SNAS801B
June 2020 – June 2021
LMK05318B
PRODUCTION DATA
1
Features
2
Applications
3
Description
4
Revision History
5
Description (continued)
6
Pin Configuration and Functions
6.1
Device Start-Up Modes
7
Specifications
7.1
Absolute Maximum Ratings
7.2
ESD Ratings
7.3
Recommended Operating Conditions
7.4
Thermal Information: 4-Layer JEDEC Standard PCB
7.5
Thermal Information: 10-Layer Custom PCB
7.6
Electrical Characteristics
7.7
Timing Diagrams
7.8
Typical Characteristics
8
Parameter Measurement Information
8.1
Output Clock Test Configurations
9
Detailed Description
9.1
Overview
9.1.1
ITU-T G.8262 (SyncE) Standards Compliance
9.2
Functional Block Diagram
9.2.1
PLL Architecture Overview
9.2.2
DPLL Mode
9.2.3
APLL-Only Mode
9.3
Feature Description
9.3.1
Oscillator Input (XO_P/N)
9.3.2
Reference Inputs (PRIREF_P/N and SECREF_P/N)
9.3.2.1
Programmable Input Hysteresis
9.3.3
Clock Input Interfacing and Termination
9.3.4
Reference Input Mux Selection
9.3.4.1
Automatic Input Selection
9.3.4.2
Manual Input Selection
9.3.5
Hitless Switching
9.3.5.1
Hitless Switching With 1-PPS Inputs
9.3.6
Gapped Clock Support on Reference Inputs
9.3.7
Input Clock and PLL Monitoring, Status, and Interrupts
9.3.7.1
XO Input Monitoring
9.3.7.2
Reference Input Monitoring
9.3.7.2.1
Reference Validation Timer
9.3.7.2.2
Amplitude Monitor
9.3.7.2.3
Frequency Monitoring
9.3.7.2.4
Missing Pulse Monitor (Late Detect)
9.3.7.2.5
Runt Pulse Monitor (Early Detect)
9.3.7.2.6
Phase Valid Monitor for 1-PPS Inputs
9.3.7.3
PLL Lock Detectors
9.3.7.4
Tuning Word History
9.3.7.5
Status Outputs
9.3.7.6
Interrupt
9.3.8
PLL Relationships
9.3.8.1
PLL Frequency Relationships
9.3.8.2
Analog PLLs (APLL1, APLL2)
9.3.8.3
APLL Reference Paths
9.3.8.3.1
APLL XO Doubler
9.3.8.3.2
APLL1 XO Reference (R) Divider
9.3.8.3.3
APLL2 Reference (R) Dividers
9.3.8.4
APLL Phase Frequency Detector (PFD) and Charge Pump
9.3.8.5
APLL Feedback Divider Paths
9.3.8.5.1
APLL1 N Divider With SDM
9.3.8.5.2
APLL2 N Divider With SDM
9.3.8.6
APLL Loop Filters (LF1, LF2)
9.3.8.7
APLL Voltage Controlled Oscillators (VCO1, VCO2)
9.3.8.7.1
VCO Calibration
9.3.8.8
APLL VCO Clock Distribution Paths (P1, P2)
9.3.8.9
DPLL Reference (R) Divider Paths
9.3.8.10
DPLL Time-to-Digital Converter (TDC)
9.3.8.11
DPLL Loop Filter (DLF)
9.3.8.12
DPLL Feedback (FB) Divider Path
9.3.9
Output Clock Distribution
9.3.10
Output Channel Muxes
9.3.11
Output Dividers (OD)
9.3.12
Clock Outputs (OUTx_P/N)
9.3.12.1
AC-Differential Output (AC-DIFF)
9.3.12.2
HCSL Output
9.3.12.3
1.8-V LVCMOS Output
9.3.12.4
Output Auto-Mute During LOL
9.3.13
Glitchless Output Clock Start-Up
9.3.14
Clock Output Interfacing and Termination
9.3.15
Output Synchronization (SYNC)
9.3.16
Zero-Delay Mode (ZDM) Synchronization for 1-PPS Input and Output
9.4
Device Functional Modes
9.4.1
Device Start-Up Modes
9.4.1.1
EEPROM Mode
9.4.1.2
ROM Mode
9.4.2
PLL Operating Modes
9.4.2.1
Free-Run Mode
9.4.2.2
Lock Acquisition
9.4.2.3
Locked Mode
9.4.2.4
Holdover Mode
9.4.3
PLL Start-Up Sequence
9.4.4
Digitally-Controlled Oscillator (DCO) Mode
9.4.4.1
DCO Frequency Step Size
