AD7849BNZ

Overview

The AD7849BNZ is a 16-bit serial input multiplying digital-to-analog converter (DAC) from Analog Devices. It features guaranteed monotonicity over the specified temperature range and utilizes a versatile three-wire serial interface compatible with opto-isolators. The device includes internal output control during power-up and power-down sequences, clamping VOUT to 0 V via low-impedance paths. It supports both unipolar and bipolar output ranges, clearing to 0 V in either configuration. The part operates with analog supplies of ±15 V nominal and a 5 V digital supply, housed in a 20-lead PDIP package.

Feature Summary

• 16-bit resolution with guaranteed monotonicity
• Versatile serial interface for daisy-chain or standalone operation
• Internal output clamp to 0 V during power transitions
• Configurable binary or two's complement coding

Applications

• Industrial process controls
• PC analog I/O boards
• Instrumentation systems

Procurement Notes

Verify the specific grade B designation for 16-bit performance and monotonicity guarantees. Confirm the 20-lead PDIP package requirement against PCB footprint specifications. Ensure supply voltage rails match the ±15 V analog and 5 V digital requirements defined in the datasheet.

Selection Notes

Select this component when 16-bit accuracy and monotonicity are required in a serial interface architecture. The A version offers only 14-bit guaranteed monotonicity; therefore, the B or C grades are necessary for full 16-bit linearity. Consider the external reference requirements as the AD7849 uses an external reference input rather than an internal one.

Part Context

The AD7849 series comprises 14-bit/16-bit multiplying DACs. The BNZ suffix indicates the B grade variant, which provides 16-bit resolution and monotonicity, packaged in a 20-lead Plastic Dual In-Line (PDIP) format. This distinguishes it from the AR (SOIC) package options and the AN (PDIP) A-grade variants.

Replacement Considerations

AD7849ANZ

FAQ

How does the AD7849 handle output stability during power-up?

During power-up and power-down, the VOUT pin is clamped to 0 V via a low-impedance path. Transmission gate G1 opens to prevent shorting the amplifier output, maintaining this state until supplies stabilize and a valid word is written.

What is the function of the BIN/COMP pin?

The BIN/COMP pin selects the data coding format. Setting it to Logic 0 enables straight binary coding, while Logic 1 enables two's complement coding, allowing the DAC to reset to 0 V in both unipolar and bipolar ranges.

Can multiple AD7849 devices be connected in a chain?

Yes, by connecting the DCEN pin high, the device enters daisy-chain mode. Data ripples out of SDOUT on rising SCLK edges, allowing cascading multiple units where total clock cycles equal 16 times the number of devices.