AP2125N-4.2TRG1

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

The AP2125N-4.2TRG1 is a fixed-output positive voltage regulator IC fabricated using CMOS process technology. It provides a nominal output voltage of 4.2V with a maximum output current capability of 300mA. The device operates within an input voltage range up to 6V and maintains high output voltage accuracy of ±2%. Key electrical characteristics include a typical quiescent current of 60µA, standby current of 0.01µA, and extremely low output noise of 50µVrms. It features excellent ripple rejection of 65dB at 1kHz and includes integrated overcurrent and overtemperature shutdown protection circuits.

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

• Integrated chip enable circuit for active-high logic control and ultra-low standby current consumption
• Extremely low output noise performance suitable for sensitive analog and RF signal paths
• Built-in thermal shutdown and current limit circuits to prevent damage during fault conditions
• Compatible with low ESR ceramic capacitors for stable operation without additional compensation

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

• Battery-powered equipment requiring efficient power management
• CDMA/GSM cellular handsets and portable communication devices
• Laptops, palmtops, and notebook computers
• Hand-held instruments and PCMCIA cards
• Portable information appliances

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

Verify the specific package configuration matches the design requirements, as the AP2125 series is available in SOT-23-3, SOT-23-5, and SC-70-5 packages. Confirm that the ordering suffix corresponds to the desired tape and reel packing format. Ensure compliance with RoHS and halogen-free specifications if required by the target market regulations. Cross-reference the manufacturer's latest datasheet revision to confirm pinout assignments and electrical parameters remain unchanged.

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

Select this component when a fixed 4.2V rail is required with minimal quiescent current draw from a battery source. The SOT-23-3 package offers a compact footprint for space-constrained designs but lacks the dedicated enable pin found in the SOT-23-5 variant. Evaluate the dropout voltage characteristics against the minimum expected input voltage to ensure regulation is maintained under load. Consider the thermal resistance of the chosen package if operating near maximum current limits.

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

This part belongs to the AP2125 series of high-speed, extremely low noise CMOS LDO regulators manufactured by Diodes Incorporated. The series encompasses multiple fixed output voltage options ranging from 1.8V to 4.2V. The 'N' designation specifically identifies the SOT-23-3 package variant, which provides three pins for input, ground, and output functions. This family is designed for applications demanding high ripple rejection and low noise in portable electronic systems.

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

AP2125K-4.2TRG1 (SOT-23-5 package)

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

Does the AP2125N-4.2TRG1 have an enable pin?

No, the SOT-23-3 package version does not include a Chip Enable (CE) pin. To utilize the enable feature and achieve ultra-low standby current, the SOT-23-5 or SC-70-5 package variants must be selected.

What is the typical output noise specification for this regulator?

The AP2125 series typically exhibits an RMS output noise of 50µV across the frequency range of 10Hz to 100kHz, making it suitable for noise-sensitive applications.