Part Number Hot Search : 
3KP70CA CJ130 C1651 88XS25D7 M68HC11K DS1780 C15019 MNTXG
Product Description
Full Text Search
 

To Download AD5425YRM-REEL7 Datasheet File

  If you can't view the Datasheet, Please click here to try to view without PDF Reader .  
 
 


  Datasheet File OCR Text:
 8-Bit, High Bandwidth Multiplying DAC with Serial Interface AD5425*
FEATURES 2.5 V to 5.5 V Supply Operation 50 MHz Serial Interface 8-Bit (Byte Load) Serial Interface, 6 MHz Update Rate 10 MHz Multiplying Bandwidth 10 V Reference Input Low Glitch Energy < 2 nV-s Extended Temperature Range -40 C to +125 C 10-Lead MSOP Package Guaranteed Monotonic 4-Quadrant Multiplication Power On Reset with Brownout Detection LDAC Function 0.4 A Typical Power Consumption APPLICATIONS Portable Battery-Powered Applications Waveform Generators Analog Processing Instrumentation Applications Programmable Amplifiers and Attenuators Digitally-Controlled Calibration Programmable Filters and Oscillators Composite Video Ultrasound Gain, Offset, and Voltage Trimming FUNCTIONAL BLOCK DIAGRAM
VDD VREF R RFB IOUT1 IOUT2
AD5425
8-BIT R-2R DAC
LDAC POWER-ON RESET
DAC REGISTER
INPUT LATCH
SYNC SCLK SDIN
CONTROL LOGIC AND INPUT SHIFT REGISTER
GND
GENERAL DESCRIPTION
The AD5425 is a CMOS 8-bit current output digital-to-analog converter that operates from a 2.5 V to 5.5 V power supply, making it suited to battery-powered applications and many other applications. This DAC utilizes a double buffered 3-wire serial interface that is compatible with SPI(R), QSPITM, MICROWIRETM, and most DSP interface standards. In addition, an LDAC pin is provided, which allows simultaneous update in a multi-DAC configuration. On power-up, the internal shift register and latches are filled with 0s and the DAC outputs are at 0 V.
As a result of processing on a CMOS submicron process, this DAC offers excellent 4-quadrant multiplication characteristics, with large signal multiplying bandwidths of 10 MHz. The applied external reference input voltage (VREF) determines the full-scale output current. An integrated feedback resistor (RFB) provides temperature tracking and full-scale voltage output when combined with an external I-to-V precision amplifier. The AD5425 DAC is available in a small 10-lead MSOP package.
*Protected by U.S. Patent No. 5,969,657; other patents pending.
REV. 0
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. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781/329-4700 www.analog.com Fax: 781/326-8703 (c) 2004 Analog Devices, Inc. All rights reserved.
(V = 2.5 V to V, = 10 V, x = O V. T to T , noted. with OP177, AC with AD5425-SPECIFICATIONS1 otherwiseunless5.5DC VperformanceI measuredAll specificationsperformanceunless AD8038, otherwise noted.)
DD REF OUT MIN MAX
Parameter STATIC PERFORMANCE Resolution Relative Accuracy Differential Nonlinearity Gain Error Gain Error Temperature Coefficient2 Output Leakage Current REFERENCE INPUT2 Reference Input Range VREF Input Resistance RFB Resistance Input Capacitance Code Zero Scale Code Full Scale DIGITAL INPUTS Input High Voltage, VIH Input Low Voltage, VIL Input Leakage Current, IIL Input Capacitance DYNAMIC PERFORMANCE Reference Multiplying Bandwidth Output Voltage Settling Time Digital Delay 10% to 90% Settling Time Digital-to-Analog Glitch Impulse Multiplying Feedthrough Error Output Capacitance IOUT2 IOUT1 Digital Feedthrough Total Harmonic Distortion Digital THD Clock = 1 MHz 50 kHz fOUT Output Noise Spectral Density SFDR Performance (Wide Band) Clock = 2 MHz 50 kHz fOUT 20 kHz fOUT SFDR Performance (Narrow Band) Clock = 2 MHz 50 kHz fOUT 20 kHz fOUT Intermodulation Distortion Clock = 2 MHz f1 = 20 kHz, f2 = 25 kHz
2
Min
Typ
Max 8 0.25 0.5 10 5 25
Unit Bits LSB LSB mV ppm FSR/C nA nA V k k pF pF V V A pF MHz ns ns ns nV-s dB dB pF pF pF pF nV-s dB dB nVHz
Conditions
Guaranteed monotonic
5
Data = 0x0000, TA = 25C, IOUT Data = 0x0000, IOUT
8 8
10 10 10 3 5
12 12 6 8
Input resistance TC = -50 ppm/C Input resistance TC = -50 ppm/C
1.7 0.6 2 10
4 10 50 40 15 2 70 48 22 10 12 25 0.1 -81 70 25
100 75 30
VREF = 3.5 V; DAC loaded all 1s Measured to 16 mV. RLOAD = 100 , CLOAD = 15 pF DAC latch alternately loaded with 0s and 1s Rise and Fall time, VREF = 10 V, RLOAD = 100 1 LSB change around major carry VREF = 0 V DAC latch loaded with all 0s. VREF = 3.5 V, 1 MHz 10 MHz All 0s loaded All 1s loaded All 0s loaded All 1s loaded Feedthrough to DAC output with SYNC high and alternate loading of all 0s and all 1s VREF = 3.5 V pk-pk; all 1s loaded, f = 1 kHz 8k Codes @ 1 kHz 8k Codes, VREF = 3.5 V
25 12 17 30
55 63
dB dB
73 80
dB dB 8k codes, VREF = 3.5 V
79
dB
-2-
REV. 0
AD5425
Parameter POWER REQUIREMENTS Power Supply Range IDD Min 2.5 0.4 Typ Max 5.5 5 0.6 Unit V A A Conditions
Logic inputs = 0 V or VDD TA = 25C, Logic inputs = 0 V or VDD
NOTES 1 Temperature range is as follows: Y version: -40C to +125C. 2 Guaranteed by design, not subject to production test. Specifications subject to change without notice.
REV. 0
-3-
AD5425 TIMING CHARACTERISTICS1, 2
Parameter fSCLK t1 t2 t3 t4 t5 t6 t7 t8 t9 t10 t11 Limit at TMIN, TMAX 50 20 8 8 13 5 3 5 30 0 12 10
(VDD = 2.5 V to 5.5 V, VREF = 10 V, IOUT2 = O V. All specifications TMIN to TMAX, unless otherwise noted.)
