STMicroelectronics TS4994EIJT

Overview

TS4994EIJT from STMicroelectronics is a 1.2 W differential-input/output audio power amplifier in a 9-bump flip-chip package, operating from 2.5 V to 5.5 V supply. It delivers rail-to-rail output into 8 Ω at 1 kHz with 1% THD, achieves 100 dB PSRR and 90 dB CMRR at 217 Hz, and features ultra-low 10 nA standby current with selectable active-high/active-low standby control - deployed in mobile phone audio stages for noise-immune speaker drive.

For engineers reviewing the TS4994EIJT datasheet, TS4994EIJT pinout, TS4994EIJT application, or TS4994EIJT equivalent, this page provides verified functional identity, validated pin roles, confirmed thermal shutdown behavior, exact differential gain configuration support, and real-world mobile/audio system integration context - all derived from ST's official TS4994FC datasheet Rev 2 (Dec 2006).

Technical Context

The TS4994EIJT implements a fully differential architecture with common-mode feedback that maintains output bias at VCC/2 regardless of input common-mode voltage, enabling robust operation with single-ended or differential sources. Its internal thermal shutdown activates at 150 °C, and startup time is 15 ms typical.

Standby mode is controlled via the STBY pin, configurable for active-high or active-low assertion by external logic; standby current remains ≤1000 nA across –40 °C to +85 °C. PSRR and CMRR are optimized for 217 Hz interference rejection - critical for GSM-band mobile audio immunity.

Key Specifications

Pinout & Package

TS4994EIJT uses a lead-free 9-bump flip-chip (FC9) package with back coating, 300 µm bump diameter, and tape-and-reel packaging. Pin numbering follows standard top-view orientation with pin 1 at top-left corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX9718ETE+T and TAS5706PAG, the TS4994EIJT uniquely combines differential analog inputs, sub-10 nA standby, and GSM-optimized PSRR in a minimal 9-bump FC package - making it optimal for cost-sensitive, noise-prone, space-constrained mobile audio where analog integrity is prioritized over raw efficiency.

Availability

TS4994EIJT is available at Aetrix Electronics and suitable for mobile phone audio subsystems, laptop speaker drivers, portable media players, and PDA audio outputs requiring stable component supply across extended production lifecycles.

Supply support for TS4994EIJT 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, MCU, power, and sensor solutions for automotive, industrial, and consumer markets.

The TS4994 belongs to ST's audio power amplifier product line, engineered specifically for high-fidelity, low-power, noise-immune audio output in battery-operated portable electronics - emphasizing differential signaling, ultra-low standby, and GSM-band interference resilience.

FAQ

What is the minimum recommended bypass capacitor value on the Bypass pin?

A 1 µF ceramic capacitor is specified in the datasheet for the Bypass pin to stabilize the internal VCC/2 reference node. This value ensures stable common-mode bias under dynamic load conditions and prevents low-frequency oscillation. Lower values (e.g., 0.47 µF) degrade PSRR below 1 kHz; larger values (>2.2 µF) offer no measurable benefit and increase start-up delay.

Can TS4994EIJT drive a 4 Ω load reliably?

Yes - the datasheet specifies operation down to 4 Ω loads with derated output power: 1.4 W max at 5 V with 10% THD, or 0.8 W at 1% THD. Thermal derating must be applied per Figure 14; with no heatsink, continuous 4 Ω operation above 0.6 W requires ambient <45 °C. Internal thermal shutdown protects against sustained overload.

How does the Stdby Mode pin configure standby polarity?

The Stdby Mode pin selects standby polarity by its DC voltage level: tying it to GND configures Stdby as active-high; tying it to VCC configures Stdby as active-low. This is implemented via internal comparator thresholds and requires no external components - enabling direct interfacing with either open-drain or push-pull microcontroller GPIOs.

Is external input coupling required for single-ended source connection?

No - the TS4994EIJT supports true single-ended input via VIN+ with VIN− tied to the Bypass node (VCC/2), as shown in Figure 12 of the datasheet. This eliminates need for AC-coupling capacitors and preserves low-frequency response. However, differential input is preferred for maximum noise immunity in noisy environments.