WM5621L
Production Data
Jan. 1997 Rev. 1.0
Low-power Quadruple 8-Bit DAC
Description
WM5621L is a quadruple 8-bit digital to analogue converter
(DAC) with buffered reference inputs (high impedance). The
DAC produces an output voltage that ranges between
either one or two times the reference voltage and GND. The
DAC is monotonic. The device operates from a single
supply in the range 2.7V to 5.5V. A power-on reset function
is incorporated to provide repeatable start-up conditions. A
global hardware shut-down terminal and the capacity to
shut-down each individual DAC with software are provided
to minimize power consumption.
WM5621L interfaces to all popular microcontrollers and
microprocessors via a three wire serial interface with CMOS
compatible, schmitt trigger, digital inputs. Alternatively a two
wire serial interface can be activated. An 11-bit command
word consists of eight bits of data, two DAC select bits and
a range bit for selection between the times one or times two
output range. The DACregisters are double buffered which
allows a complete set of new values to be written to the
device, and then under control of HWACT, all of the DAC
outputs are simultaneously updated.
Ideal in space critical applications WM5621L is available
in small outline and DIP packages and is characterized for
operation from -25
o
C to 85
o
C.
Features
•
•
•
•
•
•
•
•
•
•
•
•
•
Individual (or all) DAC's can be powered-down
One low-power 8-bit voltage output DAC
Three 8-bit voltage output DACs
Fast serial interface (1 MHz max)
Simple 2 or 3 wire interface
Programmable for 1 or 2 times output range
High impedance reference inputs for each DAC
Simultaneous update facility
Extended temperature range (-25
o
C to 85
o
C)
Single supply operation, range 2.7 V to 5.5 V
0 to 4 V output (x2 output range) at 5 V V
DD
0 to 2.5 V output (x2 output range) at 3 V V
DD
Low power specification:
All DACs on
: 3.6 mW at 3.6 V typ
: 6 mW at 5 V typ
Low power DAC
: 0.54 mW at 3.6V typ
All DAC's shutdown
: 0.18 mW at 3.6V typ
Guaranteed monotonic output
•
Applications
•
•
•
•
•
Mobile Communications
Programmable d.c. voltage sources
Digitally controlled attenuator/amplifier
Signal synthesis
Automatic test equipment
Block Diagram
Production Data
data sheets contain final
specifications current on publication date. Supply
of products conforms to Wolfson Microelectronics
standard terms and conditions
Wolfson Microelectronics
Lutton Court, Bernard Terrace, Edinburgh EH8 9NX, UK
© 1996 Wolfson Microelectronics
Tel: +44 (0) 131 667 9386
Fax: +44 (0) 131 667 5176
email: admin@wolfson.co.uk
www: http://www.wolfson.co.uk
WM5621L
Pin Configuration
Top View
N or D Packages
Ordering Information
DEVICE
WM5621LED
WM5621LEN
TEMP. RANGE
-25
o
C to 85
o
C
-25
o
C to 85
o
C
PACKAGE
14 pin plastic SO
14 pin DIP
GND
REF A
REF B
REF C
REF D
DATA
CLK
1
2
3
4
5
6
7
14
13
12
11
10
9
8
V
DD
HWACT
DACA
DACB
DACC
DACD
EN
(note 1)
Supply Voltage (V
DD
- GND) . . . . . . . . . . . +7V
Digital Inputs . . . . . . . . . GND - 0.3 V, V
DD
+ 0.3 V
Reference inputs . . . . . . . GND - 0.3 V, V
DD
+ 0.3 V
Absolute Maximum Ratings
Operating temperature range, T
A
. . . . . -25 C to +85 C
Storage Temperature . . . . . . . . . -50
o
C to +150
oo
C
Lead Temperature (soldering, 10 sec) . . . . . +260 C
o
o
Recommended Operating Conditions
Supply Voltage
Reference input range
DAC output load resistance to GND
High level digital input voltage
Low level digital input voltage
Clock frequency
Operating free-air temperature, T
A
MIN
2.7
GND
10
0.8 V
DD
NOMINAL
3.3
MAX
5.5
V
DD
- 1.5
UNIT
V
V
kΩ
V
V
MHz
O
C
-25
0.2 V
DD
1
85
5
Electrical Characteristics
V
DD
= 3 V to 3.6V, GND = 0 V, V
REF
= 1.25 V, R
L
= 10 kΩ, C
L
= 100 pF, x1 gain output range, T
A
= full range
unless otherwise stated.
