Datasheet ADS-112MM, ADS-112MC, ADS-112-883 Datasheet (DATEL)

® ®

REGISTERREGISTER

3-STATE OUTPUT REGISTER

START CONVERT 16

DIGITAL CORRECTION LOGIC

+5V SUPPLY

+15V SUPPLY

ANALOG GROUND

DIGITAL GROUND

–15V SUPPLY

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

ADS-112

12-Bit, 1MHz, Low-Power

Sampling A/D Converters

GENERAL DESCRIPTION

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.

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.

+10V REF. 21

S2

S/H

S1

BUFFER

BIPOLAR 20

ANALOG INPUT 19

–
+

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

DAC

REF

FLASH

ADC

17 ENABLE (1-12)

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)

COMP BIN 18

EOC 15

TIMING AND

CONTROL LOGIC

13

14

22

23

24

Figure 1. ADS-112 Functional Block Diagram

DATEL, Inc., 11 Cabot Boulevard, Mansfield, MA 02048-1151 (U.S.A.) • Tel: [phone] Fax: [phone] • For immediate assistance: [phone]

ADS-112

® ®

ABSOLUTE MAXIMUM RATINGS

PARAMETERS LIMITS UNITS

+15V Supply (Pin 22) 0 to +18 Volts
–15V Supply (Pin 24) 0 to –18 Volts
+5V Supply (Pin 13) 0 to +6 Volts
Digital Inputs (Pin 16, 17, 18) –0.3 to +V

DD +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, 1MHz sampling rate, and a minimum 1 minute
warmup unless otherwise specified.)

ANALOG INPUTS MIN. TYP. MAX. UNITS

Input Voltage Range ➀

Bipolar — ±5 — Volts
Unipolar — 0 to +10 — Volts

Input Impedence 4.5 5 — kΩ
Input Capacitance — 6 15 pF

DIGITAL INPUTS

Logic Levels

Logic "1" +2.0 — — Volts
Logic "0" — — +0.8 Volts
Logic Loading "1" — — +10 µA
Logic Loading "0" — — –600 µA

PERFORMANCE

Resolution 12 Bits
No Missing Codes

in = 1MHz) Over the operating temperature range

(12 Bits; f

Integral Non-Linearity

+25°C — ±1/4 ±3/4 LSB
0°C to +70°C — ±1/4 ±3/4 LSB
–55°C to +125°C — ±1/2 ±1.5 LSB

Differential Non-Linearity

+25°C — ±1/4 ±3/4 LSB
0°C to +70°C — ±1/4 ±3/4 LSB
–55°C to +125°C — ±1/2 ±1 LSB

Full Scale Absolute Accuracy

+25°C — ±0.13 ±0.25 %FSR
0°C to +70°C — ±0.15 ±0.44 %FSR
–55°C to +125°C — ±0.25 ±0.78 %FSR

Unipolar Zero Error †

0°C to +70°C — ±0.074 ±0.265 %FSR
–55°C to +125°C — ±0.224 ±0.43 %FSR

Bipolar Zero Error †

0°C to +70°C — ±0.074 ±0.166 %FSR
–55°C to +125°C — ±0.124 ±0.210 %FSR

Bipolar Offset Error †

0°C to +70°C — ±0.1 ±0.38 %FSR
–55°C to +125°C — ±0.3 ±0.60 %FSR

Gain Error †

0°C to +70°C — ±0.1 ±0.38 %
–55°C to +125°C — ±0.3 ±0.60 %

Internal Reference Voltage, +25°C +9.98 +10.0 +10.02 Volts

Drift — ±5 ±30 ppm/°C
External Current — — 1.5 mA

DYNAMIC PERFORMANCE

In-Band Harmonics (–0.5dB)

dc to 100kHz — –81 –75 dB
100kHz to 500kHz — –75 –70 dB

Total Harm. Distort. (–0.5dB)

dc to 100kHz — –78 –75 dB
100kHz to 500kHz — –73 –68 dB

† See Tech Note 1

DYNAMIC PERF. (cont) MIN. TYP. MAX. UNITS

Signal-to-Noise Ratio

(wo/distort., –0.5dB)
dc to 100kHz 68 72 — dB
100kHz to 500kHz 67 71 — dB

Signal-to-Noise Ratio ➁

(& distort., –0.5dB)
dc to 100kHz 66 70 — dB
100kHz to 500kHz 66 70 — dB

Two-tone Intermodulation
Distortion (f

in = 75kHz,

s = 1MHz, –0.7dB) — –88 –80 dB

105kHz, f

Two-tone Intermodulation
Distortion (f

in = 480kHz,

s = 1MHz, –0.7dB) — –68 –65 dB

490kHz, f

Input Bandwith (–3dB)

Small Signal (–20dB input) 8 10 — MHz
Large Signal (–0.5dB input) 6 8 — MHz

Slew Rate — ±150 — V/µs
Apperture Delay TIme — — 20 ns
Effect. Aperture Delay Time — — 16 ns
Apperture Uncertainity (Jitter)

RMS — — 15 ps
Peak — — ±50 ps

Overvoltage Recovery Time — — 1000 ns
S/H Acquisition Time 160 250 280 ns
Conversion Rate

(Changing Inputs)
+25°C 1 — — MHz
0°C to +70°C 1 — — MHz
–55°C to +125°C 1 — — MHz

DIGITAL OUTPUTS

Output Coding

Pin 18 High
Pin 18 Low

Logic Level

Staight binary/Offset binary

Complementary binary

Complementary offset binary

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 ➂

+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 — +24 +35 mA
–15V Supply — –40 –48 mA
+5V Supply — +80 +95 mA

Power Dissipation — 1.3 1.7 Watts
Power Supply Rejection — — ±0.07 %FSR%V

PHYSICAL/ENVIRONMENTAL

Operating Temp. Range, Case

ADS-112MC 0 — +70 °C
ADS-112MM, 883 –55 — +125 °C

Storage Temperature Range –65 — +150 °C
Package Type 24-pin, metal-sealed, ceramic DDIP

Weight 0.42 ounces (12 grams)

➀ See Table 3 also
➁ Effective bits is equal to:

(SNR + Distortion) – 1.76 + 20 log

Full Scale Amplitude

Actual Input Amplitude

6.02

➂ For ±12V, +5V operation, contact DATEL

2

® ®

Note: Scale is approximately 50ns per division.

