ETC ADS-112/883

®
®
ADS-112
12-Bit, 1MHz, Low-Power
Sampling A/D Converters
FEATURES
•
•
•
•
•
•
•
•
12-bit resolution
No missing codes
1MHz minimum sampling rate
Functionally complete
Small 24-pin DDIP
Low-power, 1.3 Watts
Three-state output buffers
Samples to Nyquist frequencies
GENERAL DESCRIPTION
INPUT/OUTPUT CONNECTIONS
DATEL’s ADS-112 is a 12-bit, functionally complete, sampling
A/D converter that is packaged in a space-saving 24-pin DDIP.
Requiring ±15V and +5V supplies, a minimum sampling rate of
1MHz is achieved while only dissipating 1.3 Watts. The
ADS-112 digitizes signals up to Nyquist frequencies. Models
are available for use in either commercial (0 to + 70°C) or
military (–55 to +125°C) operating temperature ranges.
PIN
FUNCTION
PIN
FUNCTION
1
2
3
4
5
6
7
8
9
10
11
12
BIT 12 (LSB)
BIT 11
BIT 10
BIT 9
BIT 8
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1 (MSB)
24
23
22
21
20
19
18
17
16
15
14
13
–15V SUPPLY
ANALOG GROUND
+15V SUPPLY
+10V REFERENCE
BIPOLAR
ANALOG INPUT
COMP BIN
ENABLE (1-12)
START CONVERT
EOC
DIGITAL GROUND
+5V SUPPLY
Typical applications include spectrum, transient, vibration and
waveform analysis. This device is also ideally suited for radar,
sonar, video digitization, medical instrumentation and highspeed data acquisition systems.
17 ENABLE (1-12)
DAC
12 BIT 1 (MSB)
REF
S/H
S1
BUFFER
ANALOG INPUT 19
REGISTER
BIPOLAR 20
–
+
3-STATE OUTPUT REGISTER
FLASH
ADC
DIGITAL CORRECTION LOGIC
S2
11 BIT 2
REGISTER
+10V REF. 21
10 BIT 3
9
BIT 4
8
BIT 5
7
BIT 6
6
BIT 7
5
BIT 8
4
BIT 9
3
BIT 10
2
BIT 11
1
BIT 12 (LSB)
COMP BIN 18
START CONVERT 16
TIMING AND
CONTROL LOGIC
EOC 15
13
14
22
23
24
+5V SUPPLY
DIGITAL GROUND
+15V SUPPLY
ANALOG GROUND
–15V SUPPLY
Figure 1. ADS-112 Functional Block Diagram
DATEL, Inc., 11 Cabot Boulevard, Mansfield, MA 02048-1151 (U.S.A.) • Tel: (508) 339-3000 Fax: (508) 339-6356 • For immediate assistance: (800) 233-2765
®
®
ADS-112
ABSOLUTE MAXIMUM RATINGS
PARAMETERS
+15V Supply (Pin 22)
–15V Supply (Pin 24)
+5V Supply (Pin 13)
Digital Inputs (Pin 16, 17, 18)
Analog Input (Pin 19)
Lead Temp. (10 seconds)
DYNAMIC PERF. (cont)
LIMITS
UNITS
0 to +18
0 to –18
0 to +6
–0.3 to +VDD +0.3
–9 to +15
+300
Volts
Volts
Volts
Volts
Volts
°C
Signal-to-Noise Ratio
(wo/distort., –0.5dB)
dc to 100kHz
100kHz to 500kHz
Signal-to-Noise Ratio ➁
(& distort., –0.5dB)
dc to 100kHz
100kHz to 500kHz
Two-tone Intermodulation
Distortion (fin = 75kHz,
105kHz, fs = 1MHz, –0.7dB)
Two-tone Intermodulation
Distortion (fin = 480kHz,
490kHz, fs = 1MHz, –0.7dB)
Input Bandwith (–3dB)
Small Signal (–20dB input)
Large Signal (–0.5dB input)
Slew Rate
Apperture Delay TIme
Effect. Aperture Delay Time
Apperture Uncertainity (Jitter)
RMS
Peak
Overvoltage Recovery Time
S/H Acquisition Time
Conversion Rate
(Changing Inputs)
+25°C
0°C to +70°C
–55°C to +125°C
FUNCTIONAL SPECIFICATIONS
(TA = +25°C, ±VCC = ±15V, +VDD =+5V, 1MHz sampling rate, and a minimum 1 minute
warmup unless otherwise specified.)
ANALOG INPUTS
MIN.
TYP.
MAX.
