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Texas Instruments LM4549BVH
- Part No.:
- LM4549BVH
- Manufacturer:
- Texas Instruments
- Category:
- CODECS
- Package:
- 48-LQFP
- Datasheet:
-
LM4549BVH.pdf
- Description:
- IC AUDIO CODEC 2MULTICH 48-LQFP
- Quantity:
- Payment:
- Shipping:
Inventory:3,637
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Product details
Overview
LM4549BVH from Texas Instruments is a dual-channel AC '97 Rev 2.1 audio codec IC with integrated stereo/mono analog mixers, 18-bit sigma-delta ADCs and DACs, sample rate conversion (4 kHz–48 kHz in 1-Hz steps), TI 3D Sound enhancement, and EAPD control - used as the analog front-end in PC audio subsystems on PCI/AMR/MDC cards and motherboard chipsets.
For engineers reviewing the LM4549BVH datasheet, LM4549BVH pinout, LM4549BVH application, or LM4549BVH equivalent, key selection criteria include AC Link interface timing compliance, analog mixer dynamic range (97 dB typ), line-level output gain control resolution (1.5 dB steps), and multi-codec identity configuration via ID0#/ID1# pins.
Technical Context
The LM4549BVH implements a deterministic AC Link interface with BIT_CLK (12.288 MHz in primary mode), SYNC frame synchronization, and bidirectional SDATA_IN/SDATA_OUT for PCM and control data transfer. It supports up to 8 simultaneous input streams and 2 output streams across multiple codecs using Extended AC Link topology.
Its analog signal path includes two independent 18-bit sigma-delta ADCs (90 dB DR) and DACs (89 dB DR), programmable microphone boost (0 dB / 20 dB), and four stereo + four mono analog inputs routed through MIX1 and MIX2 with per-input gain/attenuation/mute control - all configurable via 16-bit AC '97 register map (e.g., 02h Master Volume, 0Eh Mic Volume, 20h General Purpose).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| DAC Resolution | 18-bit sigma-delta; enables 89 dB typical dynamic range for high-fidelity playback |
| ADC Resolution | 18-bit sigma-delta; delivers 90 dB typical dynamic range for clean recording |
| Sample Rate Range | 4 kHz to 48 kHz in 1-Hz increments; supports flexible clock domain bridging without external SRC |
| Analog Mixer DR | 97 dB typical; ensures low-noise mixing of up to 8 analog sources before DAC output |
| Line Output Level | 1 Vrms nominal; meets AC '97 Rev 2.1 line-out specification with ±0.5 dB channel matching |
| Power Supply | AVDD: 4.2–5.5 V; DVDD: 3–5.5 V; supports dual-voltage operation for mixed-signal isolation |
| Operating Temp | −40°C to +85°C; qualified for industrial and extended-temperature PC/embedded applications |
Pinout & Package
LM4549BVH is housed in a 48-pin LQFP package (7.00 mm × 7.00 mm) with exposed thermal pad, compliant with JEDEC MO-153. Pin functions are defined for AC Link digital interface, analog I/O, power domains (AVDD/AVSS/DVDD1/DVDD2/DVSS1/DVSS2), crystal oscillator (XTL_IN/XTL_OUT), and codec identity (ID0#/ID1#).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SDATA_OUT (Pin 5) | AC Link Input Frame receiver | Samples controller-to-codec frames on falling edge of BIT_CLK; carries DAC PCM and register writes |
| SDATA_IN (Pin 8) | AC Link Output Frame transmitter | Drives codec-to-controller frames on rising edge of BIT_CLK; carries ADC PCM and status reads |
| BIT_CLK (Pin 6) | AC Link bit clock | 12.288 MHz output in primary mode; input in secondary mode; defines 256-cycle frame boundary |
| SYNC (Pin 10) | AC Link frame sync & warm reset | 48 kHz active-high pulse marking frame start; asynchronous high pulse triggers warm reset |
| RESET# (Pin 11) | Hardware cold reset | Active-low signal restoring all registers and analog circuits to default state; enables PC_BEEP passthrough |
| EAPD (Pin 47) | External amplifier power-down | Open-drain logic output controlling external amp shutdown; defaults high (enabled) after reset |
| ID0#, ID1# (Pins 45, 46) | Codec identity select | Inverted inputs setting 2-bit address (00–11) for multi-codec AC Link arbitration; internal pull-ups |
| LINE_OUT_L/R (Pins 35, 36) | Main stereo line outputs | 1 Vrms nominal outputs driven by MIX2 and controlled by Master Volume register (02h) |
Key Features
| Feature | Design Value |
|---|---|
| AC '97 Rev 2.1 Compliance | Fully implements AC Link protocol, register map, timing, and electrical specs - interoperable with Intel 8x0/ICH chipsets |