Unit MHz max ns min ns min ns min ns min ns min ns min ns min ns min ns min ns min ns min Conditions/Comments Max clock frequency SCLK cycle time SCLK high time SCLK low time SYNC falling edge to SCLK falling edge setup time Data setup time Data hold time SYNC rising edge to SCLK falling edge Minimum SYNC high time SCLK falling edge to LDAC falling edge LDAC pulse width SCLK falling edge to LDAC rising edge
NOTES 1 See Figure 1. Temperature range is as follows: Y version: -40C to +125C. Guaranteed by design and characterization, not subject to production test. 2 All input signals are specified with tr = tf = 1 ns (10% to 90% of V DD) and timed from a voltage level of (V IL + VIH)/2. Specifications subject to change without notice.
t1
SCLK
t2 t8 t4
SYNC
t3 t7
t6 t5
DIN DB7 DB0
t10 t9
LDAC1
t11
LDAC2
NOTES 1ASYNCHRONOUS LDAC UPDATE MODE 2SYNCHRONOUS LDAC UPDATE MODE
Figure 1. Timing Diagram
-4-
REV. 0
AD5425
ABSOLUTE MAXIMUM RATINGS 1
(TA = 25C, unless otherwise noted.)
VDD to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 V to +7 V VREF, RFB to GND . . . . . . . . . . . . . . . . . . . . . . -12 V to +12 V IOUT1, IOUT2 to GND . . . . . . . . . . . . . . . . . . . . -0.3 V to +7 V Logic Inputs and Output2 . . . . . . . . . . . -0.3 V to VDD + 0.3 V Operating Temperature Range Extended Industrial (Y Version) . . . . . . . . -40C to +125C Storage Temperature Range . . . . . . . . . . . . . -65C to +150C Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . 150C 10-lead MSOP JA Thermal Impedance . . . . . . . . . . . 206C/W Lead Temperature, Soldering (10 seconds) . . . . . . . . . . 300C IR Reflow, Peak Temperature (<20 seconds) . . . . . . . . 235C
NOTES 1 Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions above those listed in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Only one absolute maximum rating may be applied at any one time. 2 Overvoltages at SCLK, SYNC, DIN, and LDAC will be clamped by internal diodes.
ORDERING GUIDE
Model AD5425YRM AD5425YRM-REEL AD5425YRM-REEL7 EVAL-AD5425EB
Resolution (Bits) 8 8 8
INL (LSBs) 0.25 0.25 0.25
Temperature Range -40oC to +125oC -40oC to +125oC -40oC to +125oC
Package Description MSOP MSOP MSOP Evaluation Kit
Branding D1P D1P D1P
Package Option RM-10 RM-10 RM-10
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 the AD5425 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. 0
-5-
AD5425
PIN CONFIGURATION
IOUT1 1 IOUT2 2 GND 3 SCLK 4 SDIN 5
10 RFB
AD5425
(Not to Scale)
9 8 7
VREF VDD LDAC
6 SYNC
PIN FUNCTION DESCRIPTIONS
Pin No. 1 2 3 4 5 6
Mnemonic IOUT1 IOUT2 GND SCLK SDIN SYNC
Function DAC Current Output. DAC Analog Ground. This pin should normally be tied to the analog ground of the system. Digital Ground Pin. Serial Clock Input. Data is clocked into the input shift register on each falling edge of the serial clock input. This device can accommodate clock rates of up to 50 MHz. Serial Data Input. Data is clocked into the 8-bit input register on each falling edge of the serial clock input. 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 the input shift register is enabled. Data is transferred on each falling edge of the following 8 clocks. Load DAC Input. Updates the DAC output. The DAC is updated when this signal goes low or alternatively, if this line is held permanently low, an automatic update mode is selected whereby the DAC is updated after 8 SCLK falling edges with SYNC low. Positive Power Supply Input. This part can be operated from a supply of 2.5 V to 5.5 V. DAC Reference Voltage Input Terminal. DAC Feedback Resistor Pin. Establishes voltage output for the DAC by connecting to external amplifier output.
7
LDAC
8 9 10
VDD VREF RFB
-6-
REV. 0
Typical Performance Characteristics-AD5425
0.20 0.15 0.10
DNL (LSB)
0.20
1.6
TA = 25 C VREF = 10V VDD = 5V
IOUT LEAKAGE (nA)
TA = 25 C VREF = 10V VDD = 5V
0.15 0.10 0.05 0
1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 -40 -20 IOUT1 VDD 3V IOUT1 VDD 5V
INL (LSB)
0.05 0
-0.05 -0.10 -0.15 -0.20
-0.05 -0.10 -0.15
0
50
100 150 CODE
200
250
-0.20
0
50
100
150 CODE
200
250
0 20 40 60 80 TEMPERATURE ( C)
100 120
TPC 1. INL vs. Code (8-Bit DAC)
TPC 2. DNL vs. Code (8-Bit DAC)
TPC 3. IOUT1 Leakage Current vs. Temperature
1.4
5 4 3 2 ERROR (mV) 1 0 -1 -2 -3 -4 -5 VDD = 2.5V
LSBs
0.5 TA = 25 C VDD = 3V VREF = 0V MAX INL 0.1
1.2 GAIN ERROR 1.0 TA = 25 C VDD = 3V VREF = 0V OFFSET ERROR
VDD = 5V
0.3
VOLTAGE (mV)
MAX DNL
0.8 0.6 0.4 0.2 0
-0.1 MIN INL MIN DNL
-0.3
VREF = 10V
-60 -40 -20 0 20 40 60 80 100 120 140 TEMPERATURE ( C)
-0.2
-0.5 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 VBIAS (V)
-0.4 0.5
1.0 VBIAS (V)
1.5
TPC 4. Gain Error vs. Temperature
TPC 5. Linearity vs. VBIAS Voltage Applied to IOUT2
TPC 6. Gain and Offset Errors vs. VBIAS Voltage Applied to IOUT2
10.0
0.5 VDD = 5V VREF = 0V 0.3
2.5 VDD = 5V VREF = 0V GAIN ERROR
VOLTAGE (mV) 8.0 6.0
2.0
MAX INL MAX DNL
TA = 25 C VDD = 5V VREF = 2.5V
1.5
VOLTAGE (mV)
0.1
4.0 2.0 0 OFFSET ERROR
LSBs
1.0 OFFSET ERROR 0.5
-0.1 MIN INL -0.3 MIN DNL
0
-2.0 -4.0
