Renesas 9DB803DGLFT

Overview

9DB803DGLFT from IDT is an eight-output 0.7V current-mode differential buffer optimized for PCIe Gen1 and Gen2 reference clock distribution. It supports both PLL-based zero-delay buffer (ZDB) mode (50–100 MHz) and bypass/fanout mode (50–400 MHz), delivers <50 ps cycle-to-cycle jitter, <50 ps output-to-output skew, and meets PCIe Gen2 phase jitter requirements (<3.1 ps rms). It serves as a DB800v2-compliant clock fanout solution in server motherboard and add-in card timing architectures.

For engineers reviewing the 9DB803DGLFT datasheet, 9DB803DGLFT pinout, 9DB803DGLFT application, or 9DB803DGLFT equivalent, this page provides verified technical context, validated pin functions, confirmed PCIe Gen2 timing compliance, SMBus programmability details, and real-world power management behavior under PD# and SRC_STOP# control.

Technical Context

The 9DB803DGLFT integrates a PLL with selectable bandwidth (via HIGH_BW#) and dual-mode operation-BYPASS#/PLL pin selects between low-jitter fanout (no PLL) and zero-delay buffered output. Its 0.7V current-mode differential outputs drive 100Ω HCSL-terminated loads with precision IREF-biasing (475Ω to ground).

It features asynchronous power-down (PD#) and clock-stop (SRC_STOP#) with configurable drive modes, spread-spectrum tolerance (±0.25% center, 0 to −0.5% down), and SMBus interface (SCLK/SDATA, 5V-tolerant, ≤100 kHz) for register-level output enable, PLL bandwidth, and stop-control configuration.

Key Specifications

Pinout & Package

9DB803DGLFT is housed in a 48-pin TSSOP package (7.0 mm × 4.4 mm, 0.5 mm pitch) with exposed thermal pad. Power domains include VDDA/VDDR/GNDA for analog PLL core and VDD/GND for digital I/O.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 9DB801DGLFT and 9DB403DGLFT, the 9DB803DGLFT uniquely combines eight HCSL outputs, SMBus programmability, and selectable PLL bandwidth - making it the only option supporting dynamic, per-output clock control and adaptive jitter optimization in full-featured server and storage platforms.

Availability

9DB803DGLFT is available at Aetrix Electronics and suitable for server motherboard design, PCIe add-in card development, and enterprise storage controller timing requiring stable component supply, long-term lifecycle support, and guaranteed DB800v2 compliance.

Supply support for 9DB803DGLFT 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

IDT (Integrated Device Technology), now part of Renesas Electronics, is a leader in timing, memory interface, and RF power solutions for datacenter, communications, and industrial applications.

The 9DB803DGLFT belongs to IDT's PCIe-optimized clock buffer family, designed specifically to meet Intel DB800v2 and PCIe Gen2/Gen3 timing specifications while delivering flexible power management and configurability for high-density computing platforms.

FAQ

What is the maximum input frequency supported by the 9DB803DGLFT in bypass mode?

The 9DB803DGLFT supports up to 400 MHz in bypass mode, as specified in the Electrical Characteristics table (FiBYPASS = 33–400 MHz). This allows direct fanout of high-frequency reference clocks such as 100 MHz PCIe Gen3 x4 or 200 MHz Gen4 sources without PLL-induced jitter. Operation above 100 MHz requires verification of input slew rate (≥0.4 V/ns) and amplitude (300–1450 mV p-p) per the datasheet.

Does the 9DB803DGLFT support spread-spectrum clocking (SSC)?

Yes, the 9DB803DGLFT is explicitly designed to be spread-spectrum modulation tolerant, supporting 0 to −0.5% down-spread and ±0.25% center-spread modulation at frequencies between 30–33 kHz. This capability is confirmed in the Features/Benefits section and ensures stable operation when driven by SSC-enabled main clock generators like the CK410B+, CK505, or CK509B - critical for EMI reduction in dense server environments.

How does the IREF pin function in the 9DB803DGLFT, and what resistor value is required?

The IREF pin establishes the reference current for all eight 0.7V differential output drivers. It must be connected to a precision 475Ω resistor to ground to set the nominal 2.32 mA reference, enabling correct 6×IREF output drive into 100Ω differential loads. Deviations from 475Ω directly scale output current and voltage swing - e.g., 390Ω yields ~2.8 mA and higher VOD, while 560Ω yields ~2.0 mA and reduced drive strength.

Can the 9DB803DGLFT be used in industrial temperature applications?

Yes, the 9DB803DGLFT is rated for industrial operating temperatures from −40°C to +85°C, as stated in the Absolute Maximum Ratings table. Its IDD3.3OPI (full-active supply current) is specified at 190–225 mA, and power-down current remains ≤8 mA across this range - confirming robust performance in extended-temperature embedded and storage systems where thermal stability is critical.

What is the purpose of the OE_INV pin on the 9DB803DGLFT?

OE_INV is a latched input that selects the polarity of all eight output-enable pins (OE_0–OE_7). When OE_INV = 0, OE_x pins are active-high; when OE_INV = 1, they become active-low (labeled OE0#–OE7# in pin descriptions). This flexibility allows direct interfacing with either GPIOs or dedicated enable logic without external inverters - simplifying PCB design in systems using mixed-signal control architectures.