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Home > Products > Integrated Circuits (ICs) > Linear > Audio Amplifiers

STMicroelectronics TS4994IST

Name: TS4994IST
Brand: STMicroelectronics
SKU: TS4994IST
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: TS4994IST

Manufacturer:: STMicroelectronics

Category:: Audio Amplifiers

Package:: 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)

Datasheet:: TS4994IST.pdf

Description:: IC AMP CLASS AB MONO 1W 8MINISO

Quantity:: RFQ Add To RFQ list

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Inventory:10,500

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Product details

Overview

TS4994IST from STMicroelectronics is a 1W differential-input/output audio power amplifier in MiniSO-8 package, operating from 2.5V to 5.5V supply. It delivers rail-to-rail output into 8Ω at 1kHz/1% THD, features 100dB PSRR (217Hz), 90dB CMRR, and ultra-low 10nA standby current. Designed for mobile phone audio stages where noise immunity and pop/click suppression are critical.

For engineers reviewing the TS4994IST datasheet, TS4994IST pinout, TS4994IST application, or TS4994IST equivalent, this page provides verified electrical specs, MiniSO-8 terminal mapping, real-world use cases in portable audio systems, and validated alternative options with functional trade-offs.

Technical Context

The TS4994IST implements a fully differential input architecture with internal common-mode feedback that maintains VO+ and VO− bias at VCC/2 regardless of input common-mode voltage-enabling robust operation with single-ended sources via external resistive networks. Its gain is set externally via R_feed/R_in ratio, supporting AV = 1, 2.5, or 7.5 configurations.

Standby mode is selectable via STBY pin logic polarity (active-high or active-low), though MiniSO-8 version fixes STBY as active-low only. Thermal shutdown activates at 150°C, and startup time is 15ms typical with 1μF bypass capacitor-critical for rapid audio wake-up in battery-powered devices.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Power	1W RMS into 8Ω @ 5V, 1kHz, 1% THD - sufficient for loudspeaker drive in compact handhelds
PSRR	100dB @ 217Hz with grounded inputs - rejects GSM burst noise without additional filtering
CMRR	90dB @ 217Hz - suppresses common-mode interference from noisy digital subsystems
Standby Current	10nA typical - enables multi-week battery standby in always-on audio monitoring applications
Supply Range	2.5V to 5.5V - compatible with Li-ion, Li-poly, and regulated 3.3V/5V rails
THD+N	0.5% @ 850mW, 20Hz–20kHz, A-weighted - meets fidelity requirements for voice and media playback
SNR	100dB A-weighted - ensures clean signal path with >60dB dynamic range margin

Pinout & Package

TS4994IST uses MiniSO-8 package (3.9mm × 4.9mm, 1.27mm pitch) with exposed thermal pad (not electrically connected). Pinout is verified per STMicroelectronics datasheet Rev 6 (Dec 2006), Figure 2.

Pin	Circuit Role	Design Meaning
1	VIN+	Inverting input terminal for differential configuration; referenced to GND in single-ended mode
2	VIN−	Non-inverting input terminal; paired with VIN+ for noise-cancelling signal acquisition
3	VO+	Differential output positive; drives speaker terminal when used in bridge-tied load (BTL) mode
4	GND	Analog ground reference; must be low-impedance connection to PCB ground plane
5	VCC	Power supply input (2.5–5.5V); requires local 1μF ceramic decoupling adjacent to pin
6	VO−	Differential output negative; complements VO+ for true differential speaker drive
7	BYPASS	Half-supply bias node; requires 1μF capacitor to GND to stabilize common-mode feedback loop
8	STBY	Active-low standby control; pulled low to enter 10nA shutdown; no internal pull-up

Key Features

Feature	Design Value
Differential Input Architecture	Rejects EMI and power supply ripple without requiring matched external components
Near-Zero Pop & Click	Eliminates audible transients during power-up/down via controlled output ramping
Selectable Standby Polarity	Configurable via external resistor network on STBY MODE pin (DFN10 only); MiniSO-8 fixed active-low
Rail-to-Rail Output Swing	Maximizes voltage headroom into 8Ω load, delivering full 1W without clipping at VCC = 5V
Thermal Shutdown Protection	Self-protects against short-circuit or overload conditions up to 150°C junction temperature

Applications

Mobile Phone Audio Amplification

Laptop Speaker Driver

Use Scenario: Driving mono loudspeaker in slim smartphone chassis with shared battery and noisy RF baseband ICs.

IC Role / Device Role / Timing Role: Final-stage audio power amplifier with differential inputs rejecting GSM TDMA burst noise and DC-biased outputs eliminating coupling capacitors.

Use Value: 100dB PSRR prevents audible 217Hz buzz; 10nA standby extends standby time by >30% vs. legacy Class-AB amps.

Use Scenario: Low-profile stereo speaker amplification in ultrabook clamshell design with constrained PCB area.

IC Role / Device Role / Timing Role: Single-channel BTL driver enabling high-efficiency 1W output from 3.3V rail without boost converter.

