Replacing the AD7874 with the GX7874 Four-Channel 12-Bit 50 kSPS Simultaneous-Sampling ADC in Acoustic Arrays

An acoustic array is an acoustic system that achieves directional sound pickup, noise suppression, and sound field control through beamforming, sound source localization, and spatial filtering. It is composed of multiple acoustic transducers and is widely used in smart speakers, conference systems, in-vehicle voice, medical ultrasound, and underwater acoustic detection, among other fields.

Beamforming algorithms rely on the time delay differences between array elements to calculate the direction of the sound source. Inconsistency in sampling instants translates into pointing errors. The design of the GX7874 four-channel 12-bit 50 kSPS simultaneous-sampling ADC meets this requirement. Each channel of the ADC is equipped with an independent track-and-hold amplifier, and the four channels sample simultaneously. The aperture delay of the four sample-and-hold amplifiers is very small, and minimum and maximum limits are specified to allow multiple devices to simultaneously sample multiple input channels without causing phase errors between signals connected to multiple devices.

The GX7874‘s reference voltage output/reference voltage input facility allows multiple ADCs to be driven by the same reference voltage source. In addition, the ADC has a standard digital interface, creating the conditions for interfacing the device with a microprocessor or DSP.

Product Advantages:

Powered by a 5V supply, supporting conversion of true bipolar input signals of +10V.

Single 5V supply, compatible with ±5V power supply pins, facilitating application.

Product dimensions, pinout, and functions are PIN TO PIN compatible with the AD7874.

Better signal-to-noise ratio and higher linearity.

Lower bipolar zero-level error and lower positive/negative full-scale error.

Higher channel isolation.

ENOB: 11.8 Bit (typical).

SINAD: 73.4 dB (typical).

SFDR: 95 dB (typical).

INL: ±0.1 LSB (typical).

DNL: ±0.1 LSB (typical).

Operating power consumption: 70 mW (typical).

For array systems, the GX7874 ADC‘s four independent track-and-hold channels, nanosecond-level aperture delay matching, and multi-device expansion through shared reference and triggering enable the construction of an acquisition architecture that prioritizes phase fidelity.