Texas Instruments PCM3794RHBT

Overview

PCM3794RHBT from Texas Instruments is a 16-bit stereo audio CODEC with integrated headphone amplifier, analog mixing, microphone bias, and digital tone control - delivering 40 mW + 40 mW into 16 Ω headphones and 93 dB DAC dynamic range. It operates from 1.71–3.6 V digital supplies and 2.4–3.6 V analog/power amplifier rails, supporting 5–50 kHz sampling and I²S/Left-Justified/DSP audio formats for portable audio systems.

For engineers reviewing the PCM3794RHBT datasheet, PCM3794RHBT pinout, PCM3794RHBT application, or PCM3794RHBT equivalent, this device serves as a low-power, single-chip audio interface for battery-powered consumer electronics requiring programmable gain, ALC, pop-noise reduction, and headphone plug detection - with register-controlled 3-band tone, high-pass filtering, and capless headphone output mode.

Technical Context

The PCM3794RHBT integrates delta-sigma ADC and DAC with decimation/interpolation filters, configurable high-pass (4 Hz or 240 Hz) and dual programmable notch filters, and digital 3-D sound enhancement. Its analog front end supports stereo single-ended or mono differential inputs with 0/20 dB boost and 30 dB to –12 dB PGA gain per channel.

Unlike the PCM3793, the PCM3794RHBT omits Class-D speaker amplifier outputs (SPOLP/SPOLN/SPORP/SPORN), retaining full headphone/line output, microphone bias, ALC, and digital signal processing - all controlled via 2-wire I²C or 3-wire SPI interface with zero-cross volume update and soft mute.

Key Specifications

Pinout & Package

PCM3794RHBT uses a 32-pin, 5-mm × 5-mm QFN package (RHB) with exposed thermal pad. Pin functions are defined per TI SLES193C datasheet, with dedicated analog/digital/ground domains and no speaker amplifier pins - distinguishing it from PCM3793.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV320AIC3106IRHBT, PCM3794RHBT delivers higher DAC dynamic range (93 dB vs. 92 dB) and capless headphone capability, while PCM3793RHBT adds speaker amplification at the cost of higher thermal dissipation and larger PCB footprint - making PCM3794RHBT optimal for compact, headphone-centric portable audio.

Availability

PCM3794RHBT is available at Aetrix Electronics and suitable for portable media players, digital still cameras, and cellular handsets requiring stable component supply, long-term lifecycle support, and guaranteed traceability for production ramp.

Supply support for PCM3794RHBT 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 high-performance audio signal chains.

The PCM3794RHBT belongs to TI's portable audio CODEC product line, designed specifically for space-constrained, battery-powered consumer electronics requiring integrated analog front-end, digital audio processing, and intelligent power management.

FAQ

What is the primary function of the PCM3794RHBT in an audio system?

The PCM3794RHBT serves as a complete stereo audio CODEC, performing analog-to-digital conversion for microphone inputs and digital-to-analog conversion for headphone/line outputs - while integrating programmable gain amplifiers, ALC, tone control, high-pass filtering, and headphone plug detection. Its role in the PCM3794RHBT-based system is to replace discrete ADC/DAC, amplifier, and signal-conditioning components with a single, register-configurable IC.

Does the PCM3794RHBT support capless headphone output, and how is it configured?

Yes, the PCM3794RHBT supports capless headphone output on HPOL/HPOR/HPCOM pins. Configuration requires setting register 74 (HPS[2:0] = 0b100 or 0b101) and ensuring VCOM is properly decoupled with a 10-µF capacitor. This mode eliminates external DC-blocking capacitors, reducing BOM cost and PCB area - a key feature distinguishing PCM3794RHBT from legacy audio codecs.

How does the PCM3794RHBT differ from the PCM3793RHBT?

The PCM3794RHBT is functionally identical to the PCM3793RHBT except it omits the Class-D speaker amplifier outputs (SPOLP/SPOLN/SPORP/SPORN). All other features - including 16-bit ADC/DAC, headphone/line outputs, microphone bias, ALC, tone control, and pin compatibility - are retained. The PCM3794RHBT is intended for headphone-centric applications where speaker drive is unnecessary, reducing thermal load and simplifying layout.

What sampling rates and audio data formats does the PCM3794RHBT support?

The PCM3794RHBT supports sampling frequencies from 5 kHz to 50 kHz and accepts I²S, left-justified, right-justified, and DSP audio data formats - all with MSB-first, two's complement 16-bit data. System clock options include 256×fS or 384×fS multiples (e.g., 12/24 MHz, 19.2/38.4 MHz), enabling flexible interface to audio DSPs, baseband processors, or microcontrollers without requiring PLL circuitry.

Can the PCM3794RHBT perform analog mixing of multiple input sources?

Yes, the PCM3794RHBT includes analog mixing amplifiers (MXL/MXR) that combine gain-controlled signals from AIN1/AIN2/AIN3 inputs - bypassing the ADC/DAC path entirely. This allows simultaneous routing of FM radio, line-in, or auxiliary analog sources directly to headphone or line outputs, controlled via registers 87–89. Analog mixing in PCM3794RHBT enables low-latency, power-efficient multi-source audio without host CPU involvement.