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Texas Instruments LMH1981MT/NOPB
- Part No.:
- LMH1981MT/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- Video Processing
- Package:
- 14-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
LMH1981MT/NOPB.pdf
- Description:
- IC VIDEO SYNC 14TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,562
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Product details
Overview
LMH1981MT/NOPB from Texas Instruments is a multi-format video sync separator IC that extracts composite, horizontal, vertical, burst/back porch, odd/even field, and 11-bit video format timing signals from analog CVBS, S-Video (Y/C), and component (YPbPr/GBR) inputs. It supports NTSC, PAL, 480i/p, 576i/p, 720p, 1080i/p, and 1080PsF with bi-level or tri-level sync, delivers rail-to-rail CMOS outputs, and achieves ≤±3 ns HSync propagation delay variation over temperature.
For engineers reviewing the LMH1981MT/NOPB datasheet, LMH1981MT/NOPB pinout, LMH1981MT/NOPB application, or LMH1981MT/NOPB equivalent, this page provides verified pin functions, jitter performance data, format detection behavior, VFOUT timing structure, and real-world sync lock time metrics for broadcast-grade video system integration.
Technical Context
The LMH1981MT/NOPB implements adaptive 50% sync slicing across SD/ED/HD formats-bi-level sync sliced between blanking level and negative sync tip, tri-level sync sliced between negative and positive sync tips-enabling stable extraction from 0.14 VPP to 1.2 VPP input amplitudes. Its internal bias current is set by a precision 10 kΩ REXT resistor, eliminating manual RSET configuration required in legacy sync separators like the LM1881.
It features automatic video format detection without microcontroller programming, outputting total horizontal line count per field as an 11-bit serial stream on VFOUT clocked by HSync edges. All logic outputs are negative-polarity CMOS (VOH ≥ 3.0 V at 3.3 V, VOL ≤ 0.3 V), with HSync leading-edge jitter optimized for downstream PLL clock clean-up in genlock and video capture systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supported Video Formats | NTSC, PAL, 480i/p, 576i/p, 720p, 1080i/p, 1080PsF - enables single-chip support across broadcast, DTV, and professional video equipment |
| Input Sync Amplitude Range | 0.14–0.60 VPP (bi-level), 0.30–1.20 VPP (tri-level) - accommodates improperly terminated or attenuated sources without amplitude adjustment |
| HSync Propagation Delay | 30–475 ns depending on format - low variation (±3 ns typ over 0°C–70°C) ensures deterministic timing in FPGA-based video pipelines |
| Video Format Output (VFOUT) | 11-bit binary serial stream clocked on HSync edges - conveys exact lines-per-field (e.g., 560 for 1080i Field 1) for dynamic scaler/color space selection |
| Supply Voltage Range | 3.3 V ±5% to 5 V ±5% - interoperable with both 3.3 V and 5 V logic domains without level-shifting |
| Operating Temperature | −40°C to +85°C - qualified for industrial and broadcast equipment enclosures with passive thermal management |
| Package | 14-pin TSSOP (PW package) - surface-mount compatible with standard reflow profiles and 0.65 mm pitch PCB layout |
Pinout & Package
LMH1981MT/NOPB is housed in a 14-pin Thin Shrink Small Outline Package (TSSOP), PW variant, with exposed pad not electrically connected. Pin spacing is 0.65 mm, body dimensions 5.0 mm × 4.4 mm × 1.2 mm, and recommended solder profile complies with JEDEC J-STD-020C.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | REXT | Bias current reference terminal - requires 10 kΩ ±1% resistor to set internal reference voltage and ensure <±3 ns HSync jitter stability |
| 2, 5, 10 | GND | Ground return - three dedicated ground pins minimize ground bounce across analog input, digital outputs, and supply domains |
| 3, 6, 11 | VCC | Power supply - three independent VCC pins (VCC1/VCC2/VCC3) decouple supply paths for input stage, logic core, and output drivers |
| 4 | VIN | Analog video input - accepts CVBS, Y (S-Video), YPbPr, or GBR with AC coupling; supports 75 Ω source termination |
| 7 | HSOUT | Negative-polarity horizontal sync output - low-jitter falling edge used as clock reference for pixel clock generation or frame synchronization |
| 8 | VSOUT | Negative-polarity vertical sync output - 3H pulse width aligned to first vertical serration, enabling field/frame boundary detection |
| 9 | VFOUT | 11-bit serial video format data - outputs total horizontal lines per field (e.g., 01000110000b = 560) starting at 3rd HSync after VSync |
| 12 | CSOUT | Composite sync output - direct reproduction of input sync pulses below blanking level, with propagation delay matching input OH |
