DATEL ADS-917MM, ADS-917MC, ADS-917GM, ADS-917GC, ADS-927MM Datasheet

® ®

REGISTERREGISTER

START CONVERT 16

DIGITAL CORRECTION LOGIC

+5V SUPPLY

+12V/+15V SUPPLY

ANALOG GROUND

DIGITAL GROUND

–12V/–15V SUPPLY

FEATURES

• 14-bit resolution

• 1MHz sampling rate

• Functionally complete; No missing codes

• Edge-triggered; No pipeline delays

• Small 24-pin DDIP or SMT package

• Low power, 1.9 Watts maximum

• Operates from ±15V or ±12V supplies

• Unipolar 0 to +10V input range

ADS-917

14-Bit, 1MHz, Low-Power

Sampling A/D Converters

GENERAL DESCRIPTION

The ADS-917 is a high-performance, 14-bit, 1MHz sampling
A/D converter. This device samples input signals up to Nyquist
frequencies with no missing codes. The ADS-917 features
outstanding dynamic performance including a THD of –80dB.

Housed in a small 24-pin DDIP or SMT (gull-wing) package,
the functionally complete ADS-917 contains a fast-settling
sample-hold amplifier, a subranging (two-pass) A/D converter,
a precise voltage reference, timing/control logic, and error­correction circuitry. Digital input and output levels are TTL.

Requiring ±15V (or ±12V) and +5V supplies, the ADS-917
dissipates 1.9W (1.6W for ±12V) maximum. The unit is offered
with a unipolar input (0 to +10V). Models are available for use
in either commercial (0 to +70°C) or military (–55 to +125°C)
operating temperature ranges. Applications include radar,
sonar, spectrum analysis, and graphic/medical imaging.

+10V REF. OUT 21

S

2

ANALOG INPUT 20

S/H

–
+

S

1

BUFFER

INPUT/OUTPUT CONNECTIONS

PIN FUNCTION PIN FUNCTION

1 BIT 14 (LSB) 24 –12V/–15V SUPPLY
2 BIT 13 23 ANALOG GROUND
3 BIT 12 22 +12V/+15V SUPPLY
4 BIT 11 21 +10V REFERENCE OUT
5 BIT 10 20 ANALOG INPUT
6 BIT 9 19 ANALOG GROUND
7 BIT 8 18 BIT 1 (MSB)
8 BIT 7 17 BIT 2

9 BIT 6 16 START CONVERT
10 BIT 5 15 EOC
11 BIT 4 14 DIGITAL GROUND
12 BIT 3 13 +5V SUPPLY

DAC

18 BIT 1 (MSB)

REF

FLASH

ADC

17 BIT 2
12 BIT 3
11 BIT 4
10 BIT 5
9 BIT 6
8 BIT 7
7 BIT 8
6 BIT 9
5 BIT 10
4 BIT 11
3 BIT 12
2 BIT 13
1 BIT 14 (LSB)

TIMING AND

13

CONTROL LOGIC

14

22

19, 23

24

EOC 15

Figure 1. ADS-917 Functional Block Diagram

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

ADS-917

® ®

ABSOLUTE MAXIMUM RATINGS

PARAMETERS LIMITS UNITS

+12V/+15V Supply (Pin 22) 0 to +16 Volts
–12V/–15V Supply (Pin 24) 0 to –16 Volts
+5V Supply (Pin 13) 0 to +6 Volts
Digital Input (Pin 16) –0.3 to +V
Analog Input (Pin 20) –4 to +17 Volts
Lead Temperature (10 seconds) +300 °C

DD +0.3 Volts

PHYSICAL/ENVIRONMENTAL

PARAMETERS MIN. TYP. MAX. UNITS

Operating Temp. Range, Case

ADS-917MC, GC 0 — +70 °C
ADS-917MM, GM –55 — +125 °C

Thermal Impedance

θjc 6 °C/Watt
θca 24 °C/Watt

Storage Temperature –65 — +150 °C
Package Type 24-pin, metal-sealed, ceramic DDIP or SMT
Weight 0.42 ounces (12 grams)

FUNCTIONAL SPECIFICATIONS

(TA = +25°C, ±VCC = ±15V (or ±12V), +VDD = +5V, 1MHz sampling rate, and a minimum 1 minute warmup ➀ unless otherwise specified.)

+25°C 0 to +70°C –55 to +125°C

ANALOG INPUT MIN. TYP. MAX. MIN. TYP. MAX. MIN. TYP. MAX. UNITS

Input Voltage Range ➁ — 0 to +10 — — 0 to +10 — — 0 to +10 — Volts
Input Resistance — 1 — — 1 — — 1 — kΩ
Input Capacitance — 7 15 — 7 15 — 7 15 pF

DIGITAL INPUT

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" — — –20 — — –20 — — –20 µA

Start Convert Positive Pulse Width ➂ 20 200 — 20 200 — 20 200 — ns

STATIC PERFORMANCE

Resolution — 14 — — 14 — — 14 — Bits
Integral Nonlinearity (f
Differential Nonlinearity (f

in = 10kHz) — ±0.5 — — ±0.75 — — ±1.5 — LSB

in = 10kHz) — ±0.5 ±0.95 — ±0.5 ±0.95 –0.95 ±0.75 +1.25 LSB

Full Scale Absolute Accuracy — ±0.05 ±0.1 — ±0.1 ±0.2 — ±0.15 ±0.4 %FSR
Unipolar Offset Error (Tech Note 2) — ±0.1 ±0.2 — ±0.1 ±0.2 — ±0.15 ±0.4 %FSR
Gain Error (Tech Note 2) — ±0.1 ±0.25 — ±0.1 ±0.25 — ±0.25 ±0.4 %
No Missing Codes (f

in = 10kHz) 14 — — 14 — — 14 — — Bits

DYNAMIC PERFORMANCE

Peak Harmonics (–0.5dB)

dc to 100kHz — –87 –82 — –87 –82 — –85 –80 dB
100kHz to 500kHz — –81 –76 — –81 –76 — –79 –74 dB