GAIN ERROR 0 0.5 1.0 1.5 2.0 2.5
-0.5 0.5
1.0
1.5 VBIAS (V)
2.0
2.5
-0.5 0.5
1.0
1.5 VBIAS (V)
2.0
2.5
VBIAS (V)
TPC 7. Linearity vs. VBIAS Voltage Applied to IOUT2
TPC 8. Gain and Offset Errors vs. Voltage Applied to IOUT2
TPC 9. Gain and Offset Errors vs. VBIAS Voltage Applied to IOUT2
REV. 0
-7-
AD5425
1.0 0.8 0.6 0.4 0.2
LSBs THRESHOLD VOLTAGE (V)
TA = 25 C VDD = 5V VREF = 2.5V MAX INL BIAS MIN INL BIAS
0.7 0.6 0.5
1.8 TA = 25 C 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 VIL VIH
CURRENT (mA)
VDD = 5V 0.4 0.3 TA = 25 C 0.2 0.1 0 VDD = 2.5V VDD = 3V
0
-0.2 -0.4 -0.6 -0.8 -1.0 0 0.5 1.0 VBIAS (V) 1.5 2.0 MIN DNL BIAS MAX DNL BIAS
0
1
2 3 INPUT VOLTAGE (V)
4
5
0 2.5
3.0
3.5 4.0 4.5 VOLTAGE (V)
5.0
5.5
TPC 10. Linearity vs. VBIAS Voltage Applied to IOUT2
TPC 11. Supply Current vs. Input Voltage
TPC 12. Threshold Voltages vs. Supply Voltage
0.2
0.060 0.050
0
VDD 5V, 0V REF NRG = 2.049nVs 7FFH TO 800H
OUTPUT VOLTAGE (V)
0.040 0.030 0.020 0.010 0.000
VDD 5V, 0V REF NRG = 0.119nVs, 800H TO 7FFH
TA = 25 C VREF = 0V AD8038 AMP CCOMP = 1.8pF AD5443
GAIN (dB)
GAIN (dB)
-0.2
VDD 3V, 0V REF NRG = 0.088nVs 800H TO 7FFH VDD 3V, 0V REF NRG = 1.877nVs 7FFH TO 800H
-0.4 TA = 25 C VDD = 5V VREF = 3.5V CCOMP = 1.8pF AD5445 AMPLIFIER 1 10 100 1k 10k 100k 1M 10M 100M FREQUENCY (Hz)
-0.6
-0.010 -0.020
-0.8
6 0 -6 -12 -18 -24 -30 -36 -42 -48 -54 -60 -66 -72 -78 -84 -90 -96 -102 1
TA = 25 C LOADING ZS TO FS
ALL ON DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
ALL OFF
TA = 25 C VDD = 5V VREF = 3.5V INPUT CCOMP = 1.8pF AD5445 AMPLIFIER
0
50
100
150 200 TIME (ns)
250
300
10
100 1k 10k 100k 1M 10M 100M FREQUENCY (Hz)
TPC 13. Reference Multiplying Bandwidth--All 1s Loaded
TPC 14. Midscale Transition, VREF = 3.5 V
TPC 15. Reference Multiplying Bandwidth vs. Frequency and Code
20 TA = 25 C VDD = 3V 0 AMP = AD8038
3
0
THD + N (dB)
-70
POWER SUPPLY REJECTION
TA = 25 C VDD = 5V AD8038 AMPLIFIER
-60
TA = 25 C VDD = 3V -65 VREF = 3.5V p-p
-20 -40 -60 -80 -100 -120
GAIN (dB)
-3
-75
FULL SCALE ZERO SCALE
-80
-6
-9 10k
VREF = VREF = VREF = VREF = VREF =
2V, AD8038 CC 1.47pF 2V, AD8038 CC 1pF 0.15V, AD8038 CC 1pF 0.15V, AD8038 CC 1.47pF 3.51V, AD8038 CC 1.8pF
-85
-90
100k 1M 10M FREQUENCY (Hz)
100M
1
10
100 1k 10k FREQUENCY (Hz)
100k
1M
1
10
100 1k 10k 100k FREQUENCY (Hz)
1M
10M
TPC 16. Reference Multiplying Bandwidth vs. Frequency and Compensation Capacitor
TPC 17. THD and Noise vs. Frequency
TPC 18. Power Supply Rejection vs. Frequency
-8-
REV. 0
AD5425
0 -10 -20 -30 TA = 25 C VDD = 5V VREF = 3.5V AD8038 AMPLIFIER CCOMP = 1.8pF 8k CODES
0 -10 -20 -30
SFDR (dB)
0
TA = 25 C VDD = 5V VREF = 3.5V AD8038 AMPLIFIER CCOMP = 1.8pF
-10 -20 -30 SFDR (dB) -40 -50 -60 -70 -80 -90 -100
SFDR (dB)
-40 -50 -60 -70 -80 -90
-40 -50 -60 -70 -80 -90
TA = 25 C VDD = 5V VREF = 3.5V AD8038 AMPLIFIER CCOMP = 1.8pF 8k CODES
8k CODES
-100 -110 0 200k 400k 600k 800k 1M FREQUENCY (Hz)
-100 -110 0 200k 400k 600k 800k 1M FREQUENCY (Hz)
-110 10k 12k 14k 16k 18k 20k 22k 24k 26k 28k 30k FREQUENCY (Hz)
TPC 19. Wideband SFDR, Clock = 2 MHz, fOUT = 50 kHz
TPC 20. Wideband SFDR, Clock = 2 MHz, fOUT = 20 kHz
TPC 21. Narrowband SFDR, Clock = 2 MHz, fOUT = 20 kHz
0 -10 -20 -30 TA = 25 C VDD = 5V VREF = 3.5V AD8038 AMPLIFIER CCOMP = 1.8pF 8k CODES
0 -10 -20 -30 TA = 25 C VDD = 5V VREF = 3.5V AD8038 AMPLIFIER CCOMP = 1.8pF 8k CODES
SFDR (dB)
-40 -50 -60 -70 -80 -90
IMD (dB)
-40 -50 -60 -70 -80 -90
-100 -110 25k 30k 35k 40k 45k 50k 55k 60k 65k 70k 75k FREQUENCY (Hz)
-100 10k
15k
20k
25k
30k
35k
FREQUENCY (Hz)
TPC 22. Narrowband SFDR, Clock = 2 MHz, fOUT = 50 kHz
TPC 23. Narrowband IMD ( 50%) Clock = 2 MHz, fOUT1 = 20 kHz, fOUT2 = 25 kHz
REV. 0
-9-
AD5425
TERMINOLOGY Relative Accuracy
depending upon whether the glitch is measured as a current or voltage signal.
Digital Feedthrough
Relative accuracy or endpoint nonlinearity is a measure of the maximum deviation from a straight line passing through the endpoints of the DAC transfer function. It is measured after adjusting for zero and full scale and is normally expressed in LSBs or as a percentage of full-scale reading.
Differential Nonlinearity
When the device is not selected, high frequency logic activity on the device digital inputs is capacitively coupled through the device to show up as noise on the IOUT pins and subsequently into the following circuitry. This noise is digital feedthrough.
Multiplying Feedthrough Error
Differential nonlinearity is the difference between the measured change and the ideal 1 LSB change between any two adjacent codes. A specified differential nonlinearity of -1 LSB max over the operating temperature range ensures monotonicity.
Gain Error
This is the error due to capacitive feedthrough from the DAC reference input to the DAC IOUT1 terminal, when all 0s are loaded to the DAC.
Total Harmonic Distortion (THD)
Gain error or full-scale error is a measure of the output error between an ideal DAC and the actual device output. For these DACs, ideal maximum output is VREF - 1 LSB. Gain error of the DACs is adjustable to 0 with external resistance.
