a

CMOS

JDC /4 DQPSK Baseband Transmit Port

AD7010

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 617/329-4700

Fax: 617/326-8703

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.

GENERAL DESCRIPTION

The AD7010 is a complete low power, CMOS,

π/4 DQPSK

modulator with single +5 V power supply. The part is designed

to perform the baseband conversion of I and Q transmit

waveforms in accordance with the Japanese Digital Cellular

Telephone system.

The on-chip

π/4 Differential Quadrature Phase Shift Keying

(DQPSK) digital modulator, which includes the Root Raised

Cosine filters, generates I and Q data in response to the transmit

data stream. The AD7010 also contains ramp control envelope

logic to shape the I and Q output waveforms when ramping up

or down at the beginning or end of a transmit burst.

Besides providing all the necessary logic to perform

π/4 DQPSK

modulation, the part also provides reconstruction filters to

smooth the DAC outputs, providing continuous time analog

outputs. The AD7010 generates differential analog outputs for

both the I and Q signals.

As it is a necessity for all digital mobile systems to use the lowest

possible power, the device has power down options. The

AD7010 is housed in a space efficient 24-pin SSOP (Shrink

Small Outline Package).

FEATURES

Single +5 V Supply

On-Chip

/4 DQPSK Modulator

Root-Raised-Cosine Tx Filters,

= 0.5

Two 10-Bit D/A Converters

4th Order Reconstruction Filters

Differential Analog Outputs

On-Chip Ramp Up/Down Power Control

On-Chip Tx Offset Calibration

Very Low Power Dissipation, 30 mW typ

Power Down Mode < 5

A

On-Chip Voltage Reference

24-Pin SSOP

APPLICATIONS

Japanese Digital Cellular Telephony

FUNCTIONAL BLOCK DIAGRAM

Tx CLK

BOUT

QTx

V

AA

MODE1

AD7010

10-BIT

I-DAC

2.46V

REFERENCE

POWER

CALIBRATION CIRCUITRY

π/4 DQPSK

MODULATOR

10-BIT

Q-DAC

Tx DATA

DGND

V

DD

MODE2

AGND

BYPASS

BIN

MCLK

READY

RECONSTRUCTION

FILTERS

RECONSTRUCTION

FILTERS

ITx

ITx

QTx