Analog Devices AD876 b Datasheet

10-Bit 20 MSPS 160 mW

A/D

D/A

A/D

D/A A/D D/A

A/D

CORRECTION LOGIC

AIN

REFTF REFTS

REFBS REFBF

STBY

THREE-

STATE

(MSB) D9

D0 (LSB)

DRV

CLK

DRV

CML

AD876

SHA SHA SHAGAIN SHA GAINGAIN

OUTPUT BUFFERS

FEATURES CMOS 10-Bit 20 MSPS Sampling A/D Converter Pin-Compatible 8-Bit Option Power Dissipation: 160 mW +5 V Single Supply Operation Differential Nonlinearity: 0.5 LSB Guaranteed No Missing Codes Power Down (Standby) Mode Three-State Outputs Digital I/Os Compatible with +5 V or +3.3 V Logic Adjustable Reference Input Small Size: 28-Lead SOIC, 28-Lead SSOP, or 48-Lead

Thin Quad Flatpack (TQFP)

PRODUCT DESCRIPTION

The AD876 is a CMOS, 160 mW, 10-bit, 20 MSPS analog-todigital converter (ADC). The AD876 has an on-chip input sample-and-hold amplifier. By implementing a multistage pipelined architecture with output error correction logic, the AD876 offers accurate performance and guarantees no missing codes over the full operating temperature range. Force and sense connections to the reference inputs minimize external voltage drops.

The AD876 can be placed into a standby mode of operation reducing the power below 50 mW. The AD876’s digital I/O interfaces to either +5 V or +3.3 V logic. Digital output pins can be placed in a high impedance state; the format of the output is straight binary coding.

The AD876’s speed, resolution and single-supply operation ideally suit a variety of applications in video, multimedia, imaging, high speed data acquisition and communications. The AD876’s low power and single-supply operation satisfy requirements for high speed portable applications. Its speed and resolution ideally suit charge coupled device (CCD) input systems such as color scanners, digital copiers, electronic still cameras and camcorders.

CMOS A/D Converter

AD876

FUNCTIONAL BLOCK DIAGRAM

The AD876 comes in a space saving 28-lead SOIC and 48-lead thin quad flatpack (TQFP) and is specified over the commercial (0°C to +70°C) temperature range.

PRODUCT HIGHLIGHTS Low Power

The AD876 at 160 mW consumes a fraction of the power of presently available 8- or 10-bit, video speed converters. Powerdown mode and single-supply operation further enhance its desirability in low power, battery operated applications such as electronic still cameras, camcorders and communication systems.

Very Small Package

The AD876 comes in a 28-lead SOIC, 28-lead SSOP, and 48lead surface mount, thin quad flat package. The TQFP package is ideal for very tight, low headroom designs.

Digital I/O Functionality

The AD876 offers three-state output control.

Pin Compatible Upgrade Path

The AD876 offers the option of laying out designs for eight bits and migrating to 10-bit resolution if prototype results warrant.

REV. B

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: 781/329-4700 World Wide Web Site: http://www.analog.com Fax: 781/326-8703 © Analog Devices, Inc., 1998

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AD876–SPECIFICATIONS

MIN

+2.0 V, f

with AVDD = +5.0 V, DVDD = +5.0 V, DRVDD = +3.3 V, V

MAX

= 20 MSPS, unless otherwise noted)

CLOCK

= +4.0 V, V

REFB

AD876JR-8 AD876

Parameter Min Typ Max Min Typ Max Units

RESOLUTION 8 10 Bits DC ACCURACY

Integral Nonlinearity (INL) ±0.3 ±1.0 ±1.0 LSB Differential Nonlinearity (DNL) ±0.1 ±0.75 ±0.5 ±1 LSB No Missing Codes GUARANTEED GUARANTEED Offset Error 0.1 0.4 % FSR Gain Error 0.1 0.2 % FSR

