Overview
The LMK00304SQX/NOPB from Texas Instruments is a 3-GHz, 4-output ultra-low additive jitter differential clock buffer and level translator. This device is designed for high-frequency, low-jitter clock and data distribution, making it ideal for various high-speed digital systems. It features a 3:1 input multiplexer with two universal inputs that can operate up to 3.1 GHz and accept multiple clock formats such as LVPECL, LVDS, CML, SSTL, HSTL, HCSL, or single-ended clocks. Additionally, it includes a crystal input that can accept a 10-MHz to 40-MHz crystal or single-ended clock.
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 | |||
| Crystal Input Frequency Range | 10 MHz | 40 MHz | ||
| LVPECL Additive Jitter (10 kHz to 1 MHz) | 20 fs RMS | |||
| LVPECL Additive Jitter (12 kHz to 20 MHz) | 51 fs RMS | |||
| PSRR (LVPECL/LVDS) at 156.25 MHz | -65 / -76 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.
- Ultra-low additive jitter: 20 fs RMS (10 kHz to 1 MHz) and 51 fs RMS (12 kHz to 20 MHz) for LVPECL outputs.
- High PSRR: -65 / -76 dBc (LVPECL/LVDS) at 156.25 MHz.
- LVCMOS output with synchronous enable input for runt-pulse-free operation.
- Pin-controlled configuration.
- 3.3 V core supply and 3 independent 3.3 V/2.5 V output supplies.
- 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.
- High-frequency backplanes, switches, routers, line cards, timing cards.
- Servers, computing, 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 LMK00304 accept?
The LMK00304 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 is the additive jitter performance of the LMK00304 for LVPECL outputs?
The additive jitter is 20 fs RMS (10 kHz to 1 MHz) and 51 fs RMS (12 kHz to 20 MHz) for LVPECL outputs.
- What is the PSRR of the LMK00304 at 156.25 MHz?
The PSRR is -65 / -76 dBc (LVPECL/LVDS) at 156.25 MHz.
- What are the output configuration options for the differential outputs?
The differential outputs can be configured as LVPECL, LVDS, HCSL, or Hi-Z.
- What is the operating temperature range of the LMK00304?
The operating temperature range is -40°C to +85°C.
- What is the package type of the LMK00304?
The package type is a 32-lead WQFN (5 mm × 5 mm).
- What are some common applications of the LMK00304?
Common applications include clock distribution and level translation for high-speed digital systems, servers, computing, and remote radio units.
- How is the output supply voltage configured for the LMK00304?
The LMK00304 has 3 independent output supplies that can operate at 3.3 V or 2.5 V.
