PCM1704U-K/2K

ADCs/DACs - Special Purpose Overview

The PCM1704U-K/2K is a precision 24-bit digital-to-analog converter (DAC) utilizing BiCMOS sign-magnitude architecture. It supports sampling frequencies from 16kHz to 96kHz with 8x oversampling capability at 96kHz. The device features a serial audio interface accepting 20- or 24-bit data words in MSB-first, two's complement format. Key electrical specifications include a typical dynamic range of 112dB and a signal-to-noise ratio of 120dB for the K grade. It operates on dual ±5V supplies and provides a bipolar current output of ±1.2mA with a settling time of 200ns.

ADCs/DACs - Special Purpose Feature Summary

• BiCMOS Sign-Magnitude Architecture: Eliminates glitches and nonlinearities around bipolar zero for superior low-level performance.
• High Dynamic Performance: Achieves 112dB typical dynamic range and 120dB SNR (K Grade).
• Fast Current Output: Provides ±1.2mA output with a 200ns settling time.
• Pin-Programmable Control: Supports selectable input word length (20/24-bit) and data inversion via dedicated pins.

ADCs/DACs - Special Purpose Applications

• High-end consumer audio systems requiring ultra-low distortion.
• Professional audio equipment demanding high dynamic range.
• Waveform synthesis applications requiring very low noise and distortion.

ADCs/DACs - Special Purpose Procurement Notes

Verify component authenticity through authorized distributors or direct manufacturer channels. Confirm the specific 'K' grade suffix corresponds to the required dynamic performance specifications (112dB DR, 0.0008% THD+N). Ensure the '/2K' suffix matches the required tape and reel packaging quantity of 2000 units for production integration.

ADCs/DACs - Special Purpose Selection Notes

Select the PCM1704U-K/2K when design requirements specify a resolution of 24 bits with a maximum sampling frequency of 96kHz. This model is appropriate for designs utilizing a serial interface compatible with standard audio data formats. Consider the ±5V supply requirement and the need for external current-to-voltage conversion circuitry due to the current-output nature of the device.

ADCs/DACs - Special Purpose Part Context

The PCM1704 series was originally developed by Burr-Brown Corporation before its acquisition by Texas Instruments. The U-K variant represents the premium grade within the PCM1704 family, distinguished by tighter tolerances for total harmonic distortion plus noise and dynamic range compared to the standard U or J grades.

ADCs/DACs - Special Purpose Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Designers should consult official Texas Instruments resources for legacy replacement strategies or cross-reference with other high-performance stereo DACs from the same era if this obsolete component is no longer sourced.

ADCs/DACs - Special Purpose FAQ

What is the function of the 20BIT pin?

The 20BIT pin selects the input data word length. When connected to DGND (Logic High), it defaults to 24-bit data mode. When connected to –VDD (Logic Low), it configures the device for 20-bit data words.

How does the sign-magnitude architecture benefit the PCM1704?

The sign-magnitude architecture eliminates unwanted glitches and nonlinearities around the bipolar zero crossing point. This ensures ideal low-level operation and allows for true 24-bit resolution accuracy near zero signals.

What are the power supply requirements for the PCM1704U-K/2K?

The device requires dual supplies: +VCC/+VDD must be between +4.75V and +5.25V, and –VCC/–VDD must be between –4.75V and –5.25V. Both positive and negative supplies can share common ground references but require proper decoupling.