Skyworks Solutions Inc. SI52112-A1-GM2

Overview

SI52112-A1-GM2 from Skyworks Solutions is a PCIe Gen 1 dual-output clock generator IC that sources two 100 MHz HCSL differential clocks from a 25 MHz crystal or clock input, operates at 3.3 V, supports –40 to +85 °C extended temperature range, and uses a 10-pin TDFN (3×3 mm) package for compact embedded timing applications.

For engineers reviewing the SI52112-A1-GM2 datasheet, SI52112-A1-GM2 pinout, SI52112-A1-GM2 application, or SI52112-A1-GM2 equivalent, key selection criteria include PCIe Gen 1 compliance, absence of spread spectrum, dual 100 MHz HCSL outputs, 3.3 V supply, and 10-pin TDFN footprint compatibility with high-density PCB layouts.

Technical Context

The SI52112-A1-GM2 integrates a PLL-based frequency synthesis architecture to generate two identical 100 MHz differential clock outputs from a single 25 MHz reference, with no external termination resistors required due to integrated HCSL output drivers. It accepts either crystal (XIN/XOUT) or single-ended clock input (CLKIN), and features internal power regulation optimized for low-noise timing performance.

Unlike the A2 variant, the SI52112-A1-GM2 lacks spread spectrum modulation-making it suitable for systems where deterministic jitter behavior is prioritized over EMI reduction. Its DC specifications include 17 mA typical supply current and 3–5 pF input/output pin capacitance, supporting stable operation across the full extended temperature range.

Key Specifications

Pinout & Package

SI52112-A1-GM2 is housed in a 10-pin TDFN package (3×3 mm, 0.75 mm height) with exposed thermal pad, compliant with JEDEC MO-229 and RoHS6/Pb-free standards.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SI52112-A2-GM2, SI52112-A1-GM2 offers lower peak-to-peak jitter (no modulation sidebands) but no EMI suppression; versus IDT8T49N242BGI, it trades programmability and Gen 2/3 readiness for minimal size, lower power, and cost efficiency in fixed Gen 1 deployments.

Availability

SI52112-A1-GM2 is available at Aetrix Electronics and suitable for Network Attached Storage, Multi-function Printers, Wireless Access Points, Routers, and other PCIe Gen 1–based embedded systems requiring stable component supply and long-term lifecycle continuity.

Supply support for SI52112-A1-GM2 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

Skyworks Solutions is a global semiconductor company specializing in analog and mixed-signal connectivity solutions, with leadership in RF, timing, and power management technologies.

The SI52112-A1-GM2 belongs to Skyworks' Si521xx PCIe clock generator family, designed specifically to replace legacy crystal oscillators and simplify timing architecture in cost-sensitive, space-constrained consumer and embedded platforms.

FAQ

Does SI52112-A1-GM2 support spread spectrum clocking?

No, SI52112-A1-GM2 does not support spread spectrum clocking. This capability is exclusive to the SI52112-A2 variant, which implements a fixed –0.5% down-spread profile at 31.5 kHz. The SI52112-A1-GM2 delivers deterministic, fixed-frequency 100 MHz outputs ideal for jitter-sensitive applications where modulation artifacts must be avoided.

What is the maximum allowable input clock duty cycle for SI52112-A1-GM2?

The SI52112-A1-GM2 specifies a CLKIN duty cycle range of 45% to 55% at VDD/2 threshold, per Table 3 in the datasheet. Operation outside this window may degrade cycle-to-cycle jitter performance or cause startup failure. For reliable operation, ensure the 25 MHz input clock maintains tight duty cycle control, especially in noisy or high-temperature environments where SI52112-A1-GM2 remains active.

Can SI52112-A1-GM2 drive both PCIe and SATA interfaces simultaneously?

Yes, SI52112-A1-GM2 supports SATA at 100 MHz as stated in its features list, and its dual 100 MHz HCSL outputs meet both PCIe Gen 1 and SATA Gen II clock requirements. Each DIFF output can independently feed a PCIe root port or SATA controller, provided trace lengths and impedance matching follow Skyworks' recommended layout guidelines to maintain <60 ps skew and <86 ps Pk-Pk jitter for SI52112-A1-GM2.

Is the XOUT pin required when using an external 25 MHz clock source on SI52112-A1-GM2?

No, the XOUT pin must be left floating when using an external 25 MHz clock applied to the XIN/CLKIN pin. The SI52112-A1-GM2 automatically disables its internal crystal oscillator circuitry in CLKIN mode, and driving or loading XOUT in this configuration may cause instability or increased jitter. Always follow the "Float XOUT" instruction in Table 7 of the SI52112-A1-GM2 datasheet.

What is the thermal resistance (θJA) of the SI52112-A1-GM2 in its 10-pin TDFN package?

The SI52112-A1-GM2 has a junction-to-ambient thermal resistance (θJA) of 90.4 °C/W under JEDEC JESD 51 conditions, as specified in Table 4. This value assumes standard 2-layer PCB layout with adequate copper pour under the exposed thermal pad. For sustained full-load operation above 70 °C ambient, thermal simulation or empirical testing is recommended to verify junction temperature stays below the 150 °C absolute maximum limit for SI52112-A1-GM2.