ADS805

®

International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111 • Twx: 910-952-1111

Internet: http://www.burr-brown.com/ • FAXLine: (800) 548-6133 (US/Canada Only) • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132

PDS-1397C

Printed in U.S.A. October, 1998

12-Bit, 20MHz Sampling

ANALOG-TO-DIGITAL CONVERTER

TM

FEATURES

q HIGH SFDR: 74dB at 9.8MHz f

IN

q HIGH SNR: 68dB

q LOW POWER: 300mW

q LOW DLE: 0.25LSB

q SMALL 28-LEAD SSOP AND SOIC

PACKAGES

q FLEXIBLE INPUT RANGE

q OVER-RANGE INDICATOR

APPLICATIONS

q STUDIO CAMERAS

q IF AND BASEBAND DIGITIZATION

q COPIERS

q TEST INSTRUMENTATION

DESCRIPTION

The ADS805 is a 20MHz, high dynamic range, 12-bit pipelined

analog-to-digital converter. This converter includes a high-band-

width track/hold that gives excellent spurious performance up to

and beyond the Nyquist rate. This high-bandwidth, linear track/hold

minimizes harmonics and has low jitter, leading to excellent SNR

performance. The ADS805 is also pin-compatible with the 10MHz

ADS804 and the 5MHz ADS803.

The ADS805 provides an internal reference or an external reference

can be used. ADS805 can be programmed for a 2Vp-p input range

which is the easiest to drive with a single op amp and provides the

best spurious performance. Alternatively, the 5Vp-p input range can

be used for the lowest input-referred noise of 0.09 LSBs rms giving

ADS805U

ADS805E

superior imaging performance. There is also the capability to set the

input range between 2Vp-p and 5Vp-p, either single-ended or

differential. The ADS805 also provides an overrange flag that

indicates when the input signal has exceeded the converter’s full

scale range. This flag can also be used to reduce the gain of the front

end signal conditioning circuitry.

The ADS805 employs digital error techniques to provide excellent

differential linearity for demanding imaging applications. Its low

distortion and high SNR give the extra margin needed for commu-

nications, medical imaging, video and test instrumentation applica-

tions. The ADS805 is available in 28-lead SSOP and SOIC pack-

ages.

12-Bit

Pipelined

A/D Core

Reference and

Mode Select

Reference Ladder

and Driver

Timing Circuitry

Error

Correction

Logic

3-State

Outputs

T/H

D0

D11

•

•

•

CLK

+V

S

ADS805

VDRV

OE

SEL

REFB

V

REF

REFT

IN

V

IN

IN

CM

OVR