Output Leakage Current
The DAC is driven by an ac reference. The ratio of the rms sum of the harmonics of the DAC output to the fundamental value is the THD. Usually only the lower order harmonices are included, such as second to fifth. THD = 20 log
Output leakage current is current that flows in the DAC ladder switches when these are turned off. For the IOUT1 terminal, it can be measured by loading all 0s to the DAC and measuring the IOUT1 current. Minimum current will flow in the IOUT2 line when the DAC is loaded with all 1s.
Output Capacitance
(V
2
2
+ V3 + V4 + V5 V1
2
2
2
)
Spurious-Free Dynamic Range (SFDR)
Capacitance from IOUT1 or IOUT2 to AGND.
Output Current Settling Time
This is the amount of time it takes for the output to settle to a specified level for a full-scale input change. For these devices, it is specified with a 100 resistor to ground. The settling time specification includes the digital delay from SYNC rising edge of the full scale output charge.
Digital-to-Analog Glitch lmpulse
It is the usable dynamic range of a DAC before spurious noise interferes or distorts the fundamental signal. SFDR is the measure of difference in amplitude between the fundamental and the largest harmonically or nonharmonically related spur from dc to full Nyquist bandwidth (half the DAC sampling rate, or fs/2). Narrow band SFDR is a measure of SFDR over an arbitrary window size, in this case 50% of the fundamental. Digital SFDR is a measure of the usable dynamic range of the DAC when the signal is digitally generated sine wave.
The amount of charge injected from the digital inputs to the analog output when the inputs change state. This is normally specified as the area of the glitch in either pA-secs or nV-secs
-10-
REV. 0
AD5425
DAC SECTION Low Power Serial Interface
The AD5425 is an 8-bit current output DAC consisting of a standard inverting R-2R ladder configuration. A simplified diagram is shown in Figure 2. The feedback resistor RFB has a value of R. The value of R is typically 10 k (minimum 8 k and maximum 12 k). If IOUT1 and IOUT2 are kept at the same potential, a constant current flows in each ladder leg, regardless of digital input code. Therefore, the input resistance presented at VREF is always constant and nominally of value R. The DAC output (IOUT) is code-dependent, producing various resistances and capacitances. External amplifier choice should take into account the variation in impedance generated by the DAC on the amplifiers inverting input node.
R VREF 2R S1 2R S2 2R S3 2R S8 2R R RFB A IOUT1 IOUT 2 DAC DATA LATCHES AND DRIVERS R R
To minimize the power consumption of the device, the interface powers up fully only when the device is being written to, i.e., on the falling edge of SYNC. The SCLK and SDIN input buffers are powered down on the rising edge of SYNC.
CIRCUIT OPERATION Unipolar Mode
Using a single op amp, this device can easily be configured to provide 2-quadrant multiplying operation or a unipolar output voltage swing as shown in Figure 4. When an output amplifier is connected in unipolar mode, the output voltage is given by: VOUT = -VREF x D 2n
where D is the fractional representation of the digital word loaded to the DAC, in this case 0 to 255, and n is the number of bits. Note that the output voltage polarity is opposite to the VREF polarity for dc reference voltages. This DAC is designed to operate with either negative or positive reference voltages. The VDD power pin is used by only the internal digital logic to drive the DAC switches' on and off states. This DAC is also designed to accommodate ac reference input signals in the range of -10 V to +10 V.
VDD R2 C1 RFB IOUT1 IOUT2 GND A1 VOUT = 0 TO -VREF
Figure 2. Simplified Ladder
Access is provided to the VREF, RFB, IOUT1 and IOUT2 terminals of the DAC, making the device extremely versatile and allowing it to be configured in several different operating modes, for example, to provide a unipolar output, bipolar output, or in single-supply modes of operation in unipolar mode or 4-quadrant multiplication in bipolar mode. Note that a matching switch is used in series with the internal RFB feedback resistor. If users attempt to measure RFB, power must be applied to VDD to achieve continuity.
SERIAL INTERFACE
VDD VREF R1 SYNC SCLK SDIN VREF
AD5425
The AD5425 has a simple 3-wire interface which is compatible with SPI/QSPI/MICROWIRE and DSP interface standards. Data is written to the device in 8 bit words. This 8-bit word consists of 8 data bits as shown in Figure 3.
DB7 (MSB) DB7 DB6 DB5 DB4 DB0 (LSB) DB3 DB2 DB1 DB0
MICROCONTROLLER
AGND
NOTES 1. R1 AND R2 USED ONLY IF GAIN ADJUSTMENT IS REQUIRED. 2. C1 PHASE COMPENSATION (1pF - 2pF) MAY BE REQUIRED IF A1 IS A HIGH SPEED AMPLIFIER.
DATA BITS
Figure 4. Unipolar Operation
Figure 3. 8-Bit Input Shift Register Contents
SYNC is an edge-triggered input that acts as a frame synchronization signal and chip enable. Data can be transferred into the device only while SYNC is low. To start the serial data transfer, SYNC should be taken low, observing the minimum SYNC falling to SCLK falling edge setup time, t4. After loading eight data bits to the shift register, the SYNC line is brought high. The contents of the DAC register and the output will be updated by bringing LDAC low any time after the 8-bit data transfer is complete as seen in the timing diagram of Figure 1. LDAC may be tied permanently low if required. For another serial transfer to take place, the interface must be enabled by another falling edge of SYNC.
With a fixed 10 V reference, the circuit shown in Figure 4 will give an unipolar 0 V to -10 V output voltage swing. When VIN is an ac signal, the circuit performs 2-quadrant multiplication. Table I shows the relationship between digital code and the expected output voltage for unipolar operation.
Table I. Unipolar Code Table
Digital Input 1111 1111 1000 0000 0000 0001 0000 0000
Analog Output (V) -VREF (255/256) -VREF (128/256) = -VREF/2 -VREF (1/256) -VREF (0/256) = 0
REV. 0
-11-
AD5425
R3 10k VDD VDD R1 VREF 10V VREF RFB IOUT1 IOUT 2 GND R2 C1 A1 A2 VOUT = -VREF to +VREF AGND R5 20k R4 10k
AD5425
SYNC SCLK SDIN
MICROCONTROLLER
NOTES 1. R1 AND R2 ARE USED ONLY IF GAIN ADJUSTMENT IS REQUIRED. ADJUST R1 FOR VOUT = 0 V WITH CODE 10000000 LOADED TO DAC. 2. MATCHING AND TRACKING IS ESSENTIAL FOR RESISTOR PAIRS R3 AND R4. 3. C1 PHASE COMPENSATION (1pF-2pF) MAY BE REQUIRED IF A1/A2 IS A HIGH SPEED AMPLIFIER.
