WM2638 Datasheet, PDF (1/11 Pages) Wolfson Microelectronics plc – Dual 12-Bit Serial Input Voltage Output DAC with Internal reference

WM2638
Dual 12-Bit Serial Input Voltage Output DAC
with Internal reference
Production Data, Rev 1.0, July 1999
FEATURES
• Two 12-bit voltage output DACs
• Single 2.7V to 5.5V supply operation
• DNL ±0.4 LSBs, INL ±2 LSBs
• Low power consumption
• 12mW typical in fast mode
• 6mW typical in slow mode
• TMS320, (Q)SPI™, and Microwire™ compatible
serial interface
• Programmable settling time 1µs or 3.5µs typical
• Power down mode 10nA
APPLICATIONS
• Battery powered test instruments
• Digital offset and gain adjustment
• Battery operated/remote industrial controls
• Machine and motion control devices
• Cellular telephones
• Wireless telephones and communication systems
• Speech synthesis
• Arbitrary waveform generation
ORDERING INFORMATION
DESCRIPTION
The WM2638 is a dual 12-bit voltage output, resistor string, digital-
to-analogue converter. A software controlled power down mode is
provided that reduces current consumption to 10nA.
The WM2638 features an internal programmable voltage reference
simplifying overall system design. A reference voltage may also be
supplied externally.
The device has been designed to interface efficiently to industry
standard microprocessors and DSPs, including the TMS320
family. The WM2638 is programmed with a 16-bit serial word
comprising of a latch address, mode control bits and DAC or
control data.
Excellent performance is delivered with a typical DNL of 0.4LSBs.
The programmable settling time allows the designer to optimise
speed versus power consumption. The output stage is buffered by
a x2 gain near rail-to-rail amplifier.
The device is available in an 8-pin SOIC package ideal for space-
critical applications. Commercial temperature (0° to 70°C) and
Industrial temperature (-40° to 85°C) variants are supported.
DEVICE
WM2638CD
WM2638ID
TEMP. RANGE
0° to 70°C
-40° to 85°C
PACKAGE
8-pin SOIC
8-pin SOIC
BLOCK DIAGRAM
REF(6)
REFERENCE
OUTPUT BUFFER
WITH OUPUT
ENABLE
X1
1.024V/2.048V
SELECTABLE
REFERENCE
VDD
(8)
c
DIN (1)
SCLK (2)
NCS (3)
16-BIT
SHIFT
REGISTER
AND
CONTROL
LOGIC
POWER-ON
RESET
(5)
AGND
2-BIT
REFERENCE
SELECT
LATCH
12-BIT
DAC A
LATCH
12-BIT
DAC B
HOLDING
LATCH
REFERENCE
INPUT
BUFFER
X1
REFERENCE
INPUT BUFFER
X1
12-BIT
DAC B
LATCH
DAC
OUTPUT
BUFFER
X2
(4) OUTA
DAC
OUTPUT
BUFFER
X2
(7) OUTB
2-BIT
CONTROL
LATCH
POWERDOWN/
SPEED
CONTROL
WM2638
TYPICAL PERFORMANCE
1
5V = VDD, VREF = External, Speed = Fast mode, Load = 10k/100pF
0.8
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
-1
0
512
1024
1536
2048
2559
DIGITAL CODE
3071
3583
4095
WOLFSON MICROELECTRONICS LTD
Lutton Court, Bernard Terrace, Edinburgh, EH8 9NX, UK
Tel: [phone]
Fax: [phone]
Email: [e-mail]
http://www.wolfson.co.uk
Production Data contains final specifications
current on publication date. Supply of products
conforms to Wolfson Microelectronics' Terms
and Conditions.
Last printed 15/07/99 15:58
©1999 Wolfson Microelectronics Ltd.