Renesas 9DB433AGLFT

Overview

9DB433AGLFT from Renesas Electronics (formerly IDT) is a 4-output, 0.7V current-mode differential HCSL zero-delay/fanout buffer optimized for PCIe Gen1–3 clock distribution. It supports PLL and bypass modes, delivers <50ps output-to-output skew and <1.0ps rms phase jitter in PCIe Gen3 mode, and operates across 5–166MHz depending on mode - deployed in server motherboard clock trees and add-in card reference clock fanout.

For engineers reviewing the 9DB433AGLFT datasheet, 9DB433AGLFT pinout, 9DB433AGLFT application, or 9DB433AGLFT equivalent, key selection criteria include PCIe Gen3-compliant additive jitter (<1.0ps rms), tri-level SMBus address selection for multi-device bus sharing, OE#-controlled output enable/disable for ExpressCard power management, and spread-spectrum compatibility for EMI reduction.

Technical Context

The 9DB433AGLFT implements a dual-path architecture: a low-jitter PLL path (50–110MHz, selectable 0.7–4.1MHz bandwidth) for dejittering upstream clocks, and a direct bypass path (5–166MHz) with <10ps additive jitter. Its four HCSL outputs are independently controllable via OE1#/OE6# pins and SMBus registers, supporting both free-run and stoppable operation per output pair.

It features analog-sensitive power domains - VDDR (differential input supply), VDDA (PLL core supply), and GNDA - requiring separate filtering; IREF pin sets output current via external 475Ω resistor to achieve 100Ω differential impedance. Tri-level inputs (BYP#_HIBW_LOBW, SMB_ADR_tri) latch at power-up and define operating mode and SMBus address without external logic.

Key Specifications

Pinout & Package

9DB433AGLFT is housed in a RoHS-compliant, lead-free 28-pin TSSOP package (JEDEC MO-153, 9.6×4.4mm body, 0.65mm pitch). The package supports automated assembly and provides thermal and electrical performance suitable for high-density PCIe clock routing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 9DB433AGLFT, the 9DB434AGLFT adds hardware OE control flexibility at identical cost and footprint, while the PI6C557-03LEX trades PCIe-specific jitter performance for broader signaling and frequency coverage - making 9DB433AGLFT the preferred choice for Gen3-constrained, jitter-critical server and storage designs.

Availability

9DB433AGLFT is available at Aetrix Electronics and suitable for server motherboard design, PCIe add-in card development, and industrial backplane integration requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for 9DB433AGLFT 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, formed through the acquisition of IDT in 2019, is a global semiconductor leader delivering trusted analog, mixed-signal, and timing solutions for infrastructure, automotive, and industrial markets.

The 9DB433AGLFT belongs to Renesas' high-performance timing portfolio, engineered specifically for PCIe Gen1–3 clock distribution - emphasizing ultra-low jitter, spread-spectrum compatibility, and flexible power management in dense compute platforms.

FAQ

What is the maximum input frequency supported by the 9DB433AGLFT in bypass mode?

The 9DB433AGLFT supports input frequencies from 5MHz to 166MHz in bypass mode, as specified in the Electrical Characteristics table (Fibyp parameter). This range covers PCIe Gen1 (100MHz), Gen2 (200MHz requires divider), and Gen3 (250MHz requires external divider or PLL mode), though Gen3 compliance is achieved via PLL dejittering rather than direct bypass at 250MHz.

Does the 9DB433AGLFT require an external crystal or oscillator?

No, the 9DB433AGLFT does not require an external crystal or oscillator. It is a buffer - not a clock generator - and relies entirely on an external differential clock source (e.g., from an IDT 932S421 or equivalent main clock generator) applied to SRC_IN/SRC_IN#. The internal PLL uses this input as its reference; no standalone timing element is needed.

How is the 9DB433AGLFT's output impedance configured for 100Ω differential loads?

The 9DB433AGLFT's output impedance is set via the IREF pin: connecting a precision 475Ω resistor from IREF to GND establishes 2.32mA reference current, which configures the internal current sources to deliver 0.7V HCSL output into a 100Ω differential load (50Ω per side). Deviations from 475Ω adjust drive strength for non-standard impedances.

Can the 9DB433AGLFT operate in industrial temperature range (–40°C to +85°C)?

The 9DB433AGLFT variant is rated for commercial temperature range (0°C to +70°C). For industrial operation, Renesas offers the 9DB433AGILFT (Tape & Reel, TSSOP, –40°C to +85°C). Electrical parameters including jitter, skew, and PLL bandwidth are characterized and guaranteed across the full industrial range in that variant.

What happens to the outputs when the PD# pin is asserted on the 9DB433AGLFT?

When PD# is asserted (low), the 9DB433AGLFT disables its PLL and VCO, then drives outputs either high (if PD_Mode bit = 0) or into high-impedance (if PD_Mode bit = 1), based on SMBus register setting. All outputs settle within 1ms, and OE# states are overridden - ensuring deterministic, glitch-free shutdown regardless of prior output enable configuration.