Overview
The LMX2594RHAT from Texas Instruments is a high-performance, wideband synthesizer designed to generate frequencies from 10 MHz to 15 GHz without the need for an internal doubler, thereby eliminating the requirement for sub-harmonic filters. This device features a high-performance PLL with a figure of merit of –236 dBc/Hz and a high-phase detector frequency, enabling very low in-band noise and integrated jitter. The synthesizer supports phase synchronization across multiple devices and includes features for generating or repeating SYSREF signals compliant with the JESD204B standard, making it suitable for low-noise clock sources in high-speed data converters.
Key Specifications
| Specification | Value |
|---|---|
| Output Frequency Range | 10 MHz to 15 GHz |
| Phase Noise at 100-kHz Offset | –110 dBc/Hz (at 15-GHz carrier) |
| RMS Jitter | 45 fs at 7.5 GHz (100 Hz to 100 MHz) |
| Figure of Merit | –236 dBc/Hz |
| Normalized 1/f Noise | –129 dBc/Hz |
| Phase Detector Frequency | High phase detector frequency |
| Integer Mode | Up to 400 MHz |
| Fractional Mode | Up to 300 MHz |
| Fractional-N Divider | 32-bit |
| VCO Calibration Speed | < 20 µs |
| Power Supply | 3.3 V single power supply |
| Output Power | Up to 7 dBm at 15-GHz carrier frequency |
| Operating Temperature Range | –40°C to 85°C |
| Package | 40-pin VQFN (RHA) |
Key Features
- Programmable output power
- High-speed N-divider with no pre-divider, reducing spurs
- Programmable input multiplier to mitigate integer boundary spurs
- Synchronization of output phase across multiple devices
- Support for SYSREF with 9-ps resolution programmable delay (compliant to JESD204B standard)
- Frequency ramp and chirp generation ability for FMCW applications
- Fast VCO calibration speed of less than 20 µs
- Integrated LDOs eliminating the need for on-board low noise LDOs
Applications
The LMX2594RHAT is suitable for a variety of high-performance applications, including:
- High-speed data converters requiring low-noise clock sources
- Frequency Modulated Continuous Wave (FMCW) radar systems
- Phase-locked loop (PLL) applications needing high phase detector frequency and low jitter
- Wireless communication systems requiring wideband frequency synthesis
- Test and measurement equipment demanding precise frequency generation
Q & A
- What is the output frequency range of the LMX2594RHAT?
The output frequency range of the LMX2594RHAT is from 10 MHz to 15 GHz. - What is the phase noise performance of the LMX2594RHAT?
The phase noise at a 100-kHz offset is –110 dBc/Hz with a 15-GHz carrier. - What is the RMS jitter of the LMX2594RHAT at 7.5 GHz?
The RMS jitter at 7.5 GHz is 45 fs (100 Hz to 100 MHz). - Does the LMX2594RHAT support SYSREF signals?
Yes, it supports SYSREF signals with 9-ps resolution programmable delay, compliant to the JESD204B standard. - What is the VCO calibration speed of the LMX2594RHAT?
The VCO calibration speed is less than 20 µs. - What is the power supply requirement for the LMX2594RHAT?
The device operates from a single 3.3-V power supply. - What is the maximum output power of the LMX2594RHAT at 15 GHz?
The maximum output power is up to 7 dBm at 15-GHz carrier frequency. - Can the LMX2594RHAT synchronize output phases across multiple devices?
Yes, it supports synchronization of output phase across multiple devices. - What is the operating temperature range of the LMX2594RHAT?
The operating temperature range is from –40°C to 85°C. - What type of package does the LMX2594RHAT come in?
The device comes in a 40-pin VQFN (RHA) package.