Total Harmonic Distortion (–0.5dB)

dc to 100kHz — –85 –82 — –85 –82 — –84 –80 dB
100kHz to 500kHz — –80 –76 — –80 –76 — –79 –74 dB

Signal-to-Noise Ratio

(w/o distortion, –0.5dB)
dc to 100kHz 75 79 — 75 79 — 73 77 — dB
100kHz to 500kHz 73 78 — 73 78 — 72 76 — dB

Signal-to-Noise Ratio ➃

(& distortion, –0.5dB)
dc to 100kHz 74 77 — 74 77 — 72 76 — dB
100kHz to 500kHz 72 76 — 72 76 — 71 75 — dB

Two-Tone Intermodulation

Distortion (f

240kHz, f

in = 100kHz,

s = 1MHz, –0.5dB) — –87 — — –86 — — –85 — dB

Noise — 300 — — 400 — — 600 — µVrms
Input Bandwidth (–3dB)

Small Signal (–20dB input) — 7 — — 7 — — 7 — MHz
Large Signal (–0.5dB input) — 5 — — 5 — — 5 — MHz

Feedthrough Rejection (f

in = 500kHz) — 84 — — 84 — — 84 — dB

Slew Rate — ±60 — — ±60 — — ±60 — V/µs
Aperture Delay Time — ±20 — — ±20 — — ±20 — ns
Aperture Uncertainty — 5 — — 5 — — 5 — ps rms
S/H Acquisition Time

(to ±0.003%FSR, 10V step) 530 570 610 530 570 610 530 570 610 ns

Overvoltage Recovery Time ➄ — 400 1000 — 400 1000 — 400 1000 ns
A/D Conversion Rate 1 — — 1 — — 1 — — MHz

2

® ®

ADS-917

+25°C 0 to +70°C –55 to +125°C

ANALOG OUTPUT MIN. TYP. MAX. MIN. TYP. MAX. MIN. TYP. MAX. UNITS

Internal Reference

Voltage +9.95 +10.0 +10.05 +9.95 +10.0 +10.05 +9.95 +10.0 +10.05 Volts
Drift — ±5 — — ±5 — — ±5 — ppm/°C

External Current — — 1.5 — — 1.5 — — 1.5 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 EOC

to Output Data Valid — — 35 — — 35 — — 35 ns

Output Coding Straight Binary

POWER REQUIREMENTS, ±15V

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 +5.25 Volts

Power Supply Currents

+15V Supply — +50 +65 — +50 +65 — +50 +65 mA
–15V Supply — –41 –50 — –41 –50 — –41 –50 mA
+5V Supply — +70 +85 — +70 +85 — +70 +85 mA

Power Dissipation — 1.7 1.9 — 1.7 1.9 — 1.7 1.9 Watts
Power Supply Rejection — — ±0.01 — — ±0.01 — — ±0.01 %FSR/%V

POWER REQUIREMENTS, ±12V

Power Supply Ranges

+12V Supply +11.5 +12.0 +12.5 +11.5 +12.0 +12.5 +11.5 +12.0 +12.5 Volts
–12V Supply –11.5 –12.0 –12.5 –11.5 –12.0 –12.5 –11.5 –12.0 –12.5 Volts
+5V Supply +4.75 +5.0 +5.25 +4.75 +5.0 +5.25 +4.75 +5.0 +5.25 Volts

Power Supply Currents

+12V Supply — +50 +65 — +50 +65 — +50 +65 mA
–12V Supply — –40 –48 — –40 –48 — –40 –48 mA
+5V Supply — +70 +80 — +70 +80 — +70 +80 mA

Power Dissipation — 1.4 1.6 — 1.4 1.6 — 1.4 1.6 Watts
Power Supply Rejection — — ±0.01 — — ±0.01 — — ±0.01 %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. There is a slight
degradation in performance when using ±12V supplies.

➁ See Ordering Information for availability of ±5V input range. Contact DATEL for

availability of other input voltage ranges.

➂ A 1MHz clock with a 200ns wide start convert pulse is used for all production

testing. See Timing Diagram for more details.

TECHNICAL NOTES

1. Obtaining fully specified performance from the ADS-917
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 (14, 19 and 23) directly to a
large analog ground plane beneath the package.

Bypass all power supplies, as well as the REFERENCE
OUTPUT (pin 21), 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. If the
user-installed offset and gain adjusting circuit shown in
Figure 2 is used, also locate it as close to the ADS-917 as
possible.

2. The ADS-917 achieves its specified accuracies without the

➃ Effective bits is equal to:

(SNR + Distortion) – 1.76 + 20 log

6.02

➄ This is the time required before the A/D output data is valid after the analog input

is back within the specified range.

Full Scale Amplitude

Actual Input Amplitude

need for external calibration. If required, the device's small
initial offset and gain errors can be reduced to zero using
the input circuit of Figure 2. When using this circuit, or any
similar offset and gain-calibration hardware, make adjust­ments following warmup. To avoid interaction, always
adjust offset before gain.

3. When operating the ADS-917 from ±12V supplies, do not
drive external circuitry with the REFERENCE OUTPUT. The
reference's accuracy and drift specifications may not be
met, and loading the circuit may cause accuracy errors
within the converter.

4. Applying a start convert pulse while a conversion is in
progress (EOC = logic "1") initiates a new and inaccurate
conversion cycle. Data from the interrupted and subsequent
conversions will be invalid.

3