AD7244AQ

Overview

The AD7244AQ is a dual, complete 14-bit voltage output digital-to-analog converter fabricated in LC2MOS technology. It integrates two DAC channels, each with an output buffer amplifier, and includes an on-chip 3 V buried Zener reference. The device operates from ±5 V supplies, providing a bipolar analog output range of ±3 V. It features a high-speed serial interface for direct connection to DSPs and microcontrollers, with asynchronous control via separate LDAC inputs. Key electrical specifications include a settling time of 4 µs to ±1/2 LSB, integral nonlinearity of ±2 LSB max, and differential nonlinearity of ±1 LSB max. Total power dissipation is typically 130 mW.

Feature Summary

• Dual 14-bit resolution with integrated output buffer amplifiers
• On-chip 3 V temperature-compensated buried Zener voltage reference
• High-speed serial interface compatible with standard DSP and microcontroller protocols
• Asynchronous independent DAC updating via separate LDACA and LDACB inputs

Applications

• Industrial process control systems requiring precise voltage generation
• Programmable gain amplifiers and variable power supplies
• Waveform generation and signal processing equipment
• Test and measurement instrumentation

Procurement Notes

Verify the package type Q-24 (Cerdip) matches the design requirements. Confirm that the operating temperature range of –40°C to +85°C aligns with the system environment. Ensure supply voltages are strictly maintained within ±5% of ±5 V for specified performance. Check for ESD sensitivity during handling and storage.

Selection Notes

Select the AD7244AQ when 14-bit resolution and dual-channel output are required. Compare against the AD7242 if 12-bit resolution is sufficient, as they share pinouts. Consider the internal reference capability to reduce external component count. Verify serial interface timing constraints against the host processor's clock speeds.

Part Context

The AD7244AQ belongs to the AD7242/AD7244 family of LC2MOS DACs. It shares the same physical footprint and pinout as the 12-bit AD7242, facilitating easy upgrades from 12-bit to 14-bit performance without redesigning the PCB layout. The 'Q' suffix denotes the hermetic Cerdip package option.

Replacement Considerations

The AD7242AQ is a pin-compatible alternative offering 12-bit resolution. For higher resolution or different packaging, consult the full AD7242/AD7244 ordering guide for variants such as AD7244JN (Plastic DIP) or AD7244JR (SOIC).

FAQ

How is the internal reference utilized?

Connect the REF OUT pin to both REF INA and REF INB pins to use the on-chip 3 V reference. This configuration provides up to 500 μA of load current.

What is the channel-to-channel isolation?

Channel-to-channel isolation is typically 110 dB when using the recommended decoupling scheme for the reference output or an external reference source.

How does the serial interface handle data loading?

The device expects a 16-bit serial stream. For the AD7244, the first 2 bits are don't cares, followed by the 14-bit data word starting with the MSB. Data is latched on the falling edge of TCLK.