MIC9131YQS

Overview

The MIC9131YQS is a current-mode PWM controller designed for high-voltage telecom DC/DC applications. It efficiently converts -48V telecom voltages to logic levels, featuring a high-voltage start-up circuit that tolerates input voltages up to 180V. This capability protects the device from common line transients in telecom systems while saving board space by integrating external components. The controller supports internal oscillator operation above 2.5MHz and offers synchronization up to 6MHz. Key electrical characteristics include a 75% maximum duty cycle, 34ns current sense delay, and less than 25ns minimum pulse width. It achieves approximately 90% efficiency with a 1.3mA quiescent current and 1µA shutdown current.

Feature Summary

• High-voltage start-up circuitry enabling connection to input voltages as high as 180V for transient protection
• Current-mode PWM control with programmable under-voltage lockout and selectable soft-start retry
• Integrated oscillator supporting frequencies greater than 2.5MHz with external synchronization capability up to 6MHz
• Low power consumption features including 1µA shutdown current and resistor-programmable current sense threshold

Applications

• Telecom power supplies
• ISDN network terminators
• DSL line cards
• Micro- and pico-cell base stations
• Low power dc-dc converters

Procurement Notes

Verify the manufacturer source carefully, as Micrel Semiconductor was acquired by Microchip Technology. Ensure the datasheet corresponds to the specific MIC9131YQS variant. Confirm package type matches the QSOP designation. Check for any specific environmental or automotive qualifications if required for your design. Validate pin compatibility with existing designs before procurement.

Selection Notes

Select this component for designs requiring robust handling of high-voltage telecom transients. The integrated start-up circuit reduces external component count compared to standard controllers. Consider the 34ns current sense delay when designing for high-frequency switching applications. The programmable current sense threshold allows customization for different load requirements. Ensure the operating temperature range meets system specifications.

Part Context

The MIC9131 series belongs to Microchip's portfolio of high-speed telecom power management solutions. Originally developed by Micrel Semiconductor, these controllers are optimized for -48V telecom environments. The YQS suffix typically denotes a specific package and temperature grade within the family. This part is part of a broader range of high-voltage PWM controllers designed for reliability in harsh industrial and telecommunications settings.

Replacement Considerations

Direct replacements include MIC9131YM, MIC9131BM, and MIC9131BQS. Verify pinout and electrical parameters match exactly. Check package dimensions for mechanical compatibility. Review updated datasheets for any feature changes introduced after acquisition.