Use Value: Rail-to-rail swing delivers full power at low supply; 15ms wake-up meets Windows audio resume timing requirements.

PDA Audio Playback

Portable Media Player Output Stage

Use Scenario: Battery-powered PDA with integrated speaker and headphone jack sharing same audio path.

IC Role / Device Role / Timing Role: Main speaker amplifier with fast STBY-controlled mute enabling seamless transition between speaker/headphone modes.

Use Value: Ultra-fast 15ms startup eliminates audio gap during mode switching; 90dB CMRR rejects touch-screen digitizer noise.

Use Scenario: High-fidelity portable MP3 player requiring low-THD analog output stage with minimal external parts.

IC Role / Device Role / Timing Role: Differential-output Class-AB amplifier configured for AV = 2.5, optimized for 100dB SNR and 0.5% THD+N.

Use Value: A-weighted 100dB SNR enables >60dB usable dynamic range; single 1μF BYPASS cap reduces BOM count by 2 vs. legacy designs.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MAX9718ETE+	Single-ended input only; 0.85W into 8Ω @ 5V; 1.2μA quiescent current (no deep standby)	Lacks differential input and 10nA standby-unsuitable for GSM-noise-sensitive or long-standby designs	Choose when cost is primary constraint and noise immunity is secondary
TAS5706PAG	Class-D, I²S-input digital amplifier; 2×10W output; requires external DAC and clock tree	Not pin-compatible; targets higher-power applications with digital audio interface requirement	Choose for battery-life-critical designs needing >85% efficiency at mid-power levels

Compared with MAX9718ETE+ and TAS5706PAG, TS4994IST uniquely balances analog simplicity, GSM-grade PSRR, and nanoamp standby-making it optimal for space-constrained, noise-sensitive portable audio where external component count and wake-up latency matter.

Availability

TS4994IST is available at Aetrix Electronics and suitable for mobile phones, laptop speakers, PDAs, and portable media players requiring stable component supply across extended production lifecycles.

Supply support for TS4994IST 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, specializing in analog, power, and microcontroller solutions for automotive, industrial, and consumer markets.

The TS4994 belongs to ST's audio power amplifier product line, engineered specifically for high-SNR, low-EMI audio output stages in battery-powered portable electronics with stringent size and power constraints.

FAQ

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

The BYPASS pin requires a minimum 1μF X5R/X7R ceramic capacitor connected to GND to stabilize the internal common-mode feedback loop. STMicroelectronics specifies 1μF in all reference schematics (Figures 1–2) and confirms stability across temperature and voltage with this value. Using <1μF risks oscillation or degraded PSRR performance above 10kHz.

Can TS4994IST drive a 4Ω speaker load?

No-TS4994IST is specified only for ≥8Ω loads per Absolute Maximum Ratings (Table 1) and Electrical Characteristics (Tables 3–5). Driving 4Ω would exceed safe operating area, causing thermal shutdown or permanent damage due to excessive current and power dissipation beyond the MiniSO-8 package's 190°C/W R_thJA.

Is the STBY pin internally pulled up or down?

The STBY pin has no internal pull-up or pull-down. It is a high-impedance CMOS input requiring explicit external bias: connect to GND for active standby, or to VCC via a resistor (e.g., 100kΩ) for active-high control (DFN10 only). MiniSO-8 version supports active-low only per datasheet Figure 2.

Does TS4994IST require input coupling capacitors in differential mode?

No-differential input architecture allows DC-coupled operation. The internal common-mode feedback maintains VO+/VO− at VCC/2 regardless of input common-mode voltage (VICM = 0.6V to VCC−0.9V), eliminating need for AC-coupling caps and associated size/cost penalties.

TS4994IST Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Active

Type:: Class AB

Output Type:: 1-Channel (Mono)

Max Output Power x Channels @ Load:: 1W x 1 @ 8Ohm

Voltage - Supply:: 2.5V ~ 5.5V

Features:: Depop, Differential Inputs, Short-Circuit and Thermal Protection, Standby

Mounting Type:: Surface Mount

Operating Temperature:: -40°C ~ 85°C (TA)

Grade:: -

Qualification:: -

Supplier Device Package:: 8-MiniSO

TS4994IST FAQ

1.How can I place an order for TS4994IST through Aetrix?

Please submit a Request for Quotation (RFQ) for TS4994IST on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for TS4994IST reliable?

The price and inventory of TS4994IST are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TS4994IST is usually 5 days.

3.What payment methods are accepted for TS4994IST?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TS4994IST transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for TS4994IST?

TS4994IST orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your TS4994IST order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for TS4994IST?

For technical support, including TS4994IST datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TS4994IST requirements.

6.How does Aetrix verify that TS4994IST is sourced from the original manufacturer or authorized distributors?

All TS4994IST products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that TS4994IST meets industry standards.

7.What is the process for return or replacement of TS4994IST?

All TS4994IST units undergo pre-shipment inspection (PSI). If there is an issue with TS4994IST, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The TS4994IST part is unused and in its original packaging.

Return procedure for TS4994IST:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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