STMicroelectronics DEMOTS472Q

Overview

TS472 from STMicroelectronics is a fully-differential microphone preamplifier IC with 2.0 V low-noise bias output, active-low standby mode, 10 nV/√Hz input noise at 1 kHz, 40 kHz bandwidth independent of gain, and 20 dB gain operation at 1.8 mA supply current. It targets high-fidelity audio front-ends in portable electret microphone systems.

For engineers reviewing the TS472 datasheet, TS472 pinout, TS472 application, or TS472 equivalent, this page delivers verified specifications, QFN24 and flip-chip package details, differential signal path design guidance, and real-world use cases in notebook audio and voice recognition systems.

Technical Context

The TS472 implements a fully-differential amplifier architecture with internal common-mode feedback to maintain output bias at VCC/2, maximizing dynamic range and enabling rail-to-rail swing. Its gain is programmable from –1.5 dB to 42.5 dB via external resistor on GS pin or fixed at 20 dB using BIAS voltage.

It integrates a dedicated 2.0 V bias generator (±0.1 V tolerance, 100 Ω output impedance, 2 mA drive capability) with 80 dB PSRR at 217 Hz and <5 μVRMS A-weighted noise. Standby mode reduces current to ≤1 μA while placing outputs and bias into high-impedance state.

Key Specifications

Pinout & Package

TS472 is available in two lead-free packages: QFN24 (4 × 4 mm, 0.5 mm pitch) and flip-chip (12-bump). The QFN24 variant is used in the DEMOTS472Q evaluation platform and provides full pin access for prototyping.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microphone preamplifier applications.

Compared with MAX4466 and INA217, TS472 uniquely combines differential I/O, integrated 2.0 V bias, sub-1 μA standby, and 40 kHz flat bandwidth in a single 4×4 mm QFN-making it optimal for space-constrained, battery-operated voice interface hardware.

Availability

TS472 is available at Aetrix Electronics and suitable for notebook computers, video conferencing systems, voice-controlled IoT devices, and digital cameras requiring stable component supply and long-term production continuity.

Supply support for TS472 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, mixed-signal, power, and microcontroller products for industrial, automotive, and consumer markets.

The TS472 belongs to ST's high-performance audio signal conditioning product line, engineered specifically for low-noise, low-power electret microphone interfaces in portable and always-on voice applications.

FAQ

What is the minimum recommended bypass capacitor value for the BYP pin?

A 1 μF ceramic capacitor is specified in the datasheet for optimal PSRR and startup behavior. Using <1 μF increases power supply ripple sensitivity and extends wake-up time beyond 5 ms. The capacitor must be placed within 2 mm of the BYP pin with short, low-inductance traces to maintain stability across temperature and supply voltage ranges.

Can the TS472 drive a 10 kΩ load differentially without performance degradation?

Yes-the datasheet specifies R_LOAD = 10 kΩ as the standard test condition for THD+N, PSRR, and bandwidth measurements. At 20 dB gain and 3 V supply, differential output swing remains linear up to ±1.2 V into 10 kΩ, with distortion staying below 0.1% across 20 Hz–20 kHz. Lower loads increase current demand and may reduce PSRR above 10 kHz.

How does the GS pin function when driven by a microcontroller GPIO instead of a resistor?

When GS is driven to ≥1.5 V (e.g., 3.3 V GPIO), gain locks at 20 dB; when pulled ≤0.4 V, gain drops to minimum (–1.5 dB). Intermediate voltages yield non-linear gain interpolation. For reliable operation, avoid floating GS-tie to BIAS (20 dB) or GND (min gain) unless actively controlled with level-shifted logic compatible with VCC.

Is the 2.0 V BIAS output stable under dynamic microphone current draw?

Yes-the BIAS output maintains ±0.1 V regulation from 0 to 2 mA load, as confirmed by Figure 8 in the datasheet. At 2 mA, output voltage drops to 1.9 V due to 100 Ω internal resistance. For best SNR, use C3 ≥1 μF to suppress switching noise; load transients cause <100 μs settling time with proper decoupling.