DATEL ADS-117 Service Manual

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REF
REGISTER
REGISTER
3-STATE OUTPUT REGISTER
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)
TIMING AND
CONTROL LOGIC
BIPOLAR 20
+10V REF. 21
START CONVERT 16
EOC 15
DIGITAL CORRECTION LOGIC
DAC
FLASH
ADC
COMP BIN 18
BUFFER
+
S/H
ANALOG INPUT 19
17 ENABLE (1-12)
S
2
S
1
13
+5V SUPPLY
22
+15V SUPPLY
23
ANALOG GROUND
14
DIGITAL GROUND
24
–15V SUPPLY
查询ADS-117供应商查询ADS-117供应商
FEATURES
12-bit resolution
2MHz minimum throughput
Functionally complete
Small 24-pin DDIP
Low-power, 1.6 Watts
Three-state output buffers
Samples to Nyquist frequencies
ADS-117
12-Bit, 2MHz, Low-Power
Sampling A/D Converters
GENERAL DESCRIPTION
DATEL's ADS-117 is a functionally complete, 12-bit, 2MHz, sampling A/D converter. Its standard, 24-pin, double-width DIP contains a fast-settling sample-hold amplifier, a 12-bit subranging (two-step) A/D converter, a precision reference, three-state output register and all the timing and control logic necessary to operate from a single start convert pulse. Digital input and output levels are TTL.
Total harmonic distortion (THD) and signal-to-noise ratio (including distortion) typically run –78dB and 70dB, respectively, with full scale inputs up to 100kHz. The ADS­117 requires ±15V and +5V power supplies and typically consumes 1.6 Watts. Models are available for use in either commercial (0 to +70°C) or military (–55 to +125°C) operating temperature ranges.
INPUT/OUTPUT CONNECTIONS
PIN FUNCTION PIN FUNCTION
1 BIT 12 (LSB) 24 –15V SUPPLY 2 BIT 11 23 ANALOG GROUND 3 BIT 10 22 +15V SUPPLY 4 BIT 9 21 +10V REFERENCE 5 BIT 8 20 BIPOLAR 6 BIT 7 19 ANALOG INPUT 7 BIT 6 18 COMP BIN 8 BIT 5 17 ENABLE (1-12)
9 BIT 4 16 START CONVERT 10 BIT 3 15 EOC 11 BIT 2 14 DIGITAL GROUND 12 BIT 1 (MSB) 13 +5V SUPPLY
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
Figure 1. ADS-117 Functional Block Diagram
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ADS-117
®®
ABSOLUTE MAXIMUM RATINGS
PARAMETERS LIMITS UNITS
+15V Supply (Pin 22) 0 to +16 Volts –15V Supply (Pin 24) 0 to –16 Volts +5V Supply (Pin 13) 0 to +6.0 Volts Digital Inputs (Pin 16, 17, 18) –0.3 to +VDD +0.3 Volts Analog Input (Pin 19) –9 to +15 Volts Lead Temp. (10 seconds) +300 °C
FUNCTIONAL SPECIFICATIONS
(TA = +25°C, ±VCC = +15V, +VDD =+5V, 2MHz sampling rate, and a minimum 3 minute warmup unless otherwise specified.)
ANALOG INPUTS MIN. TYP. MAX. UNITS
Input Voltage Range
Bipolar ±5 Volts Unipolar 0 to +10 Volts
Input Impedence 4.5 5 k Input Capacitance —615pF
DIGITAL INPUTS
Logic Levels
Logic "1" +2.0 Volts Logic "0" +0.8 Volts Logic Loading "1" +5 µA Logic Loading "0" –6 00 µA
PERFORMANCE
Resolution 12 Bits No Missing Codes
(12 Bits; fin = 1MHz) 0 to +70°C
Integral Non-Linearity
0°C to +70°C ±1/2 ±3 LSB –55°C to +125°C ±1 ±4 LSB
Differential Non-Linearity
0°C to +70°C ±1/2 ±0.95 LSB –55°C to +125°C ±1 +1.5 LSB
Full Scale Absolute Accuracy
(see Tech Note 1)
0°C to +70°C ±0.13 ±0.44 %FSR –55°C to +125°C ±0.25 ±0.73 %FSR
Unipolar/Bipolar Zero Error
0°C to +70°C (see Tech Note 1) ±0.07 ±0.38 %FSR –55°C to +125°C ±0.22 ±0.73 %FSR
Bipolar Offset Error
0°C to +70°C (see Tech Note 1) ±0.1 ±0.38 %FSR –55°C to +125°C ±0.53 ±0.73 %FSR
Gain Error (see Tech Note 1)
0°C to +70°C ±0.1 ±0.38 % –55°C to +125°C ±0.53 ±0.73 %
Internal Reference Voltage
0°C to +70°C +9.97 +10.0 +10.03 Volts –55°C to +125°C +9.95 +10.05 Volts
External Current ——1.5mA
DYNAMIC PERFORMANCE
Spurious Free Dynamic Range (–0.5dB)
dc to 100kHz –81 dB 100kHz to 500kHz –75 –70 dB 500kHz to 1MHz –70 dB
Total Harm. Distort. (–0.5dB)
dc to 100kHz –78 dB 100kHz to 500kHz –73 –68 dB 500kHz to 1MHz –71 dB
Input Bandwith (–3dB)
Small Signal (–20dB input) 8 10 MHz Large Signal (–0.5dB input) 7 9 MHz
Feedthrough (1MHz) –72 –74 dB
See Table 1 also
Same specifications for in-band harmonics.
