Texas Instruments LMX1205 JESD Buffer/Multiplier/Divider
Texas Instruments LMX1205 JESD Buffer/Multiplier/Divider has a high-frequency capability, extremely low jitter, and programmable clock input and output delay. These features make this device a great approach to clock high precision, high-frequency data converters without degradation of signal-to-noise ratio. Each of the four high-frequency clock outputs and additional LOGICLK outputs with a larger divider range is paired with a SYSREF output clock signal. The SYSREF signal for JESD204B/C interfaces can either be passed or internally generated as input and re-clocked to the device clocks. The noiseless delay adjustment at the input path of the high-frequency clock input and individual clock output paths ensures low-skew clocks in a multi-channel system. For the data converter clocking application, having the jitter of the clock less than the aperture jitter of the data converter is essential. In applications where more than four data converters need to be clocked, various cascading architectures can be developed using multiple devices to distribute all the SYSREF signals and high-frequency clocks required. The Texas Instruments LMX1205 is an exemplary choice for clocking data converters when combined with an ultra-low noise reference clock source, especially when sampling above 3GHz.Features
- Output frequency of 300MHz to 12.8GHz
- Noiseless adjustable input delay up to 60ps with 1.1ps resolution
- Individual adjustable output delays up to 55ps with 0.9ps resolution
- Four high-frequency clocks with corresponding SYSREF outputs
- Shared divide by 1 (Bypass), 2, 3, 4, 5, 6, 7, and 8
- Shared programmable multiplier x2, x3, x4, x5, x6, x7 and x8
- LOGICLK output with corresponding SYSREF output
- On separate divider bank
- 1, 2, 4 pre-divider
- 1 (bypass), 2, …, 1023 post divider
- Second logic clock option with additional dividers 1, 2, 4, and 8
- Ultra-low noise
- Noise floor: –159dBc/Hz at 6GHz output
- Additive jitter (DC to fCLK): 36fs
- Additive jitter (100Hz to 100MHz): 10fs
- Six programmable output power levels
- Synchronized SYSREF clock outputs
- 508 delay step adjustments of less than 2.5ps at 12.8GHz
- Generator, repeater, and repeater retime modes
- Windowing feature for SYSREFREQ pins to optimize timing
- SYNC feature to all divides and multiple devices
- 2.5V operating voltage
- –40ºC to +85ºC operating temperature
Applications
- Test and measurement
- Oscilloscope
- Wireless equipment testers
- Wideband digitizers
- General purpose
- Data converter clocking
- Clock buffer distribution/division
- Aerospace and defense
- Radar
- Electronic warfare
- Seeker front end
- Munitions
- Phase array antenna/beam forming
Block Diagram
Đã phát hành: 2025-03-06
| Đã cập nhật: 2025-03-28
