aperture Delay
Aperture Jitter
Internal Clock Frequency
External Clock Frequency
500
30
100
2.4
ꢀ
ꢀ
ꢀ
ꢀ
ns
ns
ps
MHz
MHz
MHz
SHDN = VDD
0.024
0
2.4
2.4
ꢀ
ꢀ
ꢀ
ꢀ
Data Transfer Only
DYNAMIC CHARACTERISTICS
Total Harmonic Distortion(2)
Signal-to-(Noise + Distortion)
Spurious-Free Dynamic Range
Channel-to-Channel Isolation
VIN = 5Vp-p at 10kHz
VIN = 5Vp-p at 10kHz
VIN = 5Vp-p at 10kHz
VIN = 5Vp-p at 10kHz
–96
85
98
ꢀ
ꢀ
ꢀ
ꢀ
dB
dB
dB
dB
105
REFERENCE INPUT
Range
0.5
+VCC/2
ꢀ
ꢀ
V
Resistance
Input Current
DCLK Static
DCLK Static
5
40
0.001
ꢀ
ꢀ
ꢀ
GΩ
µA
µA
100
3
ꢀ
ꢀ
DIGITAL INPUT/OUTPUT
Logic Family
Logic Levels
VIH
VIL
VOH
CMOS
ꢀ
| IIH | ≤ +5µA
| IIL | ≤ +5µA
IOH = –250µA
IOL = 250µA
3.0
–0.3
3.5
5.5
+0.8
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
V
V
V
V
VOL
0.4
ꢀ
Data Format
Binary Two’s Complement
ꢀ
POWER-SUPPLY REQUIREMENTS
+VCC
Quiescent Current
Specified Performance
4.75
5.25
2.0
ꢀ
ꢀ
ꢀ
V
1.5
1.2
ꢀ
ꢀ
mA
mA
µA
fSAMPLE = 10kHz
Power-Down Mode(3), CS = +VCC
3
10
ꢀ
ꢀ
Power Dissipation
7.5
ꢀ
mW
TEMPERATURE RANGE
Specified Performance
–40
+85
ꢀ
ꢀ
°C
ꢀ Same specifications as ADS8345E, N.
NOTES: (1) LSB means Least Significant Bit. With VREF equal to +2.5V, one LSB is 76µV. (2) First nine harmonics of the test frequency. (3) Auto power-down mode
(PD1 = PD0 = 0) active or SHDN = GND.
3
ADS8345
SBAS177C
www.ti.com
ELECTRICAL CHARACTERISTICS: +2.7V
At TA = –40°C to +85°C, +VCC = +2.7V, VREF = +1.25V, fSAMPLE = 100kHz, and fCLK = 24 • fSAMPLE = 2.4MHz, unless otherwise noted.
ADS8345E, N
ADS8345EB, NB
PARAMETER
RESOLUTION
CONDITIONS
MIN
TYP
MAX
MIN
TYP
MAX
UNITS
16
ꢀ
Bits
ANALOG INPUT
Full-Scale Input Span
Absolute Input Range
Positive Input-Negative Input
–VREF
–0.2
–0.2
+VREF
+VCC + 0.2
+VCC + 0.2
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
V
V
V
+IN
–IN
Capacitance
Leakage Current
25
±1
ꢀ
ꢀ
pF
µA
SYSTEM PERFORMANCE
No Missing Codes
Integral Linearity Error
Bipolar Error
Bipolar Error Match
Gain Error
Gain Error Match
Noise
Power-Supply Rejection
14
15
Bits
LSB
mV
LSB
% of FSR
LSB
±8
±1.0
4
±0.05
4
±6
±0.5
ꢀ
±0.024
ꢀ
2
ꢀ
1
20
3
ꢀ
ꢀ
ꢀ
µVrms
LSB(1)
+2.7 < VCC < +3.3V
SAMPLING DYNAMICS
Conversion Time
Acquisition Time
16
ꢀ
ꢀ
CLK Cycles
CLK Cycles
kHz
4.5
ꢀ
Throughput Rate
100
Multiplexer Settling Time
Aperture Delay
Aperture Jitter
Internal Clock Frequency
External Clock Frequency
500
30
