NB2308AI3DG

Overview

The NB2308AI3DG is a 3.3 V zero delay clock buffer manufactured by onsemi, designed for high-speed clock distribution in industrial applications. It features an internal phase-locked loop (PLL) that locks to an input clock on the REF pin, with feedback driven to the FBK pin from one of the outputs. The device supports an input frequency range of 15 MHz to 133 MHz and provides eight buffered clock outputs organized into two banks of four. Key electrical specifications include an input-to-output propagation delay of less than 250 ps, output-to-output skew under 200 ps, and cycle-to-cycle jitter below 200 ps at 66.67 MHz. It operates within a supply voltage range of 3.0 V to 3.6 V and is housed in a 16-pin SOIC package.

Feature Summary

• Zero delay buffer architecture with adjustable input-output propagation delay via capacitive load on the FBK input
• Configurable frequency multiplication: Bank A outputs operate at 4X reference frequency while Bank B outputs operate at 2X reference frequency when feedback is sourced from Bank A
• Low skew performance with output-to-output skew guaranteed less than 200 ps and device-to-device skew less than 700 ps
• Two banks of four outputs each, controllable via S1 and S2 select inputs for three-state control or bypass mode

Applications

• High-speed clock distribution in industrial computing systems
• Datacom and telecom equipment requiring precise clock synchronization
• Workstation and server motherboard clock generation
• System testing modes utilizing direct reference clock bypass

Procurement Notes

Verify component authenticity through authorized distributors as the NB2308A series has reached end-of-life status. Confirm the 'I' suffix indicates industrial temperature rating (-40°C to 85°C) and the 'G' suffix denotes lead-free packaging compliant with RoHS standards. Check for alternative packages such as TSSOP if board space constraints require it.

Selection Notes

Select the NB2308AI3DG specifically when 4X and 2X frequency multiplication is required simultaneously across two output banks. Ensure the application can accommodate the specific feedback configuration where Bank A drives the FBK pin to achieve these ratios. Verify that the load capacitance requirements (15 pF for frequencies above 100 MHz) are met to maintain specified timing parameters.

Part Context

The NB2308AI3DG belongs to the NB2308A family of 3.3 V zero delay buffers. The 'I' designation specifies the industrial temperature grade, distinguishing it from commercial variants. The 'DG' suffix identifies the lead-free 16-pin SOIC package variant. This part is distinct from other configurations like the NB2308AI1DG which provides 1X frequency division only.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.