ASNT8051-PQB

Overview

The ASNT8051-PQB is a programmable clock multiplication unit (CMU) fabricated in SiGe technology, featuring dual-range phase-locked loops (PLLs) with integrated voltage-controlled oscillators (VCOs). It operates on a single +3.3V supply with 570mW power consumption and supports junction temperatures from -40°C to 125°C. The device synthesizes high-speed clocks up to 17 GHz from lower-speed references. Key electrical parameters include a closed-loop SSB phase noise better than 98dB/Hz at 10MHz offset, peak-to-peak jitter of 6ps at 12.5GHz, and LVDS/CML/PECL input interface options. It is housed in a standard 40-pin QFN package.

Feature Summary

• Dual-range PLL with selectable VCO frequency bands: 9.9-12.1 GHz and 11-12.9 GHz
• Supports full-rate or half-rate CML output and LVDS divided clock output with 90° phase adjustment
• Integrated loss-of-lock detection circuit and open-loop VCO control capability
• Flexible reference input accepting LVDS, CML, or PECL interfaces via universal input buffer

Applications

• High-speed serial data transceivers requiring low-jitter clock synthesis
• Test and measurement equipment needing precise frequency generation
• Telecommunications infrastructure utilizing multi-standard clocking
• Radars and microwave systems requiring stable local oscillator signals

Procurement Notes

Verify the specific ordering suffix against manufacturer documentation to confirm package type and pinout configuration. Ensure external loop filter components are selected according to the recommended schematic for target bandwidth and phase noise performance. Confirm thermal management requirements for the 40-pin QFN package given the 570mW power dissipation and operating temperature range.

Selection Notes

Select the appropriate VCO range using the off12g control signal based on the required output frequency. Choose between full-rate and half-rate outputs via the offcho pin depending on downstream interface requirements. Ensure the reference clock source matches the supported input interface modes (LVDS, CML, or PECL) configured by the offecl pin. Verify that the external termination resistors match the specified impedance levels for optimal signal integrity.

Part Context

The ASNT8051 series belongs to Advanced Science And Novel Technology Company's portfolio of high-performance RF clock generators. This specific model integrates both the PLL and VCO stages on a single SiGe die, reducing board space compared to discrete solutions. The -PQB suffix denotes the 40-pin QFN package variant, distinguishing it from other packaging options within the broader family.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. When evaluating alternatives, ensure compatibility with the 40-pin QFN footprint, +3.3V supply voltage, and similar frequency ranges (up to 17 GHz output). Verify that replacement devices support the required CML/LVDS interfaces and offer comparable jitter specifications.