ADS-112MC - Datel, Inc. - Product.Network

® ®

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

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

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 high-

speed data acquisition systems.

INPUT/OUTPUT CONNECTIONS

PIN FUNCTION PIN FUNCTION

1BIT 12 (LSB) 24 –15V SUPPLY

2BIT 11 23 ANALOG GROUND

3BIT 10 22 +15V SUPPLY

4BIT 9 21 +10V REFERENCE

5BIT 8 20 BIPOLAR

6BIT 7 19 ANALOG INPUT

7BIT 6 18 COMP BIN

8BIT 5 17 ENABLE (1-12)

9BIT 4 16 START CONVERT

10 BIT 3 15 EOC

11 BIT 2 14 DIGITAL GROUND

12 BIT 1 (MSB) 13 +5V SUPPLY

REF

REGISTERREGISTER

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)

+5V SUPPLY

+15V SUPPLY

ANALOG GROUND

DIGITAL GROUND

–15V SUPPLY

® ®

ADS-112

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

(12 Bits; fin = 1MHz) Over the operating temperature range

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

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 (fin = 75kHz,

105kHz, fs = 1MHz, –0.7dB) —–88 –80 dB

Two-tone Intermodulation

Distortion (fin = 480kHz,

490kHz, fs = 1MHz, –0.7dB) —–68 –65 dB

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

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)

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 +VDD +0.3 Volts

Analog Input (Pin 19) –9 to +15 Volts

Lead Temp. (10 seconds) +300 °C

† See Tech Note 1 6.02

(SNR + Distortion) – 1.76 + 20 log Full Scale Amplitude

Actual Input Amplitude

➁Effective bits is equal to:

➀ See Table 3 also

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

Staight binary/Offset binary

Complementary binary

Complementary offset binary

® ® ADS-112

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.

TECHNICAL NOTES

1. Applications which are unaffected by endpoint errors or

remove them through software will use the typical connec-

tions 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

Figure 2. ADS-112 Timing Diagram

START

CONVERT

INTERNAL S/H

NN+1

150ns, ±25ns

Acquisition Time

250ns

10ns min.

20ns max.

EOC

20ns max.

Conversion Time

600ns max.

60ns max.

Note: Scale is approximately 50ns per division.

35ns max.

OUTPUT

DATA DATA N-1 VALID INVALID

DATA

DATA N VALID

800ns min. INVALID

DATA

200ns max.

Hold

® ®

ADS-112

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 potentiom-

eter 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.

Figure 3. Typical ADS-112 Connection Diagram

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

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

To Pin19

of ADS-112

–15V

+15V

For values of R1 and R2 refer to Table 3.

5kΩ

50Ω

10kΩ

ZERO/

OFFSET

ADJUST

SIGNAL

INPUT

GAIN

ADJUST

5kΩ

➀

Figure 4. Optional Calibration Circuit

Table 2. Zero and Gain Adjust

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

0.1µF

4.7µF

ADS-112

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)

ANALOG INPUT

START CONVERT

+5V

–15V

+15V +

0.1µF

4.7µF 23

0.1µF

4.7µF

COMP BIN

0.1µF

4.7µF

21 +10V REF.

UNIPOLAR

OPERATION

BIPOLAR

OPERATION

18 +5V

Note: Always bypass pin 21 to ground

® ® ADS-112

Table 4. Output Coding

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

00.0000 0000 0000 0000 1111 1111 1111 –5.0000 –FS

STRAIGHT BIN. COMP. BINARY

OFF. BINARYCOMP. OFF. BIN.

Figure 5. FFT Analysis of ADS-112

–10

–20

–30

–40

–50

–60

–70

–80

–90

–100

–110

–120

–130

0 50 100 150 200 250 300 350 400 450 500

Frequency (kHz)

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

Amplitude Relative to Full Scale (dB)

® ®

ADS-112

® ®

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.

DS-0149F 10/96

MECHANICAL DIMENSIONS INCHES (mm)

ORDERING INFORMATION

ACCESSORIES

ADS-EVAL4 Evaluation Board (without ADS-112)

HS-32 Heat Sink for all ADS-112 models

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.

0.200 MAX.

(5.080)

0.235 MAX.

(5.969)

0.600 ±0.010

(15.240)

0.80 MAX.

(20.32)

0.100 TYP.

(2.540)

0.100

(2.540)

0.018 ±0.002

(0.457)

0.100

(2.540)

0.040

(1.016)

1.31 MAX.

(33.27)

112

1.100

(27.940)

0.190 MAX.

(4.826)

0.010

(0.254)

+0.002

–0.001

SEATING

PLANE

0.025

(0.635)

Dimension Tolerances (unless otherwise indicated):

2 place decimal (.XX) ±0.010 (±0.254)

3 place decimal (.XXX) ±0.005 (±0.127)

Lead Material: Kovar alloy

Lead Finish: 50 microinches (minimum) gold plating

over 100 microinches (nominal) nickel plating

PIN 1 INDEX

ISO 9001

ISO

9001

REGISTERED

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

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