100
2.4
ꢀ
ꢀ
ꢀ
ꢀ
ns
ns
ps
MHz
MHz
MHz
MHz
SHDN = VDD
0.024
0.024
0
2.4
2.0
2.4
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
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
VIN = 2.5Vp-p at 1kHz
–95
81
95
ꢀ
ꢀ
ꢀ
ꢀ
dB
dB
dB
dB
V
V
IN = 2.5Vp-p at 1kHz
IN = 2.5Vp-p at 1kHz
V
IN = 2.5Vp-p at 10kHz
108
REFERENCE INPUT
Range
0.5
+VCC/2
ꢀ
ꢀ
V
Resistance
Input Current
DCLK Static
DCLK Static
5
13
0.001
ꢀ
ꢀ
ꢀ
GΩ
µA
µA
40
3
ꢀ
ꢀ
DIGITAL INPUT/OUTPUT
Logic Family
Logic Levels
VIH
VIL
VOH
CMOS
ꢀ
| IIH | ≤ +5µA
| IIL | ≤ +5µA
IOH = –250µA
IOL = 250µA
+VCC • 0.7
–0.3
+VCC • 0.8
5.5
+0.8
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
V
V
V
V
VOL
0.4
ꢀ
Data Format
Binary Two’s Complement
ꢀ
POWER-SUPPLY REQUIREMENTS
+VCC
Quiescent Current
Specified Performance
2.7
3.6
1.85
ꢀ
ꢀ
ꢀ
V
mA
µA
µA
mW
1.2
950
ꢀ
ꢀ
fSAMPLE = 10kHz
Power-Down Mode(3), CS = +VCC
3
5
ꢀ
ꢀ
Power Dissipation
3.2
ꢀ
TEMPERATURE RANGE
Specified Performance
–40
+85
ꢀ
ꢀ
°C
ꢀ Same specifications as ADS8345E, N.
NOTES: (1) LSB means Least Significant Bit. With VREF equal to +1.25V, 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
ADS8345
SBAS177C
www.ti.com
TYPICAL CHARACTERISTICS: +5V
At TA = +25°C, +VCC = +5V, VREF = +2.5V, fSAMPLE = 100kHz, and fDCLK = 24 • fSAMPLE = 2.4MHz, unless otherwise noted.
FREQUENCY SPECTRUM
(4096 Point FFT; fIN = 9.985kHz, –0.2dB)
FREQUENCY SPECTRUM
(4096 Point FFT; fIN = 1.001kHz, –0.2dB)
0
–20
0
–20
–40
–40
–60
–60
–80
–80
–100
–120
–140
–100
–120
–140
0
10
20
30
40
50
0
10
20
30
40
50
Frequency (kHz)
Frequency (kHz)
SPURIOUS-FREE DYNAMIC RANGE
AND TOTAL HARMONIC DISTORTION
vs INPUT FREQUENCY
SIGNAL-TO-NOISE RATIO AND
SIGNAL-TO-(NOISE + DISTORTION)
vs INPUT FREQUENCY
–110
–100
–90
110
100
90
100
90
80
70
60
SFDR
THD(1)
SNR
SINAD
–80
80
–70
70
NOTE: (1) First Nine Harmonics
of the Input Frequency
–60
60
1
10
100
1
10
100
Frequency (kHz)
Frequency (kHz)
EFFECTIVE NUMBER OF BITS
vs INPUT FREQUENCY
CHANGE IN SIGNAL-TO-(NOISE + DISTORTION)
vs TEMPERATURE
15.0
14.5
14.0
13.5
13.0
12.5
12.0
11.5
11.0
0.4
0.2
fIN = 4.956kHz, –0.2dB
0.0
–0.2
–0.4
–0.6
–0.8
–50
–25
0
20
50
75
100
1
10
100
Temperature (°C)
Frequency (kHz)
5
ADS8345
SBAS177C
www.ti.com
TYPICAL CHARACTERISTICS: +5V (Cont.)
At TA = +25°C, +VCC = +5V, VREF = +2.5V, fSAMPLE = 100kHz, and fDCLK = 24 • fSAMPLE = 2.4MHz, unless otherwise noted.
