CDCDB803ERSLR: Complete Guide to TI's 8-Output PCIe Gen 1-6 Clock Buffer

The Texas Instruments CDCDB803ERSLR is a DB800ZL-compliant, 8-output low-power HCSL (LP-HCSL) clock buffer engineered for PCIe Gen 1 through Gen 6, QPI, UPI, SAS, and SATA reference clock distribution. It takes a single HCSL input clock and fans it out 1:8 to eight differential outputs, each capable of driving 100-ohm differential transmission lines, with support up to a 250 MHz maximum frequency. The device operates from a 3.3 V supply, features an SMBus interface for configuration, and provides eight individual output enable pins for independent power management of each output. It is packaged in a 48-VFQFN (6x6 mm) surface-mount package with an exposed pad, operates from -40C to +85C, and is RoHS compliant. The device meets or exceeds both the DB800ZL and DB2000Q specifications, and lifecycle status is active. As of 2026-09-02, XAIPART lists the CDCDB803ERSLR in stock (99,999 units) with pricing from $4.50 (qty 1) down to $2.88 (qty 1,000+), MOQ 1.

What Is the CDCDB803ERSLR and Why Does It Matter for PCIe Designs?

The CDCDB803ERSLR is a high-performance clock buffer from Texas Instruments in the Clock & Timing category. A clock buffer takes one input clock signal and distributes it to multiple outputs with minimal skew and jitter, keeping timing synchronized across a system — a critical function in servers, networking equipment, and data centers.

What sets the CDCDB803ERSLR apart is its LP-HCSL output signaling, a low-power variant of HCSL that reduces power consumption while maintaining signal integrity. Because it is a DB800ZL-compliant derivative that also meets or exceeds the DB2000Q specification, it drops directly into designs standardized on Intel reference clock requirements for PCIe.

How Do You Select and Design In the CDCDB803ERSLR?

Follow these steps to design the CDCDB803ERSLR into a PCIe or server clock tree:

Step 1 — Confirm interface compatibility. The buffer supports PCIe Gen 1 to Gen 6, QPI, UPI, SAS, and SATA. For PCIe designs, the input is HCSL logic (pins 43 CLKIN / 44 CLKIN#) and each output is LP-HCSL, capable of driving 100-ohm differential transmission lines directly to PCIe clock inputs without external translation.

Step 2 — Plan the power delivery. The device runs from a single 3.3 V supply with multiple VDD pins (3, 7, 11, 15, 19, 23, 27, 31, 45) paired with adjacent GND pins. Place decoupling capacitors close to the power pins; a clean, well-decoupled supply is essential for optimal jitter performance.

Step 3 — Terminate the LP-HCSL outputs correctly. Proper termination of each LP-HCSL output is required for signal integrity on 100-ohm differential transmission lines. [VERIFY_NEEDED: exact termination network component values — consult the TI datasheet termination guidance.]

Step 4 — Configure control. Use the eight output enable pins (OE0–OE7, pins 35–42) for hardwired per-output control, and the SMBus interface (SMB_CLK pin 33, SMB_DAT pin 34) for dynamic configuration: enabling/disabling individual outputs, setting output slew rates, and adjusting other parameters from an SMBus host. Powering down unused outputs saves energy in power-managed systems.

Step 5 — Feed a clean input clock. The input clock must be clean and within the specified frequency range (maximum 250 MHz) to achieve optimal additive jitter performance. For PCIe, this is typically the 100 MHz reference clock.

Step 6 — Layout for the 6x6 mm VQFN. The 48-VFQFN package has an exposed pad for thermal dissipation and suits compact PCB designs. Keep differential pairs length-matched and route clock traces away from noisy signals [VERIFY_NEEDED: specific trace length matching tolerances — see datasheet layout section].

What Are the Key Pins of the CDCDB803ERSLR?

The 48-pin VQFN arranges eight differential output pairs symmetrically around the die, with VDD/GND pairs between each output pair, the SMBus and OE control cluster on pins 33–42, and the differential clock input on pins 43–44. The full pin table lives on the CDCDB803ERSLR product page; the functionally critical pins are summarized below.

Which Alternatives and Drop-In Replacements Exist for the CDCDB803ERSLR?

The verified alternatives below come directly from the XAIPART product database. Cross-brand options are pin-compatible but always verify pinout and specifications against the datasheet before substitution.

[DATA_NEEDED: detailed specification values (frequency, supply voltage, package) for each alternative — these are not in the provided database.]

Where Is the CDCDB803ERSLR Used? Real-World Application Scenarios

PCIe Reference Clock Distribution. The buffer distributes a single 100 MHz reference clock to multiple PCIe slots or devices with low jitter and skew. LP-HCSL outputs drive PCIe clock inputs directly, DB800ZL compliance guarantees Intel platform compatibility, and SMBus-based dynamic enabling/disabling reduces overall system power.

