TFA9894 SDS High Efficiency Class-D Audio Amplifier Rev. 3.1 13 May 2019 Product data sheet 1 General description The TFA9894 is a high efficiency 10 V boosted class-D audio amplifier with a sophisticated SpeakerBoost and Protection algorithm. It can deliver up to 5.6 W (AVG) output power into an 8 speaker and up to 6.2 W (AVG) output power into 4 speaker, at a battery supply voltage of 4.0 V. The internal adaptive DC-to-DC converter raises the power supply voltage up to 10 V, providing ample headroom for major improvements in sound quality. A safe working environment is provided for the speaker under all operating conditions. The TFA9894 maximizes acoustic output while ensuring membrane displacement and voice coil temperature do not exceed their rated limits. This function is based on a speaker box model that operates in all speaker environments (e.g. free air, closed box or vented box). Furthermore, advanced signal processing ensures that the quality of the audio signal is never degraded by unwanted clipping or distortion in the amplifier or speaker. The adaptive sound maximizer algorithm uses feedback to calculate both the temperature and the excursion accurately, allowing the TFA9894 to adapt to changes in the acoustic environment. Internal adaptive DC-to-DC conversion boosts the supply rail to provide additional headroom and power output. The supply voltage is only raised when necessary. This maximizes the output power of the class-D audio amplifier while limiting quiescent power consumption. The device can be configured to drive either a hands-free speaker for audio playback, or a receiver speaker, for handset playback, allowing it to be embedded in platforms supporting both a hands-free speaker and a handset speaker. The maximum output power, the gain, and the noise levels are lower in handset call use case than in hands- free call use case. The TFA9894 also incorporates battery protection. By limiting the supply current when the battery voltage is low, it prevents the audio system from drawing excessive load currents from the battery, which could cause a system undervoltage. This circuitry minimizes the impact of a falling battery voltage by preventing unexpected device switch off due to excessive current drawn from the battery. The device features a second order closed loop architecture, used in a class-D audio amplifier, providing excellent audio performance and high supply voltage ripple rejection. The audio input interface is TDM and the control settings are communicated via an I2C- bus interface. The TFA9894 is available in a 48-bump Wafer Level Chip-Size Package (WLCSP) with a 400 m pitch.NXP Semiconductors TFA9894 SDS High Efficiency Class-D Audio Amplifier 2 Features and benefits Sophisticated SpeakerBoost and Protection algorithm that maximizes speaker performance while protecting the speaker: Fully embedded software, no additional license fee, or porting required Fully integrated solution, including DSP, amplifier, DC-to-DC, thermal sensing Adaptive excursion control - guarantees that the speaker membrane excursion never exceeds its rated limit Real-time temperature protection - direct measurement ensures that voice coil temperature never exceeds its rated limit Environmentally aware - automatically adapts speaker parameters to acoustic and thermal changes including compensation for speaker-box leakage Clip avoidance - DSP algorithm prevents clipping even with sagging supply voltage Automatic bandwidth extension to increase low-frequency response TFA9894 high output power: 5.6 W (AVG) into 8 at 4.0 V supply voltage (THD = 1 %, VBST = 10 V), 6.2 W (AVG) into 4 at 4.0 V supply voltage (THD = 1 %, VBST = 9 V) Supports handset and hands-free (4 to 32 ) speaker configurations High efficiency, low power dissipation, and low noise speaker driver (Dynamic Range > 110 dB). Adaptive DC-to-DC converter increases the supply voltage smoothly when switching between fixed boost and adaptive boost mode, preventing large battery supply spikes and limiting quiescent power consumption. Wide supply voltage range (fully operational from 2.7 V to 5.5 V) Very low noise output (typical 14 V with null DATA input at Fs = 48 kHz) 2 I C-bus control interface (400 kHz) Speaker current and voltage monitoring (via the TDM-bus), as well as DSP data output (with and without pilot tone) for Acoustic Echo Cancellation (AEC) at the Host. Various sample frequencies supported: TFA9894/N1: 44.1 kHz, 48 kHz, and 96 kHz TFA9894/N2: 16 kHz, 32 kHz, 44.1 kHz, 48 kHz, and 96 kHz Configurable full duplex 4-wires TDM input interface. Programmable interrupt control via a dedicated interrupt pin Thermal foldback and over temperature protection 15 kV system-level ESD protection without external components on amplifier output TFA9894 SDS All information provided in this document is subject to legal disclaimers. NXP B.V. 2019. All rights reserved. Product data sheet Rev. 3.1 13 May 2019 2 / 42