INTEGRAL LINEARITY ERROR vs CODE
DIFFERENTIAL LINEARITY ERROR vs CODE
3
2
3
2
1
1
0
0
–1
–2
–3
–1
–2
–3
8000H
C000H
0000H
4000H
7FFFH
8000H
C000H
0000H
4000H
7FFFH
Output Code
Output Code
SUPPLY CURRENT vs TEMPERATURE
CHANGE IN BPZ vs TEMPERATURE
1.7
1.6
1.5
1.4
1.3
1.2
4
3
2
1
0
–1
–2
–50
–25
0
25
50
75
100
–50
–25
0
25
50
75
100
Temperature (°C)
Temperature (°C)
WORST-CASE CHANNEL-TO-CHANNEL
BPZ MATCH vs TEMPERATURE
CHANGE IN GAIN vs TEMPERATURE
1.0
0.5
0
5.0
4.5
4.0
3.5
3.0
2.5
2.0
–0.5
–50
–25
0
25
50
75
100
–50
–25
0
25
50
75
100
Temperature (°C)
Temperature (°C)
6
ADS8345
SBAS177C
www.ti.com
TYPICAL CHARACTERISTICS: +5V (Cont.)
At TA = +25°C, +VCC = +2.5V, VREF = +2.5V, fSAMPLE = 100kHz, and fDCLK = 24 • fSAMPLE = 2.4MHz, unless otherwise noted.
WORST-CASE CHANNEL-TO-CHANNEL
GAIN MATCH vs TEMPERATURE
COMMON-MODE REJECTION vs FREQUENCY
0.5
0.4
0.3
0.2
0.1
100
90
80
70
60
50
VCM = 2Vp-p Sinewave Centered Around VREF
–50
–25
0
25
50
75
100
0.1
1
10
100
Temperature (°C)
Frequency (kHz)
TYPICAL CHARACTERISTICS: +2.7V
At TA = +25°C, +VCC = +2.7V, VREF = +1.25V, fSAMPLE = 100kHz, and fDCLK = 24 • fSAMPLE = 2.4MHz, unless otherwise noted.
FREQUENCY SPECTRUM
(4096 Point FFT; fIN = 9.985kHz, –0.2dB)
FREQUENCY SPECTRUM
(4096 Point FFT; fIN = 1.001kHz, –0.2dB)
0
–20
0
–20
–40
–40
–60
–60
–80
–80
–100
–120
–140
–100
–120
–140
0
10
20
30
40
50
0
10
20
30
40
50
Frequency (kHz)
Frequency (kHz)
SPURIOUS-FREE DYNAMIC RANGE
AND TOTAL HARMONIC DISTORTION
vs INPUT FREQUENCY
SIGNAL-TO-NOISE RATIO AND
SIGNAL-TO-(NOISE + DISTORTION)
vs INPUT FREQUENCY
–100
–90
–80
–70
–60
–50
100
90
80
70
60
50
95
85
75
65
55
SNR
SFDR
THD(1)
SINAD
NOTE: (1) First Nine Harmonics
of the Input Frequency
1
10
100
1
10
Frequency (kHz)
100
Frequency (kHz)
7
ADS8345
SBAS177C
www.ti.com
TYPICAL CHARACTERISTICS: +2.7V (Cont.)
At TA = +25°C, +VCC = +2.7V, VREF = +1.25V, fSAMPLE = 100kHz, and fDCLK = 24 • fSAMPLE = 2.4MHz, unless otherwise noted.
