S-8521B28MC-ATNT2G

Overview

The S-8521B28MC-ATNT2G is a CMOS step-down switching regulator controller from ABLIC Inc., designed for high-efficiency power management. It operates with an input voltage range of 2.5V to 16V and features a fixed switching frequency of 180kHz. The device supports PWM or PFM control modes, automatically switching to PFM under light loads to maintain efficiency. It includes a soft-start circuit to prevent startup overshoot and offers an enable function for power control. Packaged in a compact SOT-23-5 (SC-74A) surface-mount housing, it functions within a temperature range of -40°C to 85°C.

Feature Summary

• Supports automatic switching between PWM and PFM control modes for optimized efficiency across varying load conditions
• Integrates a soft-start circuit to prevent output voltage overshoot during initial power-up
• Features an enable pin for precise power management and system state control

Applications

• Battery-powered portable electronic devices requiring efficient step-down conversion
• Embedded systems utilizing single-cell lithium-ion battery inputs
• Consumer electronics needing compact DC-DC power regulation solutions

Procurement Notes

Verify the specific suffix ATNT2G against official ABLIC documentation to confirm package type and tape/reel specifications. Ensure compatibility with existing PCB footprints for the SOT-23-5 configuration. Confirm that the 180kHz switching frequency aligns with electromagnetic interference requirements for the target application environment.

Selection Notes

Select this component when a balance between efficiency and switching noise is required for moderate-load applications. The S-8521 series is suitable for designs where variable load profiles necessitate adaptive control mode switching. Consider external component selection based on the 180kHz frequency to optimize inductor size and ripple current characteristics.

Part Context

This part belongs to the S-8520/8521 series of CMOS step-down switching regulator controllers. While the S-8520 series utilizes fixed PWM control, the S-8521 variant incorporates flexible PWM/PFM switching capabilities. This distinction allows the S-8521 series to achieve superior light-load efficiency compared to strictly PWM-controlled counterparts.

Replacement Considerations

The S-8520B28MC-ATNT2U serves as a functional alternative within the same family, offering identical electrical parameters but utilizing fixed PWM control instead of PWM/PFM switching. Verify if the loss of automatic PFM transition impacts the specific efficiency requirements of the design.