Server Motherboards. Provides clean reference clocks to CPU, memory, and I/O controllers; the 8 outputs fan out to multiple PCIe root complexes and QPI/UPI links. The applications database cites low additive jitter (typically <1 ps) for reliable high-speed transfer. Verified specs used: 3.3 V supply, 48-VFQFN (6x6 mm), 8 outputs.

Networking Switches. Distributes reference clocks to PHYs, MACs, and switch fabrics; PCIe Gen 1-6 support ensures compatibility with modern high-speed Ethernet controllers, while individual output enables let unused ports power down and SMBus enables remote configuration and monitoring.

Storage Arrays. Provides reference clocks to multiple SAS/SATA disk controllers and expanders; DB800ZL compliance ensures signal integrity on high-speed serial links and the 250 MHz maximum frequency supports future storage standards in power-constrained enclosures.

High-Performance Computing. Distributes clocks to multiple GPUs, accelerators, and interconnects; low jitter maintains data integrity in high-speed links, SMBus allows dynamic clock gating during idle periods, and the small footprint enables high-density boards.

Telecom Infrastructure. Distributes reference clocks to line cards and network processors; multi-standard support (PCIe, QPI, UPI) adds versatility and the compact 48-pin VQFN suits dense line cards.

How Do You Build a Complete PCIe Clock Distribution Solution With This Buffer?

Problem: A server motherboard needs to distribute one 100 MHz PCIe reference clock to eight PCIe devices with low skew, per-output power control, and Intel DB800ZL platform compliance.

Approach: Feed a clean 100 MHz HCSL source into CLKIN/CLKIN# (pins 43/44). Connect all nine VDD pins to a 3.3 V rail with local decoupling at each pin pair. Route each of the eight LP-HCSL output pairs (OUT0–OUT7, pins 1–30) as 100-ohm differential transmission lines to the target devices. Wire OE0–OE7 (pins 35–42) to the BMC GPIO or pull to the desired logic level for per-slot control, and attach SMB_CLK/SMB_DAT (pins 33/34) to the chassis SMBus for runtime slew and enable configuration.

Calculations: Input:output ratio is 1:8, so one buffer covers eight loads; two cascaded buffers cover 16 slots. Frequency margin: 100 MHz PCIe reference clock is 40% of the 250 MHz maximum frequency rating. Supply current per output and total power [DATA_NEEDED: supply current specification].

Results: A DB800ZL/DB2000Q-compliant, RoHS-compliant clock tree across -40C to +85C, with dynamic power management via SMBus and eight independent enables, in a 6x6 mm footprint.

What Is the Market Position, Lifecycle, and Supply Situation for the CDCDB803ERSLR?

Lifecycle status is active in the XAIPART database. As of 2026-09-02, XAIPART stocks 99,999 units with MOQ 1. Distributor data (as of 2026-08-25) shows DigiKey and Mouser list the part in stock with 'ships today' status; lead times may extend to 8-12 weeks for larger quantities. Pricing as of 2026-09-02 on XAIPART: $4.50 at qty 1, $4.05 at qty 10, $3.60 at qty 100, $3.24 at qty 500, and $2.88 at qty 1,000. [DATA_NEEDED: manufacturer lifecycle forecast, competing product market share data.]

What Should Buyers Watch Next for PCIe Clock Buffers Like the CDCDB803ERSLR?

Anchored to verified specifications, three trends matter:

1. PCIe Gen 6 readiness. The CDCDB803ERSLR supports PCIe Gen 1 through Gen 6 — future-proofing designs as Gen 6 adoption grows. Its DB800ZL and DB2000Q compliance plus low additive jitter (typically <1 ps per applications data) keep timing margins viable for next-generation links.

2. Frequency headroom. The 250 MHz maximum frequency exceeds the typical 100-250 MHz PCIe reference clock range, giving designers margin for future storage and interconnect standards, as noted in the storage array application.

3. Power-managed clock trees. The combination of LP-HCSL low-power outputs, SMBus dynamic configuration, and eight individual output enables aligns with energy-saving requirements in dense servers, switches, and storage enclosures. Buyers should prioritize buffers with per-output control and standard interfaces when sourcing for 2026+ platforms.

Given active lifecycle status and deep stock (99,999 units as of 2026-09-02), supply risk is currently low, but long-quantity buyers should still plan 8-12 week lead times. Compare the CDCDB803ERSLR on XAIPART, browse our Clock & Timing components, or read more in our PCIe clock design guides.