AD7937 Analog Devices, AD7937 Datasheet
AD7937
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AD7937 Summary of contents
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... GENERAL DESCRIPTION The AD7937 contains two 12-bit current output DACs on one monolithic chip. A separate reference input is provided for each DAC. The dual DAC saves valuable board space, and the mono- lithic construction ensures excellent thermal tracking. Both DACs are guaranteed 12-bit monotonic over the full temperature range. ...
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... AD7937–SPECIFICATIONS Parameter A Version ACCURACY Resolution 12 ± 1 Relative Accuracy ± 1 Differential Nonlinearity ± 6 Gain Error 2 Gain Temperature Coefficient ; ∆Gain/∆Temperature ± 5 Output Leakage Current I 5 OUTA OUTB 10 REFERENCE INPUT Input Resistance REFA REFB ± 3 Input Resistance Match DIGITAL INPUTS ...
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... 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 AD7937 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 ...
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... FBA (see Figures 4 and 5) to convert the current flowing voltage output. EQUIVALENT CIRCUIT ANALYSIS Figure 3 shows the equivalent circuit for one of the D/A con- verters (DAC A) in the AD7937. A similar equivalent circuit can be drawn for DAC B. V REFA C is the output capacitance due to the N-channel switches OUT and varies from about 100 pF with digital input code ...
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... IN and potentiometers should have a low Temperature Coefficient. In many applications, because of the excellent Gain T.C. and Gain Error specifications of the AD7937, Gain Error trimming is not necessary. In fixed reference applications, full scale can also be adjusted by omitting R1, R2, R3, R4 and trimming the reference voltage magnitude. ...
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... AD7937 SEPARATE AGND PINS The DACs in the AD7937 have separate AGND lines taken to pins AGNDA and AGNDB on the package. This increases the applications versatility of the part. Figure example of this. DAC A is connected in standard fashion as a programmable attenuator. AGNDA is at ground potential. DAC B is operating with AGND B biased the AD584 ...
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... Figure 8 shows an example 8-bit interface between the AD7937 and a generic 8-bit microcontroller/DSP processor. Pins where the processor are connected to pins the AD7937. OS When writing to the DACs, the lower 8 bits must be written be no greater than first, followed by the upper four bits ...
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... AD7937 PIN 1 0.0118 (0.30) 0.0040 (0.10) OUTLINE DIMENSIONS Dimensions shown in inches and (mm). 24-Lead Small Outline SOIC (R-24) 0.6141 (15.60) 0.5985 (15.20 0.2992 (7.60) 0.2914 (7.40) 0.4193 (10.65 0.3937 (10.00) 0.1043 (2.65) 0.0926 (2.35) 8 0.0500 0.0192 (0.49) SEATING 0 0.0125 (0.32) (1.27) PLANE 0.0138 (0.35) 0.0091 (0.23) BSC 0.0291 (0.74) 45 0.0098 (0.25) 0.0500 (1.27) 0.0157 (0.40) ...