WOLFSON WM2613

WM2613
Byte-wide Parallel Input, 12-bit Voltage Output DAC
Production Data, June 1999, Rev 1.0
FEATURES
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DESCRIPTION
Dual 12-bit voltage output DAC
Dual supply 2.7V to 5.5V operation
DNL ± 0.4 LSB, INL ± 1.5 LSB
Programmable settling time 1µ
µ s or 3µ
µ s typical
8-bit micro controller compatible interface
Power down mode (10nA)
The WM2613 is a 12-bit voltage output, resistor string, digital-toanalogue converter. The DAC can be powered down under
software or hardware control, reducing power consumption to
10nA.
The device has an 8-bit microcontroller compatible parallel
interface. The eight data LSBs, the four data MSBs, and the three
control bits are written using three different addresses.
APPLICATIONS
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Excellent performance is delivered with a typical DNL of 0.4 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
settling time of the DAC is software programmable to allow the
designer to optimize speed versus power dissipation.
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
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.
ORDERING INFORMATION
DEVICE
TEMP. RANGE
PACKAGE
WM2613CDT
0° to 70°C
20-pin TSSOP
WM2613IDT
-40° to 85°C
20-pin TSSOP
BLOCK DIAGRAM
TYPICAL PERFORMANCE
DVDD
(10)
AVDD
(11)
1
AVDD = DVDD = 5V, VREF = 2.048V, Speed = Fast mode, Load = 10k/100pF
0.8
REFIN(12)
POWERDOWN/
SPEED
CONTROL
NPD (15)
3-BIT
CONTROL
LATCH
A[0-1] (8,7)
NCS (18)
NWE (17)
PARALLEL
INTERFACE
AND
CONTROL
LOGIC
0.6
X1
0.4
DNL - LSB
SPD (9)
REFERENCE
INPUT BUFFER
DAC
OUTPUT
BUFFER
4-BIT DAC
MSW
HOLDING
LATCH
12-BIT DAC
LATCH
X2
(13) OUT
0.2
0
-0.2
-0.4
8-BIT DAC
LSW
HOLDING
LATCH
-0.6
-0.8
-1
D[0-7]
(19,20, 1-6)
0
POWER-ON
RESET
WM2613
(14)
GND
512
1024
1536
2048
2559
3071
3583
4095
DIGITAL CODE
(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: [email protected]
http://www.wolfson.co.uk
Production Data Datasheets contain final
specifications current on publication date.
Supply of products conforms to Wolfson
Microelectronics’ Terms and conditions.
Master rev 1.0.doc June 17, 1999 14:12
1999 Wolfson Microelectronics Ltd.
WM2613
Production Data Rev 1.0
PIN CONFIGURATION
D2
1
20
D1
D3
2
19
D0
D4
3
18
NCS
D5
4
17
NWE
D6
5
16
NLDAC
D7
6
15
NPD
A1
7
14
GND
A0
8
13
OUT
SPD
9
12
REFIN
DVDD
10
11
AVDD
PIN DESCRIPTION
PIN NO
NAME
TYPE
1
D2
Digital input
Data input.
2
D3
Digital input
Data input.
3
D4
Digital input
Data input.
4
D5
Digital input
Data input.
5
D6
Digital input
Data input.
6
D7
Digital input
Data input.
7
A1
Digital input
Address input.
8
A0
Digital input
Address input.
9
SPD
Digital input
Speed select. Digital input.
10
DVDD
Supply
11
AVDD
Supply
12
REFIN
Analogue input
Voltage reference input.
13
OUT
Analogue output
DAC analogue voltage output.
14
GND
Supply
15
NPD
Digital input
Power down. Active low digital input which powers down all analogue
circuits.
16
NLDAC
Digital input
Load DAC. Digital input active low. NLDAC must be taken low to update
the DAC latch from the holding latches.
17
NWE
Digital input
Write enable. Digital input active low.
18
NCS
Digital input
Chip select. Digital input active low.
19
D0
Digital input
Data input.
20
D1
Digital input
Data input.
WOLFSON MICROELECTRONICS LTD
DESCRIPTION
Digital positive power supply.
Analogue positive power supply.
Ground.
