ZL30681LFG7

Overview

The ZL30681LFG7 is a single-channel line card timing IC from the ZL3068x family, manufactured by Microchip Technology. It features one Digital Phase-Locked Loop (DPLL) and five output frequency families derived from two low-jitter synthesizers and one general-purpose synthesizer. The device accepts up to ten differential or CMOS inputs ranging from 1kHz to 900MHz and generates outputs from <1Hz to 1045MHz with high-resolution fractional conversion. Key electrical parameters include input jitter monitoring, per-DPLL phase adjustment with 1ps resolution, and output alignment under 200ps. It operates within a temperature range of -40°C to +85°C and is housed in an 80-lead LGA package measuring 11 x 11 mm.

Feature Summary

• Single DPLL channel with programmable bandwidth (14Hz to 470Hz), hitless reference switching, and high-resolution holdover averaging.
• Five output frequency families: two low-jitter synthesizers (Synth1/2) producing <0.3ps RMS jitter integer dividers and <1ps RMS fractional dividers, plus one general-purpose synthesizer (Synth0).
• Supports up to 10 differential or CMOS inputs (1kHz to 900MHz) with per-input activity/frequency monitoring and 1ps resolution phase measurement.
• Integrated local oscillator support for XOs (23.75-125MHz) or external TCXO/OCXO stability references without requiring external VCXO or loop filter components.

Applications

• Synchronous Ethernet (SyncE) and SyncE+1588 line cards.
• SONET/SDH and OTN carrier-grade system timing.
• Wireless base station synchronization.
• JESD204B clocking and SYSREF signal generation.

Procurement Notes

Verify the ordering suffix 'LFG7' corresponds to the 80-lead LGA package with NiAu (Pb-free) finish and tray packaging as specified in the datasheet. Confirm the operating temperature range requirement is -40°C to +85°C. Ensure design compatibility with the 1.8V and 3.3V core VDD voltages. Check that the application requires only one DPLL channel, as this model differs from the ZL30682 (2-channel) and ZL30683 (3-channel) variants.

Selection Notes

Select the ZL30681LFG7 when a single DPLL channel is sufficient for the timing architecture. Compare against ZL30682 and ZL30683 if multiple independent DPLLs are required for redundant or multi-domain timing. Consider the output count requirements; this device provides up to 16 single-ended or 8 differential outputs from Synth1/2. Verify that the input frequencies do not exceed 900MHz (180MHz max for CMOS inputs) and that the output frequencies fit within the 1045MHz limit (180MHz max for Synth0).

Part Context

The ZL30681LFG7 belongs to the ZL3068x family of line card timing ICs, which also includes the ZL30682 (2-channel) and ZL30683 (3-channel). All models share the same 80-lead LGA package, pinout structure, and core synthesizer capabilities. The primary distinction lies in the number of integrated DPLL channels available for reference selection and holdover management.

Replacement Considerations

Publicly confirmed substitute part numbers are not provided in the source documentation. Designers should consult Microchip for current alternative recommendations or cross-reference based on specific DPLL count and output configuration needs.