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Texas Instruments LM4550VH/NOPB
- Part No.:
- LM4550VH/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- CODECS
- Package:
- 48-LQFP
- Datasheet:
-
LM4550VH/NOPB.pdf
- Description:
- IC AC '97 CODEC 48-LQFP
- Quantity:
- Payment:
- Shipping:
Inventory:3,358
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Product details
Overview
LM4550VH/NOPB from Texas Instruments is an AC '97 Rev 2.1–compliant multi-channel audio codec featuring dual 18-bit sigma-delta ADCs and DACs, stereo headphone amplifier with independent gain control, TI 3D Sound stereo enhancement, and sample rate conversion from 4 kHz to 48 kHz in 1 Hz steps. It delivers 90 dB ADC dynamic range, 89 dB DAC dynamic range, and supports up to 6 DAC channels in multi-codec systems for PC audio subsystems.
For engineers reviewing the LM4550VH/NOPB datasheet, LM4550VH/NOPB pinout, LM4550VH/NOPB application, or LM4550VH/NOPB equivalent, this page provides verified technical context, validated pin functions, confirmed AC '97 interface timing behavior, real-world mixer routing capabilities, and direct alternative part comparisons for desktop PC audio, embedded multimedia, and multi-channel audio system design.
Technical Context
The LM4550VH/NOPB implements a full-duplex AC '97 Rev 2.1 analog front-end with deterministic bit-clock (BIT_CLK) timing, supporting primary/secondary codec modes via ID0#/ID1# pins and TI's proprietary chaining function that shares a single SDATA_IN line across multiple codecs. Its analog signal path includes programmable 18-bit ADCs/DACs, dual-stage mixers (MIX1/MIX2), and configurable input routing for CD, LINE_IN, AUX, VIDEO, PHONE, MIC1/MIC2, and PC_BEEP sources.
It integrates a dedicated stereo headphone amplifier (HP_OUT_L/R/C) with 0 dB to –46.5 dB volume control in 1.5 dB steps, TI 3D Sound circuitry (enabled via General Purpose register bit D13), and EAPD-controlled external amplifier shutdown. Power management includes digital/analog shutdown modes drawing ≤19 µA and ≤70 µA respectively, with dual 3.3 V / 5 V supply support and extended industrial temperature range (–40°C to +85°C).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| ADC Resolution | 18-bit sigma-delta - enables high-fidelity digitization of microphone and line inputs with A-weighted 90 dB dynamic range. |
| DAC Resolution | 18-bit sigma-delta - delivers low-noise analog output to LINE_OUT and HP_OUT with 89 dB typical dynamic range. |
| Sample Rate Conversion | 4 kHz to 48 kHz in 1 Hz increments - allows precise synchronization between host controller clock and audio source rates without external PLL. |
| Headphone Amp Output | 50 mW into 32 Ω with 0.02% THD+N - sufficient drive capability for consumer-grade headphones without external amplification. |
| Analog Mixer Dynamic Range | 97 dB typical - ensures minimal noise floor degradation when mixing up to eight analog inputs (CD, LINE_IN, MIC, etc.). |
| AC '97 Interface Compliance | Rev 2.1 fully compliant - guarantees interoperability with standard AC '97 digital controllers (e.g., Intel ICH chipsets) using BIT_CLK, SYNC, SDATA_IN/OUT protocol. |
| Supply Voltage Ranges | Digital: 3.0–5.5 V; Analog: 4.2–5.5 V - supports mixed-voltage system integration with separate DVDD/AVDD domains for noise isolation. |
Pinout & Package
LQFP-48 package (7.0 mm × 7.0 mm body size), thermally enhanced with exposed pad; RoHS-compliant, lead-free (NOPB suffix).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SDATA_IN (Pin 8) | AC Link Input Frame Output | Transmits PCM audio data and status from codec to AC '97 controller on rising edge of BIT_CLK; supports chaining when CIN is asserted. |
| SDATA_OUT (Pin 5) | AC Link Output Frame Input | Receives DAC PCM data and control commands from controller on falling edge of BIT_CLK; requires proper AC '97 frame alignment via SYNC. |
| HP_OUT_L / HP_OUT_R / HP_OUT_C (Pins 39/41/40) | Stereo Headphone Driver Outputs | Single-ended line-level outputs (1 Vrms) with independent volume control; HP_OUT_C serves as AC ground reference for improved common-mode rejection. |
| MIC1 / MIC2 (Pins 21/22) | Programmable Mic Inputs | Each supports 0 dB or 20 dB boost amplifier gain; selectable via MS bit (D8) in General Purpose register 20h for flexible microphone sensitivity matching. |
| ID0# / ID1# (Pins 45/46) | Codec Identity Configuration | Inverted logic inputs determining Primary/Secondary mode and address in multi-codec AC Link systems; define register 28h bits ID0/ID1. |
