NB2309AI1D

Overview

The NB2309AI1D is a 3.3 V zero delay clock buffer manufactured by onsemi, designed for distributing high-speed clocks in industrial applications. It accepts one reference input and drives nine low-skew outputs (4 + 4 + 1 configuration) using an internal PLL locked to the REF pin. The device operates within a frequency range of 15 MHz to 133 MHz and utilizes advanced 0.35 µm CMOS technology. Key electrical specifications include output-to-output skew less than 250 ps, device-to-device skew less than 700 ps, and cycle-to-cycle jitter under 200 ps. It supports test mode bypassing the PLL and is available in SOIC-16 or TSSOP-16 packages.

Feature Summary

• Zero Input-Output Propagation Delay with internal PLL feedback
• Nine Low-Skew Outputs grouped as Bank A (4), Bank B (4), and CLKOUT (1)
• Operating Frequency Range: 15 MHz to 133 MHz
• Test Mode allows direct application of input clock to outputs

Applications

• CPU and PCI Bus Clock Distribution
• Pentium/C0082 Based Systems
• High-Speed Digital Circuit Timing

Procurement Notes

Verify the specific suffix for package type and shipping method. The 'D' suffix indicates an SOIC-16 package, while 'DT' indicates TSSOP-16. The 'R2' suffix denotes tape and reel packaging, whereas absence implies rail/tube shipping. Confirm industrial temperature grade (-40°C to +85°C) matches system requirements. Check for Pb-Free status if required by environmental regulations.

Selection Notes

Select the NB2309AI1D for industrial temperature ranges (-40°C to +85°C). Choose between standard drive (-1) or high drive (-1H) variants based on load capacitance needs; -1H offers faster rise/fall times. Ensure all outputs, including CLKOUT, have equal capacitive loading to maintain zero input-output delay. Verify that the 3.3 V supply voltage remains within the 3.0 V to 3.6 V operating window.

Part Context

This component belongs to the NB2309A series of 3.3 V zero delay buffers. The 'I' designation specifies the Industrial temperature rating, distinguishing it from Commercial ('C') variants. The base model NB2309A provides the core functionality, with suffixes defining physical packaging and distribution format.

Replacement Considerations

NB2309AC1D (Commercial Temp, SOIC-16)

FAQ

How is zero input-output propagation delay achieved?

Zero delay is achieved when all outputs, including the CLKOUT feedback pin, are uniformly loaded with equal capacitive loads. Adjusting the load on CLKOUT can fine-tune the input-output delay.

What is the function of the S1 and S2 select inputs?

The S1 and S2 inputs control the output state. They allow users to three-state Bank B, bypass the PLL to drive outputs directly from the REF pin for testing, or shut down the PLL.

What is the difference between the -1 and -1H versions?

The -1H version is a high-drive variant with significantly faster rise and fall times compared to the standard -1 devices, suitable for heavier loads or higher speed requirements.