EFFECTIVE NUMBER OF BITS
vs INPUT FREQUENCY
CHANGE IN SIGNAL-TO-(NOISE + DISTORTION)
vs TEMPERATURE
0.4
0.2
14.0
13.5
13.0
12.5
12.0
11.5
11.0
10.5
10.0
9.5
fIN = 4.956kHz, –0.2dB
0
–0.2
–0.4
–0.6
–0.8
–1.0
9.0
–50
–25
0
20
50
75
100
7FFFH
100
1
10
100
Temperature (°C)
Frequency (kHz)
INTEGRAL LINEARITY ERROR vs CODE
DIFFERENTIAL LINEARITY ERROR vs CODE
3
2
3
2
1
1
0
0
–1
–2
–3
–1
–2
–3
8000H
C000H
0000H
4000H
7FFFH
8000H
C000H
0000H
4000H
Output Code
Output Code
SUPPLY CURRENT vs TEMPERATURE
CHANGE IN BPZ vs TEMPERATURE
1.3
1.0
1.2
1.1
1.0
0.9
0.5
0
–0.5
–1.0
–50
–25
0
25
50
75
100
–50
–25
0
25
50
75
Temperature (°C)
Temperature (°C)
8
ADS8345
SBAS177C
www.ti.com
TYPICAL CHARACTERISTICS: +2.7V (Cont.)
At TA = +25°C, +VCC = +2.7V, VREF = +1.25V, fSAMPLE = 100kHz, and fDCLK = 24 • fSAMPLE = 2.4MHz, unless otherwise noted.
WORST-CASE CHANNEL-TO-CHANNEL
BPZ MATCH vs TEMPERATURE
CHANGE IN GAIN vs TEMPERATURE
1.0
0.5
0
1.0
0.9
0.8
0.7
0.6
0.5
–0.5
–50
–25
0
25
50
75
100
–50
0.1
2.5
–25
0
25
50
75
100
100
5.0
Temperature (°C)
Temperature (°C)
WORST-CASE CHANNEL-TO-CHANNEL
GAIN MATCH vs TEMPERATURE
COMMON-MODE REJECTION vs FREQUENCY
0.35
0.30
0.25
0.20
80
70
60
50
40
VCM = 1Vp-p Sinewave Centered Around VREF
–50
–25
0
25
50
75
100
1
10
Temperature (°C)
Frequency (kHz)
POWER-DOWN SUPPLY CURRENT
vs TEMPERATURE
SUPPLY CURRENT vs VSS
140
1.5
1.4
1.3
1.2
1.1
1.0
0.9
120
100
80
60
40
20
0
External Clock Disabled
fSAMPLE = 100kHz
–50
–25
0
25
50
75
100
3.0
3.5
4.0
4.5
Temperature (°C)
+VSS (V)
9
ADS8345
SBAS177C
www.ti.com
determines the range over which the common voltage may
vary (see Figure 3).
THEORY OF OPERATION
The ADS8345 is a classic Successive Approximation
Register (SAR) A/D converter. The architecture is based on
capacitive redistribution which inherently includes a sample-
and-hold function. The converter is fabricated on a 0.6µm
CMOS process.
When the input is differential, the amplitude of the input is the
difference between the CHX and COM input (see Figure 4).
A voltage or signal is common to both of these inputs. The
peak-to-peak amplitude of each input is VREF about this
common voltage. However, since the input are 180°C out-of-
phase, the peak-to-peak amplitude of the difference voltage is
2 • VREF. The value of VREF also determines the range of the
voltage that may be common to both inputs (see Figure 5).
The basic operation of the ADS8345 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/2. 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 ADS8345.
In each case, care should be taken to ensure that the output
impedance of the sources driving the CHX and COM inputs
are matched. If this is not observed, the two inputs could
have different settling times. This may result in offset error,
gain error, and linearity error which changes with both
temperature and input voltage. If the impedance cannot be
matched, the errors can be lessened by giving the ADS8345
additional acquisition time.
The analog input to the converter is differential and is
provided via an eight-channel multiplexer. The input can be
provided in reference to a voltage on the COM pin (which is
generally +VCC/2) or differentially by using four of the eight
input channels (CH-CH7). The particular configuration is
selectable via the digital interface.
The input current on the analog inputs depends on a number
of factors: sample rate, input voltage, and source impedance.
Essentially, the current into the ADS8345 charges the inter-
nal capacitor array during the sample period. After this
capacitance has been fully charged, there is no further input
current.