| TI 3D Sound Enhancement | Fixed-depth stereo widening circuit activated via D13 in General Purpose register (20h); uses 3DP/3DN pins |
| Programmable Mic Boost | Configurable 0 dB or 20 dB gain via D6 in Mic Volume register (0Eh); supports 0.1 Vrms (20 dB) or 1 Vrms (0 dB) mic inputs |
| PC_BEEP Passthrough | During Cold Reset, routes PC_BEEP directly to LINE_OUT_L/R bypassing volume controls - enables POST tone output |
| Multi-Codec Support | Extended AC Link mode allows up to 8 input streams and 2 output streams across up to 4 codecs using ID0#/ID1# addressing |
| Advanced Power Management | Individual analog/digital shutdown (PR543210 = 111111) reduces IDD to 19 µA digital / 70 µA analog quiescent current |
Applications
| Desktop PC Audio Systems | Portable PC Audio Subsystems |
|---|---|
Use Scenario: Integrated audio on AMR/PCI add-in cards or motherboard southbridge with AC Link interface. IC Role / Device Role / Timing Role: Primary AC '97 codec handling full-duplex stereo ADC/DAC, analog mixing, and 3D sound enhancement. Use Value: Eliminates need for external SRC or analog switches; 97 dB mixer DR preserves SNR across 8-input routing. |
Use Scenario: Audio subsystem on MDC cards or laptop motherboards with chipset-provided AC Link controller. IC Role / Device Role / Timing Role: Secondary codec in multi-codec topology, providing additional line-in/mic inputs and line-out channels. Use Value: ID0#/ID1# pin-selectable addressing enables plug-and-play expansion without firmware reconfiguration. |
| Automotive Telematics HMI | General Multichannel Audio Systems |
Use Scenario: Voice/audio interface in infotainment head units requiring wide temperature operation and noise immunity. IC Role / Device Role / Timing Role: Analog front-end converting microphone and line inputs to digital PCM for DSP processing. Use Value: −40°C to +85°C rating and 90 dB ADC DR ensure reliable voice capture in cabin environments. |
Use Scenario: Non-PC audio systems needing AC Link compatibility, such as industrial VoIP gateways or broadcast monitors. IC Role / Device Role / Timing Role: Standalone audio codec interfacing with FPGA-based AC Link controllers for custom timing and routing. Use Value: Deterministic sample timing (1-Hz SR conversion granularity) simplifies real-time buffer management in embedded firmware. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar audio codec applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM4550B | Same AC '97 Rev 2.1 compliance, but supports only 6-channel output frames (vs. LM4549BVH's 8-channel input frames); no TI 3D Sound | Limited to simpler multi-codec systems where 3D enhancement and extended input streaming are not required | Select when cost-sensitive designs prioritize basic AC Link functionality over advanced mixing and stereo enhancement |
| AD1885 | AC '97 Rev 2.1 codec with 20-bit converters (96 dB DR), but lacks sample rate conversion and TI 3D Sound; different register map and pinout | Requires redesign of driver software and PCB layout; suited for legacy systems prioritizing maximum DR over flexibility | Choose only if existing AD1885 firmware and layout can be reused; not drop-in compatible with LM4549BVH |
Compared with LM4549BVH, LM4550B offers reduced input streaming capability and no 3D audio, while AD1885 provides higher DR but requires full hardware and software rework - making LM4549BVH optimal for new AC Link designs needing SR conversion, mixer flexibility, and TI 3D integration.
Availability
LM4549BVH is available at Aetrix Electronics and suitable for desktop PC audio systems, portable PC subsystems, automotive telematics HMIs, and general multichannel audio frequency systems requiring stable component supply and long-term lifecycle support.
Supply support for LM4549BVH 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 specializing in analog and embedded processing technologies, with leadership in audio, power management, and interface solutions.
The LM4549BVH belongs to TI's AC '97 audio codec product line, designed specifically to deliver PC99-compliant, high-fidelity analog audio processing with integrated mixers, sample rate conversion, and system-level power management for PC and embedded platforms.
