WM2636

12-bit Serial Input Voltage Output DAC

with Internal Reference

Production Data, July 1999, Rev 1.0

WOLFSON MICROELECTRONICS LTD

Lutton Court, Bernard Terrace, Edinburgh, EH8 9NX, UK

Tel: +44 (0) 131 667 9386

Fax: +44 (0) 131 667 5176

Email: sales@wolfson.co.uk

http://www.wolfson.co.uk

Production Data contain final specifications

current on publication date. Supply of

products conforms to Wolfson

Microelectronics’ Terms and Conditions.

1999 Wolfson Microelectronics Ltd

.

FEATURES

• 12-bit voltage output DAC

• Single supply from 2.7V to 5.5V

• DNL ±0.5 LSBs, INL ±2.0 LSBs

• Very low power consumption (3V supply):

-

4.2mW, slow mode

-

8.1mW, fast mode

• TMS320, (Q)SPI, and Microwire compatible serial

interface

• Programmable settling time of 3.5µs or 1µs typical

• High impedance reference input buffer

• Power down mode 10nA

APPLICATIONS

• Battery powered test instruments

• Digital offset and gain adjustment

• Battery operated/remote industrial controls

• Machine and motion control devices

• Wireless telephone and communication systems

• Speech synthesis

• Arbitrary waveform generation

ORDERING INFORMATION

DEVICE

TEMP. RANGE

PACKAGE

WM2636CD

0° to 70°C

8-pin SOIC

WM2636ID

-40° to 85°C

8-pin SOIC

DESCRIPTION

The WM2636 is a 12-bit voltage output, resistor string digital-to-

analogue converter that can be powered down under software

control. Power down reduces current consumption to 10nA.

An internal precision voltage reference is provided which can

source up to 1mA. This can therefore be used as an external

system reference.

The device has been designed to interface efficiently to industry

standard microprocessors and DSPs, including the TMS320

family. The WM2636 is programmed with a 16-bit serial word

comprising 4 control bits and 12 data bits.

Excellent performance is delivered with a typical DNL of 0.5

LSBs. The settling time of the DAC is programmable to allow

the designer to optimize speed versus power dissipation. The

output stage is buffered by a x2 gain near rail-to-rail amplifier.

The device is available in an 8-pin SOIC package. Commercial

temperature (0

° to 70°C) and Industrial temperature (-40° to

85

°C) variants are supported.

BLOCK DIAGRAM

TYPICAL PERFORMANCE

(7) OUT

12-BIT

DAC

LATCH

POWER-ON

RESET

DIN (1)

SCLK (2)

FS (4)

(5)

AGND

VDD

(8)

POWERDOWN/

SPEED

CONTROL

2-BIT

CONTROL

LATCH

REFERENCE INPUT

BUFFER

16-BIT

SHIFT

REGISTER

AND

CONTROL

LOGIC

data

X1

X2

DAC

OUTPUT

BUFFER

NCS (3)

2-BIT

REFERENCE

SELECT

LATCH

1.024V/2.048V

SELECTABLE

REFERENCE

X1

REFERENCE

OUTPUT BUFFER

WITH OUPUT

ENABLE

REF(6)

WM2636

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

0

512

1024

1536

2048

2559

3071

3583

4095

DIGITAL CODE