Figure 5. Bipolar Operation (4-Quadrant Multiplication)
Bipolar Operation
In some applications, it may be necessary to generate full 4-quadrant multiplying operation or a bipolar output swing. This can be easily accomplished by using another external amplifier and some external resistors as shown in Figure 5. In this circuit, the second amplifier A2 provides a gain of 2. Biasing the external amplifier with an offset from the reference voltage results in full 4-quadrant multiplying operation. The transfer function of this circuit shows that both negative and positive output voltages are created as the input data (D) is incremented from code zero (VOUT = -VREF) to midscale (VOUT = 0 V ) to full scale (VOUT = + VREF).
VOUT = VREF x D / 2n -1 - VREF
value of C1 can produce ringing at the output, while too large a value can adversely affect the settling time. C1 should be found empirically but 1 pF-2 pF is generally adequate for compensation.
SINGLE-SUPPLY APPLICATIONS Current Mode Operation
Figure 6 shows a typical circuit for operation with a single 2.5 V to 5 V supply. In the current mode circuit of Figure 6, IOUT2 and hence IOUT1 is biased positive by an amount applied to VBIAS. In this configuration, the output voltage is given by
VOUT = D x (RFB /RDAC ) x VBIAS - VIN
(
)
{
(
)} + V
BIAS
As D varies from 0 to 255, the output voltage varies from
Where D is the fractional representation of the digital word loaded to the DAC and n is the resolution of the DAC. When VIN is an ac signal, the circuit performs 4-quadrant multiplication. Table II shows the relationship between digital code and the expected output voltage for bipolar operation.
VIN
VOUT = VBIAS toVOUT = 2VBIAS -VIN
VDD C1 RFB IOUT1 IOUT2 GND A1 VOUT
VDD VREF
Table II. Bipolar Code Table
Digital Input 1111 1111 1000 0000 0000 0001 0000 0000
Stability
Analog Output (V) +VREF (127/128) 0 -VREF (127/128) -VREF (128/128)
VBIAS
In the I-to-V configuration, the IOUT of the DAC and the inverting node of the op amp must be connected as close as possible, and proper PCB layout techniques must be employed. Since every code change corresponds to a step function, gain peaking may occur if the op amp has limited GBP and there is excessive parasitic capacitance at the inverting node. This parasitic capacitance introduces a pole into the open-loop response, which can cause ringing or instability in closed-loop applications. An optional compensation capacitor, C1 can be added in parallel with RFB for stability as shown in Figures 6 and 7. Too small a
NOTES 1. ADDITIONAL PINS OMITTED FOR CLARITY 2. C1 PHASE COMPENSATION (1pF-2pF) MAY BE REQUIRED IF A1 IS A HIGH SPEED AMPLIFIER.
Figure 6. Single-Supply Current Mode Operation
VBIAS should be a low impedance source capable of sinking and sourcing all possible variations in current at the IOUT2 terminal without any problems. It is important to note that VIN is limited to low voltages because the switches in the DAC ladder no longer have the same sourcedrain drive voltage. As a result their on resistance differs and this degrades the linearity of the DAC.
-12-
REV. 0
AD5425
Voltage Switching Mode of Operation ADDING GAIN
Figure 7 shows this DAC operating in the voltage switching mode. The reference voltage, VIN is applied to the IOUT1 pin, IOUT2 is connected to AGND and the output voltage is available at the VREF terminal. In this configuration, a positive reference voltage results in a positive output voltage making single-supply operation possible. The output from the DAC is voltage at a constant impedance (the DAC ladder resistance), thus an op amp is necessary to buffer the output voltage. The reference input no longer sees a constant input impedance, but one that varies with code. So, the voltage input should be driven from a low impedance source.
VDD R1 R2
In applications where the output voltage is required to be greater than VIN, gain can be added with an additional external amplifier or it can also be achieved in a single stage. It is important to take into consideration the effect of temperature coefficients of the thin film resistors of the DAC. Simply placing a resistor in series with the RFB resistor will causing mismatches in the temperature coefficients resulting in larger gain temperature coefficient errors. Instead, the circuit of Figure 9 is a recommended method of increasing the gain of the circuit. R1, R2, and R3 should all have similar temperature coefficients, but they need not match the temperature coefficients of the DAC. This approach is recommended in circuits where gains of greater than 1 are required.
VDD
RFB VIN IOUT1 IOUT2
VDD VREF GND A1 VOUT
VDD R2 VIN VREF GND
RFB IOUT1 IOUT2
C1
A1 R3 R2
VOUT
NOTES 1. ADDITIONAL PINS OMITTED FOR CLARITY 2. C1 PHASE COMPENSATION (1pF- 2pF) MAY BE REQUIRED IF A1 IS A HIGH SPEED AMPLIFIER.
GAIN = R2 + R3 R2 R1 = R2R3 R2 + R3
Figure 7. Single-Supply Voltage Switching Mode Operation
It is important to note that VIN is limited to low voltage because the switches in the DAC ladder no longer have the same sourcedrain drive voltage. As a result, their on resistance differs, which degrades the linearity of the DAC. Also, VIN must not go negative by more than 0.3 V or an internal diode will turn on, exceeding the max ratings of the device. In this type of application, the full range of multiplying capability of the DAC is lost.
POSITIVE OUTPUT VOLTAGE
NOTES 1. ADDITIONAL PINS OMITTED FOR CLARITY 2. C1 PHASE COMPENSATION (1pF- 2pF) MAY BE REQUIRED IF A1 IS A HIGH SPEED AMPLIFIER.
Figure 9. Increasing Gain of Current Output DAC
USED AS A DIVIDER OR PROGRAMMABLE GAIN ELEMENT
Note that the output voltage polarity is opposite to the VREF polarity for dc reference voltages. To achieve a positive voltage output, an applied negative reference to the input of the DAC is preferred over the output inversion through an inverting amplifier because of the resistor tolerance errors. To generate a negative reference, the reference can be level shifted by an op amp such that the VOUT and GND pins of the reference become the virtual ground and -2.5 V respectively, as shown in Figure 8.
VDD = 5V
Current steering DACs are very flexible and lend themselves to many different applications. If this type of DAC is connected as the feedback element of an op amp and RFB is used as the input resistor as shown in Figure 10, then the output voltage is inversely proportional to the digital input fraction D. For D = 1 - 2n the output voltage is
VOUT = -VIN /D = -VIN / 1 - 2-n
VDD VIN RFB IOUT1 IOUT2 GND VDD VREF
(
)
ADR03
VOUT VIN GND +5V VDD -2.5V A2 VREF GND -5V RFB IOUT1 IOUT2 A1 VOUT = 0 TO +2.5V C1
A1
VOUT
1/2 AD8552
NOTE ADDITIONAL PINS OMITTED FOR CLARITY
1/2 AD8552
NOTES 1. ADDITIONAL PINS OMITTED FOR CLARITY 2. C1 PHASE COMPENSATION (1pF- 2pF) MAY BE REQUIRED IF A1 IS A HIGH SPEED AMPLIFIER.
