Diodes Incorporated PI6CG15401ZHIEX

Overview

PI6CG15401 from Diodes Incorporated is an ultra-low-power, 4-output PCIe Gen1–Gen4 clock generator with on-chip HCSL termination, 25 MHz crystal/CMOS input, and 100 MHz differential outputs. It integrates a proprietary low-jitter PLL, supports SMBus or strapping-pin configuration, and delivers <50 ps cycle-to-cycle jitter and <50 ps output-to-output skew for high-speed serial link timing in server backplanes and storage controllers.

For engineers reviewing the PI6CG15401 datasheet, PI6CG15401 pinout, PI6CG15401 application, or PI6CG15401 equivalent, key selection criteria include PCIe Gen4 compliance, per-output enable/disable control (OE0#–OE3#), programmable slew rate/amplitude via SMBus or pins, spread-spectrum selection (0% / –0.25% / –0.5%), and integrated 33 Ω on-die series termination eliminating 16 external resistors.

Technical Context

The PI6CG15401 employs a fully integrated PLL architecture optimized for PCIe reference clock distribution, with independent analog (VDDA/VDD_OSC) and digital (VDD_DIG/VDDO) power domains to isolate noise-sensitive oscillator and output stages. Its phase-locked loop achieves sub-1 ps RMS phase jitter on the CMOS REFOUT and meets PCIe Gen4 integrated jitter limits (≤0.5 ps RMS) across all four HCSL outputs.

Configuration is supported via dual modes: hardwired strapping (SS_SEL_TRI, SADR, OE# pins) for boot-time setup, and 3.3 V-tolerant SMBus interface (SCLK/SDATA) for runtime reprogramming of slew rate, amplitude, spread spectrum, and output enables - enabling board-level optimization without hardware changes.

Key Specifications

Pinout & Package

Package: 32-lead 5×5 mm TQFN (ZH), 0.5 mm pitch, exposed thermal pad.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT8T49N242 and Si53320-B-GM, the PI6CG15401 uniquely combines 1.5 V operation, on-die HCSL termination, and tri-level spread-spectrum control - delivering lower system BOM cost, reduced layout complexity, and superior EMI suppression for Gen4-capable server and storage platforms.

Availability

PI6CG15401 is available at Aetrix Electronics and suitable for server backplanes, PCIe switch cards, storage controllers, and embedded AI accelerator boards requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for PI6CG15401 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 timing, power management, and signal integrity solutions for computing, communications, and industrial markets.

The PI6CG15401 belongs to Diodes' PCIe-optimized clock generator product line, designed specifically to meet the low-jitter, low-power, and integration demands of Gen1–Gen4 serial link infrastructure in data center and enterprise storage systems.

FAQ

What is the function of the SS_SEL_TRI pin?

The SS_SEL_TRI pin is a tri-level latched input that sets the initial spread-spectrum modulation amount at power-up: logic '0' disables spread spectrum, 'M' (mid-voltage ≈0.5×VDD) selects –0.25% down-spread, and '1' selects –0.5% down-spread. It operates independently of SMBus and provides hardware-configurable EMI reduction without firmware dependency.

Does PI6CG15401 support PCIe Gen5 timing requirements?

No - the PI6CG15401 is specified and validated for PCIe Gen1 through Gen4 (100 MHz, 100 ppm accuracy, ≤0.5 ps RMS integrated jitter). It does not meet Gen5's 32 GT/s requirements (200 MHz output, tighter jitter specs), and its datasheet makes no Gen5 claims. For Gen5, Diodes recommends the PI6CG2040x family.

How does the on-chip HCSL termination work electrically?

The PI6CG15401 integrates a 33 Ω series resistor within each HCSL output driver (Q0+/- through Q3+/-), matched to standard 100 Ω differential PCB trace impedance. This eliminates the need for external 33 Ω resistors, reduces signal reflections at the source, and improves rise/fall time symmetry - verified by differential output swing (300–1450 mV) and skew (<50 ps) measurements.

Can REFOUT be used as a system reset synchronizer?

No - REFOUT is a buffered 100 MHz LVCMOS clock output with <1.5 ps RMS phase jitter and 45–55% duty cycle, intended as a low-noise timing reference. It lacks reset assertion capability, edge-triggered control, or glitch-free startup behavior required for reset synchronization. Use dedicated reset ICs (e.g., Diodes APX803) for that function.