Analog Devices AD976BN, AD976AAN, AD976A, AD976, AD976ABRS Datasheet

16-Bit, 100 kSPS/200 kSPS

REF

V

ANA

4kV

R

D15
D0

DGND

BYTE

R/C

CS BUSY

V

DIG

V

IN

AGND2

CAP

AGND1

2.5V

REFERENCE

4R

CONTROL LOGIC &

INTERNAL CALIBRATION CIRCUITRY

CLOCK

PARALLEL

INTERFACE

SWITCHED

CAP ADC

AD976/AD976A

4R

3

R = 6kV AD976
R = 3kV AD976A

a

FEATURES
Fast 16-Bit ADC
200 kSPS Throughput – AD976A
100 kSPS Throughput – AD976
Single 5 V Supply Operation
Input Range: ⴞ10 V
100 mW Max Power Dissipation
Choice of External or Internal 2.5 V Reference
High Speed Parallel Interface
On-Chip Clock
28-Lead Skinny DIP, SSOP or SOIC Packages

GENERAL DESCRIPTION

The AD976/AD976A is a high speed, low power 16-bit A/D
converter that operates from a single 5 V supply. The part con­tains a successive approximation, switched capacitor ADC, an
internal 2.5 V reference and a high speed parallel interface. The
ADC is factory calibrated to minimize all linearity errors. The

analog full-scale input is the standard industrial range of ±10 V.

The AD976/AD976A is comprehensively tested for ac param­eters such as SNR and THD, as well as the more traditional
parameters of offset, gain and linearity.

The AD976/AD976A is fabricated on Analog Devices’ propri­etary BiCMOS process, which has high performance bipolar
devices along with CMOS transistors.

The AD976/AD976A is available in skinny 28-lead DIP, SSOP
and SOIC packages.

BiCMOS A/D Converters

AD976/AD976A

FUNCTIONAL BLOCK DIAGRAM

PRODUCT HIGHLIGHTS

1. Fast Throughput.
The AD976/AD976A is a high speed (100 kSPS/200 kSPS
throughput rates respectively), 16-bit ADC based on a
switched capacitor architecture.

2. Single-Supply Operation.
The AD976/AD976A operates from a single 5 V supply and
dissipates only 100 mW max.

3. Comprehensive DC and AC Specifications.
The AD976/AD976A is factory calibrated and fully tested for
SNR and THD as well as the traditional specifications of
offset, gain and linearity.

4. Complete A/D Solution.
The AD976/AD976A offers a highly integrated solution
containing an accurate ADC, reference and on-chip clock.

REV. C

Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] World Wide Web Site: http://www.analog.com
Fax: [phone] © Analog Devices, Inc., 1999

AD976/AD976A

AD976A–SPECIFICATIONS

(–40ⴗC to +85ⴗC, FS = 200 kHz, Ref = Internal Reference, V
otherwise noted)

DIG

= V

ANA

= +5 V unless

Parameter Min Typ Max Min Typ Max Min Typ Max Units

AD976AA AD976AB AD976AC

RESOLUTION 16 16 16 Bits

ANALOG INPUT

Voltage Range ±10 ±10 ±10 V
Impedance 13 13 13 kΩ

Capacitance 22 22 22 pF

THROUGHPUT SPEED

Complete Cycle 5 5 5 µs

Throughput Rate 200 200 200 kHz

DC ACCURACY

Integral Linearity Error ±3 ±2 ±3 LSB

1

Differential Linearity Error –2 +3 –1 +1.75 ±2 LSB

No Missing Codes 15 16 15 Bit
Transition Noise
Full-Scale Error

3, 4

2

1.0 1.0 1.0 LSB

±0.5 ±0.25 ±0.5 %
Full-Scale Error Drift ±7 ±7 ±7 ppm/°C
Full-Scale Error, Ext. REF = 2.5 V ±0.5 ±0.25 ±0.5 %
Full-Scale Error Drift, Ext. REF = 2.5 V ±2 ±2 ±2 ppm/°C

Bipolar Zero Error

4

±10 ±10 ±15 mV
Bipolar Zero Error Drift ±2 ±2 ±2 ppm/°C

Power Supply Sensitivity

V

= V

= V

ANA

DIG

AC ACCURACY

Spurious Free Dynamic Range
Total Harmonic Distortion
Signal to (Noise + Distortion)