Production Data Rev 1.0 June 1999
2
WM2613
Production Data
ABSOLUTE MAXIMUM RATINGS
Absolute Maximum Ratings are stress ratings only. Permanent damage to the device may be caused by continuously operating at or
beyond these limits. Device functional operating limits and guaranteed performance specifications are given under Electrical
Characteristics at the test conditions specified
ESD Sensitive Device. This device is manufactured on a CMOS process. It is therefore generically susceptible to
damage from excessive static voltages. Proper ESD precautions must be taken during handling and storage of this
device.
CONDITION
MIN
MAX
Supply voltage differences, AVDD to DVDD
-2.8V
2.8V
Reference input voltage
-0.3V
DVDD + 0.3V
Supply voltages, AVDD or DVDD to GND
7V
Digital input voltage range to GND
Operating temperature range, TA
-0.3V
AVDD + 0.3V
WM2613C
0°C
70°C
WM2613I
-40°C
85°C
-65°C
150°C
Storage temperature
Lead temperature 1.6mm (1/16 inch) soldering for 10 seconds
260°C
RECOMMENDED OPERATING CONDITIONS
PARAMETER
SYMBOL
Supply voltage
AVDD, DVDD
TEST CONDITIONS
MIN
2.7
TYP
MAX
UNIT
5.5
V
High-level digital input voltage
VIH
DVDD = 2.7V to 5.5V
Low-level digital input voltage
VIL
DVDD = 2.7V to 5.5V
0.8
V
Reference voltage to REFIN
VREF
See Note
AVDD - 1.5
V
Load resistance
RL
Load capacitance
CL
Operating free-air temperature
TA
2
V
2
kΩ
100
pF
WM2613CDT
0
70
°C
WM2613IDT
-40
85
°C
Note: Reference voltages greater than AVDD/2 will cause saturation for large DAC codes.
WOLFSON MICROELECTRONICS LTD
Production Data Rev 1.0 June 1999
3
WM2613
Production Data Rev 1.0
ELECTRICAL CHARACTERISTICS
Test Conditions:
RL = 10kΩ, CL = 100pF. AVDD = DVDD = 5V ± 10%, VREF = 2.048V and AVDD = DVDD = 3V ± 10%, VREF = 1.024V over
recommended operating free-air temperature range (unless noted otherwise)
PARAMETER
SYMBOL
TEST
CONDITIONS
MIN
TYP
MAX
UNIT
Static DAC Specifications
Resolution
12
bits
Integral non-linearity
INL
See Note 1
± 1.5
±4
LSB
Differential non-linearity
DNL
See Note 2
± 0.4
±1
LSB
Zero code error
ZCE
See Note 3
3
± 20
mV
GE
See Note 4
± 0.25
± 0.5
% FSR
d.c. PSRR
See Note 5
0.5
mV/V
Zero code error temperature
coefficient
See Note 6
3
ppm/°C
Gain error temperature coefficient
See Note 6
1
ppm/°C
Gain error
D.c power supply rejection ratio
DAC Output Specifications
Output voltage range
0
Output load regulation
AVDD - 0.4
V
0.1
0.3
%
Slow
0.5
1.3
mA
Fast
1.6
3.0
mA
Slow
0.4
1.1
mA
Fast
1.4
2.7
mA
No load, all digital inputs 0V
or DVDD. See Note 9
0.01
10
µA
2kΩ to 10kΩ load. See Note 7
Power Supplies
Active supply current
IDD
No load, VIH = DVDD, VIL = 0V
AVDD = DVDD = 5V,
VREF = 2.048V See Note 8
AVDD = DVDD = 3V,
VREF = 1.024V
Power down supply current
Dynamic DAC Specifications
Slew rate
DAC code 128 to 4095,
10%-90% See Note 10
Settling time
Glitch energy
Signal to noise ratio
Signal to noise and distortion ratio
Total harmonic distortion
Spurious free dynamic range
WOLFSON MICROELECTRONICS LTD
Slow
1.5
V/µs
Fast
8
V/µs
DAC code 128 to 4095
Slow
3.5
µs
Fast
1.0
µs
1
nV-s
Code 2047 to code 2048
SNR
fS = 480ksps,
fOUT = 1kHz BW = 20kHz,
TA = 25°C See Note 12
65
78
dB
SNRD
fS = 480ksps,
fOUT = 1kHz BW = 20kHz,
TA = 25°C See Note 12
58
69
dB
THD
fS = 480ksps,
fOUT = 1kHz BW = 20kHz,
TA = 25°C See Note 12
SPFDR
fS = 480ksps,
fOUT = 1kHz BW = 20kHz, TA =
25°C See Note 12
-68
60
72
-60
dB
dB
Production Data Rev 1.0 June 1999
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WM2613
Production Data
Test Conditions:
RL = 10kΩ, CL = 100pF. AVDD = DVDD = 5V ± 10%, VREF = 2.048V and AVDD = DVDD = 3V ± 10%, VREF = 1.024V over
recommended operating free-air temperature range (unless noted otherwise)
PARAMETER
SYMBOL
TEST
CONDITIONS
MIN
TYP
MAX
UNIT
Reference
Reference input resistance
RREFIN
10
MΩ
Reference input capacitance
CREFIN
5
pF
-60
dB
Slow
1
MHz
Fast
1.6
MHz
Reference feedthrough
VREF = 1VPP at 1kHz
+ 1.024V d.c., DAC code 0
Reference input bandwidth
VREF = 0.2VPP + 1.024V d.c.
