S-8521F50MC-BQJT2G

Overview

The S-8521F50MC-BQJT2G is a CMOS step-down switching regulator controller manufactured by ABLIC Inc. It belongs to the S-8521 series, which utilizes PWM/PFM switching control for high efficiency across varying load conditions. The device operates with an input voltage range of 2.5V to 10V and features a fixed output voltage setting. It employs a SOT-23-5 package suitable for surface mount applications. The controller supports a switching frequency of 60kHz and includes internal reference voltage sources, oscillation circuits, and error amplifiers.

Feature Summary

• Supports automatic switching between PWM and PFM control modes to maintain high efficiency under light loads
• Integrates a soft-start circuit to prevent output overshoot during startup
• Provides linear duty ratio variation from 0% to 100% for low-ripple power delivery

Applications

• Portable electronic devices requiring efficient power management
• Battery-powered equipment needing extended operational time
• Embedded systems utilizing step-down DC-DC conversion

Procurement Notes

Verify the specific suffix codes against official ABLIC documentation to confirm output voltage accuracy and package variations. Confirm RoHS compliance status and check for any recent Product Change Notices (PCN) regarding marking or material changes. Ensure design-in approval as the component may be marked as not recommended for new designs depending on current inventory strategies.

Selection Notes

Select this controller when designing buck converters that require adaptive efficiency management through mode switching. Ensure external components such as inductors and capacitors are rated for the 60kHz switching frequency. Verify that the required output voltage matches the fixed setting provided by the part number suffix. Check thermal requirements for the SOT-23-5 package within the specified operating temperature range.

Part Context

This component is part of the S-8520/8521 series of CMOS step-down switching regulator controllers. The S-8521 variant specifically distinguishes itself by supporting both Pulse Width Modulation (PWM) and Pulse Frequency Modulation (PFM) controls. This series is designed to offer excellent transient characteristics and high efficiency compared to standard PWM-only controllers.

Replacement Considerations

Direct substitutes include other parts from the S-8521 series with compatible output voltage settings and pin configurations. Cross-reference with S-8520 series models if PFM operation is not required. Verify pinout compatibility and electrical specifications before substitution.