AD5065BRUZ-1REEL7 [ADI]

Fully Accurate 12-/14-/16-Bit VOUT DAC SPI Interface 2.7 V to 5.5 V in a TSSOP; 完全准确的12位/ 14位/ 16位DAC VOUT SPI接口的2.7 V至5.5 V采用TSSOP
AD5065BRUZ-1REEL7
型号: AD5065BRUZ-1REEL7
厂家: ADI    ADI
描述:

Fully Accurate 12-/14-/16-Bit VOUT DAC SPI Interface 2.7 V to 5.5 V in a TSSOP
完全准确的12位/ 14位/ 16位DAC VOUT SPI接口的2.7 V至5.5 V采用TSSOP

转换器 数模转换器 光电二极管
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Fully Accurate 12-/14-/16-Bit VOUT DAC SPI Interface  
2.7 V to 5.5 V in a TSSOP  
Preliminary Technical Data  
AD5025/45/65  
Functional Block Diagrams  
FEATURES  
V
V
V
DD  
REFA  
REFB  
Low power Dual 12-/14-/16 bit DAC, 1LSB INL  
Individual Voltage reference pins  
Rail-to-rail operation  
LDAC  
INPUT  
DAC  
DAC A  
DAC B  
V
A
SCLK  
SYNC  
DIN  
BUFFER  
BUFFER  
OUT  
OUT  
REGISTER  
REGISTER  
INTERFACE  
LOGIC  
2.7 V to 5.5 V power supply  
Power-on reset to zero scale or midscale  
Power down to 400 nA @ 5 V, 200 nA @ 3 V  
3 power-down functions  
INPUT  
REGISTER  
DAC  
REGISTER  
V
B
PDL  
SDO  
AD5025/AD5045R/AD5065  
POWER-ON  
RESET  
POWER-DOWN  
LOGIC  
Per channel power-down  
Low glitch upon power up  
LDAC CLR  
GND  
POR  
Hardware Power Down lock Out Capability  
Hardware LDAC with LDAC override function  
CLR Function to programmable code  
SDO daisy-chaining option  
Figure 1.AD5025/45/65  
Table 1. Related Devices  
14 lead TSSOP  
Part No.  
AD5666  
AD5066  
Description  
Quad,16-bit buffered D/A,16 LSB INL, TSSOP  
Quad,16-bit unbuffered D/A,1 LSB INL, TSSOP  
APPLICATIONS  
AD5064/44/24 Quad 16-bit nanoDAC, 1 LSB INL, TSSOP  
Process control  
AD5063/62  
AD5061  
AD5060/40  
16-bit nanoDAC, 1 LSB INL, MSOP  
16-/14bit nanoDAC, 4 LSB INL, SOT-23  
16-/14bit nanoDAC, 1 LSB INL, SOT-23  
Data acquisition systems  
Portable battery-powered instruments  
Digital gain and offset adjustment  
Programmable voltage and current sources  
Programmable attenuators  
GENERAL DESCRIPTION  
all DACs can be updated simultaneously using the  
function, with the added functionality of user-selectable DAC  
channels to simultaneously update. There is also an  
LDAC  
The AD5025/45/65 are low power, dual 12-/14-/16-bit buffered  
voltage-out DACs offering relative accuracy specs of 1 LSB INL  
with individual reference pins and can operate from a single 2.7  
V to 5.5 V supply. The AD5025/45/65 64 parts also offer a  
differential accuracy specification of 1 LSB. The parts use a  
versatile 3-wire, low power Schmitt trigger serial interface that  
operates at clock rates up to 50 MHz and is compatible with  
standard SPI®, QSPI™, MICROWIRE™, and DSP interface  
standards. The reference for the AD5025/45 and AD5065 are  
supplied from an external pin. A reference buffer is also  
provided on-chip. The AD5025/45/64 incorporates a power-on  
reset circuit that ensures the DAC output powers up zero scale  
or midscale and remains there until a valid write takes place to  
the device. The AD5025/45/65 contain a power-down feature  
that reduces the current consumption of the device to typically  
330 nA at 5 V and provides software selectable output loads  
while in power-down mode. The parts are put into power-down  
mode over the serial interface. Total unadjusted error for the  
parts is <2 mV.  
asynchronous  
that clears all DACs to a software-selectable  
CLR  
code—0 V, midscale, or full scale. The Part also features a power  
down lockout pin , which can be used to prevent the DAC  
PDL  
from entering power down under any circumstances over the  
serial interface.  
PRODUCT HIGHLIGHTS  
1. Dual channel available in 14-lead TSSOP package with  
individual Voltage reference pins.  
2. 12-/14-/-16 bit accurate, 1 LSB INL.  
3. Low glitch on power-up.  
4. High speed serial interface with clock speeds up to 50 MHz.  
5. Three power-down modes available to the user.  
6. Reset to known output voltage (zero scale or midscale).  
7. Power Down lockout capability.  
Both parts exhibit very low glitch on power-up. The outputs of  
Rev. PrB  
Information furnished by Analog Devices is believed to be accurate and reliable. However, no  
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other  
rights of third parties that may result from its use. Specifications subject to change without notice. No  
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.  
Trademarks and registeredtrademarks arethe property of their respective owners.  
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.  
Tel: 781.329.4700  
Fax: 781.461.3113  
www.analog.com  
© 2007 Analog Devices, Inc. All rights reserved.  
AD5025/45/65  
Preliminary Technical Data  
TABLE OF CONTENTS  
REVISION HISTORY  
Rev. PrB | Page 2 of 33  
Preliminary Technical Data  
SPECIFICATIONS  
AD5025/45/65  
VDD = 2.7 V to 5.5 V, RL = 2 kΩ to GND, CL = 200 pF to GND, 2.2V VREFIN . VDD unless otherwise specified. All specifications TMIN to  
TMAX, unless otherwise noted.  
Table 2.  