FAQ
What is the function of the EAPD pin on the LM4549BVH?
The EAPD (External Amplifier Power Down) pin on the LM4549BVH is an open-drain output controlled by bit D15 in the Powerdown Control/Status register (26h). It drives the shutdown pin of an external audio power amplifier. By default, EAPD is low after reset, enabling the amplifier. When asserted high, it disables the amplifier to reduce system power consumption - a key feature for battery-powered portable PC audio applications using the LM4549BVH.
Does the LM4549BVH support sample rate conversion for both ADC and DAC independently?
Yes, the LM4549BVH supports independent sample rate conversion for ADC and DAC paths, each programmable from 4 kHz to 48 kHz in precise 1-Hz increments. This allows asynchronous operation between recording and playback domains - for example, capturing at 44.1 kHz while playing back at 48 kHz - without requiring external SRC hardware. The conversion is implemented in dedicated digital blocks within the LM4549BVH, ensuring deterministic timing and low jitter critical for professional audio use cases.
How does the TI 3D Sound feature work in the LM4549BVH?
The TI 3D Sound feature in the LM4549BVH is a fixed-depth stereo enhancement circuit activated via bit D13 in the General Purpose register (20h). It operates on the Stereo Mix 3D signal path (MIX1), applying phase and amplitude processing to widen the perceived soundstage. The circuit requires external 0.022 µF capacitors between pins 3DP and 3DN. When disabled (default), the LM4549BVH routes signals directly through standard stereo mix paths - preserving full compatibility with legacy AC '97 drivers that do not configure the 3D bit.
What are the voltage requirements for AVDD and DVDD on the LM4549BVH?
The LM4549BVH requires AVDD between 4.2 V and 5.5 V for its analog section (including ADCs, DACs, and mixers), and DVDD between 3.0 V and 5.5 V for its digital core (AC Link interface, registers, and logic). These separate supplies enable noise isolation: AVDD powers sensitive analog circuitry, while DVDD handles switching noise from digital I/O. The LM4549BVH tolerates mismatched rail voltages - e.g., 5.0 V AVDD with 3.3 V DVDD - which is commonly used in PC audio designs to optimize SNR and power efficiency.
Can the LM4549BVH operate as both primary and secondary codec in AC Link systems?
Yes, the LM4549BVH supports both primary and secondary codec modes via the ID0# and ID1# pins (Pins 45 and 46). In primary mode, it generates BIT_CLK from XTL_IN and drives the AC Link bus; in secondary mode, it accepts BIT_CLK from the primary codec and responds to its assigned address. The two pins set a 2-bit identity (00–11), allowing up to four codecs on one AC Link bus. This dual-mode capability makes the LM4549BVH suitable for scalable audio architectures - from single-codec desktop PCs to multi-input automotive telematics systems.
LM4549BVH Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 48-LQFP
- Packaging:
- Tray
- Product Status:
- Obsolete
- Type:
- Audio, AC '97
- Data Interface:
- Serial
- Resolution (Bits):
- 18 b
- Number of ADCs / DACs:
- 2 / 2
- Sigma Delta:
- Yes
- S/N Ratio, ADCs / DACs (db) Typ:
- -
- Dynamic Range, ADCs / DACs (db) Typ:
- 90 / 89
- Voltage - Supply, Analog:
- 4.2V ~ 5.5V
- Voltage - Supply, Digital:
- 3.3V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 48-LQFP (7x7)
LM4549BVH FAQ
1.How can I place an order for LM4549BVH through Aetrix?
Please submit a Request for Quotation (RFQ) for LM4549BVH 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 LM4549BVH reliable?
The price and inventory of LM4549BVH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM4549BVH is usually 5 days.
3.What payment methods are accepted for LM4549BVH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM4549BVH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM4549BVH?
LM4549BVH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM4549BVH 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 LM4549BVH?
For technical support, including LM4549BVH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM4549BVH requirements.
6.How does Aetrix verify that LM4549BVH is sourced from the original manufacturer or authorized distributors?
All LM4549BVH 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 LM4549BVH meets industry standards.
7.What is the process for return or replacement of LM4549BVH?
All LM4549BVH units undergo pre-shipment inspection (PSI). If there is an issue with LM4549BVH, 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 LM4549BVH part is unused and in its original packaging.
Return procedure for LM4549BVH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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