SMA4021

Overview

The SMA4021 is a PNP Darlington transistor array manufactured by Sanken Electric USA Inc., designed for high-current switching applications. It features an integrated flywheel diode for flyback voltage absorption, eliminating the need for external components in inductive load circuits. The device operates with a collector-emitter voltage of -60 V and a continuous collector current of -3 A. Key electrical characteristics include a DC current gain (hFE) ranging from 2000 to 12000 at VCE=-4V and IC=-2A. The maximum power dissipation is 4 W at 25°C ambient temperature. The component is housed in a SIP-21 package and supports a junction temperature up to 150°C.

Feature Summary

• Integrated PNP Darlington configuration providing high current gain for efficient drive requirements
• Built-in flywheel diode for effective suppression of flyback voltage generated by inductive loads
• Robust surge current capability supporting peak loads up to -6 A under specified pulse conditions

Applications

• Driving inductive loads such as relays and solenoids
• High-side or low-side switching in industrial control systems
• Power management circuits requiring high-gain amplification

Procurement Notes

Verify the specific revision status before procurement, as the datasheet indicates this component is not recommended for new designs. Confirm package compatibility and thermal requirements against your system constraints. Ensure that the sourcing channel provides authentic Sanken Electric products to maintain performance reliability.

Selection Notes

Select this component when high current gain and integrated protection are required for inductive switching. Consider the thermal resistance characteristics and ensure adequate heatsinking if operating near maximum power limits. Evaluate the -60 V rating against your circuit's maximum voltage spikes to prevent breakdown.

Part Context

The SMA4021 belongs to Sanken Electric's series of PNP Darlington arrays, which also includes variants like the SMA4022 and SMA4023. These devices share similar architectural principles but may differ in pin configurations or internal resistance values. This family is typically utilized in applications demanding robust switching capabilities within compact packages.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. As the datasheet explicitly states 'Not Recommended for New Designs,' alternative components should be evaluated based on equivalent electrical ratings and package dimensions.