DAC code 2048
Digital Inputs
High level input current
IIH
Input voltage = DVDD
Low level input current
IIL
Input voltage = 0V
Input capacitance
CI
1
µA
-1
µA
8
pF
Notes:
1.
Integral non-linearity (INL) is the maximum deviation of the output from the line between zero and full scale excluding the
effects of zero code and full scale errors).
2.
Differential non-linearity (DNL) is the difference between the measured and ideal 1LSB amplitude change
of any adjacent two codes. A guarantee of monotonicity means the output voltage changes in the same
direction (or remains constant) as a change in digital input code.
3.
Zero code error is the voltage output when the DAC input code is zero.
4.
Gain error is the deviation from the ideal full scale output excluding the effects of zero code error.
5.
Power supply rejection ratio is measured by varying AVDD from 4.5V to 5.5V and measuring the
proportion of this signal imposed on the zero code error and the gain error.
6.
Zero code error and Gain error temperature coefficients are normalised to full scale voltage.
7.
Output load regulation is the difference between the output voltage at full scale with a 10kΩ load and 2kΩ
load. It is expressed as a percentage of the full scale output voltage with a 10kΩ load.
8.
IDD is measured while continuously writing code 2048 to the DAC. For VIH < DVDD - 0.7V and VIL > 0.7V supply current
will increase.
9.
Typical supply current in power down mode is 10nA. Production test limits are wider for speed of test.
10.
Slew rate results are for the lower value of the rising and falling edge slew rates.
11.
Settling time is the time taken for the signal to settle to within 0.5LSB of the final measured value for both rising and
falling edges. Limits are ensured by design and characterisation, but are not production tested
12.
SNR, SNRD, THD and SPFDR are measured on a synthesised sinewave at frequency fOUT generated with
a sampling frequency fS.