ANALOG INPUT

Input Range 2 2 V p-p Input Capacitance 5.0 5.0 pF

REFERENCE INPUT

Reference Top Voltage 3.5 4.0 4.5 3.5 4.0 4.5 V Reference Bottom Voltage 1.6 2.0 2.5 1.6 2.0 2.5 V Reference Input Resistance 250 250 Ω Reference Input Current 8.0 8.0 mA Reference Top Offset 35 35 mV Reference Bottom Offset 35 35 mV

DYNAMIC PERFORMANCE

Effective Number of Bits

fIN = 1 MHz 7.8 9.0 Bits

= 3.58 MHz 7.4 7.8 8.2 9.0 Bits

= 10 MHz 7.5 8.2 Bits

Signal-to-Noise and Distortion (S/N+D) Ratio

= 1 MHz 49 56 dB

= 3.58 MHz 46 49 51 56 dB

= 10 MHz 47 51 dB

Total Harmonic Distortion (THD)

=1 MHz –62 –62 dB

= 3.58 MHz –62 –56 –62 –56 dB

=10 MHz –60 –60 dB

Spurious Free Dynamic Range

–65 –65 dB Full Power Bandwidth 150 150 MHz Differential Phase 0.5 0.5 Degree Differential Gain 1 1 %

POWER SUPPLIES

Operating Voltage

DV DRV

+4.5 +5.25 +4.5 +5.25 Volts +4.5 +5.25 +4.5 +5.25 Volts +3.0 +5.25 +3.0 +5.25 Volts

Operating Current

IAV

IDV

IDRV

20 25 20 25 mA

12 16 12 16 mA

0.1 1 0.1 1 mA POWER CONSUMPTION 160 190 160 190 mW TEMPERATURE RANGE

Specified 0 +70 0 +70 °C

NOTES

AVDD and DVDD must be within 0.5 V of each other to maintain specified performance levels.

3.58 MHz Input Frequency.

Specifications subject to change without notice. See Definition of Specifications for additional information.

REV. B–2–

to T

DIGITAL SPECIFICATIONS

with AVDD = +5.0 V, DVDD = +5.0 V, DRVDD = +3.3 V, V

MAX

= 20 MSPS, CL = 20 pF unless otherwise noted)

CLOCK

MIN

= +4.0 V, V

REFT

AD876

Parameter Symbol DRV

Min Typ Max Units

LOGIC INPUT

High Level Input Voltage V

3.0 2.4 V

5.0 4.0 V

5.25 4.2 V

Low Level Input Voltage V

3.0 0.6 V

5.0 1.0 V

5.25 1.05 V High Level Input Current I Low Level Input Current I Low Level Input Current (CLK Only) I Input Capacitance C

IH IL IL

5.0 –10 +10 µA

5.0 –50 +50 µA

5.0 –10 +10 µA

5pF

LOGIC OUTPUTS

High Level Output Voltage V

(IOH = 50 µA) 3.0 2.4 V

5.0 3.8 V

= 0.5 mA) 5.0 2.4 V

Low Level Output Voltage V

(IOL = 50 µA) 3.6 0.7 V

5.25 1.05 V

= 0.6 mA) 5.25 0.4 V

Output Capacitance C Output Leakage Current I

Specifications subject to change without notice.

OUT

–10 10 µA

5pF

AD876

= +2.0 V,

REFB

TIMING SPECIFICATIONS

Symbol Min Typ Max Units

Maximum Conversion Rate Clock Period t Clock High t Clock Low t Output Delay t Pipeline Delay (Latency) 3.5 Clock Cycles Aperture Delay Time 4 ns Aperture Jitter 22 ps

NOTE

Conversion rate is operational down to 10 kHz without degradation in specified performance.