–60 dB Input 27 28 27 dB
Signal to Noise
Full-Power Bandwidth

= 5 V ± 5% ±8 ±8 ±8 LSB

D

5

5

5

5

7

90 96 90 dB

–90 –96 –90 dB

83 85 83 dB

83 85 83 dB

1 1 1 MHz

6

Input Bandwidth 2.7 2.7 2.7 MHz

SAMPLING DYNAMICS

Aperture Delay 40 40 40 ns
Transient Response

Full-Scale Step 1 1 1 µs

Overvoltage Recovery

8

150 150 150 ns

REFERENCE

Internal Reference Voltage 2.48 2.5 2.52 2.48 2.5 2.52 2.48 2.5 2.52 V

Internal Reference Source Current 1 1 1 µA

External Reference Voltage Range

for Specified Linearity 2.3 2.5 2.7 2.3 2.5 2.7 2.3 2.5 2.7 V
External Reference Current Drain

Ext. REF = 2.5 V 100 100 100 µA

DIGITAL INPUTS

Logic Levels

V

IL

V

IH

I

IL

I

IH

NOTES

1

LSB means least significant bit. With a ±10 V input, one LSB is 305 µV.

2

Typical rms noise at worst case transitions and temperatures.

3

Measured with fixed resistors as shown in Figure 5 (AD976) and Figure 6 (AD976A). Adjustable to zero as shown in Figure 7.

4

Full-scale error is expressed as the % difference between the actual full-scale code transition voltage and the ideal full-scale transition voltage and includes the effect
of offset error. The full-scale error is the worst case of either the –full-scale or +full-scale code transition voltage errors.

5

fIN = 20 kHz (AD976) and fIN = 45 kHz (AD976A), 0.5 dB down, unless otherwise noted.

6

All specifications in dB are referred to a full scale ±10 V input.

7

Full-power bandwidth is defined as full-scale input frequency at which signal-to-(noise + distortion) degrades to 60 dB or 10 bits of accuracy.

8

Recovers to specified performance after a 2 × F

Specifications subject to change without notice.

–0.3 +0.8 –0.3 +0.8 –0.3 +0.8 V
+2.0 V

+ 0.3 +2.0 V

DIG

+ 0.3 +2.0 V

DIG

+ 0.3 V

DIG

±10 ±10 ±10 µA
±10 ±10 ±10 µA

input overvoltage.

S

–2–

REV. C

AD976–SPECIFICATIONS

(–40ⴗC to +85ⴗC, FS = 100 kHz, Ref = Internal Reference,
V

= V

DIG

= +5 V unless otherwise noted)

ANA

AD976/AD976A

Parameter Min Typ Max Min Typ Max Min Typ Max Units

AD976A AD976B AD976C

RESOLUTION 16 16 16 Bits

ANALOG INPUT

Voltage Range ±10 ±10 ±10 V
Impedance 23 23 23 kΩ

Capacitance 22 22 22 pF

THROUGHPUT SPEED

Complete Cycle 10 10 10 µs

Throughput Rate 100 100 100 kHz

DC ACCURACY

Integral Linearity Error ±3 ±2 ±3 LSB

1

Differential Linearity Error –2 +3 –1 +1.75 ±2 LSB

No Missing Codes 15 16 15 Bit
Transition Noise
Full-Scale Error

3, 4

2

1.0 1.0 1.0 LSB

±0.5 ±0.25 ±0.5 %
Full-Scale Error Drift ±7 ±7 ±7 ppm/°C
Full-Scale Error, Ext. REF = 2.5 V ±0.5 ±0.25 ±0.5 %
Full-Scale Error Drift, Ext. REF = 2.5 V ±2 ±2 ±2 ppm/°C

Bipolar Zero Error

4

±10 ±10 ±15 mV
Bipolar Zero Error Drift ±2 ±2 ±2 ppm/°C

Power Supply Sensitivity

V

= V

= V

ANA

DIG

AC ACCURACY

Spurious Free Dynamic Range
Total Harmonic Distortion
Signal to (Noise + Distortion)

–60 dB Input 27 28 27 dB
Signal to Noise
Full-Power Bandwidth

= 5 V ± 5% ±8 ±8 ±8 LSB

D

5

5

5

5

7

90 96 90 dB

–90 –96 –90 dB

83 85 83 dB

83 85 83 dB

700 700 700 kHz

6

Input Bandwidth 1.5 1.5 1.5 MHz

SAMPLING DYNAMICS

Aperture Delay 40 40 40 ns
Transient Response

Full-Scale Step 2 2 2 µs

Overvoltage Recovery

8

150 150 150 ns

REFERENCE

Internal Reference Voltage 2.48 2.5 2.52 2.48 2.5 2.52 2.48 2.5 2.52 V

Internal Reference Source Current 1 1 1 µA

External Reference Voltage Range

for Specified Linearity 2.3 2.5 2.7 2.3 2.5 2.7 2.3 2.5 2.7 V
External Reference Current Drain

Ext. REF = 2.5 V 100 100 100 µA

DIGITAL INPUTS

Logic Levels

V

IL

V

IH

I

IL

I

IH

NOTES

1

LSB means least significant bit. With a ±10 V input, one LSB is 305 µV.