| EAPD (Pin 47) | External Amplifier Power-Down | Active-high logic output controlling shutdown of external power amps; defaults low at reset to enable audio path during cold boot. |
Key Features
| Feature | Design Value |
|---|---|
| TI 3D Sound Stereo Enhancement | Fixed-depth spatial processing enabled/disabled via register bit D13; uses 3DP/3DN pins with 0.022 µF capacitor for hardware implementation. |
| Multi-Codec Chaining | Eliminates need for separate SDATA_IN lines per codec by passing upstream data through CIN pin - reduces controller pin count and simplifies PCB routing in 5.1/7.1 systems. |
| PC_BEEP Passthrough | Bypasses all volume/mute controls during Cold Reset (RESET# active low), routing mono beep directly to LINE_OUT_L/R - ensures audible POST tones before driver initialization. |
| Independent Input Gain Control | Each analog input (LINE_IN, AUX, CD, VIDEO, PHONE, MIC) has dedicated 1.5 dB step volume/mute registers - enables precise level matching across heterogeneous sources. |
| Dual Supply Domain Isolation | Separate DVDD1/DVDD2 and AVDD1/AVDD2 supplies with dedicated grounds - minimizes digital switching noise coupling into sensitive analog paths. |
Applications
| Desktop PC Audio Subsystem | Embedded Multimedia Terminal |
|---|---|
Use Scenario: Integrated audio solution on AMR or PCI add-in cards for Windows-based desktop PCs requiring PC99 compliance and AC '97 Rev 2.1 interface. IC Role / Device Role / Timing Role: Primary AC '97 codec handling full-duplex stereo ADC/DAC conversion, analog mixing, headphone amplification, and TI 3D Sound processing. Use Value: Eliminates need for discrete op-amps, filters, and level-shifters while delivering 90 dB SNR and deterministic AC Link timing for stable driver operation. |
Use Scenario: Audio interface in kiosk, point-of-sale, or industrial HMI where local microphone capture and stereo playback coexist with limited board space. IC Role / Device Role / Timing Role: Standalone audio hub managing MIC1/MIC2 inputs, LINE_IN, and LINE_OUT/HP_OUT outputs under real-time OS control with sample-rate flexibility. Use Value: Enables simultaneous recording from two microphones and playback to headphones/speakers using one IC, reducing BOM count and layout complexity. |
| Multi-Channel Surround Sound System | Automotive Telematics Audio Interface |
Use Scenario: Building 5.1 or 7.1 channel output using multiple LM4550VH/NOPB devices chained via CIN/SDATA_IN to share controller resources. IC Role / Device Role / Timing Role: Secondary codec in daisy-chained configuration providing additional DAC channels synchronized to primary codec's BIT_CLK and SYNC. Use Value: Achieves up to 6 DAC channels without increasing controller pin count or requiring custom FPGA logic - lowers system cost and validation effort. |
Use Scenario: Voice capture and alert playback in automotive infotainment modules requiring extended temperature operation and ESD-hardened analog inputs. IC Role / Device Role / Timing Role: Audio front-end handling hands-free microphone input (MIC1/MIC2 with 20 dB boost), line-level alerts to speaker outputs, and noise-immune analog routing. Use Value: Meets –40°C to +85°C operating range and ±2000 V HBM ESD rating on all pins except XTL_IN, ensuring robustness in vehicle environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar multi-channel audio codec applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM4550B | Same silicon die, identical electrical specs and pinout; differs only in tape-and-reel packaging and RoHS compliance marking (NOPB vs B suffix). | No functional difference - both meet AC '97 Rev 2.1, support same sample rates, mixer topology, and TI 3D Sound. | Select LM4550VH/NOPB for lead-free compliance and modern distribution channels; LM4550B remains viable for legacy procurement. |
| ALC262 | Realtek AC '97 codec with 20-bit ADC/DAC, higher SNR (95 dB), but no integrated headphone amp or TI 3D Sound; requires external amplification. | Used in notebook platforms where higher resolution is prioritized over integrated drive capability and proprietary audio effects. | Choose ALC262 only if system already includes discrete headphone drivers and requires >90 dB ADC performance; LM4550VH/NOPB preferred for self-contained solutions. |
Compared with LM4550B, LM4550VH/NOPB offers identical functionality with updated environmental compliance, while ALC262 trades integrated headphone drive and TI-specific features for higher-resolution conversion - making LM4550VH/NOPB optimal for cost-sensitive, space-constrained PC audio designs needing full analog output capability.
