LMK00804B Low Skew, 1-to-4 Multiplexed Differential/LVCMOS-to-LVCMOS/TTL Fanout Buffer

1 Features

• Four LVCMOS/LVTTL Outputs with 7 Ω Output Impedance
  • Additive Jitter: 0.04 ps RMS (typ) @ 125 MHz
  • Noise Floor: –166 dBc/Hz (typ) @ 125 MHz
  • Output Frequency: 350 MHz (max)
  • Output Skew: 35 ps (max)
  • Part-to-Part Skew: 700 ps (max)
• Two Selectable Inputs
  • CLK, nCLK Pair Accepts LVPECL, LVDS, HCSL, SSTL, LVHSTL, or LVCMOS/LVTTL
  • LVCMOS_CLK Accepts LVCMOS/LVTTL
• Synchronous Clock Enable
• Core/Output Power Supplies:
  • 3.3 V/3.3 V
  • 3.3 V/2.5 V
  • 3.3 V/1.8 V
  • 3.3 V/1.5 V
• Package: 16-Lead TSSOP
• Industrial Temperature Range: –40ºC to +85ºC

2 Applications

• Wireless and Wired Infrastructure
• Networking and Data Communications
• Servers and Computing
• Medical Imaging
• Portable Test and Measurement
• High-End A/V

3 Description

The LMK00804B is a low skew, high performance clock fanout buffer which can distribute up to four LVCMOS/LVTTL outputs (3.3-V, 2.5-V, 1.8-V, or 1.5-V levels) from one of two selectable inputs, which can accept differential or single-ended inputs. The clock enable input is synchronized internally to eliminate runt or glitch pulses on the outputs when the clock enable terminal is asserted or de-asserted. The outputs are held in logic low state when the clock is disabled. A separate output enable terminal controls whether the outputs are active state or high-impedance state. The low additive jitter and phase noise floor, and guaranteed output and part-to-part skew characteristics make the LMK00804B ideal for applications demanding high performance and repeatability.

See also Device Comparison Table for descriptions of CDCLVC1310 and LMK00725 parts.

1. For all available packages, see the orderable addendum at the end of the datasheet.

4 Simplified Schematic

1. R_PU = 51 kΩ pullup, R_PD = 51 kΩ pulldown. See Figure 10

Additive Jitter vs VDDO Supply and Temperature

5 Device Comparison Table