ANALOG INPUT
The analog input is bipolar and fully differential. There are
two general methods of driving the analog input of the
ADS8345: single-ended or differential (see Figure 2). When
the input is single-ended, the COM input is held at a fixed
voltage. The CHX input swings around the same voltage and
the peak-to-peak amplitude is 2 • VREF. The value of VREF
Care must be taken regarding the absolute analog input
voltage. Outside of these ranges, the converter’s linearity
may not meet specifications. Please refer to the Electrical
Characteristics table for min/max ratings.
+2.7V to +5V
ADS8345
+VCC 20
1µF to 10µF
0.1µF
1
2
3
4
5
6
7
8
9
CH0
CH1
CH2
CH3
CH4
CH5
CH6
CH7
COM
Serial/Conversion Clock
Chip Select
DCLK 19
CS 18
Single-ended
or differential
analog inputs.
Serial Data In
DIN 17
BUSY 16
DOUT 15
GND 14
GND 13
+VCC 12
VREF 11
Serial Data Out
VREF
+1.25V to +2.5V
10 SHDN
1µF to 10µF
FIGURE 1. Basic Operation of the ADS8345.
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REFERENCE INPUT
ence between the CHX input and the COM input, as shown
in Figure 4. For example, in the single-ended mode, a 1.25V
reference with the COM pin at VCC/2, the selected input
channel (CH0-CH7) will properly digitize a signal in the range
of (VCC/2 – 1.25V) to (VCC/2 + 1.25V).
The external reference sets the analog input range. The
ADS8345 will operate with a reference in the range of 500mV
to +VCC/2. Keep in mind that the analog input is the differ-
A2-A0
(shown 00oB)(1)
CH0
CH1
CH2
CH3
CH4
CH5
CH6
CHX
(1)
±VREF
ADS8345
COM
Common-Mode
Voltage
(typically VREF
)
+IN
Converter
–IN
CH7
Single-Ended Input
(1)
VREF
±
CHX+
ADS8345
CHX–
2
(1)
Common-Mode
Voltage
VREF
2
±
Differential Input
NOTE: (1) Relative to common-mode voltage.
COM
SGL/DIF
(shown HIGH)
NOTE: (1) See Truth Tables, Table I,
and Table II for address coding.
FIGURE 2. Methods of Driving the ADS8345—Single-Ended
FIGURE 4. Simplified Diagram of the Analog Input.
or Differential.
5
VCC = 5V
4.9
5.2
5
4
VCC = 5V
4.2
4
Single-Ended Input
3
2
2.8
2.1
3
Differential Input
2
1
0.1
1
0.8
0
0.2
0
–1
0.0
1.0
1.5
2.0
2.5
0.5
1.0
1.5
2.0
2.5
VREF (V)
VREF (V)
FIGURE 3. Single-Ended Input—Common Voltage Range
vs VREF
FIGURE 5. Differential Input—Common Voltage Range vs VREF.
.
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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
(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, 152.8µV.
Most microprocessors communicate using 8-bit transfers; the
ADS8345 can complete a conversion with three such trans-
fers, for a total of 24 clock cycles on the DCLK input,
provided the timing is as shown in Figure 6.
The first eight clock cycles are used to provide the control
byte via the DIN pin. When the converter has enough informa-
tion about the following conversion to set the input multi-
plexer 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.
The noise or uncertainty of the digitized output will increase
with lower LSB size. With a reference voltage of 500mV, the
LSB size is 15.3µV. 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.
Control Byte
Figure 6 shows placement and order of the control bits within
the control byte. Tables I and II 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 ADS8345
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 III
and IV and Figure 4).
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.
BIT 7
(MSB)
BIT 0
(LSB)
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
S
A2
A1
A0
—
SGL/DIF PD1
PD0
The voltage into the VREF input is not buffered and directly
drives the Capacitor Digital-to-Analog Converter (CDAC)
portion of the ADS8345. 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.
TABLE I. Order of the Control Bits in the Control Byte.
BIT
NAME
DESCRIPTION
7
S
Start Bit. Control byte starts with first HIGH bit on
DIN
.
6-4
2
A2-A0
Channel Select Bits. Along with the SGL/DIF bit,
these bits control the setting of the multiplexer input.
SGL/DIF
Single-Ended/Differential Select Bit. Along with bits
A2-A0, this bit controls the setting of the multiplexer
input.
