S-1333B21-A4T2U3

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Overview

The S-1333B21-A4T2U3 is a CMOS positive voltage regulator from the S-1333 Series by ABLIC Inc. It provides a fixed output voltage of 2.1 V with an accuracy of ±1.0%. The device supports an input voltage range of 1.5 V to 5.5 V and delivers up to 300 mA output current. Key electrical parameters include a typical dropout voltage of 160 mV at 100 mA, a ripple rejection ratio of 70 dB typ., and a quiescent current of 25 μA typ. during operation. It features built-in overcurrent protection and thermal shutdown circuits.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Feature Summary

• Built-in discharge shunt function for rapid output capacitor discharge when turned off
• High ripple rejection capability using ceramic capacitors of 1.0 μF or more
• Low dropout voltage characteristics suitable for battery-powered applications
• Integrated overcurrent protection and thermal shutdown circuits

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Applications

• Constant-voltage power supply for portable communication devices
• Power supply for digital cameras and digital audio players
• Battery-powered home electric appliances

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Procurement Notes

Verify the specific ordering suffix against the manufacturer's datasheet to confirm package type and environmental compliance. Ensure the selected variant matches the required ON/OFF logic and pull-down resistor configuration for the target application design.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Selection Notes

Select this component for designs requiring a fixed 2.1 V rail with low standby current. Consider the HSNT-4 (1010) package for compact surface-mount layouts. Verify that the input voltage remains within the specified range and that external capacitors meet the minimum capacitance requirements for stability.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Part Context

This part belongs to the S-1333 Series, which includes variants with different output voltages and functional configurations (Types A-D). The 'B' designation indicates active high ON/OFF logic with a discharge shunt function but without an internal pull-down resistor on the control pin.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Replacement Considerations

S-1333B21-M5T1U3

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators FAQ

What is the behavior of the output voltage when the ON/OFF pin is set to the OFF level?

When the ON/OFF pin is set to the OFF level, the internal circuit stops operating, and the built-in discharge shunt circuit activates to rapidly discharge the output capacitor, bringing the VOUT pin to the VSS level.

How does the S-1333B series differ from the S-1333A series regarding the ON/OFF pin?

The S-1333B series lacks an internal pull-down resistor on the ON/OFF pin, whereas the S-1333A series includes one. Consequently, the ON/OFF pin in the B series should not be left floating.