Part Number: AMS1117

Function: 800mA, LOW DROPOUT VOLTAGE REGULATOR

Package: SOT-223, TO-252 (DPAK) Type

Manufacturer: Advanced Monolithic Systems

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Description

The AMS1117 series of adjustable and fixed voltage regulators are designed to provide 800mA output current and to operate down to 1V input-to-output differential. The dropout voltage of the device is guaranteed maximum 1.3V at maximum output current, decreasing at lower load currents.

Its simple three-terminal design and minimal external component requirements make it a popular choice for power regulation in embedded systems, microcontrollers, communication modules, consumer electronics, and industrial equipment.

On-chip trimming adjusts the reference voltage to 1%. Current limit is also trimmed, minimizing the stress under overload conditions on both the regulator and power source circuitry. The AMS1117 devices are pin compatible with other three-terminal SCSI regulators and are offered in the low profile surface mount SOT-223 package and in the TO-252 (DPAK) plastic package.

Key Features

• Low Dropout (LDO) linear voltage regulator
• Output current up to 800mA
• Dropout voltage of 1.3V maximum at full load
• Output voltage accuracy: ±1%
• Available in adjustable and fixed output versions
• Fixed output options: 1.2V, 1.5V, 1.8V, 2.5V, 2.85V, 3.3V, and 5V
• Excellent load regulation
• Typical load regulation: 0.2%
• Optimized for low-voltage applications
• Internal current limiting
• Thermal overload protection
• Three-terminal regulator architecture
• Compatible with standard SOT-223 and TO-252 (DPAK) packages

AMS1117 Pinout

Protection Features

• Internal current limiting
• Thermal shutdown protection
• Safe operating area protection
• Precision trimmed reference voltage
• Short-circuit protection through current limiting

Design Notes

• The input voltage must exceed the desired output voltage by at least the dropout voltage. For example, an AMS1117-3.3 typically requires about 4.6V or higher input to maintain proper regulation at full load.
• Input and output bypass capacitors should be placed close to the regulator pins to improve stability and transient response.
• Power dissipation is calculated as (VIN − VOUT) × IOUT. Adequate PCB copper area or a heatsink may be necessary for high current or large input-to-output voltage differences.
• The adjustable version requires two external resistors to set the output voltage according to the internal reference voltage.
• Although rated for 800mA, the maximum usable output current depends on thermal conditions and PCB layout.
• The regulator is intended for linear regulation and is not suitable where high conversion efficiency is required; in such cases, a switching regulator is preferred.

Applications

• Consumer electronics
• IoT devices
• Networking equipment
• Portable instruments
• LCD display modules
• Development boards (Arduino, STM32, ESP32, Raspberry Pi accessories)
• Medical instrumentation
• Automotive electronics (within operating voltage limits)

Alternative / Equivalent Products

• LM1117 Series
• LD1117 Series
• NCP1117 Series
• AZ1117 Series
• AP1117 Series
• TLV1117 Series
• MIC39100 (higher current LDO alternative)
• MCP1825 (low-dropout alternative)

AMS1117 Datasheet