Overview
The LMK1D2104RHDR is a high-performance, low additive jitter LVDS clock buffer produced by Texas Instruments. This device is part of the LMK1D210x family, designed to distribute clock signals with minimal skew and low jitter. It features dual input channels that can fan out to up to eight pairs of differential LVDS clock outputs, making it suitable for applications requiring precise clock distribution.
The LMK1D2104RHDR operates in a 1.8-V, 2.5-V, or 3.3-V supply environment and is characterized over a temperature range of -40°C to 105°C. The device is packaged in a 28-pin VQFN (RHD) package with an exposed pad for enhanced thermal dissipation.
Key Specifications
| Parameter | Value | Notes |
|---|---|---|
| Package Type | VQFN (28-pin) | Exposed Pad |
| Package Size | 5.00 mm × 5.00 mm | Nominal value, includes pins |
| Supply Voltage | 1.8 V, 2.5 V, 3.3 V | |
| Operating Temperature | -40°C to 105°C | Ambient temperature |
| Input Types | LVDS, LVPECL, HCSL, CML, LVCMOS | |
| Output Configuration | Dual 1:4 differential buffer | Up to 8 pairs of differential LVDS outputs |
| Maximum Clock Frequency | Up to 2 GHz | |
| Additive Jitter | Low additive jitter (e.g., 39.7 fs RMS at 156.25 MHz) | |
| Output Skew | Low output skew |
Key Features
- Low Additive Jitter: The LMK1D2104RHDR is designed to minimize additive jitter, ensuring high signal integrity.
- Dual Input and Output Banks: The device features dual input channels that can fan out to up to eight pairs of differential LVDS clock outputs.
- Flexible Input Types: Supports LVDS, LVPECL, HCSL, CML, and LVCMOS input signals.
- Control Pin (EN): Allows for enabling or disabling of output banks.
- Fail-Safe Inputs: Designed to support fail-safe input operation, preventing damage when inputs are driven before VDD is applied.
- Input Hysteresis: Prevents random oscillation of outputs in the absence of an input signal.
- Termination Flexibility: Supports both DC- and AC-coupling schemes for LVDS outputs.
Applications
The LMK1D2104RHDR is particularly suited for applications requiring high-performance clock distribution, such as:
- JESD204B/C ADC Systems: Ideal for distributing ADC clocks and SYSREF clocks in JESD204B/C systems.
- High-Speed Data Acquisition: Suitable for systems that require low jitter and precise clock distribution.
- Telecommunication and Networking Equipment: Used in applications where high-speed clock signals need to be distributed with minimal skew and jitter.
- Industrial and Medical Equipment: Applicable in environments where precise timing and low noise are critical.
Q & A
- What is the maximum clock frequency supported by the LMK1D2104RHDR?
The LMK1D2104RHDR supports clock frequencies up to 2 GHz.
- What types of input signals does the LMK1D2104RHDR support?
The device supports LVDS, LVPECL, HCSL, CML, and LVCMOS input signals.
- How many output pairs can the LMK1D2104RHDR generate?
The device can generate up to eight pairs of differential LVDS clock outputs.
- What is the significance of the control pin (EN) in the LMK1D2104RHDR?
The control pin (EN) allows for enabling or disabling of the output banks.
- How does the LMK1D2104RHDR handle input signals in the absence of VDD?
The device is designed with fail-safe inputs, preventing damage when inputs are driven before VDD is applied.
- What is the recommended termination for LVDS outputs?
Texas Instruments recommends terminating unused outputs differentially with a 100-Ω resistor for optimum performance.
- What are the power supply voltage options for the LMK1D2104RHDR?
The device operates with supply voltages of 1.8 V, 2.5 V, or 3.3 V.
- How does the LMK1D2104RHDR manage output skew?
The device is designed to minimize output skew, ensuring precise clock distribution.
- What is the typical application scenario for the LMK1D2104RHDR in JESD204B/C systems?
The device is used to fan out ADC clocks and SYSREF clocks in JESD204B/C systems, ensuring low jitter and precise timing.
- How important is power supply noise management for the LMK1D2104RHDR?
Power supply noise can significantly impact the additive jitter of the buffer. Therefore, it is crucial to reduce noise using filter capacitors and bypass capacitors.