C CH CL OD

SAMPLE N SAMPLE N+1 SAMPLE N+2

AIN

CLK

OUT DATA N-4 DATA N-3 DATA N-2 DATA N-1 DATA N

20 MHz

50 ns 23 25 ns 23 25 ns 10 20 ns

REV. B

Figure 1. Timing Diagram

–3–

AD876

REFBS

REFTF

REFBF

D0 D1

D5 D6

D2 D3

REFTS

D8 D9

424347 4546

17 20191814 1615

36 35

32 31 30

34 33

1 2

5 6 7

3 4

373839

21 242322

28 27 26

9 10 11

TOP VIEW

(Not to Scale)

AD876

DRV

SSDVSS

CLK

THREE-STATE

STBY

DRV

AVSSAV

AIN

CML

PIN FUNCTION DESCRIPTIONS

SOIC TQFP

Symbol Pin No. Pin No. Type Name and Function

D0 (LSB) 3 1 DO Least Significant Bit. D1–D4 4–7 2–5 DO Data Bits 1 through 4. D5–D8 8–11 8–11 Data Bits 5 through 8. D9 (MSB) 12 12 DO Most Significant Bit. THREE- 16 23 DI STATE

STBY 17 24 DI

CLK 15 22 DI Clock Input. CML 26 38 AO Bypass Pin for an Internal Bias Point. REFTF 22 30 AI Reference Top Force. REFBF 24 34 AI Reference Bottom Force. REFTS 21 29 AI Reference Top Sense. REFBS 25 35 AI Reference Bottom Sense. AIN 27 39 AI Analog Input. AV

DRV

Type: AI = Analog Input; AO = Analog Output; DI = Digital Input; DO = Digital Output; P = Power.

28 42 P +5 V Analog Supply. 1 44 P Analog Ground. 18 26 P +5 V Digital Supply. 14, 19, 20 17, 27, 28 P Digital Ground. 2 45 P +3.3 V/+5 V Digital Supply. Supply for digital

13 16 P +3.3 V/+5 V Digital Ground. Ground for digital

THREE-STATE = LOW THREE-STATE = HIGH or N/C Normal Operating Mode High Impedance Outputs

STBY = LOW or N/C STBY = HIGH Normal Operating Mode Standby Mode

input and output buffers.

PIN CONFIGURATIONS

SOIC/SSOP TQFP

DRV

*D0

*D1

D2 D3

6 D4 D5 REFTS D6 D7 D8 D9 STBY

DRV

PINS D0 AND D1 ARE LEFT OPEN FOR THE AD876JR-8

AD876

TOP VIEW

(Not to Scale)

10 11 12 13 14

NC = NO CONNECT

AIN

27 26

CML

REFBS REFBF

24 23

NC REFTF

22 21 20

THREE-STATE

CLK

REV. B–4–

AD876

WARNING!

ESD SENSITIVE DEVICE

ABSOLUTE MAXIMUM RATINGS*

Parameter With Respect to Min Max Units

AV DV AV

, DRV

AV DVSS, DRV DVSS, DRV

AIN AV

–0.5 +6.5 Volts –0.5 +6.5 Volts

–0.5 +0.5 Volts

–0.5 +6.5 Volts REFTS, REFTF REFBS, REFBF AV Digital Inputs, CLK DV

, DRV

–0.5 +6.5 Volts

Junction Temperature +150 °C Storage Temperature –65 +150 °C Lead Temperature

(10 sec) +300 °C

*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 sections of this specification is not implied. Exposure to absolute maximum ratings for extended periods may effect device reliability.

DRV

a) D0–D9 b) Three-State, Standby

ORDERING GUIDE

Temperature Package Package

Model Range Description Options

AD876JR 0°C to +70°C 28-Lead SOIC R-28 AD876JST-Reel 0°C to +70°C 48-Lead TQFP ST-48

(Tape and Reel 13") AD876JR-8 0°C to +70°C 28-Lead SOIC R-28 AD876AR –40°C to +85°C 28-Lead SOIC R-28 AD876ARS –40°C to +85°C 28-Lead SSOP RS-28 AD876JRS 0°C to +70°C 28-Lead SSOP RS-28 AD876JRS-8 0°C to +70°C 28-Lead SSOP RS-28

DRV

c) CLK

REFTF

d) AIN

REFTS

REFBS

REFBF

INTERNAL REFERENCE

VOLTAGE

INTERNAL REFERENCE VOLTAGE

Figure 2. Equivalent Circuits

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 AD876 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. B

–5–

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