AD7840JPZ Analog Devices

2 LC MOS a Complete 14-Bit DAC AD7840 FEATURES FUNCTIONAL BLOCK DIAGRAM Complete 14-Bit Voltage Output DAC Parallel and Serial Interface Capability 80 dB Signal-to-Noise Ratio Interfaces to High Speed DSP Processors e.g., ADSP-2100, TMS32010, TMS32020 45 ns min WR Pulse Width Low Power 70 mW typ. Operates from 65 V Supplies GENERAL DESCRIPTION PRODUCT HIGHLIGHTS The AD7840 is a fast, complete 14-bit voltage output D/A con- 1. Complete 14-Bit D/A Function verter. It consists of a 14-bit DAC, 3 V buried Zener reference, The AD7840 provides the complete function for creating ac DAC output amplifier and high speed control logic. signals and dc voltages to 14-bit accuracy. The part features an on-chip reference, an output buffer amplifier and 14-bit The part features double-buffered interface logic with a 14-bit D/A converter. input latch and 14-bit DAC latch. Data is loaded to the input latch in either of two modes, parallel or serial. This data is then 2. Dynamic Specifications for DSP Users transferred to the DAC latch under control of an asynchronous In addition to traditional dc specifications, the AD7840 is LDAC signal. A fast data setup time of 21 ns allows direct specified for ac parameters including signal-to-noise ratio and parallel interfacing to digital signal processors and high speed harmonic distortion. These parameters along with important 16-bit microprocessors. In the serial mode, the maximum serial timing parameters are tested on every device. data clock rate can be as high as 6 MHz. 3. Fast, Versatile Microprocessor Interface The analog output from the AD7840 provides a bipolar output The AD7840 is capable of 14-bit parallel and serial interfac- range of 3 V. The AD7840 is fully specified for dynamic per- ing. In the parallel mode, data setup times of 21 ns and write formance parameters such as signal-to-noise ratio and harmonic pulse widths of 45 ns make the AD7840 compatible with distortion as well as for traditional dc specifications. Full power modern 16-bit microprocessors and digital signal processors. output signals up to 20 kHz can be created. In the serial mode, the part features a high data transfer rate of 6 MHz. The AD7840 is fabricated in linear compatible CMOS 2 (LC MOS), an advanced, mixed technology process that com- bines precision bipolar circuits with low power CMOS logic. The part is available in a 24-pin plastic and hermetic dual-in-line package (DIP) and is also packaged in a 28-termi- nal plastic leaded chip carrier (PLCC). REV. B 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Tel: 617/329-4700 Fax: 617/326-8703(V = +5 V 6 5%, V = 5 V 6 5%, AGND = DGND = O V, REF IN = +3 V, R = 2 kV, DD SS L AD7840SPECIFICATIONS C = 100 pF. All specifications T to T unless othewise noted.) L MIN MAX 1 1 1 Parameter J, A K, B S Units Test Conditions/Comments 2 DYNAMIC PERFORMANCE 3 Signal to Noise Ratio (SNR) 76 78 76 dB min V = 1 kHz Sine Wave, f = 100 kHz OUT SAMPLE 4 Typically 82 dB at +25C for 0 < V < 20 kHz OUT Total Harmonic Distortion (THD) 78 80 78 dB max V = 1 kHz Sine Wave, f = 100 kHz OUT SAMPLE 4 Typically 84 dB at +25C for 0 < V < 20 kHz OUT Peak Harmonic or Spurious Noise 78 80 78 dB max V = 1 kHz Sine Wave, f = 100 kHz OUT SAMPLE 4 Typically 84 dB at +25C for 0 < V < 20 kHz OUT DC ACCURACY Resolution 14 14 14 Bits Integral Nonlinearity 2 1 2 LSB max Differential Nonlinearity 0.9 0.9 0.9 LSB max Guaranteed Monotonic Bipolar Zero Error 10 10 10 LSB max 5 Positive Full Scale Error 10 10 10 LSB max 5 Negative Full Scale Error 10 10 10 LSB max 6 REFERENCE OUTPUT REF OUT +25C 2.99 2.99 2.99 V min 3.01 3.01 3.01 V max REF OUT TC 60 60 60 ppm/C max Reference Load Change (REF OUT vs. I) 1 1 1 mV max Reference Load Current Change (0500 A) REFERENCE INPUT Reference Input Range 2.85 2.85 2.85 V min 3 V 5% 3.15 3.15 3.15 V max Input Current 50 50 50 A max LOGIC INPUTS Input High Voltage, V 2.4 2.4 2.4 V min V = 5 V 5% INH DD Input Low Voltage, V 0.8 0.8 0.8 V max V = 5 V 5% INL DD Input Current, I 10 10 10 A max V = 0 V to V IN IN DD Input Current (CS Input Only) 10 10 10 A max V =V to V IN SS DD 7 Input Capacitance, C 10 10 10 pF max IN ANALOG OUTPUT Output Voltage Range 3 3 3 V nom DC Output Impedance 0.1 0.1 0.1 typ Short-Circuit Current 20 20 20 mA typ 7 AC CHARACTERISTICS Voltage Output Settling Time Settling Time to within 1/2 LSB of Final Value Positive Full-Scale Change 4 4 4 s max Typically 2 s Negative Full-Scale Change 4 4 4 s max Typically 2.5 s Digital-to-Analog Glitch Impulse 10 10 10 nV secs typ Digital Feedthrough 2 2 2 nV secs typ POWER REQUIREMENTS V +5 +5 +5 V nom 5% for Specified Performance DD V 5 5 5 V nom 5% for Specified Performance SS I 14 14 15 mA max Output Unloaded, SCLK = +5 V. Typically 10 mA DD I 6 6 7 mA max Output Unloaded, SCLK = +5 V. Typically 4 mA SS Power Dissipation 100 100 110 mW max Typically 70 mW NOTES 1 Temperature ranges are as follows: J, K Versions, 0C to +70C A, B Versions, 25C to +85C S Version, 55C to +125C. 2 V (pk-pk) = 3 V OUT 3 SNR calculation includes distortion and noise components. 4 Using external sample-and-hold (see Testing the AD7840). 5 Measured with respect to REF IN and includes bipolar offset error. 6 For capacitive loads greater than 50 pF, a series resistor is required (see Internal Reference section). 7 Sample tested +25C to ensure compliance. Specifications subject to change without notice. 2 REV. B