WOLFSON MICROELECTRONICS LTD
Production Data Rev 1.0 June 1999
5
WM2613
Production Data Rev 1.0
SERIAL INTERFACE
tSUD
X
D[0-7]
tHD
Data
tSUA
A[0-1]
X
X
tHA
Address
X
tSUCSWE
NCS
tWWE
NWE
tSUWELD
tWLD
NLDAC
Figure 1 Timing Diagram
SYMBOL
tSUCSWE
tSUDWE
TEST CONDITIONS
MIN
Setup time NCS low before positive NWE edge
Data ready before positive NWE edge
TYP
13
MAX
UNIT
ns
9
ns
tHD
Data hold after positive NWE edge
0
ns
tSUA
Setup time for address bits A0, A1
17
ns
tHA
Address hold after positive NWE edge
0
tSUWELD
Positive NWE edge before NLDAC low
0
ns
tWWE
High pulse width of NWE
10
ns
tWLD
Low pulse width of NLDAC
10
ns
WOLFSON MICROELECTRONICS LTD
Production Data Rev 1.0 June 1999
6
WM2613
Production Data
TYPICAL PERFORMANCE GRAPHS
3
A V D D = D V D D = 5 V , V REF = 2 . 0 4 8 V , S p e e d = F a s t m o d e , L o a d = 1 0 k / 1 0 0 p F
2
INL - LSB
1
0
-1
-2
-3
0
512
1024
1536
2048
2559
3071
3583
4095
DIGITAL CODE
Figure 2 Integral Non-Linearity
3
5
AVDD = DVDD = 5V, VREF = 2V, Input Code = 0
AVDD = DVDD =3V, VREF = 1V, Input Code = 0
4.5
2.5
4
3.5
OUTPUT VOLTAGE - V
OUTPUT VOLTAGE - V
2
1.5
3
2.5
2
1
1.5
1
0.5
0.5
0
0
0
1
2
3
4
5
6
7
8
9
ISINK - mA
Slow
0
10
1
Figure 3 Sink Current AVDD = DVDD = 3V
3
4
5
6
7
8
9
Slow
ISINK - mA
10
Fast
Figure 4 Sink Current AVDD = DVDD = 5V
4.105
2.065
AVDD = DVDD = 5V, VREF = 2V, Input Code = 4095
AVDD = DVDD = 3V, VREF = 1V, Input Code = 4095
2.06
4.1
2.055
4.095
OUTPUT VOLTAGE - V
OUTPUT VOLTAGE - V
2
Fast
2.05
2.045
2.04
4.09
4.085
4.08
2.035
4.075
2.03
4.07
2.025
4.065
0
1
2
3
4
5
6
7
ISOURCE - mA
8
9
Slow
Figure 5 Source Current AVDD = DVDD = 3V
WOLFSON MICROELECTRONICS LTD
10
Fast
0
1
2
3
4
5
6
7
8
ISOURCE - mA
9
Slow
10
Fast
Figure 6 Source Current AVDD = DVDD = 5V
Production Data Rev 1.0 June 1999
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WM2613
Production Data Rev 1.0
DEVICE DESCRIPTION
GENERAL FUNCTION
The device uses a resistor string network buffered with an op amp to convert 12-bit digital data to
analogue voltage levels (see Block Diagram). The output voltage is determined by the reference input
voltage and the input code according to the following relationship:
Output voltage = 2(VREF )
CODE
4096
INPUT
1111
1111
OUTPUT
1111
2(VREF )
:
4095
4096
:
1000
0000
0001
1000
0000
0000
0111
1111
1111
0000
0000
0001
0000
0000
0000
:
2(VREF )
2(VREF )
2049
4096
2048
= VREf
4096
2(VREF )
2047
4096
:
2(VREF )
1
4096
0V
Table 1 Binary Code Table (0V to 2VREF Output), Gain = 2
POWER ON RESET
An internal power-on-reset circuit resets the DAC register to all 0s on power-up.
BUFFER AMPLIFIER
The output buffer has a near rail-to-rail output with short circuit protection and can reliably drive a 2kΩ
load with a 100pF load capacitance.
EXTERNAL REFERENCE
The reference voltage input is buffered which makes the DAC input resistance independent of code. The
REFIN pin has an input resistance of 10MΩ and an input capacitance of typically 5pF. The reference
voltage determines the DAC full-scale output.
HARDWARE CONFIGURATION OPTIONS
The device has three configuration options that are controlled by device pins.
DEVICE POWER DOWN
The device can be powered-down by pulling pin NPD (pin 15) low. This powers down the DAC. This will
reduce power consumption significantly. The NPD pin overrides the software control bit PWR. When the
power down function is released the device reverts to the DAC code set prior to power down.
SETTLING TIME
The settling time of the device can be controlled by pin SPD (pin 9). A ONE on pin SPD will ensure a
FAST settling time; a ZERO will ensure a SLOW settling time. The SPD pin high overrides the software
control bit SPD.
SIMULTANEOUS DAC UPDATE
The NLDAC pin (Pin 16) can be held high to prevent word writes from updating the DAC latch. By writing
the new value to the DAC then pulling NLDAC low, the new DAC code is loaded into the DAC latch.
WOLFSON MICROELECTRONICS LTD
Production Data Rev 1.0 June 1999
8
WM2613
Production Data
PARALLEL INTERFACE
The device latches data on the positive edge of NWE. It must be enabled with NCS low. Whether the
data is written to one of the DAC holding latches (MSW, LSW) or the control register, depends on the
address bits A1 and A0. NLDAC low updates the DAC with the value in the holding latch, see Figure 7.
