DATEL ADS-EVAL3, ADS-930MM, ADS-930MC Datasheet

DATEL, Inc., 11

Boulevard, Mansfield, MA 02048 (U.S.A.) • Tel: [phone] Fax: [phone] • Email: [e-mail]

FEATURES

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INNOV A TION and EX CELLENCE

3-STATE

OUTPUT REGISTER

21 BIT 16 (LSB)

CUSTOM GATE ARRAY

3-PASS ANALOG-TO-DIGITAL CONVERTER

• 16-bit resolution

• 500kHz sampling rate

• Functionally complete

• Excellent dynamic performance

• 83dB SNR, –89dB THD

• No missing codes

• Small, 40-pin, TDIP package

• 3.5 Watts power dissipation

• On-board FIFO

GENERAL DESCRIPTION

The low-cost ADS-930 is a high-performance, 16-bit, 500kHz
sampling A/D converter. This device accurately samples full­scale input signals up to Nyquist frequencies with no missing
codes. The dynamic performance of the ADS-930 is optimized
to achieve a THD of –89dB and an SNR of 83dB.

Packaged in a small, 40-pin, ceramic TDIP, the functionally
complete ADS-930 contains a fast-settling sample-hold
amplifier, a subranging (three-pass) A/D converter, an internal
reference, an on-board FIFO, timing and control logic, three­state outputs and error-correction circuitry. Digital inputs/
outputs are TTL.

Requiring ±15V and +5V supplies, the ADS-930 typically
dissipates 3.5 Watts. The unit is offered with a bipolar input
range of ±5V or a unipolar input range of 0 to –10V. Models
are available for use in either commercial (0 to +70°C) or
military (–55 to +125°C) operating temperature ranges.
Typical applications include radar, sonar, medical/graphic
imaging, and FFT spectrum analysis.

ADS-930

16-Bit, 500kHz

Sampling A/D Converters

INPUT/OUTPUT CONNECTIONS

PIN FUNCTION PIN FUNCTION

1 +10V REF. OUT 40 BIT 1 (MSB)
2 BIPOLAR 39 BIT 1 (MSB)
3 ANALOG INPUT 38 BIT 2
4 ANALOG GROUND 37 BIT 3
5 OFFSET ADJUST 36 BIT 4
6 GAIN ADJUST 35 BIT 5
7 +15V SUPPLY 34 BIT 6
8 COMP. BITS 33 BIT 7

9 ENABLE 32 BIT 8
10 FIFO READ 31 BIT 9
11 ANALOG GROUND 30 ANALOG GROUND
12 –15V SUPPLY 29 BIT 10
13 ANALOG GROUND 28 BIT 11
14 OVERFLOW 27 BIT 12
15 EOC 26 BIT 13
16 +5V SUPPLY 25 BIT 14
17 START CONVERT 24 DIGITAL GROUND
18 DIGITAL GROUND 23 FIFO/DIR
19 FSTAT1 22 BIT 15
20 FSTAT2 21 BIT 16 (LSB)

POWER AND GROUNDING

+5V SUPPLY
+15V SUPPLY
–15V SUPPLY
ANALOG GROUND
DIGITAL GROUND

Cabot

4, 11, 13, 30

18, 24

16

7

12

GAIN

ADJUST

CKT.

+10V REFERENCE

OFFSET
ADJUST

CKT.

S/H

CONTROL LOGIC

PRECISION

TIMING AND

GAIN ADJUST 6

+10V REF. OUT 1

OFFSET ADJUST 5

BIPOLAR 2

ANALOG INPUT 3

START CONVERT 17

EOC 15

COMP. BITS 8

Figure 1. ADS-930 Functional Block Diagram

19 FSTAT1
20 FSTAT2
23 FIFO/DIR
10 FIFO READ

40 BIT 1 (MSB)
39 BIT 1 (MSB)
38 BIT 2
37 BIT 3
36 BIT 4
35 BIT 5
34 BIT 6
33 BIT 7
32 BIT 8
31 BIT 9
29 BIT 10
28 BIT 11
27 BIT 12
26 BIT 13
25 BIT 14
22 BIT 15

9 ENABLE

14 OVERFLOW

ADS-930

2

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ABSOLUTE MAXIMUM RATINGS

PARAMETERS LIMITS UNITS

+15V Supply (Pin 7) 0 to +16 Volts
–15V Supply (Pin 12) 0 to –16 Volts
+5V Supply (Pin 16) 0 to +6 Volts
Digital Inputs (Pin 8, 9, 10, 17, 23) –0.3 to +V
Analog Input (Pin 3)

