Skyworks Solutions Inc. SI52111-A1-GT

Overview

SI52111-A1-GT from Silicon Laboratories is a PCIe Gen 1–compliant single-output clock generator delivering a 100 MHz HCSL differential clock from a 25 MHz crystal or clock input, operating at 3.3 V with 13 mA supply current and –40 to +85 °C extended temperature range, used in network-attached storage and wireless access point timing subsystems.

For engineers reviewing the SI52111-A1-GT datasheet, SI52111-A1-GT pinout, SI52111-A1-GT application, or SI52111-A1-GT equivalent, this page provides verified package mapping (8-pin TSSOP), confirmed pin functions, PCIe Gen 1 jitter compliance (24–86 ps pk-pk), spread-spectrum exclusion, and real-world design context for embedded timing integration.

Technical Context

The SI52111-A1-GT integrates a PLL-based frequency synthesizer with fixed 4× multiplication (25 MHz → 100 MHz) and an integrated low-power HCSL output buffer. It accepts either a parallel-resonant 25 MHz crystal (with external load capacitors) or a 25 MHz CMOS clock signal on XIN/CLKIN, with no internal termination required.

Unlike the A2 variant, the SI52111-A1-GT lacks spread-spectrum modulation circuitry-its output is a fixed-frequency, zero-down-spread 100 MHz clock meeting PCIe Gen 1 jitter requirements (≤86 ps pk-pk). The device uses dual VDD pins and dual VSS pins for noise isolation and supports immediate clock stabilization within 3 ms of power-up.

Key Specifications

Pinout & Package

SI52111-A1-GT is housed in an 8-pin TSSOP package (JEDEC MO-153, Variation AA), 3.00 mm × 6.40 mm body size, 0.65 mm pitch, with exposed pad not connected internally.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PCIe Gen 1 clock generation applications.

Compared with SI52111-A2-GT, the SI52111-A1-GT delivers lower peak-to-peak jitter and eliminates spread-spectrum modulation complexity; versus IDT8T49N242AKILF, it reduces package size, power, and BOM cost at the expense of output count and gating flexibility.

Availability

SI52111-A1-GT is available at Aetrix Electronics and suitable for network-attached storage, wireless access points, and multi-function printers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for SI52111-A1-GT 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

Silicon Laboratories is a U.S.-based semiconductor company specializing in timing, MCU, and connectivity solutions, with over two decades of expertise in precision clock generation and mixed-signal IC design.

The Si52111 product line delivers single- and multi-output PCIe clock generators optimized for cost-sensitive, space-constrained embedded systems requiring Gen 1 timing compliance without design overhead.

FAQ

What is the primary clock output frequency of the SI52111-A1-GT?

The SI52111-A1-GT generates a fixed 100 MHz differential HCSL clock output, derived from a 4× PLL multiplication of its 25 MHz crystal or clock input. This frequency satisfies the PCIe Gen 1 reference clock requirement and is also compatible with SATA 100 MHz timing. No configuration or programming is required-the SI52111-A1-GT operates as a plug-and-play clock source with no external components beyond decoupling capacitors.

Does the SI52111-A1-GT support spread-spectrum clocking?

No, the SI52111-A1-GT does not support spread-spectrum clocking. Spread-spectrum functionality is exclusive to the SI52111-A2 variants (e.g., SI52111-A2-GT), which provide –0.5% down-spread modulation at 31.5 kHz. The SI52111-A1-GT delivers a fixed-frequency 100 MHz output with lower inherent jitter, making it preferred for applications where EMI reduction is handled elsewhere or where jitter-critical timing is prioritized.

What package type is used for the SI52111-A1-GT?

The SI52111-A1-GT uses an 8-pin TSSOP package (JEDEC MO-153, Variation AA), measuring 3.00 mm × 6.40 mm with 0.65 mm lead pitch. This package differs from the 10-pin TDFN used in GM2/GM2R variants and is explicitly designated by the "T" suffix in the part number. Its larger footprint improves manufacturability in wave-soldered or hand-assembled prototypes compared to TDFN.

Can the SI52111-A1-GT accept both crystal and clock inputs?

Yes, the SI52111-A1-GT accepts either a 25 MHz parallel-resonant crystal connected between XIN/CLKIN and XOUT, or a 25 MHz CMOS-level clock signal applied directly to the XIN/CLKIN pin. When using a clock input, XOUT must be left floating. The device automatically detects and adapts to the selected reference mode-no configuration pins or registers are involved. This dual-input capability simplifies design reuse across crystal- and oscillator-based platforms.

What is the maximum allowable jitter for PCIe Gen 1 compliance with the SI52111-A1-GT?

The SI52111-A1-GT guarantees PCIe Gen 1 peak-to-peak jitter of 24–86 ps, measured differentially at 0 V crossing point, fully satisfying the PCI-SIG Gen 1 specification limit of ≤1.0 UI (≈100 ps at 100 MHz). This value is validated across voltage (2.97–3.63 V) and temperature (–40 to +85 °C) ranges, ensuring robust link training and stable operation in real-world embedded systems without additional jitter cleanup circuitry.