AD7845BQ

2 LC MOS a Complete 12-Bit Multiplying DAC AD7845 FUNCTIONAL BLOCK DIAGRAM FEATURES 12-Bit CMOS MDAC with Output Amplifier 4-Quadrant Multiplication Guaranteed Monotonic (T to T ) MIN MAX Space-Saving 0.3 DIPs and 24- or 28-Terminal Surface Mount Packages Application Resistors On Chip for Gain Ranging, etc. 2 Low Power LC MOS APPLICATIONS Automatic Test Equipment Digital Attenuators Programmable Power Supplies Programmable Gain Amplifiers Digital-to-420 mA Converters GENERAL DESCRIPTION PRODUCT HIGHLIGHTS The AD7845 is the industrys first 4-quadrant multiplying D/A 1. Voltage Output Multiplying DAC converter with an on-chip amplifier. It is fabricated on the The AD7845 is the first DAC which has a full 4-quadrant 2 MOS process, which allows precision linear components LC multiplying capability and an output amplifier on chip. All and digital circuitry to be implemented on the same chip. specifications include amplifier performance. The 12 data inputs drive latches which are controlled by stan- 2. Matched Application Resistors dard CS and WR signals, making microprocessor interfacing Three application resistors provide an easy facility for gain simple. For stand-alone operation, the CS and WR inputs can ranging, voltage offsetting, etc. be tied to ground, making all latches transparent. All digital 3. Space Saving inputs are TTL and 5 V CMOS compatible. The AD7845 saves space in two ways. The integration of the The output amplifier can supply 10 V into a 2 kW load. It is output amplifier on chip means that chip count is reduced. internally compensated, and its input offset voltage is low due to The part is housed in skinny 24-lead 0.3 DIP, 28-terminal laser trimming at wafer level. For normal operation, R is tied LCC and PLCC and 24-terminal SOIC packages. FB , but the user may alternatively choose R , R or R to to V OUT A B C scale the output voltage range. REV. B Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. use, nor for any infringements of patents or other rights of third parties Tel: 781/329-4700 World Wide Web Site: 1 (V = +15 V, 6 5%, V = 15 V, 6 5%, V = +10 V, AGND = DGND = O V, AD7845SPECIFICATIONS DD SS REF V connected to R . V load = 2 kV, 100 pF. All specifications T to T unless otherwise noted.) OUT FB OUT MIN MAX Parameter J Version K Version A Version B Version S Version T Version Units Test Conditions/Comments ACCURACY V REF Resolution 12 12 12 12 12 12 Bits 1 LSB = = 2.4 mV 12 2 Relative Accuracy at +25 C 1 1/2 1 1/2 1 1/2 LSB max All Grades Are Guaranteed T to T 1 3/4 1 3/4 1 3/4 LSB max Monotonic over Temperature MIN MAX Differential Nonlinearity 1 1 1 1 1 1 LSB max DAC Register Loaded with Zero Code Offset Error All 0s. at +25 C 2 1 2 1 2 1mV max T to T 3 2 3 2 4 3mV max MIN MAX Offset Temperature Coefficient 2 (D Offset/D Temperature) 5 5 5 5 5 5 m V/ C typ Gain Error 3 2 3 2 3 2 LSB max R , V Connected FB OUT 6 6 6 6 6 6 LSB max R , V Connected, V = +5 V C OUT REF 6 6 6 6 6 6 LSB max R , V Connected, V = +5 V B OUT REF 7 7 7 7 7 7 LSB max R , V Connected, V = +2.5 V A OUT REF Gain Temperature Coefficient 2 (D Gain/D Temperature) 2 2 2 2 2 2 ppm of FSR/ CR , V Connected FB OUT typ REFERENCE INPUT Input Resistance, Pin 17 8888 88 kW min Typical Input Resistance = 12 kW 16 16 16 16 16 16 kW max APPLICATION RESISTOR RATIO MATCHING 0.5 0.5 0.5 0.5 0.5 0 5 % max Matching Between R , R , R A B C DIGITAL INPUTS V (Input High Voltage) 2.4 2.4 2.4 2.4 2.4 2.4 V min IH V (Input Low Voltage) 0.8 0.8 0.8 0.8 0.8 0.8 V max IL I (Input Current) 1 1 1 1 1 1 m A max Digital Inputs at 0 V and V IN DD 2 C (Input Capacitance) 7777 77 pF max IN 4 POWER SUPPLY V Range 14.25/15.75 14.25/15.75 14.25/15.75 14.25/15.75 14.25/15.75 14.25/15.75 V min/V max DD Range 14.25/15.75 14.25/15.75 14.25/15.75 14.25/15.75 14.25/15.75 14.25/15.75 V min/V max VSS Power Supply Rejection 0.01 0.01 0.01 0.01 0.01 0.01 % per % max V = +15 V 5%, V = 10 V D Gain/D VDD DD REF 0.01 0.01 0.01 0.01 0.01 0.01 % per % max V = 15 V 5%. D Gain/D VSS SS 6666 66 mA max V Unloaded IDD OUT I 4444 44 mA max V Unloaded SS OUT AC PERFORMANCE CHARACTERISTICS These characteristics are included for Design Guidance and are not subject to test. DYNAMIC PERFORMANCE Output Voltage Settling Time5555 55 m s max To 0.01% of Full-Scale Range Load = 2 kW , 100 pF. V OUT DAC Register Alternately Loaded with All 0s and All 1s. Typically 2.5 m s at 25 C. Load = 2 kW , 100 pF. Slew Rate 11 11 11 11 11 11 V/m s typ V OUT = 0 V. Digital-to-Analog 55 55 55 55 55 55 nVs typ Measured with V REF Glitch Impulse DAC Register Alternately Loaded with All 0s and All 1s. = 10 V, 10 kHz Sine Wave Multiplying Feedthrough5555 55 mV p-p typ V REF 3 DAC Register Loaded with All 0s. Error Unity Gain Small Signal , R Connected. DAC Loaded Bandwidth 600 600 600 600 600 600 kHz typ V OUT FB = 100 mV p-p with All 1s V REF Sine Wave. , R Connected. DAC Loaded Full Power Bandwidth 175 175 175 175 175 175 kHz typ V OUT FB = 20 V p-p with All 1s. V REF = 2 kW . Sine Wave. R L Total Harmonic Distortion 90 90 90 90 90 90 dB typ V = 6 V rms, 1 kHz Sine Wave. REF 5 OUTPUT CHARACTERISTICS Open Loop Gain 85 85 85 85 85 85 dB min V , R Not Connected OUT FB V = 10 V, R = 2 kW OUT L Output Voltage Swing 10 10 10 10 10 10 V min R = 2 kW , C = 100 pF L L Output Resistance 0.2 0.2 0.2 0.2 0.2 0.2 W typ R , V Connected, FB OUT Short Circuit Current +25 C 11 11 11 11 11 11 mA typ V Shorted to AGND OUT Output Noise Voltage Includes Noise Due to Output (0.1 Hz to 10 Hz) +25 C2222 22 m V rms typ Amplifier and Johnson Noise f = 10 Hz 250 250 250 250 250 250 nV/ Hz typ of R FB f = 100 Hz 100 100 100 100 100 100 nV/ Hz typ f = 1 kHz 50 50 50 50 50 50 nV/ Hz typ f = 10 kHz 50 50 50 50 50 50 nV/ Hz typ f = 100 kHz 50 50 50 50 50 50 nV/ Hz typ NOTES 1 Temperature ranges are as follows: J, K Versions: 0 C to +70 C A, B Versions: 40 C to +85 C S, T Versions: 55 C to +125 C. 2 Guaranteed by design and characterization, not production tested. 3 The metal lid on the ceramic D-24A package is connected to Pin 12 (DGND). 4 The device is functional with a power supply of 12 V. 5 Minimum specified load resistance is 2 kW . Specifications subject to change without notice. 2 REV. B