UNITS
Input Voltage Range ➀
Bipolar
Unipolar
Input Impedence
Input Capacitance
—
—
4.5
—
±5
0 to +10
5
6
—
—
—
15
Volts
Volts
kΩ
pF
DIGITAL INPUTS
Logic Levels
Logic "1"
Logic "0"
Logic Loading "1"
Logic Loading "0"
+2.0
—
—
—
—
—
—
—
—
+0.8
+10
–600
Volts
Volts
µA
µA
PERFORMANCE
Resolution
No Missing Codes
(12 Bits; fin = 1MHz)
Integral Non-Linearity
+25°C
0°C to +70°C
–55°C to +125°C
Differential Non-Linearity
+25°C
0°C to +70°C
–55°C to +125°C
Full Scale Absolute Accuracy
+25°C
0°C to +70°C
–55°C to +125°C
Unipolar Zero Error †
0°C to +70°C
–55°C to +125°C
Bipolar Zero Error †
0°C to +70°C
–55°C to +125°C
Bipolar Offset Error †
0°C to +70°C
–55°C to +125°C
Gain Error †
0°C to +70°C
–55°C to +125°C
Internal Reference Voltage, +25°C
Drift
External Current
12 Bits
TYP.
MAX.
UNITS
68
67
72
71
—
—
dB
dB
66
66
70
70
—
—
dB
dB
—
–88
–80
dB
—
–68
–65
dB
8
6
—
—
—
10
8
±150
—
—
—
—
—
20
16
MHz
MHz
V/µs
ns
ns
—
—
—
160
—
—
—
250
15
±50
1000
280
ps
ps
ns
ns
1
1
1
—
—
—
—
—
—
MHz
MHz
MHz
DIGITAL OUTPUTS
Over the operating temperature range
—
—
—
±1/4
±1/4
±1/2
±3/4
±3/4
±1.5
LSB
LSB
LSB
—
—
—
±1/4
±1/4
±1/2
±3/4
±3/4
±1
LSB
LSB
LSB
—
—
—
±0.13
±0.15
±0.25
±0.25
±0.44
±0.78
%FSR
%FSR
%FSR
—
—
±0.074
±0.224
±0.265
±0.43
%FSR
%FSR
—
—
±0.074
±0.124
±0.166
±0.210
%FSR
%FSR
—
—
±0.1
±0.3
±0.38
±0.60
%FSR
%FSR
—
—
+9.98
—
—
±0.1
±0.3
+10.0
±5
—
±0.38
±0.60
+10.02
±30
1.5
%
%
Volts
ppm/°C
mA
—
—
–81
–75
–75
–70
dB
dB
—
—
–78
–73
–75
–68
dB
dB
Output Coding
Pin 18 High
Pin 18 Low
Logic Level
Logic "1"
Logic "0"
Logic Loading "1"
Logic Loading "0"
Staight binary/Offset binary
Complementary binary
Complementary offset binary
+2.4
—
—
—
—
—
—
—
—
+0.4
–160
+6.4
Volts
Volts
µA
mA
+14.25
–14.25
+4.75
+15.0
–15.0
+5.0
+15.75
–15.75
+5.25
Volts
Volts
Volts
—
—
—
—
—
+24
–40
+80
1.3
—
+35
–48
+95
1.7
±0.07
mA
mA
mA
Watts
%FSR%V
POWER REQUIREMENTS
Power Supply Ranges ➂
+15V Supply
–15V Supply
+5V Supply
Power Supply Current
+15V Supply
–15V Supply
+5V Supply
Power Dissipation
Power Supply Rejection
PHYSICAL/ENVIRONMENTAL
Operating Temp. Range, Case
ADS-112MC
ADS-112MM, 883
Storage Temperature Range
Package Type
Weight
DYNAMIC PERFORMANCE
In-Band Harmonics (–0.5dB)
dc to 100kHz
100kHz to 500kHz
Total Harm. Distort. (–0.5dB)
dc to 100kHz
100kHz to 500kHz
MIN.
0
—
+70
°C
–55
—
+125
°C
–65
—
+150
°C
24-pin, metal-sealed, ceramic DDIP
0.42 ounces (12 grams)
➀ See Table 3 also
➁ Effective bits is equal to:
(SNR + Distortion) – 1.76 +
Full Scale Amplitude
20 log
6.02
† See Tech Note 1
➂ For ±12V, +5V operation, contact DATEL
2
Actual Input Amplitude
®
®
ADS-112
TECHNICAL NOTES
has an internal pull-up resistor on this pin. To obtain
complementary binary or complementary offset binary
output coding, tie pin 18 to ground. The pin 18 signal is
compatible with CMOS/TTL logic levels for those users
desiring dynamic control of this function.
