AD767–SPECIFICATIONS (T = +258C, 615 volt power supplies, Unipolar Mode, unless otherwise noted.) A Model AD767J/A/S1 Min Typ Max DIGITAL INPUTS Resolution Logic Levels (TTL Compatible, TMIN–TMAX)3 VIH (Logic “1”) +2.0 VIL (Logic “0”) J, K, A, B 0 0 VIL (Logic “0”) S IIH (VIH = 5.5 V) IIL (VIL = 0.
AD767 Ref Out, VOUT (Pins 6, 9) . . . Indefinite short to power ground Momentary Short to VCC Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . 1000 mW ABSOLUTE MAXIMUM RATINGS* VCC to Power Ground . . . . . . . . . . . . . . . . . . . . .0 V to +18 V VEE to Power Ground . . . . . . . . . . . . . . . . . . . . . 0 V to –18 V Digital Inputs (Pins 11, 13–24) to Power Ground . . . . . . . . . . . . . . . . . . . . –1.0 V to +7.0 V Ref In to Reference Ground . . . . . . . . . . . . . . .
AD767 THE AD767 OFFERS TRUE 12-BIT PERFORMANCE OVER THE FULL TEMPERATURE RANGE LINEARITY ERROR: Analog Devices defines linearity error as the maximum deviation of the actual, adjusted DAC output from the ideal analog output (a straight line drawn from 0 to F.S. – 1 LSB) for any bit combination. This is also referred to as relative accuracy. The AD767 is laser trimmed to typically maintain linearity errors at less than ± 1/8 LSB for the K and B versions and ± 1/2 LSB for the J, A and S versions.
AD767 The AD767 reference output should be buffered with an external op amp if it is required to supply more than 0.1 mA output current. The reference is typically trimmed to ± 0.2%, then tested and guaranteed to ± 1.0% max error. The temperature coefficient is comparable to that of the full-scale TC for a particular grade. BIPOLAR CONFIGURATION (Figure 3) This configuration will provide a bipolar output voltage from –5.000 to +4.9976 volts, with positive full scale occurring with all bits ON (all 1s).
AD767 USING THE AD767 WITH THE AD588 HIGH PRECISION VOLTAGE REFERENCE The AD767 is specified for gain drift from 15 ppm/°C to 30 ppm/°C (depending on grade) using its internal 10 volt reference. Since the internal reference contributes the majority of this drift, an external high-precision voltage reference will greatly improve performance over temperature. As shown in Figure 4, the 10 volt output from the AD588 is used as the reference. With a 1.
AD767 Figure 5e. Fine-Scale Settling, CF = 20 pF Figure 6. 68000 – AD767 Interface DIGITAL INPUT CONSIDERATIONS 8086 – AD767 INTERFACE The threshold of the digital input circuitry is set at 1.4 volts and does not change with supply voltage. Thus the AD767 digital interface may be driven with any of the popular types of 5 volt logic. Interfacing the AD767 to the 8086 16-bit microprocessor requires a minimal amount of external components.
C1068a–10–4/88 AD767 Figure 11. TMS320C25 – AD767 Interface Figure 9. TMS32020 – AD767 Interface ADSP-2100 – AD767 INTERFACE OUTLINE DIMENSIONS The ADSP-2100 single chip DSP processor may be interfaced to the AD767 as shown in Figure 10. With a clock frequency of 32 MHz, and instruction execution in a single 125 ns cycle, the processor will support the AD767 interface with a single wait state. Dimensions shown in inches and (mm). 24-Pin Ceramic (Suffix D) 24-Pin Plastic (Suffix N) Figure 10.
