Texas Instruments PCM3794ARHBT

Overview

PCM3794ARHBT from Texas Instruments is a 16-bit stereo audio CODEC with integrated headphone amplifier, analog mixing, microphone bias, and digital tone control - supporting I²C/SPI control, 5–50 kHz sampling, 93 dB DAC dynamic range, and 90 dB ADC dynamic range. It delivers 40 mW + 40 mW headphone output into 16 Ω and operates from 1.71–3.6 V digital supplies and 2.4–3.6 V analog/power amplifier supplies for portable audio playback and recording.

For engineers reviewing the PCM3794ARHBT datasheet, PCM3794ARHBT pinout, PCM3794ARHBT application, or PCM3794ARHBT equivalent, key selection considerations include its QFN-32 package, absence of speaker amplifier outputs (vs. PCM3793A), capless headphone drive capability, programmable high-pass and notch filters, and support for automatic level control (ALC) in recording paths.

Technical Context

The PCM3794ARHBT implements delta-sigma ADC/DAC architecture with decimation/interpolation filtering, configurable high-pass filter (4/120/240 Hz), and two-stage programmable notch filters for noise suppression. It supports right-justified, left-justified, I²S, and DSP audio data formats at sampling rates from 5 to 50 kHz using a single system clock input without PLL.

Its analog front end includes stereo single-ended and mono differential inputs with 0/20 dB boost, programmable gain amplifiers (30 dB to –12 dB), and microphone bias (0.75×VCC, 2 mA). The back end provides stereo headphone/line outputs with 6 dB to –70 dB analog volume control, 3-band tone control (±12 dB), and 3-D sound enhancement - all register-configurable via 2- or 3-wire serial interface.

Key Specifications

Pinout & Package

PCM3794ARHBT is housed in a 5-mm × 5-mm, 32-pin QFN package with exposed thermal pad (RHB suffix). Pin functions are fully defined per TI SLAS529A datasheet, with dedicated analog/digital/ground domains and no speaker output pins - distinguishing it from PCM3793A.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar stereo audio CODEC applications.

Compared with PCM3793ARHBT, PCM3794ARHBT removes speaker outputs to reduce die size, power, and thermal dissipation - making it optimal for headphone-centric devices. Against TLV320AIC3106IRHBT, it trades resolution and integration for proven feature depth (notch filters, 3-D sound) and register-level compatibility within the PCM379x family.

Availability

PCM3794ARHBT is available at Aetrix Electronics and suitable for portable audio players, smartphone voice recording subsystems, and digital camera audio interfaces requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for PCM3794ARHBT 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies - with decades of expertise in precision audio signal chains and low-power mixed-signal ICs.

The PCM379x series was designed specifically for battery-powered portable audio applications demanding high-fidelity CODEC functionality, integrated analog peripherals, and minimal external component count - targeting PMPs, smartphones, and digital cameras.

FAQ

What is the key functional difference between PCM3794ARHBT and PCM3793ARHBT?

The PCM3794ARHBT omits the integrated Class-D stereo speaker amplifier found in PCM3793ARHBT - removing SPOLP, SPOLN, SPORP, and SPORN pins. This reduces power consumption (13 mW record vs. higher in PCM3793A), thermal load, and package complexity while retaining identical headphone/line output, ADC, and digital audio processing capabilities. PCM3794ARHBT is optimized for headphone-only or line-output applications.

Does PCM3794ARHBT support capless headphone output operation?

Yes, PCM3794ARHBT supports capless headphone drive on HPOL/HPOR outputs when configured in stereo single-ended mode (register 74, HPS[1:0] = 0b00). This eliminates the need for external DC-blocking capacitors, reducing BOM cost and PCB area. The HPCOM/MONO pin serves as the common-mode reference, biased to 0.5×VCC via internal circuitry.

How does the automatic level control (ALC) function in PCM3794ARHBT?

The PCM3794ARHBT implements digital ALC in the ADC path to maintain optimal signal level during microphone recording. It dynamically adjusts gain based on input amplitude - expanding low-level signals and compressing peaks - using programmable attack/recovery times and threshold levels set via register 83. ALC operates independently of analog PGA settings and requires no host processor intervention.

What are the supported audio interface formats and clocking requirements for PCM3794ARHBT?

PCM3794ARHBT supports I²S, left-justified, right-justified, and DSP serial audio formats with master or slave operation. It accepts a single system clock (SCKI) from 3.072 MHz to 18.432 MHz - no PLL required - and derives LRCK (8–48 kHz) and BCK internally. Supported oversampling ratios include 256 fS and 384 fS, enabling flexible integration with audio DSPs and codecs.

Can PCM3794ARHBT be used with electret microphones, and how is bias provided?

Yes, PCM3794ARHBT integrates a dedicated microphone bias source on the MICB pin, delivering 0.75×VCC (typical) at up to 2 mA - sufficient for standard electret condenser microphones. Bias voltage and current are stable across temperature and supply variation, and the MICB output remains active during low-power modes unless explicitly disabled via register control.