1. Applications which are unaffected by endpoint errors or
remove them through software will use the typical connections shown in Figure 3. Remove system errors or adjust
the small initial errors of the ADS-112 to zero using the
optional external circuitry shown in Figure 4. The external
adjustment circuit has no effect on the throughput rate.
5. To enable the three-state outputs, connect ENABLE (pin 17)
to a logic "0" (low). To disable, connect pin 17 to a logic "1"
(high).
2. For best performance, always connect the analog and
digital ground pins to a ground plane beneath the converter.
The analog and digital grounds are not connected to each
other internally.
6. Do not change the status of pin 18 when EOC is high.
7. Re-initiating the START CONVERT (pin 16) while EOC is a
logic "1" (high) will result in a new conversion sequence.
3. Bypass the analog and digital supplies and the +10V
reference (pin 21) to ground with 4.7µF, 25V tantalum
electrolytic capacitors in parallel with 0.1µF ceramic
capacitors. Bypass the +10V reference (pin 21) to analog
ground (pin 23).
TIMING
Figure 2 shows the relationship between the various input
signals. The timing shown applies over the operating
temperature range and over the operating power supply
range. These times are guaranteed by design.
4. Obtain straight binary/offset binary output coding by tying
COMP BIN (pin 18) to +5V or leaving it open. The device
N
N+1
START
CONVERT
150ns, ±25ns
10ns min.
20ns max.
Acquisition Time
INTERNAL S/H
250ns
Hold
20ns max.
EOC
60ns max.
Conversion Time
600ns max.
35ns max.
OUTPUT
DATA
DATA N-1 VALID
800ns min.
DATA N VALID
INVALID
DATA
200ns max.
Note: Scale is approximately 50ns per division.
Figure 2. ADS-112 Timing Diagram
3
INVALID
DATA
®
®
ADS-112
CALIBRATION PROCEDURE
R2 ➀
1. Connect the converter per Figures 3 and 4 and Tables 1 and
3 for the appropriate input range. Apply a pulse of 150
nanoseconds to the START CONVERT input (pin 16) at a
rate of 250kHz. This rate is chosen to reduce the flicker if
LED’s are used on the outputs for calibration purposes.
+15V
➀
R1
SIGNAL
INPUT
2. Zero Adjustments
To Pin19
of ADS-112
5kΩ
50Ω
GAIN
ADJUST
Apply a precision voltage reference source between the
amplifier’s analog input and ground. Adjust the output of the
reference source per Table 2. For unipolar, adjust the zero
trimming potentiometer so that the output code flickers
equally between 0000 0000 0000 and 0000 0000 0001 with
COMP BIN (pin 18) tied high (straight binary) or between
1111 1111 1111 and 1111 1111 1110 with pin 18 tied low
(complementary binary).
–15V
5kΩ
10kΩ
ZERO/
OFFSET
ADJUST
➀ For values of R1 and R2 refer to Table 3.
For bipolar operation, adjust the potentiometer such that the
code flickers equally between 1000 0000 0000 and 1000
0000 0001 with pin 18 tied high (offset binary) or between
0111 1111 1111 and 0111 1111 1110 with pin 18 tied low
(complementary offset binary).
Figure 4. Optional Calibration Circuit
3. Full-Scale Adjustment
Table 2. Zero and Gain Adjust
Set the output of the voltage reference used in step 2 to the
value shown in Table 2. Adjust the gain trimming potentiometer so that the output code flickers equally between 1111
1111 1110 and 1111 1111 1111 for pin 18 tied high or between
0000 0000 0001 and 0000 0000 0000 for pin 18 tied low.
To confirm proper operation of the device, vary the precision
reference voltage source to obtain the output coding listed
in Table 4.
Zero Adjust
+1/2 LSB
Gain Adjust
+FS – 1 1/2 LSB
0 to +10V
±5V
+1.22mV
+1.22mV
+9.9963V
+4.9963V
Table 3. Input Range (using external calibration)
Table 1. Input Range Selection
INPUT RANGE
INPUT RANGE
INPUT PIN
TIE TOGETHER
±5v
0 to +10V
Pin 19
Pin 19
Pin 20 to Pin 21
Pin 20 to Ground
BIPOLAR
OPERATION
Input
Range
20
21 +10V REF.