2

Typical rms noise at worst case transitions and temperatures.

3

Measured with fixed resistors as shown in Figure 5 (AD976) and Figure 6 (AD976A). Adjustable to zero as shown in Figure 7.

4

Full-scale error is expressed as the % difference between the actual full-scale code transition voltage and the ideal full-scale transition voltage and includes the effect
of offset error. The full-scale error is the worst case of either the –full-scale or +full-scale code transition voltage errors.

5

fIN = 20 kHz (AD976) and fIN = 45 kHz (AD976A), 0.5 dB down, unless otherwise noted.

6

All specifications in dB are referred to a full scale ±10 V input.

7

Full-power bandwidth is defined as full-scale input frequency at which signal-to-(noise + distortion) degrades to 60 dB or 10 bits of accuracy.

8

Recovers to specified performance after a 2 × F

Specifications subject to change without notice.

–0.3 +0.8 –0.3 +0.8 –0.3 +0.8 V
+2.0 V

+ 0.3 +2.0 V

DIG

+ 0.3 +2.0 V

DIG

+ 0.3 V

DIG

±10 ±10 ±10 µA
±10 ±10 ±10 µA

input overvoltage.

S

REV. C

–3–

AD976/AD976A

All Grades

Parameter Conditions Min Typ Max Units

DIGITAL OUTPUTS

Data Format Parallel 16 Bits
Data Coding Binary Twos Complement

V

OL

V

OH

Leakage Current High-Z State, ±5 µA

Output Capacitance High-Z State 15 pF

DIGITAL TIMING

Bus Access Time 83 ns
Bus Relinquish Time 83 ns

POWER SUPPLIES

Specified Performance

V

DIG

V

ANA

I

DIG

I

ANA

Power Dissipation 100 mW

TEMPERATURE RANGE

Specified Performance –40 +85 °C

I

= 1.6 mA +0.4 V

SINK

I

= 500 µA+4 V

SOURCE

V

= 0 V to V

OUT

DIG

4.75 5 5.25 V

4.75 5 5.25 V

3.0 mA
11 mA

Specifications subject to change without notice.

TIMING SPECIFICATIONS

(AD976A: FS = 200 kHz; AD976: FS = 100 kHz; –40ⴗC to +85ⴗC, V

Convert Pulsewidth t
Data Valid Delay after R/C Low (AD976A/AD976) t

BUSY Delay from R/C Low t
BUSY Low (AD976A/AD976) t
BUSY Delay after End of Conversion (AD976A/AD976) t

Aperture Delay t
Conversion Time (AD976A/AD976) t
Acquisition Time t
Bus Relinquish Time t
BUSY Delay after Data Valid (AD976A/AD976) t
Previous Data Valid after R/C Low (AD976A/AD976) t
Throughput Time (AD976A/AD976) t
R/C to CS Setup Time t
Time Between Conversions (AD976A/AD976) t
Bus Access and Byte Delay t

Specifications subject to change without notice.

= V

DIG

= +5 V unless otherwise noted)

