ADS808

12-Bit

Pipelined

ADC Core

Reference and

Mode Select

Reference Ladder

and Driver

Timing Circuitry

Error

Correction

Logic

3-State

Outputs

T&H

D0

D11

•

•

•

+V

S

ADS808

CLK

CLK

OE

SEL2

REFB

V

REF

REFT

VDRV

IN

1Vp-p

1Vp-p

CM

(+2.5V)

SEL1

DV

OVR

IN

12-Bit, 70MHz Sampling

ANALOG-TO-DIGITAL CONVERTER

FEATURES

q DYNAMIC RANGE:

SNR: 64dB at 10MHz f

IN

SFDR: 68dB at 10MHz f

IN

q PREMIUM TRACK-AND-HOLD:

Low Jitter: 0.25ps rms

Differential or Single-Ended Inputs

Selectable Full-Scale Input Range

q FLEXIBLE CLOCKING:

Differential or Single-Ended

Accepts Sine or Square Wave Clocking

Down to 0.5Vp-p

Variable Threshold Level

DESCRIPTION

The ADS808 is a high-dynamic range, 12-bit, 70MHz,

pipelined Analog-to-Digital Converter (ADC). It includes a

high-bandwidth linear track-and-hold that has a low jitter of

only 0.25ps rms, leading to excellent SNR performance. The

clock input can accept a low-level differential sine wave or

square wave signal down to 0.5Vp-p, further improving the

SNR performance. It also accepts a single-ended clock

signal and has flexible threshold levels.

The ADS808 has a 2Vp-p differential input range (1Vp-p • 2

inputs) for optimum signal-to-noise ratio. The differential

operation gives the lowest even-order harmonic compo-

nents. A lower input voltage of 1.5Vp-p or 1Vp-p can also be

selected using the internal references, further optimizing

SFDR. Alternatively, a single-ended input range can be used

The ADS808 also provides an over-range 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. It also employs digital

error-correction techniques to provide excellent differential

linearity for demanding imaging applications. The ADS808 is

available in a small TQFP-48 PowerPAD™ thermally en-

hanced package.

APPLICATIONS

q BASESTATION WIDEBAND RADIOS:

CDMA, GSM, TDMA, 3G, AMPS, and NMT

q TEST INSTRUMENTATION

q CCD IMAGING

ADS808

SBAS179C – DECEMBER 2000 – REVISED SEPTEMBER 2002

www.ti.com

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

Copyright © 2000, Texas Instruments Incorporated

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

PowerPAD is a registered trademark of Texas Instruments.