Overview
The LMK61E2-SIAR from Texas Instruments is an ultra-low jitter PLLatinum programmable oscillator designed for high-performance applications. It features a fractional-N frequency synthesizer with an integrated VCO, generating commonly used reference clocks. The device is factory-programmed to produce a 156.25-MHz LVPECL output and can be configured to output LVPECL, LVDS, or HCSL signals. It operates from a single 3.3-V supply and supports industrial temperature ranges from –40°C to +85°C. The LMK61E2-SIAR is notable for its ultra-low noise and high performance, making it suitable for a variety of demanding applications.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Default Output Frequency | 156.25 | MHz |
| Output Format | LVPECL, LVDS, HCSL | |
| Output Frequency Range | LVPECL: up to 1 GHz, LVDS: up to 900 MHz, HCSL: up to 400 MHz | |
| Total Frequency Tolerance | ±50 ppm | |
| Jitter (RMS Typical) | 90 fs (fOUT > 100 MHz) | |
| PSRR | –70 dBc | |
| Operating Voltage | 3.3 V ± 5% | |
| Temperature Range | –40°C to +85°C | |
| Package Size | 7-mm × 5-mm 8-Pin QFM (SIA) |
Key Features
- Ultra-Low Noise and High Performance: The LMK61E2-SIAR offers ultra-low jitter and robust supply noise immunity.
- Flexible Output Format: User-selectable output formats including LVPECL, LVDS, and HCSL.
- Internal EEPROM and I2C Interface: Fully programmable in-system through the I2C serial interface with user-configurable default settings.
- Frequency Margining: Fine and coarse frequency margining options for system design verification tests.
- Power Conditioning: Internal power conditioning provides excellent power supply ripple rejection (PSRR).
- Industrial Temperature Range: Operates from –40°C to +85°C.
Applications
- High-Performance Replacement for Crystal-, SAW-, or Silicon-Based Oscillators: Ideal for applications requiring high stability and low jitter.
- Networking Equipment: Switches, routers, network line cards, and base band units (BBU).
- Servers and Storage: Suitable for server and storage/SAN environments.
- Test and Measurement: Used in various test and measurement equipment.
- Medical Imaging: Applies to medical imaging devices requiring precise timing.
- FPGA and Processor Attach: Used in FPGA and processor-based systems.
Q & A
- What is the default output frequency of the LMK61E2-SIAR?
The default output frequency is 156.25 MHz.
- What output formats are supported by the LMK61E2-SIAR?
The device supports LVPECL, LVDS, and HCSL output formats.
- What is the total frequency tolerance of the LMK61E2-SIAR?
The total frequency tolerance is ±50 ppm.
- What is the typical jitter performance of the LMK61E2-SIAR?
The typical jitter is 90 fs RMS for frequencies above 100 MHz.
- How does the LMK61E2-SIAR manage power supply noise?
The device features internal power conditioning with a PSRR of –70 dBc, providing robust supply noise immunity.
- What is the operating voltage range of the LMK61E2-SIAR?
The device operates from a single 3.3-V supply with a ±5% tolerance.
- What is the temperature range for the LMK61E2-SIAR?
The device operates from –40°C to +85°C.
- How is the LMK61E2-SIAR programmed?
The device is fully programmable in-system through the I2C serial interface.
- What are the frequency margining options available on the LMK61E2-SIAR?
The device provides fine and coarse frequency margining options.
- What are some common applications for the LMK61E2-SIAR?
Common applications include high-performance replacement for crystal-, SAW-, or silicon-based oscillators, networking equipment, servers, storage/SAN, test and measurement, medical imaging, and FPGA and processor attach.
