Overview
The LMH1983SQX/NOPB, produced by Texas Instruments, is a highly-integrated programmable audio/video (A/V) clock generator designed for broadcast and professional applications. This component is capable of generating multiple clock frequencies simultaneously, making it an ideal solution for systems that require precise timing for both video and audio signals. It supports SMPTE serial digital video (SDI) and digital audio AES3/EBU standards, ensuring compliance with industry standards for high-quality video and audio transmission.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Supply Voltage | 3.3 | V |
| PLL Frequencies | PLL1: 27 or 13.5 MHz, PLL2: 148.5 or 74.25 MHz, PLL3: 148.5/1.001 or 74.25/1.001 MHz, PLL4: 98.304 MHz / 2X (X = 0 to 15) | MHz |
| Output Jitter (Typical) | 2.7 ps | ps |
| Package Type | 40-pin WQFN | - |
| Operating Temperature | -40°C to 85°C | °C |
| Interface | I2C with Address Select Pin (3 states) | - |
Key Features
- Four PLLs for simultaneous A/V clock generation
- Flexible PLL bandwidth to optimize jitter performance and lock time
- Soft re-synchronization to new reference with glitch-less operation
- Digital holdover or free-run on loss of reference
- Status flags for loss of reference and loss of PLL lock
- 3.3 V single supply operation
- I2C interface with address select pin (3 states)
- Automatic input format detection and simple programming of multiple A/V output formats
- Genlock or digital free-run modes with override programmability of various automatic functions
Applications
- Triple Rate (3G/HD/SD) SDI SerDes
- FPGA Reference Clock Generation/Cleaning
- Audio Embed/De-embed
- Keyers and Logo Inserters
- Format/Standards Converters
- Video Displays and Projectors
- A/V Test and Measurement Equipment
Q & A
- What is the primary function of the LMH1983?
The LMH1983 is a highly-integrated programmable audio/video (A/V) clock generator designed for broadcast and professional applications.
- What are the typical PLL frequencies supported by the LMH1983?
The LMH1983 supports PLL frequencies such as PLL1: 27 or 13.5 MHz, PLL2: 148.5 or 74.25 MHz, PLL3: 148.5/1.001 or 74.25/1.001 MHz, and PLL4: 98.304 MHz / 2X (X = 0 to 15).
- What is the output jitter specification of the LMH1983?
The typical output jitter of the LMH1983 is 2.7 ps.
- What type of package does the LMH1983 come in?
The LMH1983 is offered in a 40-pin WQFN package.
- What is the operating temperature range of the LMH1983?
The operating temperature range of the LMH1983 is -40°C to 85°C.
- Does the LMH1983 support I2C interface?
Yes, the LMH1983 supports an I2C interface with an address select pin (3 states).
- What are some of the key applications of the LMH1983?
The LMH1983 is used in applications such as triple rate (3G/HD/SD) SDI SerDes, FPGA reference clock generation/cleaning, audio embed/de-embed, keyers and logo inserters, format/standards converters, video displays and projectors, and A/V test and measurement equipment.
- How does the LMH1983 handle loss of reference?
The LMH1983 can be programmed to hold the control voltage to maintain output accuracy within ±0.5 ppm (typical) of the previous reference when a loss of reference occurs.
- Does the LMH1983 support genlock or free-run modes?
Yes, the LMH1983 supports genlock or digital free-run modes with override programmability of various automatic functions.
- What is the supply voltage requirement for the LMH1983?
The LMH1983 operates on a 3.3 V single supply.