DYNAMIC PERF. (cont) MIN. TYP. MAX. UNITS
SNR (wo/distortion, –0.5dB)
dc to 100kHz 0°C to +70°C 72 dB –55°C to +125°C 72 dB 100kHz to 500kHz 0°C to +70°C 65 70 dB –55°C to +125°C 65 70 dB 500kHz to 1MHz 0°C to +70°C 70 dB –55°C to +125°C 70 dB
SNR (and distort., –0.5dB)
dc to 100kHz 0°C to +70°C 70 dB –55°C to +125°C 69 dB 100kHz to 500kHz 0°C to +70°C 64 70 dB –55°C to +125°C 62 69 dB 500kHz to 1MHz 0°C to +70°C 69 dB –55°C to +125°C 69 dB
Two-tone Intermodulation Distortion (fin = 970kHz,
990kHz, f
s = 2Mhz,
–0.5dB) –68 dB
Slew Rate ±210 V/µs Effect. Aperture Delay Time ——16ns Overvoltage Recovery Time; 20% 500 ns S/H Acq. Time, (to ±0.01%)
0 to +70°C 155 165 ns –55°C to +125°C 160 170 ns
Conversion Rate 2 MHz
OUTPUTS
Output Coding
Pin 18 High Pin 18 Low
Logic Level
Logic "1" +2.4 Volts Logic "0" +0.4 Volts Logic Loading "1" –160 µA Logic Loading "0" +6.4 mA
POWER REQUIREMENTS
Power Supply Ranges
+15V Supply +14.25 +15.0 +15.75 Volts –15V Supply –14.25 –15.0 –15.75 Volts +5V Supply +4.75 +5.0 +5.25 Volts
Power Supply Current
+15V Supply +48 +58 mA –15V Supply –35 –45 mA +5V Supply +75 +85 mA
Power Dissipation 1.6 1.9 Watts Power Supply Rejection ±0.07 %FSR%V
PHYSICAL/ENVIRONMENTAL
Operating Temp. Range, Case
ADS-117MC 0 +70 °C ADS-117MM, 883 –55 +125 °C
Storage Temperature Range –65 +150 °C Thermal Impedance
θ
jc 3 °C/W
θ
ca 23 °C/W
Package Type 24-pin, metal-sealed, ceramic DDIP Weight 0.42 ounces (12 grams)
Effective bits is equal to:
(SNR + Distortion) – 1.76 + 20 log
For ±12V, +5V operation, contact DATEL
Staight binary/Offset binary
Complementary binary
Complementary offset binary
Full Scale Amplitude
Actual Input Amplitude
6.02
2
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TECHNICAL NOTES
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-117 to zero using the optional external circuitry shown in Figure 4. The external adjustment circuit has no effect on the throughput rate.
2. Always connect the analog and digital grounds to a ground plane beneath the converter for best performance. The analog and digital grounds are not connected to each other internally.
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).
4. Obtain straight binary/offset binary output coding by tying COMP BIN (pin 18) to +5V or leaving it open. The device has an internal pull-up resistor on this pin. To obtain complementary binary or complementary offset binary
ADS-117
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. Do not change COMP BIN status while EOC is high.
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).
6. To meet the guaranteed conversion rate, a maximum start convert pulse is specified. A wider start convert pulse will result in slower conversion rates. An initial start convert pulse is required before performing an actual conversion after power-up to assure the sample-hold is in the acquisi­tion mode.
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.
7. Re-initiating the START CONVERT (pin 16) while EOC is a logic "1" (high) will result in a new conversion sequence.
START
CONVERT
INTERNAL S/H
EOC
OUTPUT
DATA
NN+1
50ns typ., 30ns min., 60ns max.
10ns min. 25ns max.
Hold
10ns min. 17ns max.
Conversion Time
325ns typ.
DATA N-1 VALID
350ns min.
Note: Scale is approximately 25ns per division.
Figure 2. ADS-117 Timing Diagram
Acquisition Time
165ns typ.
170ns max.
INVALID
DATA
150ns max.
60ns max.
35ns max.
DATA N VALID
INVALID
DATA
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ADS-117
T
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CALIBRATION PROCEDURE
1. Connect the converter per Figure 3, Figure 4, and Table 1 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 flicker if LED’s are used on the outputs for calibration purposes.
