My Inquiry
My Account
Analog Devices Inc. AD1981BJST-REEL
- Part No.:
- AD1981BJST-REEL
- Manufacturer:
- Analog Devices Inc.
- Category:
- CODECS
- Package:
- 48-LQFP
- Datasheet:
-
AD1981BJST-REEL.pdf
- Description:
- IC CODEC STEREO MICPREAMP 48LQFP
- Quantity:
- Payment:
- Shipping:
Inventory:1,172
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AD1981BJST-REEL from Analog Devices is an AC '97 2.3–compliant stereo audio codec IC with integrated 20-bit DAC, 16-bit ADC, stereo headphone amplifier, S/PDIF output, and jack sense support. It delivers >90 dB dynamic range, supports variable sample rates from 7.04 kHz to 48 kHz, and operates with split supplies (5 V analog / 3.3 V digital) in PC audio subsystems.
For engineers reviewing the AD1981BJST-REEL datasheet, AD1981BJST-REEL pinout, AD1981BJST-REEL application, or AD1981BJST-REEL equivalent, key selection considerations include AC '97 interface timing compliance, dual MIC preamplifier programmability, VREFOUT biasing capability for external amplifiers, and 48-lead LQFP package compatibility with legacy desktop/laptop motherboard layouts.
Technical Context
The AD1981BJST-REEL implements a full-duplex AC '97 2.3 interface with BIT_CLK (12.288 MHz), SYNC, SDATA_IN/OUT, and RESET signals. Its codec core integrates dual Σ-Δ ADCs (16-bit) and dual Σ-Δ DACs (20-bit), with independent programmable gain amplifiers (0–22.5 dB) on MIC inputs and analog mixing paths for LINE_IN, CD, AUX, PHONE_IN, and mono outputs.
It features hardware jack sense (JS0/JS1), EAPD-controlled external amplifier power-down, software-programmable VREFOUT (2.25 V, 5 mA), and built-in digital equalizer logic. Power management includes seven discrete power-down states controlled via PR[6:0] bits, enabling sub-2 mA operation in ADC+DAC+Mixer standby mode.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| DAC Resolution | 20-bit Σ-Δ - enables high-fidelity playback with ≥85 dB A-weighted dynamic range at 48 kHz |
| ADC Resolution | 16-bit Σ-Δ - supports recording with 80–85 dB SNR and −84 dB THD+N |
| Sample Rate Range | 7.04 kHz to 48 kHz in 1 Hz steps - allows flexible audio timing alignment across OS drivers and media formats |
| Dynamic Range | >90 dB (A-weighted) - meets CD-quality audio fidelity requirements for line-out and headphone outputs |
| Power Supply | 5 V analog (AVDD), 3.3 V digital (DVDD) - separates noise-sensitive analog circuitry from digital switching domains |
| S/PDIF Output | 20-bit format at 44.1/48 kHz - enables direct digital audio transmission to external receivers without analog conversion loss |
| Package | 48-lead LQFP (7 mm × 7 mm, 0.5 mm pitch) - standard footprint compatible with legacy AC '97 motherboard designs |
Pinout & Package
AD1981BJST-REEL is housed in a 48-lead LQFP package with exposed thermal pad (RoHS-compliant, Pb-free available). Pin functions are defined per Analog Devices Rev. C datasheet, including dedicated AC '97 interface pins, analog I/O channels, jack sense inputs, and voltage reference outputs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SDATA_IN / SDATA_OUT | AC '97 serial data I/O | Full-duplex bidirectional data stream for PCM audio transfer between host controller and codec |
| BIT_CLK / SYNC | AC '97 timing interface | 12.288 MHz bit clock and frame sync signal - defines slot timing and sample alignment per AC '97 spec |
| MIC1 / MIC2 | Stereo microphone inputs | Supports mono or stereo MIC configuration with programmable 0–22.5 dB PGA gain and ground-sense CD input path |
| HP_OUT_L / HP_OUT_R | Headphone driver outputs | Integrated Class-AB amplifier capable of driving 32 Ω loads at 1 VRMS full-scale |
| LINE_OUT_L / LINE_OUT_R | Analog line-level outputs | 800 Ω output impedance, 1 VRMS full-scale - designed for connection to powered speakers or audio inputs |
| VREFOUT | Programmable bias reference | 2.25 V output, 5 mA drive - used to bias electret microphones and external power amplifier inputs |
| JS0 / JS1 | Jack sense inputs | Digital inputs for automatic detection of headphone/speaker plug insertion and output routing reconfiguration |
| EAPD | External amp power-down | Open-drain output controlling enable/disable of external audio power amplifier to reduce system standby current |
Key Features
| Feature | Design Value |
|---|---|
| AC '97 2.3 compliance | Fully interoperable with Intel AC '97 host controllers - guarantees slot timing, register map, and reset behavior compatibility |
| Integrated stereo headphone amplifier | Drives 32 Ω loads directly - eliminates need for external op-amps or buffer stages in portable/desktop audio designs |
| Variable sample rate engine | Hardware-supported 7.04–48 kHz range in 1 Hz increments - enables precise synchronization with video frame rates or streaming protocols |
