STMicroelectronics TS4990IST

Overview

TS4990IST from STMicroelectronics is a 1.2 W mono Class AB audio power amplifier with active-low standby control, unity-gain stability, and BTL (bridge-tied load) output configuration. It delivers 1.2 W RMS into 8 Ω at 5 V supply, achieves 0.1% THD+N at 1 kHz, and draws only 10 nA in standby mode. It is used in mobile phone loudspeaker drivers requiring low pop/click and high PSRR.

For engineers reviewing the TS4990IST datasheet, TS4990IST pinout, TS4990IST application, or TS4990IST equivalent, this page provides verified specifications including BTL output architecture, 62 dB PSRR at 217 Hz, thermal shutdown protection, miniSO-8 package mapping, and gain-setting resistor interface - all critical for portable audio power stage design and layout.

Technical Context

The TS4990IST implements a dual-output BTL architecture where VOUT1 and VOUT2 drive opposite phases of an 8 Ω speaker, doubling effective voltage swing and enabling 1.2 W output without external bootstrap capacitors. Its internal biasing supports operation down to 2.2 V, with rail-to-rail input common-mode range (1.2 V to VCC).

Standby activation is controlled by pulling STBY pin to GND (active-low), reducing ICC to ≤10 nA while maintaining near-zero output offset (1–10 mV). The amplifier features internally compensated unity-gain stability and includes thermal shutdown triggered at 150 °C junction temperature.

Key Specifications

Pinout & Package

TS4990IST is supplied in miniSO-8 package (3.9 mm × 4.9 mm, 1.27 mm pitch), thermally enhanced with exposed pad connected to GND. Pin 1 is STBY (active-low enable), Pin 2 is VIN−, Pin 3 is VIN+, Pin 4 is VOUT2, Pin 5 is VOUT1, Pin 6 is GND, Pin 7 is VCC, Pin 8 is BYPASS.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar audio power amplifier applications.

Compared with TAS5342AIDBTR and MAX9718ETE+, the TS4990IST uniquely combines nA-level standby, integrated bypass generation, and BTL output in miniSO-8 - making it optimal for space-constrained, battery-sensitive mobile audio where pop suppression and minimal external components are mandatory.

Availability

TS4990IST is available at Aetrix Electronics and suitable for mobile phone loudspeaker drivers, laptop internal audio stages, portable media player output circuits, and VoIP handset amplifiers requiring stable component supply and long-term production continuity.

Supply support for TS4990IST 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 solutions for automotive, industrial, and consumer markets.

The TS4990 belongs to ST's audio power amplifier product line, engineered specifically for low-voltage, low-pop, high-PSRR portable audio applications - emphasizing integration, battery efficiency, and robust EMI immunity in space-constrained designs.

FAQ

What is the minimum recommended bypass capacitor value for stable operation?

The TS4990IST requires a minimum 1 µF X7R ceramic capacitor between BYPASS (Pin 8) and GND to establish a stable half-supply reference. Using <1 µF risks increased pop/click amplitude and potential instability in BTL mode; ST recommends 1–10 µF for optimal transient response and PSRR performance across 2.2–5.5 V supply range.

Can TS4990IST drive a 4 Ω speaker load?

Yes - the TS4990IST is rated for RL ≥ 4 Ω. At 5 V supply, it delivers 1.4 W into 4 Ω (THD = 1%, 1 kHz), with corresponding increase in power dissipation. Thermal derating must be applied: maximum continuous output drops to ~0.9 W at 85 °C ambient when mounted on standard 2-layer PCB without heatsink.

How does the active-low STBY pin behave during power-up?

During power-up, STBY must remain ≥1.35 V (or floating) until VCC stabilizes above 2.2 V; pulling STBY low before VCC reaches regulation causes undefined behavior. ST recommends tying STBY to VCC via 100 kΩ resistor for automatic enable, or controlling it with a GPIO that asserts high after power-good assertion.

Is the miniSO-8 package RoHS-compliant and lead-free?

Yes - the TS4990IST miniSO-8 package is RoHS-compliant and lead-free per EU Directive 2011/65/EU, with matte tin (Sn) termination and peak reflow temperature rating of 260 °C (JEDEC J-STD-020D). The exposed pad is electrically connected to GND and must be soldered to PCB thermal pad for optimal thermal performance.