Renesas 551SCMGI

Overview

The 551SCMGI from Renesas Electronics is a high-speed, low-additive-jitter 1-to-4 clock buffer IC designed for precision timing distribution in networking and communications systems. It delivers sub-50 fs RMS additive phase jitter, 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 551SCMGI datasheet, 551SCMGI pinout, 551SCMGI application, or 551SCMGI equivalent, this device serves as a critical timing component where low-noise clock fanout, fast enable/disable control, and extended industrial temperature operation (-40°C to +105°C) are required.

Technical Context

The 551SCMGI implements a non-PLL, CMOS-based fanout architecture with internal pull-up resistors on ICLK and OE inputs. Its output enable (OE) pin provides synchronous tri-state control of all four outputs without propagation delay skew between channels.

It operates across three voltage domains (1.8 V, 2.5 V, 3.3 V), with matched AC characteristics-including 0.6 ns typical rise/fall times and ≤4 ns max propagation delay-and maintains consistent 50 ps output skew regardless of supply voltage or loading condition.

Key Specifications

Pinout & Package

551SCMGI is packaged in an 8-pin DFN (2.0 × 2.0 × 0.5 mm, 0.5 mm pitch), JEDEC-compliant surface-mount package optimized for high-density PCB layouts and thermal performance (ΘJA = 140.7°C/W in still air).

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT5V9885BGI and NB3N511DG, the 551SCMGI offers the lowest additive jitter (45 fs), integrated OE functionality, and optimal balance of channel count, voltage flexibility, and industrial temperature rating for space-constrained networking designs.

Availability

551SCMGI is available at Aetrix Electronics and suitable for 10G Ethernet PHY clock distribution, PCIe Gen1 fanout, and DDR memory controller timing applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for 551SCMGI 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 is a global semiconductor leader specializing in microcontrollers, analog, power, and timing solutions for automotive, industrial, and infrastructure markets.

The 551S family was engineered specifically for high-fidelity clock distribution in networking and communications equipment, emphasizing ultra-low jitter, low skew, and industrial reliability without PLL complexity.

FAQ

What is the maximum supported clock frequency for the 551SCMGI?

The 551SCMGI supports input and output clock frequencies up to 200 MHz when driving a 5 pF load with a 33 Ω series termination resistor placed close to each output pin. This specification is validated across all supported supply voltages (1.8 V, 2.5 V, 3.3 V) and the full industrial temperature range (-40°C to +105°C). The 551SCMGI maintains consistent timing performance-including rise/fall times ≤1.0 ns and skew ≤50 ps-at this maximum frequency.

Does the 551SCMGI require external pull-up or pull-down resistors on its control pins?

No, the 551SCMGI includes internal pull-up resistors on both the ICLK and OE pins, eliminating the need for external biasing components. The OE pin is active-high and defaults to enabled (outputs active) when left floating due to the internal pull-up. This simplifies board design and reduces BOM count while ensuring predictable startup behavior across temperature and voltage variations.

How does the 551SCMGI achieve its sub-50 fs additive phase jitter specification?

The 551SCMGI achieves 45 fs additive phase jitter (RMS, 12 kHz–20 MHz) through a proprietary low-noise CMOS buffer architecture with optimized signal path symmetry and minimized internal switching noise coupling. Unlike PLL-based buffers, it uses a direct fanout topology-avoiding multiplication-induced jitter-while leveraging Renesas' advanced process and layout techniques to suppress substrate and supply noise contributions to the output clock.

Can the 551SCMGI operate with different supply voltages on the same board?

Yes, the 551SCMGI is fully specified to operate across 1.8 V, 2.5 V, and 3.3 V supply rails, with all AC and DC parameters guaranteed over each voltage range. Its input thresholds scale with VDD (VIH = 0.7×VDD, VIL = 0.3×VDD), and output drive strength adjusts accordingly (VOH/VOL specs differ per voltage). This allows seamless integration into mixed-voltage systems without level shifters or additional logic.

What package type is used for the 551SCMGI, and what are its key mechanical features?

The 551SCMGI uses an 8-pin DFN package (package code CMG8D1), measuring 2.0 mm × 2.0 mm × 0.5 mm with 0.5 mm pitch. It is JEDEC-compliant, features an exposed thermal pad for enhanced heat dissipation, and supports standard SMD reflow profiles. The recommended land pattern follows NSMD (non-solder-mask-defined) copper definition for optimal solder joint reliability and thermal transfer to the PCB ground plane.