PARAMETER
Supply Voltage
High level digital input voltage
Low level digital input voltage
Reference voltage, VREF [A|B|C|D]
Load resistance
Data input setup time
Data input hold time
CLK
↓
to EN
↓
EN
↑
to CLK
↓
CLK period high
EN low time
Clock frequency
Operating free-air temperature
SYMBOL
CONDITIONS
VDD
see note 2
VIH
VIL
x1 gain
RL
tSD
tHD
tEN
tLC
cph
tenl
fCLK
TA
see note 3
see note 3
see note 3
MIN
2.7
0.8 VDD
GND
10
50
50
100
100
400
200
-25
1.0
85
NOM
3.3
MAX
5.5
0.2 VDD
VDD-1.5
UNIT
V
V
V
V
kΩ
ns
ns
ns
ns
ns
ns
MHz
O
C
Wolfson Microelectronics
2
WM5621L
Electrical Characteristics
(continued)
V
DD
= 3 V to 3.6V, GND = 0 V, V
REF
= 1.25 V, R
L
= 10 kΩ, C
L
= 100 pF, x1 gain output range, T
A
= full range
unless otherwise stated.
PARAMETER
Max. full-scale output voltage
High level input current
Low level input current
Output sink current DACA
Output sink current DACB
Output Source Current
Input capacitance
Reference input capacitance
Supply current
Supply current One low
power DAC Active
Supply Current ALL DACs
Shutdown
Reference input current
Integral Nonlinearity
Differential Nonlinearity
Zero scale error
Zero scale error temperature
coefficient
Zero scale error supply
rejection
Full scale error
Full scale error temperature
coefficient
Full scale error supply
rejection
Feedback resistor network
resistance
Notes:
1. Absolute Maximum Ratings are stress ratings only.
Permanent damage to the device may be caused by
continuously operating at or beyond these limits. De-
vice functional operating range limits are given under
Recommended Operating Conditions. Guaranteed
performance specifications are given under Electrical
Characteristics at the test conditions specified.
2. The device operates over the supply voltage range of
2.7V to 5.5V. Over this voltage range the device re-
sponds correctly to data input by changing the voltage
output but conversion accuracy is not specified over
this extended range.
SYMBOL
Vomax
IIH
IIL
Io (sink)
Io (sink)
Io (source)
CI
IDD
IDAC
Iddsd
IREF
INL
DNL
ZCE
A, B, C, D inputs
VDD = 3.6V
VDD = 5.0V
VDD = 3.6V (Note 4)
VDD = 3.6V (see note 4)
A, B, C, D inputs
VREF = 1.25V, Range x2.
(note 5,13)
VREF = 1.25V, Range x2.
(note 6,13)
VREF = 1.25V,Range x2.
(note 7)
VREF = 1.25V,Input code = 00
Hex (note 8)
CONDITIONS
Vref=1.5V, open cct. output
,x2 gain
VI = VDD
VI = 0V
at DAC code 0
at DAC code 0
Each DAC output, at DAC
code 255
15
15
1
1
150
50
pF
pF
mA
mA
µA
µA
µA
LSB
LSB
mV
µV/
O
C
mV/V
± 60
± 25
2
168
mV
µV/
C
O
MIN
VDD-100
TYP
2
MAX UNIT
mV
± 10
± 10
µA
µA
µA
µA
mA
5
20
1
1.5
1.5
250
100
± 10
± 1.0
± 0.1
0
10
2
± 0.9
30
FSE
Range x 2. (note 9)
VREF = 1.25V,Range x2.
(note 10)
mV/V
kΩ
Wolfson Microelectronics
3
WM5621L
Electrical Characteristics
V
DD
= 3 V to 3.6V, GND = 0 V, V
REF
= 1.25 V, R
L
= 10 kΩ, C
L
= 100 pF, x1 gain output range, T
A
= full range
unless otherwise stated.
PARAMETER
Output slew rate rising DACA
Output slew rate falling DACA
Output slew rate DACB,C,D
Output settling time rising
DACA
Output settling time falling
DACA
Output settling time rising
DACB,C,D
Output settling time falling
DACB,C,D
Output settling time HWACT
or ACT↑ to output volts DACA
(note 14)
Output settling time HWACT
or ACT↑ to output volts
DACB,C,D (note 14)
Large signal Bandwidth
Digital crosstalk
Reference feedthrough
Channel-to-channel isolation
To 1/2 LSB, VDD=3V
25
75*
µS
To 1/2 LSB, VDD=3V
To 1/2 LSB, VDD=3V
To 1/2 LSB, VDD=3V
To 1/2 LSB, VDD=3V
To 1/2 LSB, VDD=3V
SYMBOL
CONDITIONS
MIN
TYP
0.8
0.5
1
20
75
10
75
40
120*
MAX UNIT
V/µS
V/µS
V/µS
µS
µS
µS
µS
µS
Measured at -3dB point
CLK=1MHz sq. wave
measured at DACA-DACD
A,B,C,D inputs (note 15)
A,B,C,D inputs (note 16)
A,B,C,D inputs
note 17
note 17
100
-50
-60
-60
-40
20
100
KHz
dB
dB
dB
dB
kHz
kHz
5
Channel-to-channel isolation
when in shutdown
Reference bandwidth DACA
Reference bandwidth
DACB,C,D
Notes:
3. This is tested by design but is not production tested.
4. This is measured with no load (open circuit output),
Vref = 1.25V, range = x2.