21
+
0.1µF
4.7µF
24
–15V
4.7µF
+
0.1µF
+
0.1µF
ADS-112
23
4.7µF
+15V
22
+
4.7µF
UNIT
2
2
2
2
6
14
kΩ
kΩ
kΩ
12 BIT 1 (MSB)
11 BIT 2
10 BIT 3
9 BIT 4
8 BIT 5
7 BIT 6
6 BIT 7
5 BIT 8
4 BIT 9
3 BIT 10
2 BIT 11
1 BIT 12 (LSB)
15 EOC
17 ENABLE (1-12)
16 START CONVERT
19 ANALOG INPUT
13
+5V
R2
0 to 10V, ±5
0 to 5V, ±2.5V
0 to +2.5V, ±1.25V
UNIPOLAR
OPERATION
20
R1
0.1µF
COMP BIN 18
14
Note: Always bypass pin 21 to ground
Figure 3. Typical ADS-112 Connection Diagram
4
+5V
®
®
ADS-112
Table 4. Output Coding
STRAIGHT BIN.
UNIPOLAR
SCALE
INPUT RANGE
0 to +10V
+FS – 1 LSB
+7/8 FS
+3/4 FS
+1/2 FS
+1/4 FS
+1/8 FS
+1 LSB
0
+9.9976
+8.7500
+7.5000
+5.0000
+2.5000
+1.2500
+0.0024
0.0000
COMP. BINARY
OUTPUT CODING
MSB LSB
MSB
1111
1110
1100
1000
0100
0010
0000
0000
1111
0000
0000
0000
0000
0000
0000
0000
1111
0000
0000
0000
0000
0000
0001
0000
0000
0001
0011
0111
1011
1101
1111
1111
OFF. BINARY
LSB
0000
1111
1111
1111
1111
1111
1111
1111
0000
1111
1111
1111
1111
1111
1110
1111
INPUT RANGE
±5V
BIPOLAR
SCALE
+4.9976
+3.7500
+2.5000
0.0000
–2.5000
–3.7500
–4.9976
–5.0000
+FS –1 LSB
+3/4FS
+1/2FS
0
–1/2FS
–3/4FS
–FS+1LSB
–FS
COMP. OFF. BIN.
0
Amplitude Relative to Full Scale (dB)
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
–110
–120
–130
0
50
100
150
200
250
300
350
400
Frequency (kHz)
(fs = 1MHz, fin = 485kHz, Vin = –0.5dB, 4,096-point FFT)
Figure 5. FFT Analysis of ADS-112
5
450
500
®
®
ADS-112
MECHANICAL DIMENSIONS INCHES (mm)
1.31 MAX.
(33.27)
24
Dimension Tolerances (unless otherwise indicated):
2 place decimal (.XX) ±0.010 (±0.254)
3 place decimal (.XXX) ±0.005 (±0.127)
13
Lead Material: Kovar alloy
0.80 MAX.
(20.32)
1
Lead Finish: 50 microinches (minimum) gold plating
over 100 microinches (nominal) nickel plating
12
0.100 TYP.
(2.540)
1.100
(27.940)
0.235 MAX.
(5.969)
PIN 1 INDEX
0.200 MAX.
(5.080)
0.010
(0.254)
0.190 MAX.
(4.826)
0.100
(2.540)
SEATING
PLANE
0.025
(0.635)
0.040
(1.016)
0.018 ±0.002
(0.457)
+0.002
–0.001
0.100
(2.540)
0.600 ±0.010
(15.240)
ORDERING INFORMATION
MODEL NUMBER
ADS-112MC
ADS-112MM
ADS-112/883
ACCESSORIES
OPERATING TEMP. RANGE
ADS-EVAL4
HS-32
0 to +70°C
–55 to +125°C
–55 to +125°C
Evaluation Board (without ADS-112)
Heat Sink for all ADS-112 models
For MIL-STD-883 product specification or availability of surface-mount packaging, contact DATEL. Receptacles for PC mounting
can be ordered through AMP Inc., Part # 3-331272-8 (Component Lead Socket), 24 required.
®
®
ISO 9001
R
E
G
I
S
T
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D
DS-0149F
DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151
Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356
Internet: www.datel.com E-mail:sales@datel.com
Data Sheet Fax Back: (508) 261-2857
10/96
DATEL (UK) LTD. Tadley, England Tel: (01256)-880444
DATEL S.A.R.L. Montigny Le Bretonneux, France Tel: 1-34-60-01-01
DATEL GmbH München, Germany Tel: 89-544334-0
DATEL KK Tokyo, Japan Tel: 3-3779-1031, Osaka Tel: 6-354-2025
DATEL makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein
do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without notice. The DATEL logo is a registered DATEL, Inc. trademark.