Diodes Incorporated PI6C4931504-04LIEX

Overview

PI6C4931504-04LIEX from Diodes Incorporated is a high-performance 4-output HCSL fanout buffer supporting up to 250MHz clock distribution with ultra-low additive phase jitter (<0.1 ps typ), 1.5ns typical propagation delay, and dual selectable inputs (CLK0/nCLK0 or CLK1). It operates from 2.5V or 3.3V supply and is qualified for industrial temperature range (–40°C to +85°C), deployed in high-speed networking switch clock trees.

For engineers reviewing the PI6C4931504-04LIEX datasheet, PI6C4931504-04LIEX pinout, PI6C4931504-04LIEX application, or PI6C4931504-04LIEX equivalent, key selection criteria include HCSL output compliance, input source select logic (CLK_SEL), output enable control (CLK_EN), IREF-based current setting, and TSSOP-20 thermal/power layout constraints.

Technical Context

This device implements a low-skew, single-ended-to-differential HCSL fanout architecture with two independent clock input paths selected via a dedicated CLK_SEL pin. Input switching is asynchronous and does not require synchronization logic.

Each of the four differential HCSL outputs (Q0/nQ0 through Q3/nQ3) delivers matched rise/fall times (175–700 ps), 48–52% duty cycle, and <100 ps output skew. Propagation delay is tightly controlled at 1.5 ns typ with <600 ps part-to-part skew under load.

Key Specifications

Pinout & Package

TSSOP-20 package (173 mil width), lead-free and RoHS 3 compliant, with exposed pad not present. Thermal resistance θ_JA = 120°C/W (JEDEC standard board).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar HCSL fanout buffer applications.

Compared with IDT 8T49N241 and NB3N5104, the PI6C4931504-04LIEX offers optimal balance of 250 MHz bandwidth, sub-0.1 ps jitter, and TSSOP-20 footprint-making it preferred for space-constrained, high-frequency fanout-only use cases without synthesis needs.

Availability

PI6C4931504-04LIEX is available at Aetrix Electronics and suitable for 10GbE line cards, PCIe Gen3 switch fabric, and high-density router backplanes requiring stable component supply, long-term lifecycle assurance, and RoHS 3-compliant sourcing.

Supply support for PI6C4931504-04LIEX includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Diodes Incorporated is a global manufacturer of discrete semiconductors and integrated circuits, specializing in high-performance analog, logic, and timing solutions for industrial, computing, and communications markets.

The PI6C4931504-04 belongs to Diodes' Pericom timing product line, engineered specifically for low-jitter clock distribution in high-speed data infrastructure where signal integrity and layout simplicity are critical.

FAQ

What is the recommended external resistor value for IREF?

The IREF pin sets HCSL output current via an external resistor to ground. For nominal 14 mA per output leg at 3.3 V, a 1.2 kΩ ±1% resistor is recommended. At 2.5 V, use 909 Ω. Resistor tolerance directly affects output swing accuracy and should be ≤1% for jitter-critical applications.

Does PI6C4931504-04LIEX support spread-spectrum clocking (SSC)?

No. The PI6C4931504-04LIEX is a fixed-frequency fanout buffer with no internal modulation circuitry or SSC input support. It preserves input clock spectral content without intentional spreading. For SSC applications, a separate modulated source must drive CLK0/nCLK0 or CLK1.

Can CLK_EN be toggled dynamically during operation?

Yes. CLK_EN supports real-time enable/disable of all HCSL outputs without disrupting internal biasing or causing glitches. Output transitions are monotonic and bounded by specified rise/fall times. No minimum pulse width is required, but metastability filtering is not implemented - avoid asynchronous assertion relative to input clocks.

Is there a thermal pad on the TSSOP-20 package?

No. The PI6C4931504-04LIEX uses a standard TSSOP-20 package (173 mil width) without an exposed thermal pad. Thermal dissipation relies on PCB copper area connected to the three VDD pins and GND pin. Recommended layout includes ≥2 cm² of 2-oz copper pour tied to Pin 1 (GND) for industrial-temp operation at full load.