AS1357

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

The AS1357 is a triple CMOS low-dropout voltage regulator in a single QFN package. It features three independent regulators with an output current of 200mA each and a supply range of 3 to 5.5V. The device supports one-time programmable (OTP) output voltages from 1.8V to 3.3V in 0.1V steps, or factory-trimmed fixed versions. Key electrical parameters include a dropout voltage of 0.2V at 200mA, shutdown current ≤1µA, and typical supply current of 175µA. PSRR is 70dB at 1kHz and 40dB at 100kHz. Output noise is 40µV rms (10Hz-100kHz). Stability is guaranteed with ceramic capacitors from 1µF to 4.7µF. Operating temperature is -40°C to +85°C.

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

• Three independent LDOs with user-programmable or factory-fixed output voltages
• Low noise performance suitable for direct connection to sensitive circuits
• Stable operation with small low ESR ceramic output capacitors
• Integrated thermal protection, over-current protection, and soft-start control

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

• Mobile phones and PDAs
• MP3 players and handheld computers
• Digital cameras and cordless phones
• Battery-powered portable devices

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

Verify the specific ordering suffix to confirm package type (12-pin QFN 4x4 or 16-pin QFN 3x3) and delivery form (Tape and Reel or Tray). Ensure the selected variant matches the required output voltage configuration, whether user-programmable via OTP or factory-trimmed. Confirm availability as standard production parts may have specific minimum order quantities for custom voltage versions.

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

Select the AS1357 when multiple regulated rails are needed in a compact space for battery-operated electronics. Choose the 12-pin QFN 4x4 or 16-pin QFN 3x3 package based on board layout constraints. Opt for factory-trimmed versions if consistent output voltages are required without onsite programming infrastructure. Ensure input voltage remains within the 3V to 5.5V range for proper regulation.

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

The AS1357 belongs to the family of triple LDO regulators designed for mobile and portable consumer electronics. Manufactured by austriamicrosystems AG (now ams OSRAM), it addresses the need for efficient power management in space-constrained designs. The device integrates programmability features to reduce development time and inventory complexity for varying voltage requirements across different product models.

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

No public confirmed substitute part numbers are provided in the datasheet.

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

What is the maximum output current per regulator?

Each of the three LDOs can deliver up to 200mA.

Can the output voltage be adjusted after manufacturing?

Yes, the AS1357-T version allows for one-time programmable (OTP) output voltage setting between 1.8V and 3.3V using a programming board.

What capacitor values ensure stability?

The device is stable with ceramic output capacitors ranging from 1µF to 4.7µF (±20% X5R).