Texas Instruments DF1704E/2K

Overview

DF1704E/2K from Texas Instruments is a stereo, 24-bit, 96kHz 8× oversampling digital interpolation filter IC designed for high-end audio signal conditioning between digital sources and DACs. It delivers ±0.00005dB passband ripple, –115dB stopband attenuation, and supports programmable sharp/slow roll-off filtering, digital de-emphasis, and independent L/R attenuation - enabling precision timing and spectral shaping in premium CD players, DAC preamps, and studio converters.

For engineers reviewing the DF1704E/2K datasheet, DF1704E/2K pinout, DF1704E/2K application, or DF1704E/2K equivalent, key selection criteria include its SSOP-28 package compatibility with PCM1704-based audio chains, 256f_S–768f_S system clock flexibility, hardware/software mode configurability, and verified 44.1/48/32kHz de-emphasis support.

Technical Context

The DF1704E/2K implements a fixed-coefficient FIR interpolation filter architecture with dual selectable response profiles (sharp roll-off: –3dB at 0.493f_S, stopband ≥0.546f_S; slow roll-off: –3dB at 0.460f_S, stopband ≥0.732f_S). Its internal clock detection circuit auto-identifies 256f_S/384f_S/512f_S/768f_S multipliers from XTI and synchronizes to LRCIN within ±6 BCKIN periods.

It features dual-mode control: hardware mode uses dedicated pins (I2S, IW0/IW1, OW0/OW1, SRO, DEM, SF0/SF1) with Schmitt-trigger inputs; software mode employs a 3-wire serial port (ML/MC/MD) to program four 16-bit registers (MODE0–MODE3) for attenuation, mute, de-emphasis, and format configuration - all operating under +5V single-supply conditions.

Key Specifications

Pinout & Package

DF1704E/2K is housed in a 28-pin SSOP (Shrink Small Outline Package) with 0.65mm lead pitch, optimized for compact high-fidelity audio PCB layouts requiring mixed-signal isolation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar digital interpolation filter applications.

Compared with CS8416-CZZ and AD1896YRSZ, DF1704E/2K uniquely combines hardware-programmable filter response, on-chip crystal oscillator, and 44.1/48/32kHz de-emphasis in a 5V SSOP-28 package - making it optimal for cost-constrained, high-fidelity 96kHz audio systems requiring minimal external components.

Availability

DF1704E/2K is available at Aetrix Electronics and suitable for high-end audio DAC modules, CD transport upgrades, studio monitor digital crossovers, and network audio streamer output stages requiring stable component supply and long-term production continuity.

Supply support for DF1704E/2K 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 and embedded processing technologies, with decades of leadership in high-performance audio signal chain solutions.

The DF1704E/2K belongs to TI's premium audio digital filter product line, engineered specifically to complement their PCM1704 DAC family and deliver studio-grade interpolation performance in consumer and professional audio equipment.

FAQ

What is the primary function of the DF1704E/2K in an audio system?

The DF1704E/2K functions as a stereo, 24-bit, 96kHz 8× oversampling digital interpolation filter that conditions digital audio streams prior to DAC conversion. It performs sample rate upconversion, applies selectable FIR filtering (sharp or slow roll-off), enables digital de-emphasis, and formats output data for optimal DAC interface timing - ensuring minimal jitter, low distortion, and accurate spectral reproduction in DF1704E/2K-based audio systems.

Does the DF1704E/2K support both hardware and software configuration modes?

Yes, the DF1704E/2K supports dual configuration modes. When MODE pin (pin 10) is low, hardware mode enables pin-strapped control of input/output format, word length, de-emphasis, and filter response. When MODE is high, software mode uses the 3-wire ML/MC/MD interface to program four internal registers (MODE0–MODE3) for attenuation, mute, de-emphasis, and format settings - giving designers flexibility in DF1704E/2K integration.

What sampling rates does the DF1704E/2K support for digital de-emphasis?

The DF1704E/2K supports digital de-emphasis at 32kHz, 44.1kHz, and 48kHz sampling rates only - selected via SF0/SF1 pins in hardware mode or SF[1:0] bits in MODE3 register in software mode. De-emphasis is not supported at 96kHz, and the device disables the function automatically when SF0/SF1 = 01 (reserved) or when DEM pin is low. This limitation is explicitly defined in the DF1704E/2K datasheet.

Can the DF1704E/2K operate without an external crystal or clock source?

Yes, the DF1704E/2K can operate using its on-chip crystal oscillator by connecting a parallel-resonant crystal between XTI (pin 6) and XTO (pin 7). The oscillator supports crystals up to 24.576MHz, covering all required system clock frequencies for 32–96kHz sampling rates except 768f_S at 96kHz. For that case, an external clock must be applied to XTI - confirming DF1704E/2K's self-contained timing capability in most configurations.

What is the significance of the 0.00005dB passband ripple specification for the DF1704E/2K?

The ±0.00005dB passband ripple specification means the DF1704E/2K introduces less than 0.0001dB amplitude variation across its audio band (up to 0.454f_S), translating to <0.001% gain deviation. This level of flatness preserves absolute signal integrity in mastering and monitoring applications, preventing subtle tonal coloration or phase-induced imaging shifts - a key differentiator of DF1704E/2K versus general-purpose interpolation filters.