Unipolar –12.5 to +12.5 Volts
Bipolar –7.5 to +12.5 Volts

Lead Temperature (10 seconds) +300 °C

DD +0.3 Volts

PHYSICAL/ENVIRONMENTAL

PARAMETERS MIN. TYP. MAX. UNITS

Operating Temp. Range, Case

ADS-930MC 0 — +70 °C
ADS-930MM –55 — +125 °C

Thermal Impedance

θjc — 4 — °C/Watt
θca — 18 — °C/Watt

Storage Temperature Range –65 — +150 °C
Package Type 40-pin, metal-sealed, ceramic TDIP

Weight 0.56 ounces (16 grams)

FUNCTIONAL SPECIFICATIONS

(TA = +25°C, ±VCC = ±15V, +VDD = +5V, 500kHz sampling rate, and a minimum 5 minute warmup ➀ unless otherwise specified.)

+25°C 0 to +70°C –55 to +125°C

ANALOG INPUTS MIN. TYP. MAX. MIN. TYP. MAX. MIN. TYP. MAX. UNITS

Input Voltage Range

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

Input Resistance 1.4 1.5 1.7 1.4 1.5 1.7 1.4 1.5 1.7 kΩ
Input Capacitance — 7 15 — 7 15 — 7 15 pF

DIGITAL INPUTS

Logic Levels

Logic "1" +2.0 — — +2.0 — — +2.0 — — Volts
Logic "0" — — +0.8 — — +0.8 — — +0.8 Volts
Logic Loading "1" — — +20 — — +20 — — +20 µA
Logic Loading "0" ➁ — — –20 — — –20 — — –20 µA

Start Convert Positive Pulse Width ➂ 175 200 215 175 200 215 175 200 215 ns

STATIC PERFORMANCE

Resolution — 16 — — 16 — — 16 — Bits
Integral Nonlinearity (f
Differential Nonlinearity (f

in = 10kHz) — ±1.0 — — ±1.5 — — ±2.0 — LSB

in = 10kHz) — ±0.75 — — ±1.0 — — ±1.5 — LSB

Full Scale Absolute Accuracy — ±0.05 ±0.18 — ±0.2 ±0.5 — ±0.5 ±0.8 %FSR
Unipolar Zero Error (Tech Note 2) — ±0.05 ±0.085 — ±0.1 ±0.25 — ±0.25 ±0.5 %FSR
Bipolar Zero Error (Tech Note 2) — ±0.05 ±0.085 — ±0.15 ±0.25 — ±0.25 ±0.5 %FSR
Bipolar Offset Error (Tech Note 2) — ±0.05 ±0.15 — ±0.1 ±0.25 — ±0.25 ±0.5 %FSR
Gain Error (Tech Note 2) — ±0.1 ±0.15 — ±0.15 ±0.35 — ±0.25 ±0.65 %
No Missing Codes (f

in = 10kHz) 16 — — 16 — — 15 — — Bits

DYNAMIC PERFORMANCE

Peak Harmonics (–0.5dB)

dc to 100kHz — –91 — — –91 — — –87 — dB
100kHz to 250kHz — –86 — — –86 — — –84 — dB

Total Harmonic Distortion (–0.5dB)

dc to 100kHz — –89 –81 — –89 –81 — –85 –76 dB
100kHz to 250kHz — –84 — — –84 — — –82 — dB

Signal–to–Noise Ratio

(w/o distortion, –0.5dB)
dc to 100kHz 81 83 — 81 83 — 75 80 — dB
100kHz to 250kHz — 80 — — 80 — — 79 — dB

Signal–to–Noise Ratio ➃

(& distortion, –0.5dB)
dc to 100kHz 78 81 — 77 81 — 72 78 — dB
100kHz to 250kHz — 78 — — 78 — — 76 — dB

Two–Tone Intermodulation

Distortion (f

240kHz, f

in = 100kHz,

s = 500kHz, –0.5dB) — –82 — — –82 — — –81 — dB

Noise — 150 — — 150 — — 150 — µVrms
Input Bandwidth (–3dB)

Small Signal (–20dB input) — 2 — — 2 — — 2 — MHz
Large Signal (–0.5dB input) — 1.1 — — 1.1 — — 1.1 — MHz

Feedthrough Rejection

in = 250kHz) — 92 — — 92 — — 92 — dB

(f

Slew Rate — ±80 — — ±80 — — ±80 — V/µs

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ADS-930

+25°C 0 to +70°C –55 to +125°C

DYNAMIC PERFORMANCE (Cont.) MIN. TYP. MAX. MIN. TYP. MAX. MIN. TYP. MAX. UNITS

Aperture Delay Time — ±10 — — ±10 — — ±10 — ns
Aperture Uncertainty — 5 — — 5 — — 5 — ps rms
S/H Acquisition Time

