Texas Instruments PCM3794RHBTG4

Overview

PCM3794RHBTG4 from Texas Instruments is a 16-bit stereo audio CODEC with integrated headphone amplifier, microphone bias, analog mixing, and digital tone control - designed for portable audio systems. It supports I²S/Left-Justified/Right-Justified/DSP audio formats, operates from 1.71–3.6 V digital supplies and 2.4–3.6 V analog/power amplifier rails, delivers 40 mW + 40 mW into 16 Ω headphones, and features 93 dB DAC dynamic range. Used in cellular phones and digital still cameras.

For engineers reviewing the PCM3794RHBTG4 datasheet, PCM3794RHBTG4 pinout, PCM3794RHBTG4 application, or PCM3794RHBTG4 equivalent, key selection criteria include its 32-pin QFN package, absence of integrated Class-D speaker amplifier (vs. PCM3793), programmable gain amplifiers (–12 dB to +30 dB), ALC for recording, and dual-wire (I²C) or three-wire (SPI) serial control interface.

Technical Context

The PCM3794RHBTG4 implements delta-sigma ADC and DAC architectures with decimation and interpolation filters, supporting sampling rates from 5 kHz to 50 kHz. Its analog front end includes six single-ended or mono differential inputs with selectable 0/20 dB microphone boost and independent channel gain control (1-dB steps).

Unlike the PCM3793, the PCM3794 omits SPOLP/SPOLN/SPORP/SPORN speaker output terminals and associated Class-D amplifier circuitry - confirmed by pin assignment diagrams and functional block diagram. All power supply domains (VDD, VIO, VCC, VPA) are independently configurable, and headphone plug detection (HDTI) enables automatic amplifier enable/disable on insertion.

Key Specifications

Pinout & Package

PCM3794RHBTG4 is housed in a 5-mm × 5-mm, 32-pin QFN package (RHB) with exposed thermal pad. Pin functions are defined per TI SLES193C datasheet Rev. February 2007, with NC (No Connect) assigned to pins 10, 11, 14, 15, and 23–25 on PCM3794RHB variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCM3793RHBT, PCM3794RHBTG4 removes speaker amplifier circuitry to lower quiescent current and thermal dissipation, while retaining full headphone/line functionality and plug detection. Versus TLV320AIC3106IRHBR, it offers hardware-assisted headphone management and capless drive at the cost of higher active power and no integrated LDOs.

Availability

PCM3794RHBTG4 is available at Aetrix Electronics and suitable for cellular phone audio subsystems, digital still camera recording, and portable media player playback requiring stable component supply and long-term industrial availability.

Supply support for PCM3794RHBTG4 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 company headquartered in Dallas, Texas, specializing in analog and embedded processing technologies with broad industrial, automotive, and consumer product portfolios.

The PCM3794RHBTG4 belongs to TI's portable audio CODEC product line, engineered specifically for space-constrained, battery-powered devices requiring high-fidelity stereo audio capture and playback with minimal external components.

FAQ

What distinguishes PCM3794RHBTG4 from PCM3793RHBT?

The PCM3794RHBTG4 excludes the integrated Class-D stereo speaker amplifier found in PCM3793RHBT - confirmed by missing SPOLP/SPOLN/SPORP/SPORN pins and absence of speaker-related registers in the PCM3794 functional description. This reduces power consumption and thermal load while retaining identical headphone, line, and microphone functionality. PCM3794RHBTG4 is recommended for designs needing only headphone/line output.

Does PCM3794RHBTG4 support capless headphone output?

Yes, PCM3794RHBTG4 supports capless headphone output via HPOL/LOL and HPOR/LOR pins when configured in capless mode using register 74 (HPS[2:0]). This eliminates the need for external DC-blocking capacitors, reducing BOM cost and PCB area. The internal common-mode voltage (VCOM = 0.5×VCC) and charge pump ensure safe biasing without external components.

What is the function of the HDTI pin on PCM3794RHBTG4?

The HDTI pin on PCM3794RHBTG4 detects mechanical insertion or removal of a 3-pole (TRRS) headphone plug. Its status is latched into register 77 (HPDS) and can trigger automatic enable/disable of headphone amplifiers when HPDE = 1. This hardware-level detection enables sub-50 ms response - critical for seamless audio routing in mobile devices using PCM3794RHBTG4.

Can PCM3794RHBTG4 operate with a single 3.3-V supply?

No - PCM3794RHBTG4 requires four separate supply domains: VDD/VIO (1.71–3.6 V for digital logic), VCC (2.4–3.6 V for analog section), and VPA (2.4–3.6 V for headphone amplifier). While 3.3 V may be applied to all rails, they must be isolated to prevent noise coupling. Using a single shared rail degrades SNR and violates recommended operating conditions in the PCM3794RHBTG4 datasheet.

What audio data formats does PCM3794RHBTG4 support?

PCM3794RHBTG4 supports I²S, left-justified, right-justified, and DSP serial audio formats - explicitly stated in the device description and electrical characteristics table. It accepts 16-bit MSB-first, two's complement data at sampling rates from 5 kHz to 50 kHz, enabling interoperability with TI C5000/C6000 DSPs, ARM-based application processors, and low-pin-count microcontrollers.