| 13 | BPOUT | Burst/back porch timing output - narrow negative pulse during back porch interval, usable as color burst gate or DC restoration clamp signal |
| 14 | OEOUT | Odd/even field indicator - logic high during odd field (Field 1), low during even field (Field 2); held high for progressive formats |
Key Features
| Feature | Design Value |
|---|---|
| Automatic multi-format detection | Eliminates MCU programming or external RSET resistor changes when switching between NTSC, PAL, 720p, or 1080i inputs |
| 50% sync slicing with amplitude tolerance | Maintains accurate HSync edge placement across 0.5–2 VPP input range, ensuring robust operation with mismatched cable impedance |
| Low-HSync-leading-edge jitter | Enables direct connection to FPGA PLL clock inputs without external jitter cleaners - typical peak-to-peak jitter <100 ps |
| 11-bit VFOUT serial format reporting | Provides machine-readable resolution identification (e.g., 747 lines for 720p) to trigger automatic color space or scaling mode changes |
| Tri-level and bi-level sync compatibility | Single device supports legacy SDTV black burst and modern HDTV tri-level sync without hardware modification or configuration |
Applications
| Broadcast Genlock Systems | HDTV Set-Top Box Input Processing |
|---|---|
|
Use Scenario: Synchronizing multiple video sources (camera feeds, graphics overlays) to a master black burst reference in live production switchers. IC Role / Device Role / Timing Role: LMH1981MT/NOPB extracts precise HSync and VSOUT from incoming black burst, feeding low-jitter edges to PLLs that lock local pixel clocks. Use Value: Sub-3 ns HSync delay variation prevents frame misalignment across channels; VFOUT confirms 1080i vs. 720p format to auto-select correct line-rate dividers. |
Use Scenario: Detecting and adapting to variable-resolution HDMI input sources (e.g., 480p game console, 1080i broadcast feed) in consumer STBs. IC Role / Device Role / Timing Role: LMH1981MT/NOPB processes analog CVBS or component video passthrough path, delivering OEOUT and VFOUT to MCU for real-time format negotiation. Use Value: Automatic 11-bit line-count reporting eliminates manual EDID parsing delays; BPOUT provides burst gate for chroma decoding without external timing logic. |
| Professional Video Capture Cards | Digital Video Recorder (DVR) Front-End |
|
Use Scenario: Capturing uncompressed SD/HD analog video into PCIe-based acquisition cards with minimal latency and format agility. IC Role / Device Role / Timing Role: LMH1981MT/NOPB generates HSOUT/VSOUT timestamps and VFOUT metadata for DMA engine synchronization and frame header tagging. Use Value: 30 ns HSync delay in 720p mode enables sub-microsecond timestamp alignment; CSOUT provides legacy composite sync for analog monitoring outputs. |
Use Scenario: Supporting multi-standard analog recording (NTSC security cam, PAL CCTV, 1080i broadcast) in embedded DVR platforms with unified firmware. IC Role / Device Role / Timing Role: LMH1981MT/NOPB conditions analog inputs and supplies OEOUT/VSOUT to ARM processor for field-aware compression and VFOUT for resolution-aware bit rate allocation. Use Value: Single-chip format detection reduces BOM cost vs. dual-LM1881 solutions; GND/VCC pin separation minimizes crosstalk in high-density DVR PCB layouts. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar video sync separation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM1881N/NOPB | Lacks automatic format detection; requires external RSET resistor tuning per line rate; no VFOUT or BPOUT; only supports bi-level sync | Suitable for fixed-format SDTV systems (e.g., NTSC-only monitors); cannot handle tri-level sync or dynamic format switching | Select LM1881N/NOPB only when cost is primary constraint and video format is static; LMH1981MT/NOPB adds 11-bit format intelligence and HD readiness. |
| MAX9526ETL+ | Integrated ADC + sync separator; outputs digital YUV over BT.656; no discrete CMOS sync outputs; requires 1.8 V/3.3 V dual supply | Targets digital baseband processing (e.g., SoC video input); not pin-compatible; no analog sync output capability | Choose MAX9526ETL+ when migrating to digital video pipeline; LMH1981MT/NOPB remains optimal for analog-domain sync distribution with CMOS logic interfacing. |
Compared with LM1881N/NOPB, LMH1981MT/NOPB eliminates manual configuration and extends to HD formats; compared with MAX9526ETL+, it preserves discrete analog sync outputs for legacy timing circuits while adding format-aware intelligence - making it the only solution supporting both broadcast-grade jitter specs and machine-readable resolution metadata in a 14-pin TSSOP.