( to ±0.003%FSR, 10V step) — 460 545 — 460 545 — 460 545 ns

Overvoltage Recovery Time — 600 1000 — 600 1000 — 600 1000 ns
A/D Conversion Rate 500 — — 500 — — 500 — — kHz

ANALOG OUTPUT

Internal Reference

Voltage +9.95 +10.0 +10.05 +9.95 +10.0 +10.05 +9.95 +10.0 +10.05 Volts
Drift — ±10 — — ±10 — — ±10 — ppm/°C

External Current — — 1 — — 1 — — 1 mA

DIGITAL OUTPUTS

Logic Levels

Logic "1" +2.4 — — +2.4 — — +2.4 — — Volts
Logic "0" — — +0.4 — — +0.4 — — +0.4 Volts
Logic Loading "1" — — –4 — — –4 — — –4 mA
Logic Loading "0" — — +4 — — +4 — — +4 mA

Delay, Falling Edge of ENABLE

to Output Data Valid — — 10 — — 10 — — 10 ns

Output Coding

POWER REQUIREMENTS

Complementary Offset Binary; Complementary Two's Complement, Offset Binary, Two's Complement

Power Supply Ranges

+15V Supply +14.5 +15.0 +15.5 +14.5 +15.0 +15.5 +14.5 +15.0 +15.5 Volts
–15V Supply –14.5 –15.0 –15.5 –14.5 –15.0 –15.5 –14.5 –15.0 –15.5 Volts
+5V Supply +4.75 +5.0 +5.25 +4.75 +5.0 +5.25 +4.75 +5.0 +5.75 Volts

Power Supply Currents

+15V Supply — +110 +130 — +110 +130 — +110 +130 mA
–15V Supply — –100 –125 — –100 –125 — –100 –125 mA
+5V Supply — +80 +90 — +80 +90 — +80 +90 mA

Power Dissipation — 3.5 4.25 — 3.5 4.25 — 3.5 4.25 Watts
Power Supply Rejection — — ±0.02 — — ±0.02 — — ±0.02 %FSR/%V

Footnotes:

➀ All power supplies must be on before applying a start convert pulse. All

supplies and the clock (START CONVERT) must be present during warmup
periods. The device must be continuously converting during this time.

➁ When COMP. BITS (pin 8) is low, logic loading "0" will be –350µA.
➂ A 200ns wide start convert pulse is used for all production testing. For

applications requiring less than a 500kHz sampling rate, wider start convert
pulses can be used.

➃ Effective bits is equal to:

(SNR + Distortion) – 1.76 + 20 log

Full Scale Amplitude

Actual Input Amplitude

6.02

TECHNICAL NOTES

1. Obtaining fully specified performance from the ADS-930
requires careful attention to pc-card layout and power
supply decoupling. The device's analog and digital
ground systems are connected to each other internally.
For optimal performance, tie all ground pins (4, 11, 13,
18, 24 and 30) directly to a large analog ground plane
beneath the package.

Bypass all power supplies and the +10V reference output
to ground with 4.7µF tantalum capacitors in parallel with

0.1µF ceramic capacitors. Locate the bypass capacitors
as close to the unit as possible.

2. The ADS-930 achieves its specified accuracies without
the need for external calibration. If required, the device's
small initial offset and gain errors can be reduced to zero
using the adjustment circuitry shown in Figure 2. When
using this circuitry, or any similar offset and gain calibra­tion hardware, make adjustments following warmup. To
avoid interaction, always adjust offset before gain. Tie
pins 5 and 6 to ANALOG GROUND (pin 4) if not using
offset and gain adjust circuits.

3. Pin 8 (COMP. BITS) is used to select the digital output coding
format of the ADS-930. See Tables 3a and 3b. When this pin
has a TTL logic "0" applied, it complements all of the
ADS-930's digital outputs.

When pin 8 has a logic "1" applied and the ADS-930 is
operated within its unipolar (0 to –10V) input range, the output
coding is straight binary. Applying a logic "0" to pin 8 under
these conditions changes the output coding to complemen­tary binary.

When pin 8 has a logic "1" applied and the ADS-930 is
operated within its bipolar (±5V) input range, the output coding
is offset binary. Applying a logic "0" to pin 8 under these
conditions changes the coding to complementary offset
binary. Using the MSB output (pin 40) instead of the MSB
output (pin 39) under these conditions changes the respective
output codings to two's complement and complementary two's
complement.

Pin 8 is TTL-compatible and can be directly driven with digital

logic in applications requiring dynamic control over its
function. There is an internal pull-up resistor on pin 8 allowing