B Grade1  
Typ  
Parameter  
STATIC PERFORMANCE2  
Min  
Max  
Unit  
Conditions/Comments  
Resolution  
16  
14  
12  
Bits  
AD5065  
AD5045  
AD5025  
Relative Accuracy  
0.5  
0.5  
0.5  
0.5  
0.5  
0.5  
1
1.5  
1
1.5  
1
1.5  
1
2
LSB  
LSB  
LSB  
AD5065 TA = -40°C to +105°C  
AD5065 TA = -40°C to +125°C  
AD5045 TA = -40°C to +105°C  
AD5045 TA = -40°C to +125°C  
AD5025 TA = -40°C to +105°C  
AD5025 TA = -40°C to +125°C  
AD5065/45/25: Guaranteed monotonic by design  
AD5065/45/25 TA = -40°C to +105°C  
AD5065/45/25 TA = -40°C to +125°C  
All 0s loaded to DAC register  
Differential Nonlinearity  
Total Unadjusted Error Tue  
LSB  
mV  
mV  
mV  
0.2  
0.2  
1
2
Offset Error  
9
Offset Error Drift  
Full-Scale Error  
Gain Error  
Gain Temperature Coefficient  
DC Power Supply Rejection  
Ratio  
2
−0.2  
μV/°C  
% FSR  
% FSR  
ppm  
dB  
−1  
1
All 1s loaded to DAC register  
2.5  
–80  
Of FSR/°C  
VDD 10%  
DC Crosstalk  
0.5  
0.5  
0.5  
LSB  
Due to single-channel full-scale output change,  
RL = 2 kΩ to GND or VDD  
Due to load current change  
LSB/m  
A
LSB  
Due to powering down (per channel)  
OUTPUT CHARACTERISTICS3  
Output Voltage Range  
0
VDD  
V
Capacitive Load Stability  
DC Output Impedance  
(Normal mode)  
1
0.5  
pF  
Ω
RL = 2 kΩ, RL = 100 kΩ and RL = ∞  
DC Output Impedance  
DAC in Power Down mode  
(output connected to 100kΩ  
network)  
(output connected to 1kΩ  
network)  
100  
1
kΩ  
kΩ  
Output impedance tolerance 20Ω  
Output impedance tolerance 400Ω  
Short-Circuit Current  
60  
45  
4.5  
-92  
-67  
mA  
mA  
μs  
dB  
dB  
DAC = full scale, o/p shorted to Gnd  
DAC = zero scale, o/p shorted to VDD  
Coming out of power-down mode VDD = 5 V  
VDD 10%, DAC = full scale  
Power-Up Time  
DC PSRR  
Wideband SFDR  
REFERENCE INPUTS  
Reference Input Range  
Reference Current  
Reference Input Impedance  
LOGIC INPUTS3  
Output frequency = 10Khz  
2.2  
VDD  
50  
V
μA  
KΩ  
30  
120  
Per DAC channel VREF = VDD = 5.5 V  
Per DAC channel  
Input Current4  
3
μA  
All digital inputs  
Rev. PrB | Page 3 of 33  
AD5025/45/65  
Preliminary Technical Data  
B Grade1  
Typ  
Parameter  
Min  
Max  
Unit  
V
V
Conditions/Comments  
VDD = 5 V  
VDD = 5 V  
Input Low Voltage, VINL  
Input High Voltage, VINH  
Pin Capacitance  
0.8  
2
4
pF  
LOGIC OUTPUTS (SDO)3  
Output Low Voltage, VOL  
Output High Voltage, VOH  
0.4  
V
ISINK = 2 mA  
ISOURCE = 2 mA  
VDD  
1
High Impedance Leakage  
Current  
0.25 ꢀA  
High Impedance Output  
Capacitance  
2
pF  
POWER REQUIREMENTS  
VDD  
2.7  
5.5  
V
All digital inputs at 0 or VDD  
DAC active, excludes load current  
VIH = VDD and VIL = GND  
IDD (Normal Mode)5  
VDD = 4.5 V to 5.5 V  
3.2  
0.4  
4
1
mA  
μA  
IDD (All Power-Down Modes)6  
VDD = 4.5 V to 5.5 V  
VIH = VDD and VIL = GND  
1 1 Temperature range is −40°C to +105°C, typical at 25°C.  
2 Linearity calculated using a reduced code range of 512 to 65,024. Output unloaded.  
3 Guaranteed by design and characterization; not production tested.  
4 Total current flowing into all pins.  
5. Interface inactive. All DACs active. DAC outputs unloaded  
6. All four DACs powered down  
Rev. PrB | Page 4 of 33  
Preliminary Technical Data  
AD5025/45/65  
AC CHARACTERISTICS  
VDD = 2.7 V to 5.5 V, RL = 2 kΩ to GND, CL = 200 pF to GND, VREFIN =4.096V unless otherwise specified . All specifications TMIN to TMAX  
,
unless otherwise noted.  
Table 3.  
Parameter1, 2  
Min Typ  
Max  
Unit  
Conditions/Comments3  
Output Voltage Settling Time  
5
μs  
¼ to ¾ scale settling to 1 LSB,RL = 5kΩ single channel update  
including DAC calibration sequence  
Output Voltage Settling Time  
14  
μs  
¼ to ¾ scale settling to 1 LSB,RL = 5kΩ all channel update including  
DAC calibration sequence  
Slew Rate  
1.5  
4
−90  
3
0.1  
0.5  
6
6.5  
6
V/μs  
nV-s  
dB  
nV-s  
nV-s  
nV-s  
nV-s  
nV-s  
nV-s  
Digital-to-Analog Glitch Impulse  
Reference Feedthrough  
SDO Feedthrough  
Digital Feedthrough  
Digital Crosstalk  
Analog Crosstalk  
DAC-to-DAC Crosstalk  
AC Crosstalk  
1 LSB change around major carry  
VREF = 2 V 0.1 V p-p, frequency = 10 Hz to 20 MHz  
Daisy-chain mode; SDO load is 10 pF  
AC PSRR  
TBD  
340  
−80  
64  
60  
6
Multiplying Bandwidth  
Total Harmonic Distortion  
Output Noise Spectral Density  
kHz  
VREF = 2 V 0.2 V p-p  
dB  
VREF = 2 V 0.1 V p-p, frequency = 10 kHz  
DAC code = 0x8400, 1 kHz  
DAC code = 0x8400, 10 kHz  
0.1 Hz to 10 Hz  
nV/√Hz  
nV/√Hz  
ꢀV p-p  
Output Noise  
1 Guaranteed by design and characterization; not production tested.  
2 See the Terminology section.  
3 Temperature range is −40°C to + 105°C, typical at 25°C.  
Rev. PrB | Page 5 of 33  
AD5025/45/65  
Preliminary Technical Data  
TIMING CHARACTERISTICS  
All input signals are specified with tr = tf = 1 ns/V (10% to 90% of VDD) and timed from a voltage level of (VIL + VIH)/2. See Figure 3 and  
Figure 5. VDD = 2.7 V to 5.5 V. All specifications TMIN to TMAX, unless otherwise noted.  
Table 4.  
Limit at TMIN, TMAX  
Parameter  
VDD = 2.7 V to 5.5 V  
Unit  
Conditions/Comments  
1
t1  
t2  
t3  
t4  
20  
10  
10  
16.5  
5
ns min  
ns min  
ns min  
ns min  
ns min  
ns min  
ns min  
us min  
us min  
ns min  
ns min  
ns min  
ns min  
ns min  
ns min  
us min  
ns max  
ns min  
ns min  
ns min  
ns min  
SCLK cycle time  
SCLK high time  
SCLK low time  
SYNC to SCLK falling edge set-up time  
Data set-up time  
t5  
t6  
t7  
5
0
Data hold time  
SCLK falling edge to SYNC rising edge  
Minimum SYNC high time (single channel update)  
Minimum SYNC high time ( all channel update)  
SYNC rising edge to SCLK fall ignore  
SCLK falling edge to SYNC fall ignore  
LDAC pulse width low  
t8  
1.9  
10.5  
16.5  
0
t8  
t9  
t10  
t11  
t12  
t13  
t14  
t15  
20  
20  
10  
10  
10.6  
22  
5
SCLK falling edge to LDAC rising edge  
CLR pulse width low  
SCLK falling edge to LDAC falling edge  
CLR pulse activation time  
2, 3  
t16  
SCLK rising edge to SDO valid  
SCLK falling edge to SYNC rising edge  
SYNC rising edge to SCLK rising edge  
SYNC rising edge to LDAC falling edge  
PDL pulse width activation time  
3
t17  
3
t18  
8
3
t19  
0
t20  
20  
1 Maximum SCLK frequency is 50 MHz at VDD = 2.7 V to 5.5 V. Guaranteed by design and characterization; not production tested.  