1-0
PD1-PD0 Power-Down Mode Select Bits. See Table V for
details.
DIGITAL INTERFACE
The ADS8345 has a 4-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 6
shows the typical operation of the ADS8345 digital interface.
TABLE II. Descriptions of the Control Bits within the Control Byte.
CS
tACQ
DCLK
DIN
1
8
1
8
1
8
1
8
1
Idle
Acquire
Conversion
Idle
Acquire
Conversion
SGL/
DIF
SGL/
DIF
S
A2 A1 A0
PD1 PD0
S
A2 A1 A0
PD1 PD0
(START)
(START)
BUSY
DOUT
15
14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
Zero Filled...
15 14
(MSB)
(MSB)
(LSB)
FIGURE 6. Conversion Timing, 24-Clocks per Conversion, 8-Bit Bus Interface. No DCLK delay required with dedicated
serial port.
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ADS8345
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The SGL/DIF-bit controls the multiplexer input mode:
either in single-ended mode, where the selected input chan-
nel is referenced to the COM pin, or in differential mode,
where the two selected inputs provide a differential input.
See Tables III and IV and Figure 4 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
DESCRIPTION
0
0
Power-down between conversions. When each
conversion is finished, the converter enters a
low-power mode. At the start of the next conver-
sion, 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.
1
0
1
0
1
1
Selects internal clock mode.
Reserved for future use.
No power-down between conversions, device al-
ways powered. Selects external clock mode.
TABLE V. Power-Down Selection.
Clock Modes
The ADS8345 can be used with an external serial clock or an
internal clock to perform the successive-approximation con-
version. 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.
A2
A1
A0 CH0 CH1 CH2 CH3 CH4 CH5 CH6 CH7 COM
0
1
0
1
0
1
0
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
+IN
–IN
–IN
–IN
–IN
–IN
–IN
–IN
–IN
+IN
+IN
If the user decides to switch from one clock mode to the
other, an extra conversion cycle will be required before the
ADS8345 can switch to the new mode. The extra cycle is
required because the PD0 and PD1 control bits need to be
written to the ADS8345 prior to the change in clock modes.
+IN
+IN
+IN
+IN
+IN
When power is first applied to the ADS8345, 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 ADS8345 be set to power-down
between conversions (i.e., PD1 = PD0 = 0). The ADS8345
maintains the clock mode it was in prior to entering the
power-down modes.
TABLE III. Single-Ended Channel Selection (SGL/DIF HIGH).
A2
A1
A0
CH0 CH1 CH2 CH3 CH4 CH5 CH6 CH7
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
External Clock Mode
–IN
+IN
–IN
+IN
In external clock mode, the external clock not only shifts data
in and out of the ADS8345, it also controls the A/D conver-
sion steps. BUSY will go HIGH for one clock period after the
last bit of the control byte is shifted in. Successive-approxi-
mation bit decisions are made and appear at DOUT on each
of the next 16 DCLK falling edges (see Figure 6). Figure 7
shows the BUSY timing in external clock mode.
–IN
+IN
TABLE IV. Differential Channel Control (SGL/DIF LOW).
CS
tCL
tCSH
tCSS
tCH
tBD
tBD
tD0
DCLK
DIN
tDH
tDS
PD0
tBDV
tBTR
BUSY
DOUT
tDV
tTR
15
14
FIGURE 7. Detailed Timing Diagram.
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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 9. CS does not need to remain LOW once a conver-
sion 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 ADS8345 (see
Figure 6). This method allows for maximum throughput and
24 clock cycles per conversion.
Data can be shifted in and out of the ADS8345 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 8, 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 7 and Tables VI and VII provide detailed timing for the
digital interface of the ADS8345.
SYMBOL
DESCRIPTION
MIN
TYP
MAX
UNITS
Internal Clock Mode
tACQ
tDS
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
1.5
100
10
µs
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
In internal clock mode, the ADS8345 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.
tDH
tDO
tDV
200
200
200
tTR
tCSS
tCSH
tCH
100
0
200
200
tCL
DCLK LOW
tBD
DCLK Falling to BUSY Rising
CS Falling to BUSY Enabled
CS Rising to BUSY Disabled
200
200
200
tBDV
tBTR
TABLE VI. Timing Specifications (+VCC = +2.7V to 3.6V,
TA = –40°C to +85°C, CLOAD = 50pF).