NLDAC is an asynchronous input and can be held low, if a synchronous update is not necessary.
Alternatively, the RLDAC bit of the control register can be used to synchonously update the DAC latch via
software control, see Figure 8.
X
D[0-7]
MSW
0
A[0-1]
X
X
LSW
X
1
X
NCS
NWE
NLDAC
Figure 7 Example of a Complete Write Cycle Using NLDAC to Update the DAC
X
D[0-7]
A[0-1]
X
MSW
0
X
X
LSW
1
X
X
Control
3
X
X
NCS
NWE
NLDAC
Figure 8 Example of a Complete Write Cycle Using the Control Word to Update the DAC. If NLDAC is held low as shown
in Figure 8, latch will be transparent. This assumes that the RLDAC control register bit is low at the start and is written high on
the final write.
WOLFSON MICROELECTRONICS LTD
Production Data Rev 1.0 June 1999
9
WM2613
Production Data Rev 1.0
SOFTWARE CONFIGURATION OPTIONS
DATA FORMAT
The WM2613 writes data either to one of the DAC holding latches or to the control register depending on
the address bits A1 and A0.
A1
A0
REGISTER
0
0
DAC LSW holding
0
1
DAC MSW holding
1
0
Reserved
1
1
Control
D7
D6
D5
D4
D3
D2
D1
D0
X
X
X
X
X
RLDAC
PWR
SPD
Table 2 Register Map
PROGRAMMABLE SETTLING TIME
Settling time is a software selectable 3.5µs or 1µs, typical to within ±0.5LSB of final value. This is
controlled by the value of SPD – Bit D12. A ONE defines a settling time of 1µs, a ZERO defines a settling
time of 3.5µs.
PIN
BIT
SPD
SPD
0
0
Slow
0
1
Fast
1
0
Fast
1
1
Fast
MODE
Table 3 Programmable Settling Time
PROGRAMMABLE POWER DOWN
The power down function can be controlled by PWR. A ZERO configures the device as active, or fully
powered up, a ONE configures the device into power down mode. When the power down function is
released the device reverts to the DAC code set prior to power down.
PIN
BIT
NPD
PWR
0
0
0
1
Down
1
0
Normal
1
1
Down
POWER
Down
Table 4 Programmable Power Down
LOAD DAC LATCH
Bit RLDAC controls the function of the DAC latch. A ONE configures the DAC latch as transparent. A
ZERO configures the DAC latch to be controlled by pin NLDAC.
PIN
BIT
NLDAC
RLDAC
LATCH
0
0
Transparent
0
1
Transparent
1
0
Hold
1
1
Transparent
Table 5 Load DAC Latch
WOLFSON MICROELECTRONICS LTD
Production Data Rev 1.0 June 1999
10
WM2613
Production Data
PACKAGE DIMENSIONS
DT: 20 PIN TSSOP (6.5 x 4.4 x 1.0 mm)
b
DM008.C
e
20
11
E1
E
GAUGE
PLANE
1
θ
10
D
0.25
c
A
A2
L
A1
-C0.05 C
Symbols
A
A1
A2
b
c
D
e
E
E1
L
θ
REF:
MIN
----0.05
0.80
0.19
0.09
6.40
4.30
0.45
0o
Dimensions
(mm)
NOM
--------1.00
--------6.50
0.65 BSC
6.4 BSC
4.40
0.60
-----
SEATING PLANE
MAX
1.20
0.15
1.05
0.30
0.20
6.60
4.50
0.75
8o
JEDEC.95, MO-153
NOTES:
A. ALL LINEAR DIMENSIONS ARE IN MILLIMETERS.
B. THIS DRAWING IS SUBJECT TO CHANGE WITHOUT NOTICE.
C. BODY DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSION, NOT TO EXCEED 0.25MM.
D. MEETS JEDEC.95 MO-153, VARIATION = AC. REFER TO THIS SPECIFICATION FOR FURTHER DETAILS.
WOLFSON MICROELECTRONICS LTD
Production Data Rev 1.0 June 1999
11