9.4.4.2
DCO Direct-Write Mode
9.4.5
Zero-Delay Mode Synchronization
9.5
Programming
9.5.1
Interface and Control
9.5.2
I2C Serial Interface
9.5.2.1
I2C Block Register Transfers
9.5.3
SPI Serial Interface
9.5.3.1
SPI Block Register Transfer
9.5.4
Register Map and EEPROM Map Generation
9.5.5
General Register Programming Sequence
9.5.6
EEPROM Programming Flow
9.5.6.1
EEPROM Programming Using Method #1 (Register Commit)
9.5.6.1.1
Write SRAM Using Register Commit
9.5.6.1.2
Program EEPROM
9.5.6.2
EEPROM Programming Using Method #2 (Direct Writes)
9.5.6.2.1
Write SRAM Using Direct Writes
9.5.6.2.2
User-Programmable Fields In EEPROM
9.5.7
Read SRAM
9.5.8
Read EEPROM
9.5.9
EEPROM Start-Up Mode Default Configuration
10
Application and Implementation
10.1
Application Information
10.1.1
Device Start-Up Sequence
10.1.2
Power Down (PDN) Pin
10.1.3
Power Rail Sequencing, Power Supply Ramp Rate, and Mixing Supply Domains
10.1.3.1
Mixing Supplies
10.1.3.2
Power-On Reset (POR) Circuit
10.1.3.3
Powering Up From a Single-Supply Rail
10.1.3.4
Power Up From Split-Supply Rails
10.1.3.5
Non-Monotonic or Slow Power-Up Supply Ramp
10.1.4
Slow or Delayed XO Start-Up
10.2
Typical Application
10.2.1
Design Requirements
10.2.2
Detailed Design Procedure
10.2.3
Application Curves
10.3
Do's and Don'ts
11
Power Supply Recommendations
11.1
Power Supply Bypassing
11.2
Device Current and Power Consumption
11.2.1
Current Consumption Calculations
11.2.2
Power Consumption Calculations
11.2.3
Example
12
Layout
12.1
Layout Guidelines
12.2
Layout Example
12.3
Thermal Reliability
12.3.1
Support for PCB Temperature up to 105 °C
13
Device and Documentation Support
13.1
Device Support
13.1.1
TICS Pro
13.1.2
Related Documentation
13.2
Receiving Notification of Documentation Updates
13.3
Support Resources
13.4
Trademarks
13.5
Electrostatic Discharge Caution
13.6
Glossary
14
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
RGZ|48
MPQF123F
Thermal pad, mechanical data (Package|Pins)
RGZ|48
QFND031W
Orderable Information
snas801b_oa
snas801b_pm
1
Features
One Digital Phase-Locked Loop (DPLL) With:
Hitless Switching: ±50-ps Phase Transient
Programmable Loop Bandwidth With Fastlock
Standards-Compliant Synchronization and Holdover Using a Low-Cost TCXO/OCXO
Two Analog Phase-Locked Loops (APLLs) With Industry-Leading Jitter Performance:
50-fs RMS Jitter at 312.5 MHz (APLL1)
125-fs
RMS Jitter at 155.52 MHz (APLL2)
Two Reference Clock Inputs
Priority-Based Input Selection
Digital Holdover on Loss of Reference
Eight Clock Outputs
with Programmable Drivers
Up to
Six
Different Output Frequencies
AC-LVDS, AC-CML, AC-LVPECL, HCSL, and 1.8-V LVCMOS Output Formats
EEPROM / ROM for Custom Clocks on Power-Up
Flexible Configuration Options
1 Hz (1 PPS) to 800 MHz on Input
and Output
XO/TCXO/OCXO Input: 10 to 100 MHz
DCO Mode: < 0.001 ppb/Step for Precise Clock Steering (IEEE 1588 PTP Slave)
Advanced Clock Monitoring and Status
I
2
C or SPI Interface
PSNR: –83 dBc (50-mVpp Noise on 3.3-V Supply)
3.3-V Supply With 1.8-V, 2.5-V, or 3.3-V Outputs
Industrial Temperature Range: –40 °C to +85 °C