2 Measured with the load circuit of Figure 16. t16 determines the maximum SCLK frequency in daisy-chain mode.  
3 Daisy-chain mode only.  
2mA  
I
OL  
TO OUTPUT  
PIN  
V
(MIN)  
OH  
C
L
50pF  
2mA  
I
OH  
Figure 2. Load Circuit for Digital Output (SDO) Timing Specifications  
Rev. PrB | Page 6 of 33  
Preliminary Technical Data  
AD5025/45/65  
Figure 3. Serial Write Operation  
t1  
SCLK  
32  
64  
t18  
t3  
t2  
t7  
t4  
t17  
SYNC  
DIN  
t8  
t9  
DB0  
DB31  
DB0  
DB31  
INPUT WORD FOR DAC N  
INPUT WORD FOR DAC N + 1  
INPUT WORD FOR DAC N  
t16  
DB31  
DB0  
SDO  
UNDEFINED  
t19  
t11  
LDAC  
Figure 4. Daisy-Chain Timing Diagram  
Rev. PrB | Page 7 of 33  
AD5025/45/65  
Preliminary Technical Data  
ABSOLUTE MAXIMUM RATINGS  
TA = 25°C, unless otherwise noted.  
Table 5.  
Stresses above those listed under Absolute Maximum Ratings  
may cause permanent damage to the device. This is a stress  
rating only; functional operation of the device at these or any  
other conditions above those indicated in the operational  
section of this specification is not implied. Exposure to absolute  
maximum rating conditions for extended periods may affect  
device reliability.  
Parameter  
Rating  
VDD to GND  
−0.3 V to +7 V  
Digital Input Voltage to GND  
VOUT to GND  
VREF to GND  
−0.3 V to VDD + 0.3 V  
−0.3 V to VDD + 0.3 V  
−0.3 V to VDD + 0.3 V  
Operating Temperature Range  
Industrial  
Storage Temperature Range  
−40°C to +125°C  
−65°C to +150°C  
+150°C  
Junction Temperature (TJ MAX  
)
TSSOP Package  
Power Dissipation  
θJA Thermal Impedance  
(TJ MAX − TA)/θJA  
150.4°C/W  
Reflow Soldering Peak Temperature  
SnPb  
Pb Free  
240°C  
260°C  
ESD CAUTION  
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on  
the human body and test equipment and can discharge without detection. Although this product features  
proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy  
electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance  
degradation or loss of functionality.  
Rev. PrB | Page 8 of 33  
Preliminary Technical Data  
AD5025/45/65  
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS  
14  
13  
12  
1
2
3
4
5
6
7
LDAC  
SCLK  
DIN  
SYNC  
V
PDL  
DD  
AD5065/45/35  
11  
10  
VrefA  
GND  
TOP VIEW  
(Not to Scale)  
V
B
V
A
OUT  
OUT  
9
8
VrefB  
CLR  
POR  
SDO  
Figure 5. 14-Lead TSSOP (RU-14)  
Table 6. Pin Function Descriptions  
Pin No.  
Mnemonic  
Description  
1
LDAC  
Pulsing this pin low allows any or all DAC registers to be updated if the input registers  
have new data. This allows all DAC outputs to simultaneously update. Alternatively, this  
pin can be tied permanently low.  
2
SYNC  
Active Low Control Input. This is the frame synchronization signal for the input data.  
When SYNC goes low, it powers on the SCLK and DIN buffers and enables the input  
shift register. Data is transferred in on the falling edges of the next 32 clocks. If SYNC is  
taken high before the 32nd falling edge, the rising edge of SYNC acts as an interrupt  
and the write sequence is ignored by the device.  
3
VDD  
Power Supply Input. These parts can be operated from 2.7 V to 5.5 V, and the supply  
should be decoupled with a 10 μF capacitor in parallel with a 0.1 μF capacitor to  
GND.  
4
5
6
VREFA  
Dac A reference input .This is the reference voltage input pin for Dac A.  
Analog Output Voltage from DAC A. The output amplifier has rail-to-rail operation.  
Power-on Reset Pin. Tying this pin to GND powers up the part to 0 V. Tying this pin to  
VDD powers up the part to midscale.  
VOUT  
A
POR  
7
SDO  
Serial Data Output. Can be used for daisy-chaining a number of these devices  
together or for reading back the data in the shift register for diagnostic purposes. The  
serial data is transferred on the rising edge of SCLK and is valid on the falling edge of  
the clock.  
8
CLR  
Asynchronous Clear Input. The CLR input is falling edge sensitive. When CLR is low,  
all LDAC pulses are ignored. When CLR is activated, the input register and the DAC  
register are updated with the data contained in the CLR code register—zero,  
midscale, or full scale. Default setting clears the output to 0 V.  
9
VREFB  
Dac B reference input .This is the reference voltage input pin for Dac B.  
Analog Output Voltage from DAC B. The output amplifier has rail-to-rail operation.  
Ground Reference Point for All Circuitry on the Part.  
The PDL pin is used to ensure hardware shutdown lockout of the device under any  
circumstance. A Logic 1 at the PLO pin will cause the device to behave as normal.  
The user may successfully enter software power down over the serial interface while  
logic 1 is applied to the PDL pin.  
10  
11  
12  
VOUT  
GND  
PDL  
B
If a logic 0 is applied to this pin, it will ensure that the device cannot enter software  
power down under any circumstances. If the device had previously been placed in  
software power down mode, a high to low transition at the PDL pin will cause the  
DAC(s) to exit power down and the output the last code in the dac register before  
the device entered software power down.  
13  
14  
DIN  
Serial Data Input. This device has a 32-bit shift register. Data is clocked into the  
register on the falling edge of the serial clock input.  
Serial Clock Input. Data is clocked into the input shift register on the falling edge of the  
serial clock input. Data can be transferred at rates of up to 50 MHz.  
