NXP Semiconductors MPC9315AC

Overview

MPC9315AC from Freescale Semiconductor is a 2.5 V and 3.3 V CMOS PLL-based clock generator IC designed for low-skew clock distribution in telecom, networking, and computing systems. It delivers 8 LVCMOS outputs with configurable frequency ratios (1:1, 1:2, 1:4, 2:1, 4:1), 120 ps max output-to-output skew, and supports clock redundancy via dual LVCMOS inputs (CLK0/CLK1) across –40°C to +85°C.

For engineers reviewing the MPC9315AC datasheet, MPC9315AC pinout, MPC9315AC application, or MPC9315AC equivalent, this device is selected for zero-delay buffer operation, phase-aligned multi-bank clocking, and mid-to-high-performance timing distribution where deterministic skew, programmable division, and 18.75–160 MHz output range are critical.

Technical Context

The MPC9315AC implements a fully integrated analog PLL with external feedback path selection (FB0/FB1) and three independent output banks (A/B/C), each controlled by dedicated divider-select pins (FSELA/FSELB/FSELC). Its VCO operates from 75 MHz to 160 MHz, enabling output frequencies up to 160 MHz (÷1), 80 MHz (÷2), or 40 MHz (÷4) depending on feedback configuration.

It supports static test mode via VCCA = GND, bypassing the PLL to route reference clock directly to outputs, and provides 180° phase inversion on QA0/QA1 via PSELA. Tristate control (OE) disables outputs while breaking the PLL feedback loop, requiring relock upon re-enable.

Key Specifications

Pinout & Package

Package: 32-lead LQFP (7×7 mm², Case 873A-04), Pb-free (AC suffix), with separate analog (VCCA) and digital (VCC) supplies and dedicated ground pins.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ICS853S01I and PI6C557-03, the MPC9315AC uniquely supports external feedback for zero-delay operation, independent bank-level frequency division, and 180° phase inversion-making it irreplaceable in telecom line cards and PowerQUICC systems demanding deterministic timing control.

Availability

MPC9315AC is available at Aetrix Electronics and suitable for telecom infrastructure, network switch fabric, and industrial computing applications requiring stable component supply, long-term lifecycle support, and guaranteed Pb-free compliance.

Supply support for MPC9315AC 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

Freescale Semiconductor (now part of NXP Semiconductors) specialized in high-performance embedded processing and analog timing solutions for communications and industrial markets.

The MPC9315AC belongs to Freescale's Advanced Clock Drivers family, engineered specifically for low-skew, multi-frequency clock generation in telecom and networking equipment operating across extended temperature ranges.

FAQ

What is the maximum output frequency supported by the MPC9315AC?

The MPC9315AC supports a maximum output frequency of 160 MHz in ÷1 configuration when the VCO operates at 160 MHz with ÷1 feedback. This occurs with f_ref = 160 MHz and FSELA/FSELB/FSELC set to select 1:1 division. Output frequencies scale down to 80 MHz (÷2) or 40 MHz (÷4) based on divider settings and feedback path selection.

How does the MPC9315AC achieve zero-delay buffer functionality?

The MPC9315AC achieves zero-delay buffering by routing one of its outputs (e.g., QB3) back to FB0 or FB1 to close the PLL feedback loop. This aligns the output edge with the reference clock edge, reducing static phase offset to ±150 ps. The effective insertion delay consists of t(∅), I/O jitter, feedback trace delay, and output skew-enabling sub-300 ps part-to-part timing uncertainty.

Can the MPC9315AC operate with both 2.5 V and 3.3 V supplies simultaneously?

Yes-the MPC9315AC supports dual-supply operation: VCC (digital core) and VCCA (analog PLL) may be independently set to either 2.5 V or 3.3 V. DC characteristics are specified separately for each voltage, and AC performance (jitter, skew, frequency range) varies accordingly-e.g., VCO range remains 75–160 MHz at both voltages, but output drive strength differs.

What is the purpose of the VCCA pin and why does it require an RC filter?

VCCA supplies the analog PLL circuitry and is highly sensitive to power supply noise-especially in the 100 kHz–20 MHz band-which directly degrades I/O jitter. An RC filter (e.g., 270 Ω + 1 µF for 3.3 V) attenuates this noise. Without filtering, VCCA noise couples into the VCO, increasing phase jitter beyond the specified 8–25 ps (1σ) limit.

Does the MPC9315AC support spread spectrum clocking (SSC)?

Yes-the MPC9315AC's fully integrated PLL supports spread spectrum clocking as stated in its official features list. SSC modulation reduces EMI by dithering the output clock frequency within a defined range, though specific modulation depth and rate parameters are not detailed in the Rev. 4 datasheet and require consultation of Freescale application notes or newer revisions.