SNAS642A June   2014  – July 2014 LMK00804B

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
  4. Simplified Schematic
  5. Device Comparison Table
  6. Pin Configuration and Functions
  7. Specifications
    1. 7.1  Pin Characteristics
    2. 7.2  Absolute Maximum Ratings
    3. 7.3  Handling Ratings
    4. 7.4  Recommended Operating Conditions
    5. 7.5  Thermal Information
    6. 7.6  Power Supply Characteristics
    7. 7.7  LVCMOS / LVTTL DC Characteristics
    8. 7.8  Differential Input DC Characteristics
    9. 7.9  Electrical Characteristics (VDDO = 3.3 V ± 5%)
    10. 7.10 Electrical Characteristics (VDDO = 2.5 V ± 5%)
    11. 7.11 Electrical Characteristics (VDDO = 1.8 V ± 0.15 V)
    12. 7.12 Electrical Characteristics (VDDO = 1.5 V ± 5%)
    13. 7.13 Typical Characteristics
  8. Parameter Measurement Information
  9. Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
      1. 9.2.1
    3. 9.3 Feature Description
      1. 9.3.1 Clock Enable Timing
    4. 9.4 Device Functional Modes
      1. 9.4.1 Clock Input Function
  10. 10Applications and Implementation
    1. 10.1 Application Information
    2. 10.2 Output Clock Interface Circuit
    3. 10.3 Input Detail
    4. 10.4 Input Clock Interface Circuits
    5. 10.5 Typical Applications
      1. 10.5.1 Design Requirements
      2. 10.5.2 Detailed Design Procedure
      3. 10.5.3 Application Curves
        1. 10.5.3.1 System-Level Phase Noise and Additive Jitter Measurement
    6. 10.6 Do's and Don'ts
      1. 10.6.1 Power Considerations
      2. 10.6.2 Recommendations for Unused Input and Output Pins
      3. 10.6.3 Input Slew Rate Considerations
  11. 11Power Supply Recommendations
    1. 11.1 Power Supply Considerations
      1. 11.1.1 Power-Supply Filtering
      2. 11.1.2 Thermal Management
  12. 12Layout
    1. 12.1 Layout Guidelines
      1. 12.1.1 Ground Planes
      2. 12.1.2 Power Supply Pins
      3. 12.1.3 Differential Input Termination
      4. 12.1.4 LVCMOS Input Termination
      5. 12.1.5 Output Termination
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
    2. 13.2 Trademarks
    3. 13.3 Electrostatic Discharge Caution
    4. 13.4 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

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.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
LMK00804B TSSOP (16) 5.00 mm × 4.40 mm
  1. For all available packages, see the orderable addendum at the end of the datasheet.

4 Simplified Schematic

0001.gif
1. RPU = 51 kΩ pullup, RPD = 51 kΩ pulldown. See Figure 10

Additive Jitter vs VDDO Supply and Temperature

C002_Jadd_at_125M_vs_VDDO_TEMP_snas626.png