2. Zero Adjustments
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 the pin 18 tied high (straight binary) or between 1111 1111 1111 and 1111 1111 1110 with the pin 18 tied low (comple­mentary binary).
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).
3. Full-Scale Adjustment
Set the output of the voltage reference used in step 2 to the value shown in Table 1. 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.
4. To confirm proper operation of the device, vary the preci­sion reference voltage source to obtain the output coding listed in Table 3.
R2
+15V
–15V
10k
ZERO/ OFFSET ADJUST
To Pin19 of ADS-117
SIGNAL
INPUT
R1
5k
50
GAIN
ADJUST
5k
For values of R1 and R2 refer to Table 1.
Figure 4. Optional Calibration Circuit
Table 1. Input Connections (using external calibration)
INPUT RANGE R1 R2 UNIT
0 +10V, ±5 2 2 k
0 to 5V, ±2.5V 2 6 k
0 to +2.5V, ±1.25V 2 14 k
Table 2. Zero and Gain Adjustments
Input Zero Adjust Gain Adjust
Range +1/2 LSB +FS – 1 1/2 LSB
0 to +10V +1.22mV +9.9963V
±5V +1.22mV +4.9963V
–15V
+15V
+5V
0.1µF
4.7µF
4.7µF
4.7µF
UNIPOLAR
OPERATION
4.7µF
0.1µF
+
0.1µF
+
+
0.1µF
12
20
BIPOLAR INPUT
+10V REF.
21
+
24
ADS-117
23
22
13
14
For unipolar operation, ground pin 20.
NOTE:
COMP BIN
18 +5V
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
BIT 11
2
BIT 12 (LSB)
1
EOC
15
ENABLE (1-12)
17
16
START CONVER
19
ANALOG INPUT
For bipolar operation, connect pin 20 to pin 21. Always bypass pin 21 as shown for both unipolar and bipolar operation.
Figure 3. ADS-117 Connection Diagram
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0
STRAIGHT BIN. COMP. BINARY
UNIPOLAR INPUT RANGE OUTPUT CODING INPUT RANGE BIPOLAR
SCALE 0 to +10V MSB LSB MSB LSB ±5V SCALE
+FS – 1 LSB +9.9976 1111 1111 1111 0000 0000 0000 +4.9976 +FS –1 LSB
+7/8 FS +8.7500 1110 0000 0000 0001 1111 1111 +3.7500 +3/4FS +3/4 FS +7.5000 1100 0000 0000 0011 1111 1111 +2.5000 +1/2FS +1/2 FS +5.0000 1000 0000 0000 0111 1111 1111 0.0000 0 +1/4 FS +2.5000 0100 0000 0000 1011 1111 1111 –2.5000 –1/2FS +1/8 FS +1.2500 0010 0000 0000 1101 1111 1111 –3.7500 –3/4FS
+1 LSB +0.0024 0000 0000 0001 1111 1111 1110 –4.9976 –FS+1LSB
0 0.0000 0000 0000 0000 1111 1111 1111 –5.0000 –FS
OFF. BINARY COMP. OFF. BIN.
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
Amplitude Relative to Full Scale (dB)
–110
–120
–130
–140
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.
ADS-117
Table 3. Output Coding
Frequency (MHz)
(fs = 2MHz, fin = 980kHz, Vin = –0.5dB, 4,096-point FFT)
Figure 5. FFT Analysis of ADS-117
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ADS-117
I
0.235 MAX. (5.969)
MECHANICAL DIMENSIONS INCHES (mm)
1.31 MAX. (33.27)
Dimension Tolerances 2 place decimal (.XX) ±0.010 (±0.254)
24
112
0.100 TYP. (2.540)
1.100
(27.940)
PIN 1 INDEX
13
0.80 MAX. (20.32)
0.200 MAX. (5.080)
3 place decimal (.XXX) ±0.005 (±0.127)
Lead Material:
Lead Finish: over 100 microinches (nominal) nickel plating
®®
(unless otherwise indicated):
Kovar alloy
50 microinches (minimum) gold plating
+0.002
0.010
–0.001
0.190 MAX. (4.826)
0.018 ±0.002 (0.457)
0.100
(2.540)
(1.016)
0.040
SEATING
PLANE
0.025
(0.635)
(0.254)
0.600 ±0.010 (15.240)
0.100
(2.540)
ORDERING INFORMATION
MODEL NUMBER OPERATING TEMP. RANGE
ADS-117MC 0 to +70°C ADS-117MM –55 to +125°C ADS-117/883 –55 to +125°C
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.
ACCESSORIES
ADS-EVAL1 Evaluation Board (without ADS-117) HS-24 Heat Sink for all ADS-117 models
®®
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
SO 9001
ISO 9001

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
DS-0230F 07/04
DATEL KK Tokyo, Japan Tel: 3-3779-1031, Osaka Tel: 6-6354-2025 DATEL China, Shanghai, China Tel:011-86-51317199
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.
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