Figure 10. Current Steering DAC Used as a Divider or Programmable Gain Element
Figure 8. Positive Voltage Output with Minimum of Components
As D is reduced, the output voltage increases. For small values of the digital fraction D, it is important to ensure that the amplifier does not saturate and also that the required accuracy is met. For example, an eight bit DAC driven with the binary code 0x/0 (00010000), i.e., 16 decimal, in the circuit of Figure 10 should -13-
REV. 0
AD5425
cause the output voltage to be 16 VIN. However, if the DAC has a linearity specification of 0.5 LSB, then D can in fact have the weight anywhere in the range 15.5/256 to 16.5/256 so that the possible output voltage will be in the range 15.5 VIN to 16.5 VIN--an error of +3% even though the DAC itself has a maximum error of 0.2%. DAC leakage current is also a potential error source in divider circuits. The leakage current must be counterbalanced by an opposite current supplied from the op amp through the DAC. Since only a fraction D of the current into the VREF terminal is routed to the IOUT1 terminal, the output voltage has to change as follows: Output Error Voltage Due to DAC Leakage = (Leakage x R)/D where R is the DAC resistance at the VREF terminal. For a DAC leakage current of 10 nA, R = 10 k and a gain (i.e., 1/D) of 16 the error voltage is 1.6 mV.
REFERENCE SELECTION AMPLIFIER SELECTION
The primary requirement for the current-steering mode is an amplifier with low input bias currents and low input offset voltage. The input offset voltage of an op amp is multiplied by the variable gain (due to the code dependent output resistance of the DAC) of the circuit. A change in this noise gain between two adjacent digital fractions produces a step change in the output voltage due to the amplifier's input offset voltage. This output voltage change is superimposed on the desired change in output between the two codes and gives rise to a differential linearity error, which if large enough, could cause the DAC to be nonmonotonic. In general, the input offset voltage should be a fraction (~<1/4) of an LSB to ensure monotonic behavior when stepping through codes. The input bias current of an op amp also generates an offset at the voltage output as a result of the bias current flowing in the feedback resistor RFB. Most op amps have input bias currents low enough to prevent any significant errors. Common-mode rejection of the op amp is important in voltage switching circuits, since it produces a code dependent error at the voltage output of the circuit. Most op amps have adequate common-mode rejection for use at 8-bit resolution. Provided the DAC switches are driven from true wideband low impedance sources (VIN and AGND), they settle quickly. Consequently, the slew rate and settling time of a voltage switching DAC circuit is determined largely by the output op amp. To obtain minimum settling time in this configuration, it is important to minimize capacitance at the VREF node (voltage output node in this application) of the DAC. This is done by using low inputs capacitance buffer amplifiers and careful board design. Most single-supply circuits include ground as part of the analog signal range, which in turns requires an amplifier that can handle rail-to-rail signals. There is a large range of single-supply amplifiers available from Analog Devices.
When selecting a reference for use with the AD5425 series of current output DACs, pay attention to the reference's output voltage temperature coefficient specification. This parameter not only affects the full-scale error, but can also affect the linearity (INL and DNL) performance. The reference temperature coefficient should be consistent with the system accuracy specifications. For example, an 8-bit system required to hold its overall specification to within 1 LSB over the temperature range 0C to 50C dictates that the maximum system drift with temperature should be less than 78 ppm/C. A 12-bit system with the same temperature range to overall specification within 2 LSB requires a maximum drift of 10 ppm/C. By choosing a precision reference with low output temperature coefficient, this error source can be minimized. Table III suggests some of the suitable references available from Analog Devices that are suitable for use with this range of current output DACs.
Table III. Suitable ADI Precision Voltage References Recommended for Use with AD5425 DACs
Part No. ADR01 ADR02 ADR03 ADR425
Output Voltage 10 V 5V 2.5 V 5V
Initial Tolerance 0.1% 0.1% 0.2% 0.04%
Temperature Drift 3 ppm/C 3 ppm/C 3 ppm/C 3 ppm/C
0.1 Hz to 10 Hz Noise 20 10 10 3.4 V p-p V p-p V p-p V p-p
Package SC70, TSOT, SOIC SC70, TSOT, SOIC SC70, TSOT, SOIC MSOP, SOIC
Table IV. Some Precision ADI Op Amps Suitable for Use with AD5425 DACs
Part No. OP97 OP1177 AD8551
Max Supply Voltage (V) 20 18 +6
VOS(max) ( V) 25 60 5
IB(max) (nA) 0.1 2 0.05
GBP (MHz) 0.9 1.3 1.5
Slew Rate (V/ s) 0.2 0.7 0.4
Table V. Some High Speed ADI Op Amps Suitable for Use with AD5425 DACs
Part No. AD8065 AD8021 AD8038 AD9631
Max Supply Voltage (V) 12 12 5 5
BW @ ACL (MHz) 145 200 350 320 -14-
Slew Rate (V/ s) 180 100 425 1300
VOS(max) ( V) 1500 1000 3000 10000
IB(max) (nA) 0.01 1000 0.75 7000 REV. 0
AD5425
MICROPROCESSOR INTERFACING
ITFS = 1, Internal Framing Signal SLEN = 0111, 8-Bit Data-Word
80C51/80L51 to AD5425 Interface
Microprocessor interfacing to this DAC is via a serial bus that uses standard protocol compatible with microcontrollers and DSP processors. The communications channel is a 3-wire interface consisting of a clock signal, a data signal, and a synchronization signal. An LDAC pin is also included. The AD5425 requires an 8-bit word with the default being data valid on the falling edge of SCLK, but this is changeable via the control bits in the data-word.
ADSP-21xx to AD5425 Interface
The ADSP-21xx family of DSPs are easily interfaced to this family of DACs without extra glue logic. Figure 11 shows an example of an SPI interface between the DAC and the ADSP-2191. SCK of the DSP drives the serial data line, DIN. SYNC is driven from one of the port lines, in this case SPIxSEL.
ADSP-2191*
SPIxSEL MOSI SCK SYNC SDIN SCLK
AD5425*
A serial interface between the DAC and the 8051 is shown in Figure 13. TxD of the 8051 drives SCLK of the DAC serial interface, while RxD drives the serial data line, DIN. P3.3 is a bit-programmable pin on the serial port and is used to drive SYNC. When data is to be transmitted to the switch, P3.3 is taken low. The 80C51/80L51 transmits data in 8-bit bytes which is perfect for the AD5425 as it only requires an 8-bit word. Data on RxD is clocked out of the microcontroller on the rising edge of TxD and is valid on the falling edge. As a result, no glue logic is required between the DAC and microcontroller interface. P3.3 is taken high following the completion of this cycle. The 8051 provides the LSB of its SBUF register as the first bit in the data stream. The DAC input register requires its data with the MSB as the first bit received. The transmit routine should take this into account.