5. Integral Nonlinearity (INL) is the maximum deviation of
the output from the line between zero and full scale (ex-
cluding the effects of zero code and full-scale er-
rors).
6. Differential Nonlinearity (DNL) is the difference be-
tween the measured and ideal 1 LSB amplitude
change of any two adjacent codes. A guarantee of
monotonicity means the output voltage changes in the
same direction (or remains constant) as a change in
the digital input code.
7. Zero-scale error is the deviation from zero voltage
output when the digital input code is zero.
8. Zero scale error temperature coefficient is given by:
ZCETC = (ZCE(T
max
) - ZCE(T
min
))/V
REF
x 10
6
/
(T
max
- T
min
)
9. Full-Scale error is the deviation from the ideal full-scale
output (Vref - 1LSB) with an output load of 10kΩ.
10. Full-Scale Temperature Coefficient is given by:
6
FSETC = (FSE(T
max
) - FSE(T
min
))/V
REF
x 10 /
(T
max
- T
min
)
11. Zero-code Error Rejection Ratio (ZCE-RR) is
measured by varying the V
DD
voltage, from 4.75 to
5.25 V d.c., and measuring the proportion of this
signal imposed on the zero-code output voltage.
Wolfson Microelectronics
4
WM5621L
Electrical Characteristics
(continued)
12. Full Scale Error Rejection Ratio (FSE-RR) is
measured by varying the V
DD
voltage, from 4.75 to
5.25 V d.c., and measuring the proportion of this
signal imposed on the full-scale output voltage.
13. Linearity is only specified for DAC codes 1 through
255.
14. The ACT bit is latched on falling edge of EN.
15. Reference feedthrough is measured at any DAC out-
put with an input code = 00 hex with a Vref input = 1Vdc
+ 1 Vpp at 10kHz.
16. Channel-to-channel isolation is measured by setting
the input code of one DAC to FF hex and the code of
all other DACs to 00 hex with Vref input = 1Vdc + 1
Vpp at 10kHz.
17. Reference bandwidth is the -3dB bandwidth with an
ideal input at Vref = 1.25 Vdc + 2 Vpp and with a dig-
ital input code of full-scale (range set to x1 and Vdd =
5V)
Typical Performance Characteristics
Typical DNL, INL and TUE at VDD = 5 V
Vd d = 5 .0 V, Vre f = 2 .5 V , R ang e = x1 @
2 5' C
Differential Nonlinearity
o
Vdd = 5 .0V, Vre f = 2. 5V, Ra ng e = x1 @ 25 'C
Integral Nonlinearity
I ntegral Non Li neari ty
V
DD
= 5.0, V
REF
= 2.5V, Range = x1 at 25 C
0.2
0.15
0.1
V
DD
= 5.0, V
REF
= 2.5V, Range = x1 at 25 C
o
0.2
0.15
Error (LSBs)
Error (LSBs)
Err o r (lsb s)
0.1
0.05
0
-0.05
-0.1
-0.15
-0.2
0
32
64
96
128
Co de
Error (lsbs)
0.05
0
-0.05
-0.1
-0.15
-0.2
160
192
224
256
0
32
64
96
128
Co d e
160
192
224
256
Input Code
Input Code
Total Unadjusted Error
Vdd = 5.0 V, Vref = 2.5 V, Rang e = x 1 @ 25 'C
Differential Nonlinearity
o
Vdd = 5 .0V, Vre f = 2 .0V, Ran ge = x2 @ 25 'C
V
DD
= 5.0, V
REF
= 2.5V, Range = x1 at 25 C
Total Unad justed Er ror
V
DD
= 5.0, V
REF
=
Differenti al Non Li neari ty
= x2 at 25 C
2.0V, Range
o
0.2
0.15
0.2
0.15
Error (LSBs)
0.1
0.05
Error (lsbs)
Error (LSBs)
Error (lsbs)
0.1
0.05
0
-0.05
-0.1
-0.15
-0.2
0
-0.05
-0.1
-0.15
-0.2
0
32
64
96
128
Cod e
160
192
224
256
0
32
64
96
128
Co d e
160
192
224
256
Input Code
Input Code
Wolfson Microelectronics
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