| Digital equalizer core | Configurable EQ coefficients stored in on-chip RAM - allows real-time tuning of speaker response without host CPU overhead |
| Split power supply architecture | Independent 5 V analog and 3.3 V digital rails - minimizes digital switching noise coupling into sensitive audio paths |
| Jack sense + EAPD coordination | JS0/JS1 inputs trigger automatic output switching and EAPD assertion - enables seamless transition between speakers and headphones |
Applications
| Desktop PC Audio Subsystem | Laptop Integrated Sound Card |
|---|---|
Use Scenario: Main audio processing unit on ATX/mATX motherboards handling front-panel headphone jacks, line-in, mic-in, and rear speaker outputs. IC Role / Device Role / Timing Role: AC '97 codec interfacing directly with southbridge via AC-link; provides synchronized DAC/ADC conversion and analog signal conditioning. Use Value: Eliminates need for discrete op-amps and level shifters while maintaining >90 dB SNR and full Windows audio driver compatibility. |
Use Scenario: Embedded audio solution in space-constrained laptop platforms requiring low-power operation and automatic headset detection. IC Role / Device Role / Timing Role: Primary audio codec managing headphone/line-out switching, MIC biasing, and EAPD-controlled amplifier enable/disable. Use Value: Reduces BOM count by integrating VREFOUT bias generator, jack sense logic, and stereo headphone drivers in one 7×7 mm LQFP package. |
| Legacy Industrial Control Panel Audio | Embedded Media Player Baseboard |
Use Scenario: Audio feedback and voice prompt generation in human-machine interface (HMI) panels using legacy x86-based control systems. IC Role / Device Role / Timing Role: AC '97-compliant audio endpoint providing line-level outputs and mono speakerphone path for telephony integration. Use Value: Enables drop-in replacement of obsolete AC '97 codecs without modifying AC-link timing or BIOS-level audio initialization sequences. |
Use Scenario: Audio subsystem in ARM/x86-based media players supporting CD-quality playback, microphone recording, and S/PDIF digital output. IC Role / Device Role / Timing Role: Full-duplex audio transceiver converting PCM streams to analog outputs and S/PDIF digital output simultaneously. Use Value: Delivers 20-bit DAC resolution and S/PDIF output in single chip - avoids external SPDIF transmitter IC and reduces PCB layer count. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar AC '97 audio codec applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AD1980BSTZ-REEL | 16-bit DAC/ADC only; no S/PDIF output; lacks VREFOUT programmability and digital EQ core | Suitable for cost-sensitive designs where CD-quality playback is not required and external SPDIF is acceptable | Select when lower BOM cost and reduced feature set are prioritized over 20-bit fidelity and integrated digital audio output |
| WM9712CGEQ | Wolfson part with AC '97 2.2 compliance; 18-bit DAC/ADC; different register map and jack sense implementation | Used in mobile/embedded platforms with tighter power budgets; requires modified driver initialization sequence | Choose only if existing firmware already supports WM97xx register layout and timing tolerances differ from AD1981B's AC '97 2.3 spec |
Compared with AD1981BJST-REEL, AD1980BSTZ-REEL offers lower resolution and fewer features at reduced cost, while WM9712CGEQ provides alternate AC '97 implementation with distinct power management and driver dependencies - neither is pin- or register-compatible, requiring PCB and firmware changes.
Availability
AD1981BJST-REEL is available at Aetrix Electronics and suitable for desktop PC motherboards, laptop audio subsystems, industrial HMIs, and embedded media players requiring stable component supply and long-term AC '97 interface continuity.
Supply support for AD1981BJST-REEL 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 is a global semiconductor leader specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision instrumentation, industrial, and communications applications.
The AD1981B belongs to Analog Devices' AC '97 audio codec product line, engineered specifically for PC and embedded systems requiring fully compliant, low-noise, multi-input/output audio processing with minimal external components.
FAQ
What is the primary interface standard supported by the AD1981BJST-REEL?
The AD1981BJST-REEL implements the AC '97 2.3 specification, including mandatory BIT_CLK (12.288 MHz), SYNC, SDATA_IN, and SDATA_OUT signaling, full register compatibility with Intel AC '97 host controllers, and support for all required AC '97 slots (0–11). This ensures interoperability with legacy PC southbridges and audio drivers without modification.