ANA

Symbol Min Typ Max Units

1

2

3

4

5

6

7

8

9

10

11

+ t

7

12

13

14

8

50 ns

4.0/8.0 µs

83 ns

4.0/8.0 µs

180/360 ns
40 ns

3.8/7.6 4.0/8.0 µs

1.0/2.0 µs

10 35 83 ns
50 180/360 ns

3.7/7.4 µs
5/10 µs

10 ns

5/10 µs

10 83 ns

–4–

REV. C

AD976/AD976A

ABSOLUTE MAXIMUM RATINGS

1

Analog Inputs

V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±25 V

IN

CAP . . . . . . . . . . . . . . . . +V

+ 0.3 V to AGND2 – 0.3 V

ANA

REF . . . . . . . . . . . . . . . . . . . . . Indefinite Short to AGND2

Ground Voltage Differences

DGND, AGND1, AGND2 . . . . . . . . . . . . . . . . . . . . ±0.3 V

Supply Voltages

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V

V

ANA

to V

V

DIG

V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V

DIG

Digital Inputs . . . . . . . . . . . . . . . . . . . –0.3 V to V

Internal Power Dissipation

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±7 V

ANA

2

DIG

+ 0.3 V

PDIP (N), SOIC (R), SSOP (RS) . . . . . . . . . . . . . 700 mW

Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . +150°C

Storage Temperature Range (N, R, RS) . . . –65°C to +150°C

Lead Temperature Range

(Soldering 10 sec) . . . . . . . . . . . . . . . . . . . . . . . . . . +300°C

NOTES

1

Stresses above those listed under Absolute Maximum Ratings may cause perma-

nent damage to the device. This is a stress rating only; functional operation of the
device at these or any other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.

2

Specification is for device in free air:

28-Lead PDIP: θJA = 74°C/W; θJC = 24°C/W,
28-Lead SOIC: θJA = 72°C/W; θJC = 23°C/W,
28-Lead SSOP: θJA = 109°C/W; θJC = 39°C/W.

PIN CONFIGURATION

DIP, SOIC and SSOP Packages

TO

OUTPUT

PIN

V

AGND1

REF
CAP

AGND2

D15 (MSB)

D14
D13
D12
D11
D10

DGND

C

100pF

IN

D9
D8

L

1
2
3
4
5

AD976A

6

TOP VIEW

(Not to Scale)

7
8

9
10
11
12
13
14

1.6mA I

500mA

AD976

28
27
26
25
24
23
22
21
20
19
18
17
16
15

OL

I

OH

V

DIG

V

ANA

BUSY

CS

R/C
BYTE
D0 (LSB)
D1
D2
D3
D4
D5
D6
D7

+2.1V

Figure 1. Load Circuit for Digital Interface Timing

ORDERING GUIDE

Temperature Max Min Throughput Package Package

Model Range INL S/(N+D) Rate Descriptions Options

AD976AN –40°C to +85°C ±3.0 LSB 83 dB 100 kSPS 28-Lead, 300 mil Plastic DIP N-28B
AD976BN –40°C to +85°C ±2.0 LSB 85 dB 100 kSPS 28-Lead, 300 mil Plastic DIP N-28B
AD976CN –40°C to +85°C 83 dB 100 kSPS 28-Lead, 300 mil Plastic DIP N-28B
AD976AAN –40°C to +85°C ±3.0 LSB 83 dB 200 kSPS 28-Lead, 300 mil Plastic DIP N-28B
AD976ABN –40°C to +85°C ±2.0 LSB 85 dB 200 kSPS 28-Lead, 300 mil Plastic DIP N-28B
AD976ACN –40°C to +85°C 83 dB 200 kSPS 28-Lead, 300 mil Plastic DIP N-28B
AD976AR –40°C to +85°C ±3.0 LSB 83 dB 100 kSPS 28-Lead Small Outline Package R-28
AD976BR –40°C to +85°C ±2.0 LSB 85 dB 100 kSPS 28-Lead Small Outline Package R-28
AD976CR –40°C to +85°C 83 dB 100 kSPS 28-Lead Small Outline Package R-28
AD976AAR –40°C to +85°C ±3.0 LSB 83 dB 200 kSPS 28-Lead Small Outline Package R-28
AD976ABR –40°C to +85°C ±2.0 LSB 85 dB 200 kSPS 28-Lead Small Outline Package R-28
AD976ACR –40°C to +85°C 83 dB 200 kSPS 28-Lead Small Outline Package R-28
AD976ARS –40°C to +85°C ±3.0 LSB 83 dB 100 kSPS 28-Lead Shrink Small Outline Package RS-28
AD976BRS –40°C to +85°C ±2.0 LSB 85 dB 100 kSPS 28-Lead Shrink Small Outline Package RS-28
AD976CRS –40°C to +85°C 83 dB 100 kSPS 28-Lead Shrink Small Outline Package RS-28
AD976AARS –40°C to +85°C ±3.0 LSB 83 dB 200 kSPS 28-Lead Shrink Small Outline Package RS-28
AD976ABRS –40°C to +85°C ±2.0 LSB 85 dB 200 kSPS 28-Lead Shrink Small Outline Package RS-28
AD976ACRS –40°C to +85°C 83 dB 200 kSPS 28-Lead Shrink Small Outline Package RS-28

CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection.
Although the AD976/AD976A features proprietary ESD protection circuitry, permanent damage
may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD
precautions are recommended to avoid performance degradation or loss of functionality.

REV. C

–5–

WARNING!

ESD SENSITIVE DEVICE