ADS-112

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-112 to zero using the
optional external circuitry shown in Figure 4. The external
adjustment circuit has no effect on the throughput rate.

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.

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

N

START

CONVERT

150ns, ±25ns

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.

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. 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.

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.

N+1

INTERNAL S/H

EOC

OUTPUT

DATA

10ns min.
20ns max.

Hold

20ns max.
Conversion Time

600ns max.

DATA N-1 VALID

800ns min.

Figure 2. ADS-112 Timing Diagram

Acquisition Time

250ns

INVALID

DATA

200ns max.

60ns max.

35ns max.

DATA N VALID

INVALID

DATA

3

ADS-112

For values of R1 and R2 refer to Table 3.

➀

® ®

CALIBRATION PROCEDURE

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.

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
COMP BIN (pin 18) tied high (straight binary) or between
1111 1111 1111 and 1111 1111 1110 with 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 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.

Table 1. Input Range Selection

INPUT RANGE INPUT PIN TIE TOGETHER

±5v Pin 19 Pin 20 to Pin 21

0 to +10V Pin 19 Pin 20 to Ground

➀

R2

➀

R1

SIGNAL

INPUT

5k

Ω

50

Ω

GAIN

ADJUST

5kΩ

Figure 4. Optional Calibration Circuit

Table 2. Zero and Gain Adjust

+15V

–15V

10k

Ω

ZERO/
OFFSET
ADJUST

To Pin19
of ADS-112

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

Table 3. Input Range (using external calibration)

INPUT RANGE R1 R2 UNIT

0 to 10V, ±5 2 2 kΩ

0 to 5V, ±2.5V 2 6 kΩ

0 to +2.5V, ±1.25V 2 14 kΩ

BIPOLAR

OPERATION

20

21

0.1µF

–15V

4.7µF

4.7µF

+15V

+5V

4.7µF

UNIPOLAR

OPERATION

20

21 +10V REF.

+

4.7µF

24

0.1µF

+

0.1µF

+

+

0.1µF

Figure 3. Typical ADS-112 Connection Diagram

23

22

13

14

Note: Always bypass pin 21 to ground

ADS-112

4

COMP BIN

12
11
10

9
8
7
6
5
4
3
2

1
15
17
16
19

18 +5V

BIT 1 (MSB)
BIT 2
BIT 3
BIT 4
BIT 5
BIT 6
BIT 7
BIT 8
BIT 9
BIT 10
BIT 11
BIT 12 (LSB)
EOC
ENABLE (1-12)
START CONVERT
ANALOG INPUT

® ®

(fs = 1MHz, fin = 485kHz, Vin = –0.5dB, 4,096-point FFT)

Amplitude Relative to Full Scale (dB)

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

–10
–20
–30
–40
–50
–60
–70
–80

–90
–100
–110
–120
–130

ADS-112

Table 4. Output Coding

STRAIGHT BIN. COMP. BINARY

OFF. BINARY COMP. OFF. BIN.

0

0 50 100 150 200 250 300 350 400 450 500

Frequency (kHz)

Figure 5. FFT Analysis of ADS-112

5

ADS-112

ISO 9001

REGISTERED

® ®

MECHANICAL DIMENSIONS INCHES (mm)

1.31 MAX.
(33.27)

0.235 MAX.

0.190 MAX.
(4.826)

0.018 ±0.002

(5.969)

(0.457)

24

1 12

0.100 TYP.
(2.540)

1.100

(27.940)

PIN 1 INDEX

0.100

(2.540)

0.040

(1.016)

13

0.80 MAX.
(20.32)

0.200 MAX.
(5.080)

SEATING

PLANE

0.025

(0.635)

Dimension Tolerances

2 place decimal (.XX) ±0.010 (±0.254)
3 place decimal (.XXX) ±0.005 (±0.127)

Lead Material: Kovar alloy
Lead Finish:

over 100 microinches (nominal) nickel plating

50 microinches (minimum) gold plating

0.010

(0.254)

0.600 ±0.010
(15.240)

(unless otherwise indicated):

+0.002
–0.001

0.100

(2.540)

ORDERING INFORMATION

MODEL NUMBER OPERATING TEMP. RANGE
ADS-112MC 0 to +70°C

ADS-112MM –55 to +125°C
ADS-112/883 –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-EVAL4 Evaluation Board (without ADS-112)

HS-32 Heat Sink for all ADS-112 models

ISO 9001

DS-0149F 10/96

DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151
Tel: [phone] [phone] Fax: [phone]
Internet: www.datel.com E-mail:[e-mail]
Data Sheet Fax Back: [phone]

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.

DATEL (UK) LTD. Tadley, England Tel: [phone]
DATEL S.A.R.L. Montigny Le Bretonneux, France Tel: [phone]
DATEL GmbH München, Germany Tel: [phone]
DATEL KK Tokyo, Japan Tel: [phone], Osaka Tel: [phone]