8051*
TxD RxD SCLK SDIN SYNC
AD5425*
*ADDITIONAL PINS OMITTED FOR CLARITY
P1.1
Figure 11. ADSP-2191 SPI to AD5425 Interface
A serial interface between the DAC and DSP SPORT is shown in Figure 12. In this interface example, SPORT0 is used to transfer data to the DAC shift register. Transmission is initiated by writing a word to the Tx register after the SPORT has been enabled. In a write sequence, data is clocked out on each rising edge of the DSPs serial clock and clocked into the DAC input shift register on the falling edge of its SCLK. The update of the DAC output takes place on the rising edge of the SYNC signal.
ADSP-2101/ ADSP-2103/ ADSP-2191*
TFS DT SCLK
*ADDITIONAL PINS OMITTED FOR CLARITY
Figure 13. 80C51/80L51 to AD5425 Interface
MC68HC11 Interface to AD5425 Interface
AD5425*
SYNC SDIN SCLK
*ADDITIONAL PINS OMITTED FOR CLARITY
Figure 12. ADSP-2101/ADSP-2103/ADSP-2191 SPORT to AD5425 Interface
Figure 14 shows an example of a serial interface between the DAC and the MC68HC11 microcontroller. The serial peripheral interface (SPI) on the MC68HC11 is configured for master mode (MSTR = 1), clock polarity bit (CPOL) = 0, and the clock phase bit (CPHA) = 1. The SPI is configured by writing to the SPI control register (SPCR)--see the 68HC11 User Manual. SCK of the 68HC11 drives the SCLK of the DAC interface, the MOSI output drives the serial data line (DIN) of the AD5516. The SYNC signal is derived from a port line (PC7). When data is being transmitted to the AD5516, the SYNC line is taken low (PC7). Data appearing on the MOSI output is valid on the falling edge of SCK. Serial data from the 68HC11 is transmitted in 8-bit bytes with only eight falling clock edges occurring in the transmit cycle. Data is transmitted MSB first. PC7 is taken high at the end of the write.
MC68HC11*
PC7 SCK MOSI SYNC SCLK SDIN
Communication between two devices at a given clock speed is possible when the following specifications are compatible: frame sync delay and frame sync setup and hold, data delay and data setup and hold, and SCLK width. The DAC interface expects a t4 (SYNC falling edge to SCLK falling edge setup time) of 13 ns minimum. Consult the ADSP-21xx User Manual for information on clock and frame sync frequencies for the SPORT register. The SPORT Control Register should be set up as follows: TFSW = 1, Alternate Framing INVTFS = 1, Active Low Frame Signal DTYPE = 00, Right Justify Data ISCLK = 1, Internal Serial Clock TFSR = 1, Frame Every Word REV. 0
AD5425*
*ADDITIONAL PINS OMITTED FOR CLARITY
Figure 14. 68HC11/68L11 to AD5425 Interface
MICROWIRE to AD5425 Interface
Figure 15 shows an interface between the DAC and any MICROWIRE compatible device. Serial data is shifted out on the falling edge of the serial clock, SK, and is clocked into the DAC input shift register on the rising edge of SK, which corresponds to the falling edge of the DAC's SCLK. -15-
AD5425
MICROWIRE*
SK SO CS SCLK SDIN SYNC
AD5425*
reduces the effects of feedthrough through the board. A microstrip technique is by far the best, but not always possible with a double-sided board. In this technique, the component side of the board is dedicated to ground plane while signal traces are placed on the solder side. It is good practice to employ compact, minimum lead length PCB layout design. Leads to the input should be as short as possible to minimize IR drops and stray inductance. The PCB metal traces between VREF and RFB should also be matched to minimize gain error. To maximize on high frequency performance, the I-to-V amplifier should be located as close to the device as possible.
EVALUATION BOARD FOR THE AD5425 DAC
*ADDITIONAL PINS OMITTED FOR CLARITY
Figure 15. MICROWIRE to AD5425 Interface
PIC16C6x/7x to AD5425
The PIC16C6x/7x synchronous serial port (SSP) is configured as an SPI master with the clock polarity bit (CKP) = 0. This is done by writing to the synchronous serial port control register (SSPCON). See the PIC16/17 Microcontroller User Manual. In this example, I/O port RA1 is being used to provide a SYNC signal and enable the serial port of the DAC. This microcontroller transfers eight bits of data during each serial transfer operation. Figure 16 shows the connection diagram.
PIC16C6x/7x*
SCK/RC3 SDI/RC4 RA1 SCLK SDIN SYNC
The board consists of an 8-bit AD5425 and a current to voltage amplifier AD8065. Included on the evaluation board is a 10 V reference ADR01. An external reference may also be applied via an SMB input. The evaluation kit consists of a CD-ROM with self-installing PC software to control the DAC. The software simply allows the user to write a code to the device.
OPERATING THE EVALUATION BOARD Power Supplies
AD5425*
*ADDITIONAL PINS OMITTED FOR CLARITY
Figure 16. PIC16C6x/7x to AD5425 Interface
PCB LAYOUT AND POWER SUPPLY DECOUPLING
The board requires 12 V, and +5 V supplies. The +12 V VDD and VSS are used to power the output amplifier, while the +5 V is used to power the DAC (VDD1) and transceivers (VCC). Both supplies are decoupled to their respective ground plane with 10 F tantalum and 0.1 F ceramic capacitors. Link1 (LK1) is provided to allow selection between the on-board reference (ADR01) or an external reference applied through J2. Link2 should be connected to LDAC position.