SCLK  
Rev. PrB | Page 9 of 33  
AD5025/45/65  
Preliminary Technical Data  
TYPICAL PERFORMANCE CHARACTERISTICS  
TBD  
Figure 6. INL  
TBD  
Figure 7. DNL  
TBD  
Figure 8. TUE  
Rev. PrB | Page 10 of 33  
Preliminary Technical Data  
AD5025/45/65  
TBD  
Figure 9. INL vs. Reference Input Voltag  
TBD  
Figure 10. DNL vs. Reference Input Voltage  
TBD  
Figure 11. TUE vs. Reference Input Voltage  
Rev. PrB | Page 11 of 33  
AD5025/45/65  
Preliminary Technical Data  
TBD  
Figure 12. Gain Error and Full-Scale Error vs. Temperature  
TBD  
Figure 13. Offset Error vs. Temperature  
TBD  
Figure 14. Gain Error and Full-Scale Error vs. Supply Voltage  
Rev. PrB | Page 12 of 33  
Preliminary Technical Data  
AD5025/45/65  
TBD  
Figure 15. Zero-Scale Error and Offset Error vs. Supply Voltage  
TBD  
Figure 16. IDD Histogram VDD = 3.0 V  
TBD  
Figure 17. IDD Histogram VDD = 5.0 V  
Rev. PrB | Page 13 of 33  
AD5025/45/65  
Preliminary Technical Data  
Figure 18. Headroom at Rails vs. Source and Sink  
TBD  
Figure 19. Source and Sink Current Capability with VDD = 3 V  
TBD  
Figure 20. Source and Sink Current Capability with VDD = 5 V  
Rev. PrB | Page 14 of 33  
Preliminary Technical Data  
AD5025/45/65  
TBD  
Figure 21. Supply Current vs. Code  
TBD  
Figure 22. Supply Current vs. Temperature  
TBD  
Figure 23. Supply Current vs. Supply Voltage  
Rev. PrB | Page 15 of 33  
AD5025/45/65  
Preliminary Technical Data  
Figure 24. Supply Current vs. Logic Input Voltage  
Figure 25. Full-Scale Settling Time  
TBD  
Figure 26. Power-On Reset to 0 V  
Rev. PrB | Page 16 of 33  
Preliminary Technical Data  
AD5025/45/65  
TBD  
Figure 27. Power-On Reset to Midscale  
TBD  
Figure 28. Exiting Power-Down to Midscale  
TBD  
Figure 29. Digital-to-Analog Glitch Impulse (See Figure 34)  
Rev. PrB | Page 17 of 33  
AD5025/45/65  
Preliminary Technical Data  
TBD  
Figure 30. Analog Crosstalk  
TBD  
Figure 31. DAC-to-DAC Crosstalk  
TBD  
Figure 32. 0.1 Hz to 10 Hz Output Noise Plot  
Rev. PrB | Page 18 of 33  
Preliminary Technical Data  
AD5025/45/65  
TBD  
Figure 33. Typical Supply Current vs. Frequency @ 5.5 V1  
TBD  
Figure 34. Digital-to-Analog Glitch Energy  
TBD  
Figure 35. Noise Spectral Density, Internal Reference  
Rev. PrB | Page 19 of 33  
AD5025/45/65  
Preliminary Technical Data  
TBD  
Figure 36. Total Harmonic Distortion  
TBD  
Figure 37. Settling Time vs. Capacitive Load  
TBD  
CLR  
Figure 38. Hardware  
TBD  
Figure 39. Multiplying Bandwidth  
Rev. PrB | Page 20 of 33  
Preliminary Technical Data  
AD5025/45/65  
TBD  
Figure 40.Typical output slew rate  
Rev. PrB | Page 21 of 33  
AD5025/45/65  
Preliminary Technical Data  
THEORY OF OPERATION  
D/A SECTION  
OUTPUT AMPLIFIER  
The AD5025/45/65 are single 12-/14 and 16-bit, serial input,  
voltage output DACs. The parts operate from supply voltages of  
2.7 V to 5.5 V. Data is written to the AD5025/45/65 in a 32-bit  
word format via a 3-wire serial interface. The AD5025/45 and  
AD5065 incorporate a power-on reset circuit that ensures the  
DAC output powers up to a known out-put state (midscale or  
zero-scale, see the Ordering Guide). The devices also have a  
software power-down mode that reduces the typical current  
consumption to less than 1 μa.  
The output buffer amplifier can generate rail-to-rail voltages on  
its output, which gives an output range of 0 V to VDD. The  
amplifier is capable of driving a load of 2 kΩ in parallel with  
1,000 pF to GND. The source and sink capabilities of the output  
amplifier can be seen in (TBD) and (TBD). The slew rate is 1.5  
V/μs with a ¼ to ¾ scale settling time of 10 μs.  
SERIAL INTERFACE  
The AD5025/45/65 has a 3-wire serial interface (  
, SCLK,  
SYNC  
Because the input coding to the DAC is straight binary, the ideal  
output voltage when using an external reference is given by  
and DIN) that is compatible with SPI, QSPI, and MICROWIRE  
interface standards as well as most DSPs. See Figure 3 for a  
timing diagram of a typical write sequence.  
D
VOUT =VREFIN  
×
2N  
STANDALONE MODE  
The ideal output voltage when using and internal reference is  
given by  
The write sequence begins by bringing the  
line low. Data  
SYNC  
from the DIN line is clocked into the 32-bit shift register on the  
falling edge of SCLK. The serial clock frequency can be as high  
as 50 MHz, making the AD5025/45/65 compatible with high  
speed DSPs. On the 32nd falling clock edge, the last data bit is  
clocked in and the programmed function is executed, that is, a  
change in DAC register contents and/or a change in the mode  
D
VOUT = 2×VREFOUT  
×
2N  
where:  
D = decimal equivalent of the binary code that is loaded to the  
DAC register. 0 to 65,535 for AD5065 (16 bits).N = the DAC  
resolution.  
of operation. At this stage, the  
line can be kept low or be  
SYNC  
brought high. In either case, it must be brought high for a  
minimum of 15 ns before the next write sequence so that a  
DAC ARCHITECTURE  
falling edge of  
can initiate the next write sequence.  
buffer draws more current when VIN = 2 V  
The DAC architecture of the AD5065 consists of two matched  
DAC sections. A simplified circuit diagram is shown in Figure  
41. The four MSBs of the 16-bit data word are decoded to drive  
15 switches, E1 to E15. Each of these switches connects one of  
15 matched resistors to either GND or VREF buffer output. The  
remaining 12 bits of the data word drive switches S0 to S11 of a  
12-bit voltage mode R-2R ladder network.  
SYNC  
Because the  
SYNC  
than it does when VIN = 0.8 V,  
should be idled low  
SYNC  
between write sequences for even lower power operation of the  
part. As is mentioned previously, however, must be  
SYNC  
brought high again just before the next write sequence.  
V
OUT  
2R  
S1  
2R  
2R  
E1  
2R  
E2  
2R  
2R  
2R  
S0  
Table 7. Command Definitions  
Command  
E15  
S11  
V
REF  
C3 C2 C1 C0 Description  
0
0
0
0
0
0
0
0
1
0
1
0
Write to Input Register n  
Update DAC Register n  
Write to Input Register n, update all  
(software LDAC)  
12-BIT R-2R LADDER  
FOUR MSBs DECODED INTO  
15 EQUAL SEGMENTS  
Figure 42. Dac Ladder Structure  
0
0
0
0
0
1
1
1
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
1
Write to and update DAC Channel n  
Power down/power up DAC  
Load clear code register  
REFERENCE BUFFER  
The AD5025/45 and AD5065 operate with an external  
reference. Each of the two onboard dacs will have a dedicated  
voltage reference pin. In either case the reference input pin has  
an input range of 2 V to VDD. This input voltage is then used to  
provide a buffered reference for the DAC core.  