Availability
LMH1981MT/NOPB is available at Aetrix Electronics and suitable for broadcast equipment, HDTV/DTV front-ends, and professional video capture devices requiring stable component supply, long-term lifecycle assurance, and guaranteed traceable sourcing.
Supply support for LMH1981MT/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 leader specializing in analog, embedded processing, and connectivity technologies, with decades of heritage in high-performance video interface solutions.
The LMH1981MT/NOPB belongs to TI's professional video analog interface product line, engineered specifically for broadcast-grade sync extraction, genlock stability, and multi-standard format adaptability in real-time video systems.
FAQ
What video standards does the LMH1981MT/NOPB support?
The LMH1981MT/NOPB supports NTSC, PAL, 480i/p, 576i/p, 720p, 1080i/p, and 1080PsF via composite (CVBS), S-Video (Y/C), and component (YPbPr/GBR) interfaces. It handles both bi-level sync (SDTV) and tri-level sync (HDTV) natively. The LMH1981MT/NOPB does not support VESA PC graphics RGB formats or digital interfaces like HDMI or SDI.
How does the LMH1981MT/NOPB achieve low HSync jitter?
The LMH1981MT/NOPB uses precision 50% sync slicing referenced to the input's OH point, combined with internal bias stabilization via the REXT resistor, to deliver ≤±3 ns HSync propagation delay variation over temperature. Its negative-polarity HSync output is optimized for falling-edge triggering, minimizing jitter accumulation in downstream PLLs. The LMH1981MT/NOPB achieves typical peak-to-peak jitter under 100 ps when paired with a 1 µF input coupling capacitor and DC-coupled video source.
What is the function of the VFOUT pin on the LMH1981MT/NOPB?
The VFOUT pin on the LMH1981MT/NOPB outputs an 11-bit binary serial stream representing the total horizontal line count per field (e.g., 560 for 1080i Field 1). This data is clocked out on the first 11 HSync leading edges after each VSync pulse, enabling host processors to auto-detect video resolution and adjust scaler, color space, or deinterlacing parameters. The LMH1981MT/NOPB outputs VFOUT continuously during active video, with undefined states outside the 11-bit window.
Can the LMH1981MT/NOPB operate from a 3.3 V supply?
Yes, the LMH1981MT/NOPB operates from 3.3 V ±5% (3.135 V to 3.465 V) up to 5 V ±5%, with full specification compliance across the range. At 3.3 V, output logic levels meet VOH ≥ 3.0 V and VOL ≤ 0.3 V under 10 kΩ load, and supply current is 9.5–11.5 mA. The LMH1981MT/NOPB maintains identical timing accuracy and format detection capability at both voltages, simplifying mixed-voltage system design.
What is the purpose of the REXT pin on the LMH1981MT/NOPB?
The REXT pin on the LMH1981MT/NOPB sets the internal bias current and reference voltage using a 10 kΩ ±1% external resistor. Unlike the adjustable RSET in the LM1881, REXT is fixed-value and ensures stable 50% sync slicing, low jitter, and wide input amplitude tolerance. Using a non-precision REXT resistor degrades HSync jitter performance and increases propagation delay variation across temperature and supply voltage - the LMH1981MT/NOPB requires this resistor for guaranteed spec compliance.
LMH1981MT/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 14-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Separator
- Applications:
- Professional Video
- Standards:
- NTSC, PAL
- Control Interface:
- Serial
- Voltage - Supply:
- 3.3V ~ 5V
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
- Supplier Device Package:
- 14-TSSOP
LMH1981MT/NOPB FAQ
1.How can I place an order for LMH1981MT/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LMH1981MT/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 LMH1981MT/NOPB reliable?
The price and inventory of LMH1981MT/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LMH1981MT/NOPB is usually 5 days.
3.What payment methods are accepted for LMH1981MT/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LMH1981MT/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LMH1981MT/NOPB?
LMH1981MT/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LMH1981MT/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 LMH1981MT/NOPB?
For technical support, including LMH1981MT/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LMH1981MT/NOPB requirements.
6.How does Aetrix verify that LMH1981MT/NOPB is sourced from the original manufacturer or authorized distributors?
All LMH1981MT/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 LMH1981MT/NOPB meets industry standards.
7.What is the process for return or replacement of LMH1981MT/NOPB?
All LMH1981MT/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LMH1981MT/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 LMH1981MT/NOPB part is unused and in its original packaging.
Return procedure for LMH1981MT/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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