WM2639
12-Bit Parallel 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 2.7V to 5.5V operation
DNL
±
0.3 LSBs, INL
±
1.2 LSBs
Internal programmable voltage reference
Settling time 1µ s typical
µ
12-bit microprocessor compatible interface
Power down mode 10nA
DESCRIPTION
The WM2639 is a 12-bit voltage output, resistor string, digital-to-
analogue converter. A hardware controlled power down mode is
provided that reduces current consumption to 10nA. The device
has been designed to interface efficiently to industry standard
microprocessors and DSPs.
The WM2639 features an internal programmable voltage reference
simplifying overall system design. The reference voltage can also
be supplied externally.
Excellent performance is delivered with a typical DNL of 0.3 LSBs
and typical INL of 1.2 LSBs. The output stage is buffered by a x2
gain near rail-to-rail amplifier, which features a Class A output
stage (slow mode, Class AB). The 12 data bits are double buffered
enabling the output to be asynchronously updated under hardware
control. The settling time of the DAC is software programmable to
allow the designer to optimise speed versus power dissipation.
The device is available in a 20-pin TSSOP 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
Mass storage devices
ORDERING INFORMATION
DEVICE
WM2639CDT
WM2639IDT
TEMP. RANGE
0° to 70°C
-40° to 85°C
PACKAGE
20-pin TSSOP
20-pin TSSOP
BLOCK DIAGRAM
VDD
(11)
REFERENCE
OUTPUT BUFFER
WITH OUPUT
ENABLE
REF(12)
X1
TYPICAL PERFORMANCE
1
5V = VDD, V
REF
1.024V/2.048V
SELECTABLE
REFERENCE
0.8
2-BIT
REFERENCE
SELECT
LATCH
0.4
REFERENCE
INPUT
BUFFER
X1
DAC
OUTPUT
BUFFER
X2
(13) OUT
0.2
DNL - LSB
-0.2
-0.4
-0.8
-1
D[0-11]
(19,20, 1-10)
12-BIT
INPUT
REGISTER
data
12-BIT
DAC
LATCH
NWE (17)
NCS (18)
REG (15)
2-BIT
CONTROL
LATCH
POWERDOWN
CONTROL
POWER-ON
RESET
WM2639
512
1024
2048
2559
3583
4095
(14)
GND
(16)
NLDAC
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..
Master 15/07/99 15:02
©1999
Wolfson Microelectronics Ltd
.
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
