Diodes Incorporated PI6LC4830ZHE

Overview

PI6LC4830ZHE from Pericom Semiconductor is a low-phase-noise LC-VCO-based clock generator optimized for PCIe® 2.0 timing applications, delivering three 100MHz HCSL outputs, one selectable 100/50MHz LVCMOS output, and one 25MHz LVPECL reference output with PLL bypass mode, all from a 3.3V supply in a 32-pin 5×5mm TQFN package.

For engineers reviewing the PI6LC4830ZHE datasheet, PI6LC4830ZHE pinout, PI6LC4830ZHE application, or PI6LC4830ZHE equivalent, key selection criteria include RMS phase jitter (≤1ps, 12kHz–20MHz), HCSL/LVCMOS/LVPECL output flexibility, crystal or differential input support, OE-controlled output enable/disable timing (≤80ns), and integrated 25MHz oscillator core with ±30ppm crystal compatibility.

Technical Context

The PI6LC4830ZHE implements an LC-based VCO architecture to achieve ultra-low phase noise-critical for PCIe 2.0 compliance-enabling >10dB noise margin improvement over traditional ring-oscillator PLLs. Its dual-input mux supports either 25MHz fundamental-mode crystal (X1/X2) or differential HCSL/LVPECL/LVDS signals (IN+/IN−), selected via LVCMOS IN_SEL.

Output routing includes independent bank control: QA0–QA2 (HCSL), QA_CMOS/QB_CMOS (LVCMOS), REF_OUT (LVPECL), and QB_DIV2-selectable 50/100MHz division. PLL_Byps enables direct input-to-output path for test-mode timing validation without PLL latency or jitter contribution.

Key Specifications

Pinout & Package

Package: 32-pin, 5mm × 5mm, 0.5mm pitch, exposed-pad TQFN (ZH code), RoHS-compliant and halogen-free.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar clock generator applications.

Compared with ICS8430I-01T and Si5338A-D-GM, the PI6LC4830ZHE delivers superior jitter performance and hardware-configurable simplicity for PCIe 2.0–focused designs, trading programmability for lower latency, smaller footprint, and guaranteed out-of-box timing compliance.

Availability

PI6LC4830ZHE is available at Aetrix Electronics and suitable for PCIe 2.0 root complexes, enterprise SSD controllers, and network switch ASIC synchronization requiring stable component supply, long-term lifecycle assurance, and consistent electrical performance across production batches.

Supply support for PI6LC4830ZHE 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 (acquired by Diodes Incorporated in 2016) specialized in high-performance timing, interface, and signal-integrity solutions for datacenter, networking, and storage applications.

The PI6LC4830 belongs to Pericom's HiFlex™ clock generator family, engineered specifically for PCIe 2.0 and high-speed serial link timing integrity-emphasizing low jitter, multi-standard output flexibility, and robust crystal integration.

FAQ

What crystal specifications are required for reliable PI6LC4830ZHE operation?

The PI6LC4830ZHE requires a 25MHz fundamental-mode parallel-resonant crystal with 18pF load capacitance, ±30ppm tolerance, and ≤50Ω ESR. Recommended parts include GC2500003 (4.0mm 49S/SMD) and FL2500047 (3.2×2.5mm SMD). C1/C2 load capacitors (27pF/33pF typical) must be tuned per board layout to achieve target ppm accuracy.

How does PLL bypass mode affect output timing and jitter?

In PLL bypass mode (PLL_Byps = high), the input signal (crystal or differential) is routed directly to output buffers-eliminating PLL-induced jitter and lock time. Output jitter reverts to the source's native phase noise (e.g., crystal's 0.2ps RMS), and timing aligns deterministically with input edges, making it ideal for debug, fail-safe operation, or jitter-sensitive test setups.

Can the PI6LC4830ZHE drive multiple HCSL loads simultaneously?

Yes-the three HCSL outputs (QA0–QA2) each support standard 100Ω differential termination and deliver ≥6mA drive current. Layout must maintain matched trace lengths and controlled impedance; each output requires its own 33Ω series resistor and 49.9Ω Thevenin termination per JEDEC HCSL guidelines to prevent signal degradation or crosstalk.

What is the role of the IREF pin and how should it be configured?

The IREF pin sets HCSL output current bias via an external 475Ω resistor to GND, establishing 2.32mA nominal reference current. This ensures accurate 900mV VOH and 150mV VOL levels across voltage/temperature. Deviation >±12% from nominal current degrades HCSL amplitude and jitter; resistor tolerance must be ≤1% and placed close to the pin with short traces.