Renesas 551SDCGI

Overview

The 551SDCGI from Renesas Electronics is a high-speed, low-jitter 1-to-4 non-inverting clock buffer in 8-SOIC package, delivering sub-50 fs additive phase jitter (45 fs typical), 50 ps max output-to-output skew, and support for input/output frequencies up to 200 MHz at 1.8–3.3 V supply. It serves as a precision timing distribution element in high-speed networking infrastructure.

For engineers reviewing the 551SDCGI datasheet, 551SDCGI pinout, 551SDCGI application, or 551SDCGI equivalent, this device is selected for low-skew clock fanout where additive jitter, thermal stability across –40°C to +105°C, and OE-controlled tri-state outputs are critical design requirements.

Technical Context

The 551SDCGI implements a fully buffered, non-PLL architecture with internal pull-up resistors on ICLK and OE inputs, enabling direct connection to open-drain or CMOS logic without external biasing. Its output enable (OE) pin asserts high-impedance state on all four Qx outputs when driven low.

It operates across three voltage rails (1.8 V, 2.5 V, 3.3 V) with rail-specific DC/AC specs - including 17 Ω nominal output impedance, 0.6–1.0 ns rise/fall times, and propagation delay of 1.5–2.5 ns - ensuring consistent signal integrity across mixed-voltage system designs.

Key Specifications

Pinout & Package

Package: 8-pin SOIC (DCG8D1), 4.90 × 3.90 × 1.75 mm body, 1.27 mm pitch, JEDEC-compliant surface-mount outline.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT 5PB1102PGI and TI LMK00304RGTT, the 551SDCGI uniquely combines quad CMOS outputs, multi-voltage operation, OE control, and industry-leading 45 fs additive jitter in an 8-pin SOIC - making it optimal for space-constrained, low-jitter, thermally demanding clock distribution.

Availability

551SDCGI is available at Aetrix Electronics and suitable for 10G Ethernet switch fabric, PCIe Gen4 clock trees, and 5G baseband unit timing modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 551SDCGI 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 specializing in microcontrollers, analog, power, and timing solutions for automotive, industrial, and infrastructure markets.

The 551S family - including 551SDCGI - was designed specifically for high-fidelity clock distribution in networking, communications, and data center applications where ultra-low jitter and thermal robustness are mandatory.

FAQ

What is the maximum supported input clock frequency for the 551SDCGI?

The 551SDCGI supports input and output clock frequencies up to 200 MHz under specified load conditions (5 pF with 33 Ω series termination near each output). This capability is validated across all supported supply voltages (1.8 V, 2.5 V, 3.3 V) and the full –40°C to +105°C operating temperature range, making the 551SDCGI suitable for high-speed DDR memory clocks and SerDes reference distribution.

Does the 551SDCGI require external pull-up or pull-down resistors on its ICLK or OE pins?

No, the 551SDCGI includes internal pull-up resistors on both ICLK and OE pins, eliminating the need for external biasing components. The OE pin is active-low and defaults to enabled (outputs active) when left floating due to the internal pull-up. This simplifies board layout and reduces BOM count while maintaining reliable startup behavior in the 551SDCGI.

How does the 551SDCGI handle different supply voltages, and are there any derating requirements?

The 551SDCGI is fully characterized and guaranteed across three discrete supply rails: 1.8 V (±5%), 2.5 V (±5%), and 3.3 V (±5%). Each voltage has dedicated AC/DC specifications - including VOH/VOL, propagation delay, and jitter - with no derating required. The 551SDCGI maintains 200 MHz operation and 45 fs additive jitter across all three rails, enabling seamless integration into mixed-voltage platforms without performance trade-offs.

What is the thermal resistance (ΘJA) of the 551SDCGI in its 8-SOIC package?

The 551SDCGI in 8-SOIC (DCG8D1) package has a thermal resistance of ΘJA = 150 °C/W under still air conditions, 140 °C/W at 1 m/s airflow, and 120 °C/W at 3 m/s airflow. These values are measured per JEDEC JESD51 standards and confirm the 551SDCGI's suitability for thermally constrained environments such as densely packed networking line cards, where junction temperature must remain below 125°C under continuous 22 mA supply current at 3.3 V.

Can the 551SDCGI be used in place of a PLL-based clock generator for jitter-sensitive applications?

The 551SDCGI is a non-PLL, zero-delay buffer - not a clock generator - so it does not synthesize new frequencies or provide multiplication/division. However, for jitter-sensitive applications requiring fanout only, the 551SDCGI delivers superior additive jitter (45 fs) compared to most PLL-based alternatives (typically >100 fs), making it ideal as a final-stage buffer after a PLL to clean and distribute a clean reference. It should not replace a PLL when frequency translation is needed, but it enhances overall system jitter performance when placed downstream.