CS
tACQ
DCLK
1
8
1
8
1
8
1
8
Idle
Acquire
Conversion
Idle
SGL/
DIF
DIN
S
A2 A1 A0
PD1 PD0
(START)
BUSY
DOUT
Zero Filled...
15
14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
(MSB)
(LSB)
FIGURE 8. External Clock Mode, 32 Clocks Per Conversion.
CS
tACQ
DCLK
1
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
Idle
Acquire
Conversion
SGL/
DIF
DIN
S
A2 A1 A0
PD1 PD0
(START)
BUSY
DOUT
15
(MSB)
14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
Zero Filled...
(LSB)
FIGURE 9. Internal Clock Mode Timing.
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If DCLK is active and CS is LOW while the ADS8345 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.
SYMBOL
DESCRIPTION
MIN
TYP
MAX
UNITS
tACQ
tDS
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
1.7
50
10
µs
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
tDH
tDO
tDV
100
70
Operating the ADS8345 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.
tTR
70
tCSS
tCSH
tCH
50
0
150
150
tCL
DCLK LOW
NOISE
tBD
DCLK Falling to BUSY Rising
CS Falling to BUSY Enabled
CS Rising to BUSY Disabled
100
70
tBDV
tBTR
The noise floor of the ADS8345 itself is rather low (see
Figures 10 and 11). The ADS8345 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 5000 conversions. The digital
output of the A/D converter will vary in output code due to the
internal noise of the ADS8345. 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 repre-
sent 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 distribu-
tion, or 99.7%, of all codes. Statistically, up to 3 codes could
fall outside the distribution when executing 1000 conver-
sions. The ADS8345, with 5 output codes for the ±3σ
distribution, will yield a < ±0.83LSB 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.
70
TABLE VII. Timing Specifications (+VCC = +4.75V to +5.25V,
TA = –40°C to +85°C, and CLOAD = 50pF).
Data Format
The output data from the ADS8345 is in Binary Two’s
Complement format, as shown in Table VIII. This table
represents the ideal output code for the given input voltage
and does not include the effects of offset, gain error, or noise.
DESCRIPTION
ANALOG VALUE
2 • VREF
DIGITAL OUTPUT
Full-Scale Range
BINARY TWO’S COMPLEMENT
Least Significant
Bit (LSB)
2 • VREF/65536
BINARY CODE
HEX CODE
7FFF
+Full-Scale
Midscale
+VREF – 1LSB
0V
0111 1111 1111 1111
0000 0000 0000 0000
1111 1111 1111 1111
1000 0000 0000 0000
0000
Midscale – 1LSB
–Full-Scale
0V – 1LSB
–VREF
FFFF
8000
TABLE VIII. Ideal Input Voltages and Output Codes.
POWER DISSIPATION
3544
There are three power modes for the ADS8345: 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 ADS8345 is being operated. For
example, at full conversion rate and 24-clocks per conver-
sion, there is very little difference between
full-power mode and auto power-down; a shutdown will not
lower power dissipation.
701
568
When operating at full-speed and 24-clocks per conversion
(see Figure 6), the ADS8345 spends most of its time acquir-
ing 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 remain approxi-
mately 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).
122
65
FFFFH
0000H
Code
0002H
FFFEH
0001H
FIGURE 10. Histogram of 5000 Conversions of a DC Input at
the Code Transition, 5V operation external clock
mode. VREF = VCOM = 2.5V.
15
ADS8345
SBAS177C
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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.
2305
938
780
436
435
With this in mind, power to the ADS8345 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.
64
28
8
6
FFFCH FFFDH FFFEH FFFFH 0000H 0001H 0002H 0003H 0004H
Code
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 ADS8345 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).
FIGURE 11. Histogram of 5000 Conversions of a DC Input at
the Code Center, 2.7V operation external clock
mode. VREF = VCOM = 1.25V.
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-
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.
The ADS8345 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.
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.
