WM2636
12-bit Serial Input Voltage Output DAC
with Internal Reference
Production Data, July 1999, Rev 1.0
FEATURES
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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
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.
APPLICATIONS
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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
WM2636CD
WM2636ID
TEMP. RANGE
0° to 70°C
-40° to 85°C
PACKAGE
8-pin SOIC
8-pin SOIC
BLOCK DIAGRAM
VDD
(8)
REFERENCE
OUTPUT BUFFER
WITH OUPUT
ENABLE
X1
1.024V/2.048V
SELECTABLE
REFERENCE
TYPICAL PERFORMANCE
1
VDD = 5V, V
REF
= External, Speed = Fast mode, Load = 10k/100pF
0.8
0.6
0.4
REF(6)
REFERENCE INPUT
BUFFER
X1
DAC
OUTPUT
BUFFER
DNL - LSB
X2
(7) OUT
2-BIT
REFERENCE
SELECT
LATCH
0.2
0
-0.2
-0.4
-0.6
-0.8
-1
2-BIT
CONTROL
LATCH
POWERDOWN/
SPEED
CONTROL
DIN (1)
SCLK (2)
16-BIT
SHIFT
REGISTER
AND
CONTROL
LOGIC
data
12-BIT
DAC
LATCH
NCS (3)
FS (4)
0
512
1024
1536
2048
DIGITAL CODE
2559
3071
3583
4095
POWER-ON
RESET
WM2636
(5)
AGND
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
.
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
