Diodes Incorporated PI6C4911504D2LIEX

Overview

PI6C4911504D2LIEX from Pericom Semiconductor is a high-performance LVPECL clock buffer with integrated ÷2 frequency division, dual selectable differential inputs (REF_IN0/REF_IN1), and four LVPECL outputs (two CLKA pairs, two CLKB pairs). It operates at up to 650 MHz, delivers 30 fs typical RMS additive jitter at 156.25 MHz (12 kHz–20 MHz), and supports 2.5 V or 3.3 V core/output supplies for low-jitter clock distribution in multi-destination 10–100GbE systems.

For engineers reviewing the PI6C4911504D2LIEX datasheet, PI6C4911504D2LIEX pinout, PI6C4911504D2LIEX application, or PI6C4911504D2LIEX equivalent, key selection criteria include its dual-muxed differential input architecture, deterministic 60 ps output skew, industrial temperature range (−40°C to +85°C), TSSOP-20 lead-free packaging, and compatibility with high-speed serial timing trees requiring sub-100 fs jitter performance.

Technical Context

The PI6C4911504D2LIEX implements a fully differential signal path with internal termination biasing and synchronous clock enable (CLK_EN) and master reset (M_RESET) control logic. Its dual-input multiplexer selects between REF_IN0± or REF_IN1± using CLK_SEL, while each output bank (CLKA/CLKB) provides one ÷2 LVPECL pair and one non-divided buffered LVPECL pair.

It uses separate VDD (core), VDDO (output), and VEE (negative supply) rails to isolate switching noise, enabling stable low-jitter operation. Input common-mode range is VEE + 0.5 V to VDD − 0.85 V, supporting both AC- and DC-coupled differential or single-ended inputs via external bias networks.

Key Specifications

Pinout & Package

PI6C4911504D2LIEX is housed in a Pb-free, green, 20-pin TSSOP (Package Code L, 173 mil wide) with exposed pad thermal enhancement per JEDEC MO-153F/AC.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LVPECL clock buffer with ÷2 applications.

Compared with IDT8T49N242A and NB3N502M, PI6C4911504D2LIEX uniquely combines dual-muxed inputs, deterministic ÷2 outputs, and 30 fs jitter - making it optimal for high-reliability, multi-source clock distribution where phase integrity and source agility are critical.

Availability

PI6C4911504D2LIEX is available at Aetrix Electronics and suitable for 10–100GbE networking equipment, wireless base station radios, and optical transport network cards requiring stable component supply, long-term lifecycle assurance, and traceable Pb-free sourcing.

Supply support for PI6C4911504D2LIEX 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

Pericom Semiconductor (now part of Diodes Incorporated) specialized in high-speed interface and timing solutions for communications, computing, and industrial markets before its 2016 acquisition.

The PI6C49xxx series was designed specifically for ultra-low-jitter clock distribution in multi-gigabit serial systems - emphasizing input flexibility, output skew control, and robust industrial operation without PLL complexity.

FAQ

What are the recommended termination networks for PI6C4911504D2LIEX LVPECL outputs?

Each LVPECL differential pair requires a Thevenin termination: 150 Ω source resistor to ground and a 100 Ω AC-coupling load across CLK/CLK#. For DC-coupled loads, use 120 Ω (3.3 V) or 82 Ω (2.5 V) pull-downs with 100 Ω across outputs. Output traces must be length-matched within 5 mm to maintain skew spec.

Can PI6C4911504D2LIEX accept single-ended input signals?

Yes - single-ended LVCMOS or LVTTL inputs can be applied to REF_IN0+ or REF_IN1+ with the complementary pin (REF_IN0−/REF_IN1−) biased to VDD/2 using a 1 kΩ resistor divider. The internal 51 kΩ pulldown on REF_IN− and pullup on REF_IN+ assist bias stability, but external biasing improves noise immunity.

How does the CLK_EN pin interact with the M_RESET pin?

CLK_EN and M_RESET operate independently: CLK_EN gates output activity synchronously with the selected input clock edge, while M_RESET forces all outputs to static states (CLKn = low, CLKn# = high) asynchronously. Both pins have internal pull resistors - CLK_EN pulls up, M_RESET pulls down - so external resistors are optional but recommended for noise immunity.

Is PI6C4911504D2LIEX pin-compatible with earlier Pericom clock buffers like PI6C20400?

No - PI6C4911504D2LIEX uses a 20-pin TSSOP with dedicated VDDO pins and dual VDD/VEE supplies, whereas PI6C20400 is a 16-pin SOIC with single VCC and no negative rail. Pin functions, supply architecture, and output count differ fundamentally; PCB redesign is required for replacement.