Overview
The LMK00304SQ/NOPB is a 3-GHz 4-output ultra-low additive jitter differential clock buffer and level translator produced by Texas Instruments. This device is designed for high-frequency, low-jitter clock and data distribution, making it ideal for various high-speed applications. It features a 3:1 input multiplexer, allowing selection from two universal inputs or one crystal input, and distributes the selected clock to two banks of differential outputs and one LVCMOS output. The device operates from a 3.3 V core supply and three independent 3.3 V/2.5 V output supplies, ensuring high performance, versatility, and power efficiency.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Ambient Temperature Range | -40 | 25 | 85 | °C |
| Junction Temperature | 125 | °C | ||
| Core Supply Voltage Range | 3.15 | 3.3 | 3.45 | V |
| Output Supply Voltage Range | 2.5 - 5% | 2.5/3.3 | 2.5 + 5% / 3.3 + 5% | V |
| Input Frequency Range (Universal Inputs) | 3.1 GHz | |||
| Input Frequency Range (Crystal Input) | 10 MHz | 40 MHz | ||
| LVPECL Additive Jitter (10 kHz to 1 MHz) | 20 fs RMS | |||
| PSRR (LVPECL at 156.25 MHz) | -65 dBc | |||
| Package Type | 32-lead WQFN (5 mm × 5 mm) |
Key Features
- 3:1 input multiplexer with two universal inputs operating up to 3.1 GHz and accepting LVPECL, LVDS, CML, SSTL, HSTL, HCSL, or single-ended clocks.
- One crystal input accepting a 10-MHz to 40-MHz crystal or single-ended clock.
- Two banks with 2 differential outputs each, configurable as LVPECL, LVDS, HCSL, or Hi-Z.
- LVCMOS output with synchronous enable input for runt-pulse-free operation.
- High PSRR: -65 dBc (LVPECL) and -76 dBc (LVDS) at 156.25 MHz.
- Pin-controlled configuration.
- Industrial temperature range: -40°C to +85°C.
Applications
- Clock distribution and level translation for ADCs, DACs, multi-gigabit Ethernet, XAUI, Fibre Channel, SATA/SAS, SONET/SDH, CPRI, and high-frequency backplanes.
- Switches, routers, line cards, and timing cards.
- Servers, computing, and PCI Express (PCIe 3.0).
- Remote radio units and baseband units.
Q & A
- What is the maximum frequency of the universal inputs on the LMK00304?
The universal inputs on the LMK00304 can operate up to 3.1 GHz.
- What types of clock signals can the universal inputs accept?
The universal inputs can accept LVPECL, LVDS, CML, SSTL, HSTL, HCSL, or single-ended clocks.
- What is the range of the crystal input frequency?
The crystal input can accept frequencies from 10 MHz to 40 MHz.
- What are the output configurations available for the differential outputs?
The differential outputs can be configured as LVPECL, LVDS, HCSL, or Hi-Z.
- What is the typical additive jitter for LVPECL outputs at 156.25 MHz?
The typical additive jitter for LVPECL outputs at 156.25 MHz is 20 fs RMS (10 kHz to 1 MHz).
- What is the power supply voltage range for the core and output supplies?
The core supply voltage range is 3.3 V ± 5%, and the output supply voltage range is 2.5 V ± 5% or 3.3 V ± 5%.
- What is the package type and size of the LMK00304?
The LMK00304 comes in a 32-lead WQFN package with dimensions of 5 mm × 5 mm.
- What is the industrial temperature range of the LMK00304?
The industrial temperature range is -40°C to +85°C.
- What are some common applications of the LMK00304?
Common applications include clock distribution and level translation for various high-speed systems, switches, routers, servers, and remote radio units.
- How does the LMK00304 ensure high PSRR?
The LMK00304 ensures high PSRR with values of -65 dBc for LVPECL and -76 dBc for LVDS at 156.25 MHz.
