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
