STMicroelectronics TDA7498L

Overview

TDA7498L from STMicroelectronics is a dual-channel BTL Class-D audio amplifier IC designed for high-power active speaker and home theater systems. It delivers 80 W + 80 W into 6 Ω at 10% THD with 32 V supply, operates from a single 14–36 V rail, achieves 90% efficiency, and features four selectable fixed gains (25.6–37.6 dB) via digital inputs GAIN0/GAIN1.

For engineers reviewing the TDA7498L datasheet, TDA7498L pinout, TDA7498L application, or TDA7498L equivalent, key selection considerations include differential input noise immunity, thermal shutdown behavior at 150 °C, open-drain diagnostic output (pin 28), and external clock synchronization capability via SYNCLK for multi-amplifier systems.

Technical Context

The TDA7498L integrates two identical fully differential Class-D channels with internal PWM modulation, configurable switching frequency (250–400 kHz), and independent gain control per channel via GAIN0/GAIN1 logic inputs. Each channel uses separate power stage grounds (PGNDA/PGNDB), dedicated PVCC rails, and dual complementary PWM outputs (OUTPA/OUTNA, OUTPB/OUTNB).

It implements comprehensive protection: overcurrent (6 A threshold), overvoltage (42 V), undervoltage (8 V), and thermal shutdown (150 °C junction). Diagnostic status is reported via open-drain DIAG pin, while standby/mute modes are controlled by dedicated STBY and MUTE inputs with defined voltage thresholds (VSTBY_H ≥ 2.7 V, VMUTE_L ≤ 0.8 V).

Key Specifications

Pinout & Package

The TDA7498L is housed in a PowerSSO-36 exposed pad up (EPU) package with thermal pad connected to ground. The exposed pad (EP) provides low thermal resistance (R_{th j-case} = 2 °C/W typ.) and must be soldered to a heatsink or large copper area for reliable 80 W/channel operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel Class-D audio amplifier applications.

Compared with TAS5630B and MAX98357A, the TDA7498L uniquely balances high analog-input power (80 W/channel), single-supply simplicity (14–36 V), thermal robustness (exposed pad + OTP), and system-level coordination (SYNCLK + DIAG), making it optimal for mid-to-high-end powered audio products.

Availability

TDA7498L is available at Aetrix Electronics and suitable for home theater receivers, powered studio monitors, smart soundbars, and multi-zone audio distribution systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for TDA7498L 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, specializing in analog, power, microcontrollers, and automotive ICs with strong emphasis on energy efficiency and industrial reliability.

The TDA7498L belongs to ST's high-power audio amplifier product line, engineered specifically for compact, thermally constrained consumer and pro-audio applications demanding high output, low distortion, and robust protection.

FAQ

What is the minimum recommended LC filter cutoff frequency for TDA7498L?

The LC filter cutoff frequency must exceed 22 kHz to preserve audio bandwidth while remaining significantly below the 250–400 kHz switching frequency to suppress EMI. For 6 Ω loads, ST recommends 22 µH inductors with 680 nF capacitors (cutoff ≈ 27 kHz); for 8 Ω, same inductor with 680 nF yields equivalent performance. Component parasitics must be minimized through tight layout.

How does the TDA7498L handle thermal overload during continuous high-power operation?

At 145 °C junction temperature, the device enters mute mode (50% PWM duty cycle) to reduce power dissipation while maintaining bias; if temperature reaches 150 °C, it shuts down completely and forces outputs to high-impedance. Recovery is automatic once junction cools below 140 °C. The exposed pad and R_{th j-case} = 2 °C/W enable rapid heat transfer to external heatsinks.

Can TDA7498L operate with a single-ended input instead of differential?

Yes - the differential inputs (INPA/INNA, INPB/INNB) accept single-ended signals by grounding the negative input (e.g., INNA or INNB) and applying the signal to the positive input. Input impedance remains ~60 kΩ, and common-mode rejection is forfeited, but THD and SNR remain within spec for most consumer applications. AC coupling capacitors (≥470 nF) are mandatory.

What happens to the DIAG pin during undervoltage protection activation?

During undervoltage protection (VCC < 8 V), the DIAG pin transitions from low (active pull-down) to high-impedance (open-drain off), signaling fault condition to an external microcontroller or LED driver. This behavior is identical for overvoltage, overcurrent, and thermal shutdown events. A 10 kΩ pull-up to 3.3 V is recommended for clean logic-level detection.