NB2309AC1HD

Overview

The NB2309AC1HD is a 3.3 V zero delay clock buffer manufactured by onsemi, designed for distributing high-speed clocks up to 133 MHz. It accepts one reference input and drives nine low-skew outputs arranged in two banks of four plus one feedback output. The device features an internal phase-locked loop (PLL) with feedback obtained from the CLKOUT pad. It operates within a supply voltage range of 3.0 V to 3.6 V and supports commercial temperature ranges from 0°C to +70°C. The component utilizes advanced 0.35 µm CMOS technology and is housed in a 16-pin SOIC package.

Feature Summary

• Zero input-to-output propagation delay with output-to-output skew less than 250 ps
• Internal PLL allows locking to an input clock on the REF pin
• Selectable output control via S1 and S2 inputs for bypass or PLL modes
• High drive capability with faster rise and fall times compared to standard -1 devices

Applications

• CPU and PCI bus frequency distribution systems
• Pentium-based system clock generation
• Multi-device clock distribution networks requiring low device-to-device skew (<700 ps)

Procurement Notes

Verify the specific ordering suffix against the manufacturer's current documentation to confirm package type and shipping configuration. The 'D' suffix indicates a SOIC-16 package, while 'DT' denotes TSSOP-16. Confirm RoHS compliance status if lead-free packaging is required, as indicated by the 'G' suffix in related part numbers. Check for any product change notices regarding manufacturing locations or material declarations.

Selection Notes

Select this component when a single reference clock must be distributed to nine loads with minimal skew. Ensure the load capacitance is uniform across all outputs, including CLKOUT, to maintain zero input-output delay characteristics. For frequencies above 100 MHz, limit load capacitance to 10 pF; for lower frequencies, up to 30 pF is acceptable. Verify that the operating temperature range aligns with the commercial specification (0°C to +70°C).

Part Context

This part belongs to the NB2309A family of 3.3 V zero delay buffers. The 'C' suffix designates the commercial temperature grade, distinguishing it from the industrial grade ('I'). The 'H' suffix identifies the high-drive version, which offers improved rise and fall times compared to the base '-1' variant. Other family members include NB2304A, NB2305A, and NB2308A, which offer different output counts.

Replacement Considerations

Direct functional substitutes within the same family include NB2309AI1HD for industrial temperature operation. For applications requiring fewer outputs, NB2304A or NB2308A variants may be considered if pin compatibility and drive requirements are met. Cross-manufacturer equivalents such as Cypress CY2305 series share similar zero-delay buffer architectures but require verification of electrical parameters and pinouts.