Analog Devices Inc. AD1980JST

Overview

AD1980JST from Analog Devices is an AC '97 2.3–compliant audio codec IC for PC motherboard and multimedia sound card applications, featuring six 20-bit DAC channels (5.1 surround), 16-bit ADCs, integrated stereo headphone amplifier, S/PDIF output, and variable sample rate support from 7 kHz to 96 kHz. It delivers >90 dB dynamic range and operates with 5.0 V analog and 3.3 V digital supplies in a 48-lead LQFP package.

For engineers reviewing the AD1980JST datasheet, AD1980JST pinout, AD1980JST application, or AD1980JST equivalent, key selection considerations include AC '97 interface timing compliance, jack-sense–enabled auto topology switching, software-controlled VREF_OUT for microphone bias, integrated parametric equalizer, and power-down state granularity across ADC, DAC, and mixer blocks.

Technical Context

The AD1980JST implements a dual-path AC '97 2.3 interface with dedicated SDATA_IN/SDATA_OUT streams, BIT_CLK (12.288 MHz), SYNC, and RESET signals. Its internal PLL supports crystal (24.576 MHz), reference clock (14.31818 MHz), or USB clock (48 MHz) inputs for system clocking.

It integrates separate analog signal chains: a 16-bit stereo ADC path with programmable gain amplifier (0–22.5 dB), and six 20-bit DAC paths (Front L/R, Center, LFE, Surround L/R) with independent volume control, mute, and EQ bypass. Analog mixing, jack sense (JS0/JS1), EAPD control, and SPDIF TX are fully register-configurable via AC '97 control registers.

Key Specifications

Pinout & Package

AD1980JST is housed in a 48-lead Low Profile Quad Flatpack (LQFP), designated ST-48 per Analog Devices' ordering guide. Thermal resistance is JA = 50.1°C/W and JC = 17.8°C/W under JEDEC 2S2P test conditions.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD1980JST, AD1981BASTZ offers superior ADC performance and power efficiency but sacrifices SPDIF and dual-MIC capability; ALC655-VD provides functional AC '97 compatibility at lower cost but omits parametric EQ, programmable VREFOUT, and 20-bit DAC resolution-making it unsuitable for high-fidelity or feature-rich embedded audio.

Availability

AD1980JST is available at Aetrix Electronics and suitable for desktop motherboard design, industrial HMI audio interfaces, legacy media players, and PC-based VoIP terminals requiring stable component supply, long-lifecycle support, and AC '97 2.3 compliance.

Supply support for AD1980JST 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

Analog Devices, Inc. is a global semiconductor company specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision instrumentation, communications, and industrial systems.

The AD1980JST belongs to Analog Devices' AC '97 audio codec product line, engineered specifically for PC platform audio subsystems requiring robust noise immunity, flexible input/output routing, and hardware-accelerated features such as jack sensing and power-state control.

FAQ

What is the maximum supported sample rate for the AD1980JST DAC and ADC paths?

The AD1980JST supports variable-rate audio up to 96 kHz for DAC playback (double-rate mode) and up to 48 kHz for ADC recording under standard AC '97 timing. The DAC rate registers (2Ch–30h) allow independent configuration per channel, while ADC rate (32h) sets the common sampling frequency for both stereo input channels. All rates are synchronized to the internal PLL, which accepts 24.576 MHz, 14.31818 MHz, or 48 MHz reference clocks.

Does the AD1980JST support true 5.1-channel analog output simultaneously?

Yes, the AD1980JST provides six dedicated analog output channels-LINE_OUT_L/R (front), CENTER_OUT, LFE_OUT, and SURR_OUT_L/R-each driven by its own 20-bit DAC. These outputs can be active concurrently with independent volume, mute, and EQ settings. The pinout confirms physical separation: Pins 35/36 (Front), 31 (Center), 32 (LFE), and 39/41 (Surround), enabling full 5.1 analog signal distribution without time-division multiplexing.

How does jack sense (JS0/JS1) function in the AD1980JST, and what configurations does it enable?

JS0 and JS1 are dedicated analog input pins that detect insertion/removal of 3.5 mm audio jacks. Their states are read via register 72h and trigger hardware-assisted topology switching: when headphones are detected, SURR_OUT_L/R automatically remaps to HP_OUT_L/R; when removed, they revert to surround output. This eliminates host software polling and enables seamless front-panel audio sharing-critical for desktop PCs with combined headphone/speaker jacks.

What are the power-down capabilities of the AD1980JST, and how are they controlled?

The AD1980JST offers 11 discrete power-down states controlled through Register 26h (Power-Down Ctrl/Stat). Each state disables specific blocks-e.g., "ADC + ALL DACs" (PR=111, PD=000 0011) reduces total current to 12 mA (AVDD) / 8 mA (DVDD), while "Standby" (PR=111, PD=011 1111) draws zero current. States are selected by writing PR[6:0] and PD[6:0] bits, enabling precise power gating for thermal and battery-life optimization in portable or fanless systems.

Can the AD1980JST generate its own AC '97 BIT_CLK, or must it be supplied externally?

The AD1980JST generates BIT_CLK internally using its integrated PLL and crystal oscillator (XTL_IN/XTL_OUT pins). In primary (master) mode, it drives BIT_CLK (Pin 6) at 12.288 MHz with ±1.0 ppm accuracy and ≤750 ps jitter. External BIT_CLK input is supported only in secondary mode (via BIT_CLK as input), but this is rarely used-designs typically configure AD1980JST as the AC '97 link master, simplifying clock tree architecture and eliminating need for external clock generator.