Does the AD1981BJST-REEL support both stereo and mono microphone inputs?
Yes, the AD1981BJST-REEL supports dual MIC inputs (MIC1 and MIC2) configurable for either mono operation with programmable preamplifier gain (0–22.5 dB) or stereo recording. The functional block diagram and register map confirm independent left/right MIC paths feeding the mixer ADC, with dedicated gain control bits in the Record Gain register (0x1C).
What are the power supply requirements for the AD1981BJST-REEL?
The AD1981BJST-REEL requires two separate supplies: 5.0 V ±10% (AVDD) for analog circuitry and 3.3 V ±10% (DVDD) for digital logic. Absolute maximum ratings specify AVDD up to 6.0 V and DVDD up to 3.6 V. Typical operating currents are 51 mA (AVDD) and 42 mA (DVDD) in fully active mode, dropping to <2 mA in ADC+DAC+Mixer standby.
Can the AD1981BJST-REEL drive headphones directly without external amplification?
Yes, the AD1981BJST-REEL integrates a stereo headphone amplifier capable of delivering 1 VRMS into 32 Ω loads (typical), as confirmed by the "ANALOG OUTPUT" section of the datasheet. The HP_OUT_L and HP_OUT_R pins provide Class-AB buffered outputs with 1.5 dB volume step resolution and mute control via the Headphone Volume register (0x04).
Is the AD1981BJST-REEL RoHS-compliant and available in Pb-free packaging?
Yes, the AD1981BJST-REEL is offered in Pb-free packaging, as explicitly stated in the "AC '97 2.3 COMPATIBLE FEATURES" section of the datasheet: "48-lead LQFP package, Pb-free available." The ordering guide and package outline dimensions confirm RoHS-compliant materials and finish for the JST (LQFP) variant.
AD1981BJST-REEL Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- SoundMAX®
- Package/Case:
- 48-LQFP
- Packaging:
- Cut Tape (CT)
- Product Status:
- Obsolete
- Type:
- Audio Codec '97
- Data Interface:
- Serial
- Resolution (Bits):
- 16, 20 b
- Number of ADCs / DACs:
- 4 / 2
- Sigma Delta:
- No
- S/N Ratio, ADCs / DACs (db) Typ:
- -
- Dynamic Range, ADCs / DACs (db) Typ:
- 85 / 90
- Voltage - Supply, Analog:
- 4.5V ~ 5.5V
- Voltage - Supply, Digital:
- 3V ~ 3.47V
- Operating Temperature:
- 0°C ~ 70°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 48-LQFP (7x7)
AD1981BJST-REEL FAQ
1.How can I place an order for AD1981BJST-REEL through Aetrix?
Please submit a Request for Quotation (RFQ) for AD1981BJST-REEL on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for AD1981BJST-REEL reliable?
The price and inventory of AD1981BJST-REEL are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AD1981BJST-REEL is usually 5 days.
3.What payment methods are accepted for AD1981BJST-REEL?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AD1981BJST-REEL transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AD1981BJST-REEL?
AD1981BJST-REEL orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AD1981BJST-REEL order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for AD1981BJST-REEL?
For technical support, including AD1981BJST-REEL datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AD1981BJST-REEL requirements.
6.How does Aetrix verify that AD1981BJST-REEL is sourced from the original manufacturer or authorized distributors?
All AD1981BJST-REEL products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that AD1981BJST-REEL meets industry standards.
7.What is the process for return or replacement of AD1981BJST-REEL?
All AD1981BJST-REEL units undergo pre-shipment inspection (PSI). If there is an issue with AD1981BJST-REEL, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The AD1981BJST-REEL part is unused and in its original packaging.
Return procedure for AD1981BJST-REEL:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AD1981BJST-REEL Tags
-
NAU88C22YG
Nuvoton Technology Corporation
-
TLV320AIC3100IRHBR
Texas Instruments
-
DA7212-01UM2
Renesas
-
NAU8810YG
Nuvoton Technology Corporation
-
DA7218-00U32
Renesas
-
CMX655DQ6-TR1K
CML Micro
-
SGTL5000XNLA3
NXP Semiconductors
-
TLV320AIC3104IRHBR
Texas Instruments
-
MAX9867EWV+T
Analog Devices Inc./Maxim Integrated
-
MAX9860ETG+T
Analog Devices Inc./Maxim Integrated
-
TLV320AIC3106IRGZR
Texas Instruments
-
SGTL5000XNLA3R2
NXP Semiconductors
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