The GND pin should be connected to a clean ground point.
In many cases, this will be the “analog” ground. Avoid
connections which 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.
LAYOUT
For optimum performance, care should be taken with the
physical layout of the ADS8345 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 connec-
tions, and digital inputs that occur just prior to latching the
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PACKAGE DRAWINGS
DBQ (R-PDSO-G**)
PLASTIC SMALL-OUTLINE
24 PINS SHOWN
0.012 (0,30)
0.008 (0,20)
0.025 (0,64)
24
0.005 (0,13)
M
13
0.244 (6,20)
0.228 (5,80)
0.008 (0,20) NOM
0.157 (3,99)
0.150 (3,81)
Gage Plane
1
12
A
0.010 (0,25)
0°–8°
0.035 (0,89)
0.016 (0,40)
0.069 (1,75) MAX
Seating Plane
0.004 (0,10)
0.010 (0,25)
0.004 (0,10)
PINS **
16
20
24
28
DIM
0.197
(5,00)
0.344
(8,74)
0.344
(8,74)
0.394
(10,01)
A MAX
0.188
(4,78)
0.337
(8,56)
0.337
(8,56)
0.386
(9,80)
A MIN
4073301/E 10/00
NOTES: A. All linear dimensions are in inches (millimeters).
B. This drawing is subject to change without notice.
C. Body dimensions do not include mold flash or protrusion not to exceed 0.006 (0,15).
D. Falls within JEDEC MO-137
17
ADS8345
SBAS177C
www.ti.com
PACKAGE DRAWINGS (Cont.)
DB (R-PDSO-G**)
PLASTIC SMALL-OUTLINE
28 PINS SHOWN
0,38
0,22
0,65
28
M
0,15
15
0,25
0,09
5,60
5,00
8,20
7,40
Gage Plane
1
14
0,25
A
0°–8°
0,95
0,55
Seating Plane
0,10
2,00 MAX
0,05 MIN
PINS **
14
16
20
24
28
30
38
DIM
6,50
5,90
6,50
5,90
7,50
8,50
7,90
10,50
9,90
10,50 12,90
A MAX
A MIN
6,90
9,90
12,30
4040065 /E 12/01
NOTES: A. All linear dimensions are in millimeters.
B. This drawing is subject to change without notice.
C. Body dimensions do not include mold flash or protrusion not to exceed 0,15.
D. Falls within JEDEC MO-150
18
ADS8345
SBAS177C
www.ti.com
PACKAGE OPTION ADDENDUM
www.ti.com
3-Oct-2003
PACKAGING INFORMATION
ORDERABLE DEVICE
STATUS(1)
PACKAGE TYPE
PACKAGE DRAWING
PINS
PACKAGE QTY
ADS8345E
ADS8345E/2K5
ADS8345EB
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
ACTIVE
SSOP
SSOP
SSOP
SSOP
SSOP
SSOP
SSOP
SSOP
DBQ
DBQ
DBQ
DBQ
DB
20
20
20
20
20
20
20
20
56
2500
56
ADS8345EB/2K5
ADS8345N
2500
68
ADS8345N/1K
ADS8345NB
DB
1000
68
DB
ADS8345NB/1K
DB
1000
(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.
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, maskworkright, orotherTIintellectualpropertyrightrelatingtoanycombination, machine, orprocess
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
Audio
Amplifiers
amplifier.ti.com
www.ti.com/audio
Data Converters
dataconverter.ti.com
Automotive
www.ti.com/automotive
DSP
dsp.ti.com
Broadband
Digital Control
Military
www.ti.com/broadband
www.ti.com/digitalcontrol
www.ti.com/military
Interface
Logic
interface.ti.com
logic.ti.com
Power Mgmt
Microcontrollers
power.ti.com
Optical Networking
Security
www.ti.com/opticalnetwork
www.ti.com/security
www.ti.com/telephony
www.ti.com/video
microcontroller.ti.com
Telephony
Video & Imaging
Wireless
www.ti.com/wireless
Mailing Address:
Texas Instruments
Post Office Box 655303 Dallas, Texas 75265
Copyright 2003, Texas Instruments Incorporated
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