Availability
LM4550VH/NOPB is available at Aetrix Electronics and suitable for desktop PC audio subsystems, embedded multimedia terminals, multi-channel surround sound systems, and automotive telematics applications requiring stable component supply, long-lifecycle support, and RoHS-compliant sourcing.
Supply support for LM4550VH/NOPB 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, embedded processing, and connectivity technologies, with decades of leadership in audio signal processing and PC platform components.
The LM4550VH/NOPB belongs to TI's AC '97 audio codec product line, designed specifically to deliver PC99-compliant, high-SNR analog audio interfaces for desktop and portable computing platforms with minimal external components.
FAQ
What is the primary interface standard supported by the LM4550VH/NOPB?
The LM4550VH/NOPB implements the AC '97 Rev 2.1 interface standard, using BIT_CLK, SYNC, SDATA_IN, and SDATA_OUT signals to communicate with a compatible digital audio controller. It operates in either Primary or Secondary mode depending on ID0#/ID1# pin states, and supports TI's chaining feature to reduce controller pin count in multi-codec systems. This interface is mandatory for PC99 compliance and ensures interoperability with Intel ICH and other AC '97 host controllers.
Does the LM4550VH/NOPB include an integrated headphone amplifier?
Yes, the LM4550VH/NOPB integrates a stereo headphone amplifier with dedicated HP_OUT_L, HP_OUT_R, and HP_OUT_C pins. It delivers 50 mW into 32 Ω with 0.02% THD+N at full scale and supports volume control from 0 dB to –46.5 dB in 1.5 dB steps via the Headphone Volume register (04h). The HP_OUT_C pin serves as an AC ground reference to improve common-mode noise rejection, and the amplifier operates independently from the line-out path.
How does the LM4550VH/NOPB handle microphone inputs with varying signal levels?
The LM4550VH/NOPB provides two dedicated mono microphone inputs (MIC1 and MIC2), each configurable with a programmable 0 dB or 20 dB boost amplifier. Input selection is controlled by the MS bit (D8) in General Purpose register 20h, and gain is set by the 20dB bit (D6) in Mic Volume register 0Eh. Nominal input levels are 1 Vrms (0 dB gain) or 0.1 Vrms (20 dB gain), enabling direct connection to electret condenser microphones without external preamplification.
Can the LM4550VH/NOPB operate across the full industrial temperature range?
Yes, the LM4550VH/NOPB is specified for operation from –40°C to +85°C ambient temperature (TA), meeting extended industrial requirements. This rating is confirmed in the Recommended Operating Conditions table (Section 7.3) and applies under nominal supply conditions (AVDD = 4.2–5.5 V, DVDD = 3.0–5.5 V). Thermal derating follows RθJA = 74°C/W, ensuring reliable performance in enclosed or high-ambient environments such as automotive telematics or industrial HMIs.
What is the purpose of the CIN pin on the LM4550VH/NOPB?
The CIN pin (Pin 48) enables TI's proprietary codec chaining function. When asserted, it disconnects the LM4550VH/NOPB's internal SDATA_IN path and passes the upstream codec's SDATA_IN signal directly to its own SDATA_IN output - allowing multiple LM4550VH/NOPB devices to share a single controller SDATA_IN line. This reduces controller pin count and simplifies routing in multi-channel surround systems. CIN must be driven (not left floating) when chaining is active; otherwise, it may be left open.
LM4550VH/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 48-LQFP
- Packaging:
- Tape & Reel (TR)
- 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:
- 3V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 48-LQFP (7x7)
LM4550VH/NOPB FAQ
1.How can I place an order for LM4550VH/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM4550VH/NOPB 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 LM4550VH/NOPB reliable?
The price and inventory of LM4550VH/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM4550VH/NOPB is usually 5 days.
3.What payment methods are accepted for LM4550VH/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM4550VH/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM4550VH/NOPB?
LM4550VH/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM4550VH/NOPB 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 LM4550VH/NOPB?
For technical support, including LM4550VH/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM4550VH/NOPB requirements.
6.How does Aetrix verify that LM4550VH/NOPB is sourced from the original manufacturer or authorized distributors?
All LM4550VH/NOPB 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 LM4550VH/NOPB meets industry standards.
7.What is the process for return or replacement of LM4550VH/NOPB?
All LM4550VH/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM4550VH/NOPB, 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 LM4550VH/NOPB part is unused and in its original packaging.
Return procedure for LM4550VH/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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