In any circuit where accuracy is important, careful consideration of the power supply and ground return layout helps to ensure the rated performance. The printed circuit board on which the AD5425 is mounted should be designed so that the analog and digital sections are separated and confined to certain areas of the board. If the DAC is in a system where multiple devices require an AGND-to-DGND connection, the connection should be made at one point only. The star ground point should be established as close as possible to the device. These DACs should have ample supply bypassing of 10 F in parallel with 0.1 F on the supply located as close to the package as possible, ideally right up against the device. The 0.1 F capacitor should have low effective series resistance (ESR) and effective series inductance (ESI), such as the common ceramic types that provide a low impedance path to ground at high frequencies, to handle transient currents due to internal logic switching. Low ESR 1 F to 10 F tantalum or electrolytic capacitors should also be applied at the supplies to minimize transient disturbance and to filter out low frequency ripple. Fast switching signals such as clocks should be shielded with digital ground to avoid radiating noise to other parts of the board, and should never be run near the reference inputs. Avoid crossover of digital and analog signals. Traces on opposite sides of the board should run at right angles to each other. This
-16-
REV. 0
AD5425
VDD1 J3 P1-3 SCLK J4 SDIN J5 SYNC J6 LDAC A LK2 P1-13 SDO B SDO/LDAC 7 SDO/LDAC SYNC 6 SYNC SDIN 5 SDIN SCLK 4 SCLK + C1 0.1 F C2 10 F R1 = 0 C7 C5 4.7pF VSS C8 4
V- V+
U1
VDD RFB IOUT1 IOUT2 GND
8
P1-2 P1-4
10 1 2
10 F + 0.1 F TP1 VOUT J1
AD8065AR
2 6
3 3 VREF 9 VREF J2
7 C9 10 F + C10 0.1 F
U3
VDD
P1-5
VREF
AD5425/AD5426/ AD5432/AD5443
VDD
LK1
P1-19 P1-20 P1-21 P1-22 P1-23 P1-24 P1-25 P1-26 P1-27 P1-28 P1-29 P1-30
2
+VIN
VOUT
6
U2 ADR01AR
C3 10 F VDD P2-3 C11 0.1 F P2-2 C13 0.1 F P2-1 VSS P2-4 C15 0.1 F + C16 10 F VDD1 + C14 10 F AGND + C12 10 F C4 0.1 F
5
TRIM GND
C5 0.1 F
4
Figure 17. Schematic of the AD5425 Evaluation Board
REV. 0
-17-
AD5425
P1
SCLK J3 SCLK SDIN J4 SDIN SYNC U1 R1 C6 C1 C2 J5 SDO/LDAC
SDO C8
U3
C11 J1 VOUT
TP1
C4 U2
SYNC
VREF LK1
C3
J2 SDO/LDAC J6 C15 C16
VREF C9 C10 C14 C13
LK2 LDAC
P2
VDD1 VDD AGND VSS
EVAL-AD5425EB
Figure 18. Silkscreen--Component Side View (Top Layer)
7C
21C
Figure 19. Silkscreen--Component Side View (Bottom Layer)
-18-
REV. 0
AD5425
Overview of AD54xx Devices
Part No. AD5403*
Resolution 8
No. DACs 2
INL 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.25 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.25 1 1 1 1 0.5 1 2 1 1 0.5 2
tS max 60 ns
Interface Package Parallel CP-40
Features
AD5410* AD5413* AD5424 AD5425 AD5426 AD5428 AD5429 AD5450 AD5404*
8 8 8 8 8 8 8 8 10
1 2 1 1 1 2 2 1 2
100 ns 100 ns 60 ns 100 ns 100 ns 60 ns 100 ns 100 ns 70 ns
Serial Serial Parallel Serial Serial Parallel Serial Serial Parallel
AD5411* AD5414* AD5432 AD5433 AD5439 AD5440 AD5451 AD5405
10 10 10 10 10 10 10 12
1 2 1 1 2 2 1 2
110 ns 110 ns 110 ns 70 ns 110 ns 70 ns 110 ns 120 ns
Serial Serial Serial Parallel Serial Parallel Serial Parallel
10 MHz Bandwidth, 10 ns CS Pulse Width, 4-Quadrant Multiplying Resistors RU-16 10 MHz Bandwidth, 50 MHz Serial, 4-Quadrant Multiplying Resistors RU-24 10 MHz Bandwidth, 50 MHz Serial, 4-Quadrant Multiplying Resistors RU-16, CP-20 10 MHz Bandwidth, 17 ns CS Pulse Width RM-10 Byte Load, 10 MHz Bandwidth, 50 MHz Serial RM-10 10 MHz Bandwidth, 50 MHz Serial RU-20 10 MHz Bandwidth, 17 ns CS Pulse Width RU-10 10 MHz Bandwidth, 50 MHz Serial RJ-8 10 MHz Bandwidth, 50 MHz Serial CP-40 10 MHz Bandwidth, 17 ns CS Pulse Width, 4-Quadrant Multiplying Resistors RU-16 10 MHz Bandwidth, 50 MHz Serial, 4-Quadrant Multiplying Resistors RU-24 10 MHz Bandwidth, 50 MHz Serial, 4-Quadrant Multiplying Resistors RM-10 10 MHz Bandwidth, 50 MHz Serial RU-20, CP-20 10 MHz Bandwidth, 17 ns CS Pulse Width RU-16 10 MHz Bandwidth, 50 MHz Serial 10 MHz Bandwidth, 17 ns CS Pulse Width RJ-8 10 MHz Bandwidth, 50 MHz Serial CP-40 10 MHz Bandwidth, 17 ns CS Pulse Width, 4-Quadrant Multiplying Resistors RU-16 10 MHz Bandwidth, 50 MHz Serial, 4-Quadrant Multiplying Resistors RU-24 10 MHz Bandwidth, 50 MHz Serial, 4-Quadrant Multiplying Resistors RM-10 10 MHz Bandwidth, 50 MHz Serial RM-10 10 MHz Bandwidth, 50 MHz Serial RU-20, CP-20 10 MHz Bandwidth, 17 ns CS Pulse Width RM-10 10 MHz Bandwidth, 50 MHz Serial RU-24 10 MHz Bandwidth, 17 ns CS Pulse Width RU-16 10 MHz Bandwidth, 17 ns CS Pulse Width RJ-8, RM-8 10 MHz Bandwidth, 50 MHz Serial RJ-8, RM-8 10 MHz Bandwidth, 50 MHz Serial RU-24
AD5412* AD5415 AD5443 AD5444 AD5445 AD5446 AD5447 AD5449 AD5452 AD5453
12 12 12 12 12 14 12 12 12 14
1 2 1 1 1 1 2 2 1 1
160 ns 160 ns 160 ns 160 ns 120 ns 180 ns 120 ns 160 ns 160 ns 180 ns
Serial Serial Serial Serial Parallel Serial Parallel Serial Serial Serial
*Future parts, contact factory for availability
REV. 0
-19-
AD5425
OUTLINE DIMENSIONS 10-Lead Mini Small Outline Package [MSOP] (RM-10)
Dimensions shown in millimeters
3.00 BSC
10
6
3.00 BSC
1 5
4.90 BSC
PIN 1 0.50 BSC 0.95 0.85 0.75 0.15 0.00 0.27 0.17 1.10 MAX 8 0 0.80 0.60 0.40
SEATING PLANE
0.23 0.08
COPLANARITY 0.10 COMPLIANT TO JEDEC STANDARDS MO-187BA
Back Page_w/Content
-20-
REV. 0
D03161-0-1/04(0)


▲Up To Search▲   

 
Price & Availability of AD5425YRM-REEL7

All Rights Reserved © IC-ON-LINE 2003 - 2022  

[Add Bookmark] [Contact Us] [Link exchange] [Privacy policy]
Mirror Sites :  [www.datasheet.hk]   [www.maxim4u.com]  [www.ic-on-line.cn] [www.ic-on-line.com] [www.ic-on-line.net] [www.alldatasheet.com.cn] [www.gdcy.com]  [www.gdcy.net]


 . . . . .
  We use cookies to deliver the best possible web experience and assist with our advertising efforts. By continuing to use this site, you consent to the use of cookies. For more information on cookies, please take a look at our Privacy Policy. X