Load LDAC register  
Reset (power-on reset)  
Set up DCEN register (Daisy chain enable)  
Set up DIO direction and Value  
Reserved  
Rev. PrB | Page 22 of 33  
Preliminary Technical Data  
AD5025/45/65  
Table 8. Address Commands  
Address (n)  
Selected DAC  
Channel  
A3  
0
A2  
0
A1  
0
A0  
0
DAC A  
0
0
0
1
DAC B  
0
0
1
0
0
1
1
1
1
0
1
1
Reserved  
Reserved  
All DACs  
Rev. PrB | Page 23 of 33  
AD5025/45/65  
Preliminary Technical Data  
INTERRUPT  
SYNC  
INPUT SHIFT REGISTER  
In a normal write sequence, the  
line is kept low for at  
SYNC  
least 32 falling edges of SCLK, and the DAC is updated on the  
32nd falling edge. However, if  
is brought high before the  
The AD5025/45/65 input shift register is 32 bits wide (see  
Figure 43). The first four bits are don’t cares. The next four bits  
are the command bits, C3 to C0 (see Table 8), followed by the 4-  
bit DAC address bits, A3 to A0 (see Table 9) and finally the bit  
data-word. The data-word comprises either 12-/14 or 16-bit  
input code followed by 8-/6 or 4 don’t care bits for the  
SYNC  
32nd falling edge, this acts as an interrupt to the write sequence.  
The shift register is reset, and the write sequence is seen as  
invalid. Neither an update of the DAC register contents nor a  
change in the operating mode occurs (see Figure 46).  
AD5025/45/65 (see Figure 43). These data bits are transferred to  
the DAC register on the 32nd falling edge of SCLK.  
DB31 (MSB)  
DB0 (LSB)  
X
X
X
X
C3 C2 C1 C0 A3 A2 A1 A0 D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0  
X
X
X
X
DATA BITS  
COMMAND BITS  
ADDRESS BITS  
Figure 43. AD5065 Input Register Content  
DB31 (MSB)  
DB0 (LSB)  
X
X
X
X
C3 C2 C1 C0 A3 A2 A1 A0 D13 D12 D11 D10 D9 D8  
D7 D6 D5 D4 D3 D2 D1 D0  
X
X
X
X
X
X
DATA BITS  
COMMAND BITS  
ADDRESS BITS  
Figure 44. AD5045 Input Register Content  
DB31 (MSB)  
DB0 (LSB)  
X
X
X
X
C3 C2 C1 C0 A3 A2 A1 A0 D11 D10 D9 D8 D7 D6  
D5 D4 D3 D2 D1 D0  
X
X
X
X
X
X
X
X
DATA BITS  
COMMAND BITS  
ADDRESS BITS  
Figure 45. AD5025 Input Register Content  
SCLK  
SYNC  
DIN  
DB31  
DB0  
DB31  
DB0  
INVALID WRITE SEQUENCE:  
SYNC HIGH BEFORE 32ND FALLING EDGE  
VALID WRITE SEQUENCE, OUTPUT UPDATES  
ON THE 32ND FALLING EDGE  
SYNC  
Figure 46.  
Interrupt Facility  
Rev. PrB | Page 24 of 33  
Preliminary Technical Data  
AD5025/45/65  
2. If a  
is generated, whilst the DAC(s) are in  
PDL  
DAISY-CHAINING  
power down mode, then the DAC (s) will come out of  
power down ( i.e. all power down registers get reset to  
0000 ) to the last valid stored DAC value. As long, as  
For systems that contain several DACs, or where the user  
wishes to read back the DAC contents for diagnostic purposes,  
the SDO pin can be used to daisy-chain several devices together  
and provide serial read-back.  
remains active software power down is disabled.  
PDL  
3. After the  
is taken from a low to a high state, then  
PDL  
The daisy-chain mode is enabled through a software executable  
DCEN (Daisy Chain Enable) command. Command 1000 is  
reserved for this DCEN function (see Table 7). The daisy-chain  
mode is enabled by setting a bit (DB1) in the DCEN register.  
The default setting is standalone mode, where Bit DCEN = 0.  
Table 9 shows how the state of the bits corresponds to the mode  
of operation of the device.  
all DAC channels will remain in normal mode and  
the user will have to re-issue a software power down  
command to the control register in order to power  
down the required channels..  
4. Transitioning the  
from a low to a high will  
PDL  
disable the feature immediately.  
5. if and are generated at the same time, then  
PLO  
CLR  
The SCLK is continuously applied to the input shift register  
signal will cause the dac register to change as  
CLR  
when  
is low. If more than 32 clock pulses are applied, the  
SYNC  
per the Clear Content Register and then DACs will  
come out of Power Down.  
data ripples out of the shift register and appears on the SDO  
line. This data is clocked out on the rising edge of SCLK and is  
valid on the falling edge. By connecting this line to the DIN  
input on the next DAC in the chain, a multi-DAC interface is  
constructed. Each DAC in the system requires 32 clock pulses;  
therefore, the total number of clock cycles must equal 32N,  
where N is the total number of devices in the chain.  
6. if  
,
and  
are generated at same time  
PLO CLR  
LDAC  
then  
will have higher precedence over  
LDAC  
this case will be same as case 2 mentioned  
CLR  
and  
PLO  
above.  
7. The user is recommended to hardwire the pin to a  
logic high or low thereby either enabling or disabling  
the feature.  
When the serial transfer to all devices is complete,  
is  
SYNC  
taken high. This prevents any further data from being clocked  
into the input shift register.  
POWER-ON RESET  
The AD5025/45/65 contains a power-on reset circuit that  
controls the output voltage during power-up. By connecting the  
POR pin low, the AD5025/45/65 output powers up to 0 V; by  
connecting the POR pin high, the AD5025/45/65 output powers  
up to mid-scale. The output remains powered up at this level  
until a valid write sequence is made to the DAC. This is useful  
in applications where it is important to know the state of the  
output of the DAC while it is in the process of powering up.  
There is also a software executable reset function that resets the  
DAC to the power-on reset code. Command 0111 is reserved  
If  
is taken high before 32 clocks are clocked into the part,  
SYNC  
it is considered an invalid frame and the data is discarded.  
The serial clock can be continuous or a gated clock. A  
continuous SCLK source can be used only if the  
held low for the correct number of clock cycles. In gated clock  
mode, a burst clock containing the exact number of clock cycles  
must be used, and  
can be  
SYNC  
must be taken high after the final  
SYNC  
clock to latch the data.  
for this reset function (see Table 7). Any events on  
or  
LDAC  
POWER DOWN LOCKOUT  
The AD5025/45/65 contains a 1-bit digital input pin  
during power-on reset are ignored.  
CLR  
.
PDL  
When activated, the power down lock out pin (  
) disables  
PDL  
software shutdown under any circumstances The user should  
hardwire the pin to a logic low ( thus preventing  
POWER-DOWN MODES  
The AD5025/45/65 contains four separate modes of operation.  
Command 0100 is reserved for the power-down function (see  
Table 7). These modes are software-programmable by setting  
two bits, Bit DB9 and Bit DB8, in the control register (refer to  
Table 12). Table 11 shows how the state of the bits corresponds  
to the mode of operation of the device. Any or all DACs (DAC  
A and DAC B) can be powered down to the selected mode by  
setting the corresponding four bits (DB3, DB2, DB1, DB0) to 1.  
