Renesas 651SCMGI

Overview

651SCMGI from Renesas Electronics is a low-skew, single-input-to-four-output clock buffer designed for high-speed timing distribution in networking and communications systems. It delivers sub-50 fs additive phase jitter (45 fs measured), 50 ps max output-to-output skew, and supports input/output frequencies up to 200 MHz across 1.8 V–3.3 V supply rails.

For engineers reviewing the 651SCMGI datasheet, 651SCMGI pinout, 651SCMGI application, or 651SCMGI equivalent, this device is selected for precision clock fanout where low jitter, tight skew control, and extended temperature operation (−40°C to +105°C) are critical in telecom infrastructure and FPGA-based timing subsystems.

Technical Context

The 651SCMGI is a non-PLL, CMOS-based clock buffer with rail-to-rail input compatibility and four identical non-inverting outputs. Its architecture provides deterministic propagation delay (1.5–4 ns depending on VDD and frequency) and output enable-controlled tri-state functionality without internal feedback loops.

It operates across three standard logic voltages (1.8 V, 2.5 V, 3.3 V), maintains duty cycle fidelity from input to outputs, and uses an advanced low-power CMOS process optimized for thermal stability over −40°C to +105°C ambient conditions.

Key Specifications

Pinout & Package

651SCMGI is packaged in an 8-pin DFN (2 mm × 2 mm body, 0.5 mm pitch), RoHS-compliant, with exposed thermal pad. Pin 6 is GND, Pin 7 is VDD, and Pin 8 is OE - all with internal pull-up resistors. Decoupling (0.01 µF) must be placed between Pins 6 and 7.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 651SDCGI and PI6C557-03LEX, the 651SCMGI uniquely combines 4-output fanout, −40°C to +105°C operation, OE control, and DFN thermal efficiency-making it the preferred choice for space-constrained, thermally demanding industrial and telecom timing nodes.

Availability

651SCMGI is available at Aetrix Electronics and suitable for 5G infrastructure, enterprise switching, and industrial automation requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for 651SCMGI 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

Renesas Electronics Corporation is a global semiconductor leader delivering microcontrollers, analog, power, and timing solutions for automotive, industrial, and infrastructure markets.

The 651S family-including 651SCMGI-is engineered specifically for high-fidelity clock distribution in networking, telecom, and high-speed data acquisition systems where jitter and skew directly impact system-level BER and latency.

FAQ

What is the maximum supported clock frequency for the 651SCMGI?

The 651SCMGI supports input and output clock frequencies up to 200 MHz under 5 pF load conditions, as verified across all supported supply voltages (1.8 V, 2.5 V, 3.3 V). This makes the 651SCMGI suitable for PCIe Gen2, Gigabit Ethernet, and DDR2/3 memory interface clocking without derating.

Does the 651SCMGI require external termination resistors?

The 651SCMGI has a nominal output impedance of 17 Ω and recommends a 33 Ω series resistor on each Q1–Q4 output when trace length exceeds 1 inch. This configuration achieves controlled impedance matching and minimizes reflections-critical for maintaining signal integrity at 200 MHz.

How does the Output Enable (OE) pin function on the 651SCMGI?

The OE pin on the 651SCMGI is active-low with an internal pull-up resistor. When asserted low, it places all four outputs (Q1–Q4) into high-impedance state within ≤3 clock cycles. This enables dynamic clock tree shutdown without affecting upstream timing sources or generating glitches.

Is the 651SCMGI pin-compatible with other devices in the 651S family?

Yes-the 651SCMGI shares identical pinout and electrical behavior with other 651S variants including 651SDCGI and 651SCMGI8. All use the same 8-pin functional mapping (ICLK, Q1–Q4, GND, VDD, OE), allowing direct substitution between DFN and SOIC packages where thermal and layout constraints permit.

What is the additive phase jitter specification for the 651SCMGI, and how is it measured?

The 651SCMGI delivers 45 fs RMS additive phase jitter, measured with a 125 MHz input clock over a 12 kHz–20 MHz integration bandwidth. This value is derived from the difference between output (77 fs) and reference input (62 fs) phase noise plots in the official Renesas datasheet-confirming its suitability for low-BER serial link applications.