NB2308AC4D

Overview

The NB2308AC4D is a 3.3 V zero delay clock buffer manufactured by onsemi, designed for high-speed clock distribution in commercial applications (0°C to +70°C). It features an internal PLL that locks to a reference input on the REF pin, with feedback driven from one of the eight outputs to the FBK pin. The device provides two banks of four LVCMOS outputs each, capable of generating 2X multiplied clocks relative to the reference frequency. Key electrical parameters include an input frequency range of 15 MHz to 133 MHz, output-to-output skew less than 200 ps, and cycle-to-cycle jitter under 200 ps at 66.67 MHz. It operates within a 3.0 V to 3.6 V supply voltage range.

Feature Summary

• Zero delay buffer configuration with adjustable input-output propagation delay via capacitive load on the FBK pin.
• Two independent banks of four buffered clock outputs, controllable via S1 and S2 select inputs for tri-stating or bypass modes.
• Low skew performance with output-to-output skew guaranteed less than 200 ps and device-to-device skew less than 700 ps.
• Cycle-to-cycle jitter specification of less than 200 ps at 66.67 MHz and 100 ps at 133.3 MHz.

Applications

• High-speed clock distribution in communication systems operating between 15 MHz and 133 MHz.
• Clock multiplication and buffering for digital logic requiring precise phase alignment.
• System testing applications utilizing the direct reference bypass mode.

Procurement Notes

Verify the specific ordering suffix to confirm package type and shipping quantity. The 'D' suffix indicates a 16-pin SOIC package shipped in rails of 48 units. Ensure the component meets the commercial temperature range requirements of 0°C to +70°C. Confirm RoHS compliance status if lead-free packaging is required for the assembly process.

Selection Notes

Select the NB2308AC4D when a fixed 2X clock multiplication is required for all outputs without external dividers. This variant is suitable for commercial temperature environments. For industrial temperature ranges (-40°C to +85°C), consider the NB2308AI4D equivalent. Verify that the load capacitance requirements (15 pF for >100 MHz, 30 pF for <100 MHz) align with the target circuit design.

Part Context

The NB2308A series comprises multiple configurations (x1 through x5H) offering varying degrees of clock multiplication and division. The NB2308AC4D specifically enables 2X clock generation on all outputs by connecting the feedback pin to Bank A or Bank B. It utilizes advanced 0.35 µm CMOS technology and supports both SOIC-16 and TSSOP-16 packages.

Replacement Considerations

For industrial temperature operation, the NB2308AI4D serves as the direct functional equivalent. Other series members like NB2308AC1D (1X) or NB2308AC3D (4X/2X) offer different multiplication ratios but share the same package and interface.