See Table 12 for the contents of the input shift register during  
power-down/power-up operation.  
PDL  
subsequent software power down) or logic high (the part can be  
placed in power down mode over the serial interface). Should  
the user decide to transition the  
pin from logic high to a  
PDL  
logic low during a valid write sequence, the device will respond  
immediately and the current write sequence will be aborted.  
Points to note about the  
feature is that  
PDL  
1. if a  
is generated ( i.e. a high to low transition)  
PDL  
while a valid write sequence is ongoing then the write  
will be aborted. The user will need to re write the  
current write command again.  
Rev. PrB | Page 25 of 33  
AD5025/45/65  
Preliminary Technical Data  
When both Bit DB9 and Bit DB8, in the control register are set to  
0, the part works normally with its normal power consumption  
of TBD at 5 V. However, for the three power-down modes, the  
supply current falls to TBD at 5 V (TBD at 3 V). Not only does  
the supply current fall, but the output stage is also internally  
switched from the output of the amplifier to a resistor network  
of known values. This has the advantage that the output  
impedance of the part is known while the part is in power-  
down mode. There are three different options. The output is  
connected internally to GND through either a 1 kΩ or a 100 kΩ  
resistor, or it is left open-circuited (three-state). The output  
stage is illustrated in Figure 47.  
The bias generator, output amplifier, resistor string, and other  
associated linear circuitry are shut down when the power-down  
mode is activated. However, the contents of the DAC register are  
unaffected when in power-down. The time to exit power-down  
is typically 2.5 μs for VDD = 5 V and VDD = 3 V (see Figure 28).  
Any combination of DACs can be powered up by setting PD1  
and PD0 to 0 (normal operation). The output powers up to the  
value in the input register (  
Low) or to the value in the  
LDAC  
DAC register before powering down (  
high).  
LDAC  
Rev. PrB | Page 26 of 33  
Preliminary Technical Data  
AD5025/45/65  
Table 9. DCEN (Daisy-Chain Enable) Register  
(DB1)  
(DB0)  
Action  
0
1
0
0
Standalone mode (default)  
DCEN mode  
Table 10. 32-Bit Input Shift Register Contents for Daisy-Chain Enable and Reference Set-Up Function  
MSB  
LSB  
DB0  
1/0  
DB31 to DB28  
X
DB27  
DB26  
DB25  
DB24  
DB23  
DB22  
DB21  
DB20  
DB2 to DB19  
X
DB1  
1
0
0
0
X
X
X
X
1/0  
Don’t cares  
Command bits (C3 to C0)  
Address bits (A3 to A0)  
Don’t cares  
DCEN  
register  
Table 11. Modes of Operation  
DB9  
DB8  
Operating Mode  
Normal operation  
Power-down modes  
1 kΩ to GND  
100 kΩ to GND  
Three-state  
0
0
0
1
1
1
0
1
Table 12. 32-Bit Input Shift Register Contents for Power-Up/Power-Down Function  
MSB  
LSB  
DB31 to  
DB28  
DB10 to  
DB19  
DB4 to  
DB7  
DB27  
DB26  
DB25  
DB24  
DB23  
DB22  
DB21  
DB20  
DB9  
DB8  
DB3  
DB2  
DB1  
DAC B  
DB0  
X
0
1
0
0
X
X
X
X
X
PD1  
PD0  
X
DAC A  
X
X
Don’t  
cares  
Command bits (C2 to C0)  
Address bits (A3 to A0)—  
don’t cares  
Don’t  
cares  
Power-down  
mode  
Don’t  
cares  
Power-down/power-up channel selection—  
set bit to 1 to select  
Figure 47. Output Stage During Power-Down  
Rev. PrB | Page 27 of 33  
AD5025/45/65  
Preliminary Technical Data  
updates synchronously; that is, the DAC register is updated  
CLEAR CODE REGISTER  
after new data is read, regardless of the state of the  
pin.  
LDAC  
The AD5025/45/65 has a hardware  
asynchronous clear input. The  
pin that is an  
input is falling edge  
CLR  
It effectively sees the  
pin as being tied low. (See Table 15  
LDAC  
CLR  
for the  
register mode of operation.) This flexibility is  
LDAC  
sensitive. Bringing the  
line low clears the contents of the  
CLR  
input register and the DAC registers to the data contained in the  
user-configurable register and sets the analog outputs  
useful in applications where the user wants to simultaneously  
update select channels while the rest of the channels are  
synchronously updating.  
CLR  
accordingly. (see Table 13) This function can be used in system  
calibration to load zero scale, midscale, or full scale to all  
channels together. These clear code values are user-  
programmable by setting two bits, Bit DB1 and Bit DB0, in the  
control register (see Table 13). The default setting clears the  
outputs to 0 V. Command 0101 is reserved for loading the clear  
code register (see Table 7).  
Writing to the DAC using command 0110 loads the 4-bit  
LDAC  
register (DB3 to DB0). The default for each channel is 0; that is,  
the pin works normally. Setting the bits to 1 means the  
LDAC  
DAC channel is updated regardless of the state of the  
LDAC  
pin. See Table 16 for the contents of the input shift register  
during the load register mode of operation.  
LDAC  
The part exits clear code mode on the 32nd falling edge of the  
POWER SUPPLY BYPASSING AND GROUNDING  
next write to the part. If  
is activated during a write  
CLR  
When accuracy is important in a circuit, it is helpful to carefully  
consider the power supply and ground return layout on the  
board. The printed circuit board containing the AD5666 should  
have separate analog and digital sections. If the AD5666 is in a  
system where other devices require an AGND-to-DGND  
connection, the connection should be made at one point only.  
This ground point should be as close as possible to the  
AD5025/45/65.  
sequence, the write is aborted.  
The pulse activation time—the falling edge of  
to when  
CLR  
CLR  
the output starts to change—is typically TBD ns. However, if  
outside the DAC linear region, it typically takes TBD ns after  
executing  
for the output to start changing (see Figure 38).  
CLR  
See Table 14 for contents of the input shift register during the  
loading clear code register operation  
The power supply to the AD5025/45/65 should be bypassed with  
10 μF and 0.1 μF capacitors. The capacitors should physically be  
as close as possible to the device, with the 0.1 μF capacitor  
ideally right up against the device. The 10 μF capacitors are the  
tantalum bead type. It is important that the 0.1 μF capacitor has  
low effective series resistance (ESR) and low effective series  
inductance (ESI), such as is typical of common ceramic types of  
capacitors. This 0.1 μF capacitor provides a low impedance path  
to ground for high frequencies caused by transient currents due  
to internal logic switching.  
FUNCTION  
LDAC  
The outputs of all DACs can be updated simultaneously using  
the hardware  
pin.  
LDAC  
Synchronous  
: After new data is read, the DAC registers  
LDAC  
are updated on the falling edge of the 32nd SCLK pulse.  
can be permanently low or pulsed as in Figure 3  
LDAC  
Asynchronous  
: The outputs are not updated at the same  
LDAC  
time that the input registers are written to. When  
low, the DAC registers are updated with the contents of the  
input register.  
goes  
LDAC  
The power supply line should have as large a trace as possible to  
provide a low impedance path and reduce glitch effects on the  
supply line. Clocks and other fast switching digital signals  
should be shielded from other parts of the board by digital  
ground. Avoid crossover of digital and analog signals if possible.  
