Overview
The LMK61E2-SIAT, produced by Texas Instruments, is an ultra-low jitter PLLatinum™ programmable oscillator. It features a fractional-N frequency synthesizer with an integrated Voltage-Controlled Oscillator (VCO) that generates commonly used reference clocks. The device is designed for high-performance applications, offering self-startup from on-chip EEPROM, which is factory-programmed to generate a 156.25-MHz LVPECL output. The device's registers and EEPROM settings are fully programmable in-system through an I2C serial interface. It operates from a single 3.3-V ± 5% supply and provides excellent power supply ripple rejection (PSRR), reducing the complexity of the power delivery network.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Operating Voltage (VDD) | 3.135 | 3.3 | 3.465 | V |
| Ambient Temperature (TA) | –40 | 25 | 85 | °C |
| Junction Temperature (TJ) | 125 | °C | ||
| Output Frequency (fOUT) | 10 | 1000 | MHz | |
| Total Frequency Tolerance | –50 | 50 | ppm | |
| RMS Phase Jitter (fOUT > 100 MHz) | 90 | 200 | fs | |
| PSRR | –70 | dBc | ||
| Output Formats | LVPECL, LVDS, HCSL | |||
| Package Size | 7-mm × 5-mm | |||
| Pins | 8 |
Key Features
- Ultra-Low Noise, High Performance: Jitter of 90 fs RMS typical for frequencies above 100 MHz.
- Robust Supply Noise Immunity: PSRR of –70 dBc.
- Flexible Output Format: User-selectable LVPECL up to 1 GHz, LVDS up to 900 MHz, and HCSL up to 400 MHz.
- Internal EEPROM: User-configurable default settings.
- Frequency Margining: Fine and coarse options through I2C serial interface.
- Device Control: I2C serial interface for programming.
- Operating Voltage: 3.3-V ± 5% supply.
- Industrial Temperature Range: –40°C to +85°C.
- Compact Package: 7-mm × 5-mm 8-Pin QFM (SIA) package.
Applications
- High-Performance Replacement: For crystal-, SAW-, or silicon-based oscillators.
- Networking Equipment: Switches, routers, network line cards, base band units (BBU).
- Servers and Storage: Servers and storage/SAN systems.
- Test and Measurement: High-precision test equipment.
- Medical Imaging: Medical imaging devices requiring low jitter clocks.
- FPGA and Processor Attach: For high-speed data processing applications.
Q & A
- What is the typical jitter of the LMK61E2? The typical jitter is 90 fs RMS for frequencies above 100 MHz.
- What are the available output formats for the LMK61E2? The device supports LVPECL up to 1 GHz, LVDS up to 900 MHz, and HCSL up to 400 MHz.
- What is the operating voltage range of the LMK61E2? The device operates from a single 3.3-V ± 5% supply.
- What is the temperature range for the LMK61E2? The device operates within an industrial temperature range of –40°C to +85°C.
- How is the LMK61E2 programmed? The device is programmed through an I2C serial interface.
- What is the package size of the LMK61E2? The device comes in a 7-mm × 5-mm 8-Pin QFM (SIA) package.
- What is the total frequency tolerance of the LMK61E2? The total frequency tolerance is ±50 ppm.
- Does the LMK61E2 have internal power conditioning? Yes, it provides excellent power supply ripple rejection (PSRR).
- What are some common applications of the LMK61E2? Common applications include high-performance replacement for oscillators, networking equipment, servers, test and measurement, medical imaging, and FPGA/processor attach.
- How does the LMK61E2 support system design verification tests? The device provides fine and coarse frequency margining options through the I2C serial interface.
