The PGA2500 is a digitally controlled analog microphone preamplifier designed for use as a front end for high-performance audio analog-to-digital converters (ADCs). The PGA2500 features include low noise, wide dynamic range, and a differential signal path. An on-chip DC servo loop is employed to minimize DC offset, while a common-mode servo function may be used to enhance common-mode rejection.
The PGA2500 is an integrated circuit designed as a front end for high-performance audio analog-to-digital converters (ADCs). It features a fully differential input-to-output architecture and allows for digitally controlled gain ranging from 10dB through 65dB in 1dB steps, or unity gain via serial port interface or dedicated control pin.
The device includes several advanced features such as zero crossing detection to minimize audible artifacts during gain switching, an integrated DC servo loop to reduce output offset voltage, and a common-mode servo function. It utilizes a four-wire serial control port for programming gain and internal functions, supporting daisy-chaining of multiple devices.
| Gain Range | 10dB through 65dB, 1dB per step |
|---|---|
| Unity Gain Setting | Available via Serial Port or Dedicated Control Pin |
| Equivalent Input Noise | -128dBu with Zs = 150 and Gain = 30dB |
| Total Harmonic Distortion plus Noise (THD+N) | 0.0004% with Gain = 30dB |
| Operating Temperature Range | -40 to +85 °C |
| Package Type | SSOP-28 |
| Power Supply Voltage (VA+) | +5V nominal (+4.75 to +5.25V) |
The gain ranges from 10dB through 65dB with steps of 1dB.
Gain settings are programmed using a 16-bit control word loaded via a simple serial port interface.
Yes, it supports daisy-chaining of multiple devices via a serial data output pin.
They are provided for controlling external switching of input pads, phantom power, high pass filters, and polarity reversal functions.