When traces cross on opposite sides of the board, ensure that  
they run at right angles to each other to reduce feedthrough  
effects through the board. The best board layout technique is  
the microstrip technique, where the component side of the  
board is dedicated to the ground plane only and the signal  
traces are placed on the solder side. However, this is not always  
possible with a 2-layer board.  
Alternatively, the outputs of all DACs can be updated  
simultaneously using the software  
function by writing to  
LDAC  
Input Register n and updating all DAC registers. Command  
0010 is reserved for this software function.  
LDAC  
register gives the user extra flexibility and control  
An  
LDAC  
over the hardware  
pin. This register allows the user to  
LDAC  
select which combination of channels to simultaneously update  
when the hardware pin is executed. Setting the bit  
LDAC  
register to 0 for a DAC channel means that this channel’s update  
is controlled by the pin. If this bit is set to 1, this channel  
LDAC  
LDAC  
Rev. PrB | Page 28 of 33  
Preliminary Technical Data  
AD5025/45/65  
Table 13. Clear Code Register  
Clear Code Register  
DB1  
CR1  
0
DB0  
CR0  
0
Clears to Code  
0x0000  
0
1
0x8000  
1
0
0xFFFF  
1
1
No operation  
Table 14. 32-Bit Input Shift Register Contents for Clear Code Function  
MSB  
LSB  
DB31 to DB28  
X
DB27  
DB26  
DB25  
DB24  
DB23  
DB22  
DB21  
DB20  
DB2 to DB19  
X
DB1  
DB0  
0
1
0
1
X
X
X
X
1/0  
1/0  
Don’t cares  
Command bits (C3 to C0)  
Address bits (A3 to A0)  
Don’t cares  
Clear code register  
(CR1 to CR0)  
Table 15.  
Overwrite Definition  
LDAC  
Load DAC Register  
LDAC Bits (DB3 to DB0)  
LDAC Pin  
1/0  
LDAC Operation  
0
1
Determined by LDAC pin  
DAC channels update, overrides the LDAC pin. DAC channels see LDAC as 0.  
X—don’t care  
Table 16. 32-Bit Input Shift Register Contents for  
Overwrite Function  
LDAC  
MSB  
LSB  
DB31  
to  
DB4  
to  
DB28  
DB27  
DB26  
DB25  
DB24  
DB23  
DB22  
DB21  
DB20  
DB19  
DB3  
DB2  
X
DB1  
DAC B  
DB0  
X
0
1
1
0
X
X
X
X
X
X
DAC A  
Don’t  
cares  
Command bits (C3 to C0)  
Address bits (A3 to A0)—  
don’t cares  
Don’t  
cares  
LDAC  
LDAC  
bit to 1 override pin  
Setting  
Rev. PrB | Page 29 of 33  
AD5025/45/65  
Preliminary Technical Data  
serial write operation is performed to the DAC. PC7 is taken  
high at the end of this procedure.  
MICROPROCESSOR INTERFACING  
AD5025/45/65 to Blackfin® ADSP-BF53X Interface  
AD5024/44/64 to 80C51/80L51 Interface  
Figure 48 shows a serial interface between the AD5025/45/65  
and the Blackfin ADSP-BF53X microprocessor. The ADSP-  
BF53X processor family incorporates two dual-channel  
synchronous serial ports, SPORT1 and SPORT0, for serial and  
multiprocessor communications. Using SPORT0 to connect to  
the AD5025/45/65, the setup for the interface is as follows:  
DT0PRI drives the DIN pin of the AD5025/45/65, while  
Figure 50 shows a serial interface between the AD5024/44/64  
and the 80C51/80L51 microcontroller. The setup for the  
interface is as follows: TxD of the 80C51/ 80L51 drives SCLK of  
the AD5025/45/65, and RxD drives the serial data line of the  
SYNC  
part. The  
signal is again derived from a bit-programmable  
pin on the port. In this case, Port Line P3.3 is used. When data is  
to be transmitted to the AD5025/45/65, P3.3 is taken low. The  
80C51/80L51 transmit data in 8-bit bytes only; thus, only eight  
falling clock edges occur in the transmit cycle. To load data to  
the DAC, P3.3 is left low after the first eight bits are transmitted,  
and a second write cycle is initiated to transmit the second byte  
of data. P3.3 is taken high following the completion of this  
cycle. The 80C51/80L51 output the serial data in a format that  
has the LSB first. The AD5025/45/65 must receive data with the  
MSB first. The 80C51/80L51 transmit routine should take this  
into account.  
SYNC  
TSCLK0 drives the SCLK of the parts. The  
TFS0.  
is driven from  
AD5065/  
AD5045/  
AD5025  
1
ADSP-BF53x  
1
TFS0  
DTOPRI  
TSCLK0  
SYNC  
DIN  
SCLK  
1
ADDITIONAL PINS OMITTED FOR CLARITY.  
AD5065/  
1
80C51/80L51  
AD5045/  
AD5025  
SYNC  
Figure 48. AD5025/45/65 to Blackfin ADSP-BF53X Interface  
1
P3.3  
TxD  
RxD  
AD5025/45/65 to 68HC11/68L11 Interface  
Figure 49 shows a serial interface between the AD5025/45/65  
and the 68HC11/68L11 microcontroller. SCK of the  
68HC11/68L11 drives the SCLK of the AD5025/45/65, and the  
MOSI output drives the serial data line of the DAC.  
SCLK  
DIN  
1
ADDITIONAL PINS OMITTED FOR CLARITY.  
Figure 50. AD5025/45/65 to 80C512/80L51 Interface  
AD5065/  
AD5045/  
AD5025/  
1
68HC11/68L11  
1
AD5025/45/65 to MICROWIRE Interface  
PC7  
SCK  
SYNC  
SCLK  
DIN  
Figure 51 shows an interface between the AD5025/45/65 and any  
MICROWIRE-compatible device. Serial data is shifted out on the  
falling edge of the serial clock and is clocked into the  
MOSI  
AD5025/45/65 on the rising edge of the SCLK.  
1
ADDITIONAL PINS OMITTED FOR CLARITY.  
Figure 49. AD5025/45/65 to 68HC11/68L11 Interface  
AD5065/  
1
MICROWIRE  
AD5045/  
1
AD5025  
SYNC  
CS  
SK  
SO  
SYNC  
The  
signal is derived from a port line (PC7). The setup  
DIN  
conditions for correct operation of this interface are as follows:  
The 68HC11/68L11 is configured with its CPOL bit as 0, and its  
CPHA bit as 1. When data is being transmitted to the DAC, the  
SCLK  
SYNC  
line is taken low (PC7). When the 68HC11/ 68L11 is  
1
ADDITIONAL PINS OMITTED FOR CLARITY.  
configured as described previously, data appearing on the MOSI  
output is valid on the falling edge of SCK. Serial data from the  
68HC11/68L11 is transmitted in 8-bit bytes with only eight  
falling clock edges occurring in the transmit cycle. Data is  
transmitted MSB first. To load data to the AD5025/45/65, PC7  
is left low after the first eight bits are transferred, and a second  
Figure 51. AD5025/45/654 to MICROWIRE Interface  
Rev. PrB | Page 30 of 33  
Preliminary Technical Data  
APPLICATIONS  
AD5025/45/65  
This is an output voltage range of 5 V, with 0x0000 corre-  
sponding to a −5 V output, and 0xFFFF corresponding to a  
+5 V output.  
USING A REFERENCE AS A POWER SUPPLY FOR  
THE AD5025/45/65  
Because the supply current required by the AD5025/45/65 is  
extremely low, an alternative option is to use a voltage reference  
to supply the required voltage to the parts (see Figure 52). This is  
especially useful if the power supply is quite noisy or if the  
system supply voltages are at some value other than 5 V or 3 V,  
for example, 15 V. The voltage reference outputs a steady supply  
voltage for the AD5025, AD5045 and AD5065. If the low  
dropout REF195 is used, it must supply 500 μA of current to the  
AD5025/ AD5045 / AD5065, with no load on the output of the  
DAC. When the DAC output is loaded, the REF195 also needs  
to supply the current to the load. The total current required  
(with a 5 kΩ load on the DAC output) is  
R2 = 10k  
+5V  
+5V  
R1 = 10kΩ  
AD820/  
OP295  
±5V  
V
V
OUT  
DD  
10µF  
0.1µF  
AD5025/45/65  
–5V  
THREE-WIRE  
SERIAL  
INTERFACE  
500 μA + (5 V/5 kΩ) = 1.5 mA  
Figure 53. Bipolar Operation with the AD5025/45/65  
The load regulation of the REF195 is typically 2 ppm/mA,  
which results in a 3 ppm (15 μV) error for the 1.5 mA current  
drawn from it. This corresponds to a 0.196 LSB error.  
USING THE AD5025/45/65 WITH A  
GALVANICALLY ISOLATED INTERFACE  
In process control applications in industrial environments,  
it is often necessary to use a galvanically isolated interface to  
protect and isolate the controlling circuitry from any hazardous  
common-mode voltages that can occur in the area where  
the DAC is functioning. iCoupler® provides isolation in excess  
of 2.5 kV. The AD5025/45/65 uses a 3-wire serial logic interface,  
so the ADuM1300 three-channel digital isolator provides the  
required isolation (see Figure 54). The power supply to the part  
also needs to be isolated, which is done by using a transformer.  
On the DAC side of the transformer, a 5 V regulator provides  
the 5 V supply required for the AD5025/45/65.  
15V  
5V  
REF195  
V
DD  
SYNC  
SCLK  
DIN  
THREE-WIRE  
SERIAL  
INTERFACE  
AD5065/  
AD5045/  
AD5025  
V
= 0V TO 5V  
OUT  
Figure 52. REF195 as Power Supply to the AD5025/45/65  
5V  
REGULATOR  
BIPOLAR OPERATION USING THE AD5025/45/65  
10µF  
0.1µF  
POWER  
The AD5025/45/65 has been designed for single-supply  
operation, but a bipolar output range is also possible using the  
circuit in Figure 53. The circuit gives an output voltage range of  
5 V. Rail-to-rail operation at the amplifier output is achievable  
using an AD820 or an OP295 as the output amplifier.  
V
DD  
SCLK  
V
V
V
V
OA  
SCLK  
IA  
ADuM1300  
AD5025/45/65  
The output voltage for any input code can be calculated as  
follows:  
V
SDI  
OUT  
SYNC  
V
IB  
OB  
OC  
D
65,536  
R1+ R2  
R1  
R2  
R1  
V = V  
×
×
V  
×
O
DD  
DD  
V
DATA  
DIN  
IC  
GND  
where D represents the input code in decimal (0 to 65,535).  
With VDD = 5 V, R1 = R2 = 10 kΩ,  
Figure 54. AD5025/45/65 with a Galvanically Isolated Interface  
10 × D  
65,536  
V =  
5 V  
O
Rev. PrB | Page 31 of 33  
AD5025/45/65  
Preliminary Technical Data  
OUTLINE DIMENSIONS  
5.10  
5.00  
4.90  
14  
8
7
4.50  
4.40  
4.30  
6.40  
BSC  
1
PIN 1  
0.65  
BSC  
1.05  
1.00  
0.80  
0.20  
0.09  
1.20  
MAX  
0.75  
0.60  
0.45  
8°  
0°  
0.15  
0.05  
0.30  
0.19  
SEATING  
PLANE  
COPLANARITY  
0.10  
COMPLIANT TO JEDEC STANDARDS MO-153-AB-1  
Figure 55. 14-Lead Thin Shrink Small Outline Package [TSSOP]  
(RU-14)  
Dimensions shown in millimeters  
5.10  
5.00  
4.90  
16  
9
8
4.50  
4.40  
4.30  
6.40  
BSC  
1
PIN 1  
1.20  
MAX  
0.15  
0.05  
0.20  
0.09  
0.75  
0.60  
0.45  
8°  
0°  
0.30  
0.19  
0.65  
BSC  
SEATING  
PLANE  
COPLANARITY  
0.10  
COMPLIANT TO JEDEC STANDARDS MO-153-AB  
Figure 56. 16-Lead Thin Shrink Small Outline Package [TSSOP]  
(RU-16)  
Dimensions shown in millimeters  
Rev. PrB | Page 32 of 33  
Preliminary Technical Data  
AD5025/45/65  
ORDERING GUIDE  
Package  
Option  
Power-On  
Reset to Code  
Model  
Temperature Range  
−40°C to +105°C  
−40°C to +105°C  
−40°C to +105°C  
−40°C to +105°C  
−40°C to +105°C  
−40°C to +105°C  
Package Description  
14-Lead TSSOP  
14-Lead TSSOP  
16-Lead TSSOP  
16-Lead TSSOP  
16-Lead TSSOP  
16-Lead TSSOP  
Evaluation board  
Evaluation board  
Evaluation board  
Accuracy  
Resolution  
16 bits  
16 bits  
14 bits  
14 bits  
12 bits  
12 bits  
AD5065BRUZ-11  
AD5065BRUZ-1REEL71  
AD5045BRUZ1  
RU-14  
RU-14  
RU-16  
RU-16  
RU-16  
RU-16  
Zero  
Zero  
Zero  
Zero  
Zero  
Zero  
1 LSB INL  
1 LSB INL  
1 LSB INL  
1 LSB INL  
1 LSB INL  
1 LSB INL  
AD5045BRUZ-REEL71  
AD5025BRUZ1  
AD5025BRUZ-REEL71  
Eval-AD5065 EBZ1  
Eval-AD5045 EBZ1  
Eval-AD5025 EBZ1  
1 Z = Pb-free part.  
©2007 Analog Devices, Inc. All rights reserved. Trademarks and  
registered trademarks are the property of their respective owners.  
D06844-0-6/07(PrB)  
Rev. PrB | Page 33 of 33  

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