Guide To The AMS1117 Voltage Regulator

The AMS1117 is a highly versatile, low dropout voltage regulator widely use in a variety of applications, from power management in notebooks to battery-powered instrumentation. In this blog post, we will explore its features, working principles, applications, and how you can use it effectively in your electronic projects.

1. What is the AMS1117?

2. AMS111 Manufacturer

3. Features of the AMS1117 Regulator

4. Pin Configuration of AMS1117

5. Working Principles

6. Applications

7. Application of AMS1117 Voltage Regulator Circuitry

8. Frequently Asked Questions [FAQ]

1. What is the AMS1117?

A low-dropout (LDO) voltage regulator design to supply a stable output voltage by reducing the voltage difference between its input and output. Unlike conventional regulators, which require a larger voltage difference to regulate the output, the component allows for a low dropout voltage, which is the difference between the input and output voltage. This feature makes the circuit highly efficient for powering low-voltage devices.

The component series includes both adjustable and fixed voltage versions. The adjustable version allows the output voltage to be set using external resistors, while the fixed versions come in a range of standard output voltages, such as 1.2V, 1.25V, 1.8V, 2.5V, 3.3V, and 5V. This versatility makes it suitable for a variety of applications, including microcontroller circuits, battery-powered devices, LED drivers, and communication systems.

AMS1117 Replacements and Equivalents 

Several equivalent and replacement available from various manufacturers. These replacements offer similar performance characteristics, such as the ability to provide stable output voltages while maintaining low dropout voltages. Below is an overview of the common replacements, along with their features and compatibility.

LM1117

Manufacturer: Texas Instruments

Provides similar output current and voltage regulation capabilities. Available in both fixed and adjustable versions, such as 1.8V, 2.5V, 3.3V, and 5V. Offer low dropout voltage and often use for general-purpose voltage regulation. Suitable for battery-powered devices, microcontrollers, and communication circuits and is fully compatible with the AMS1117, making it easy to swap in designs requiring a low-dropout regulator.

LD1117

Manufacturer: STMicroelectronics

Offer similar functionality to the AMS1117 and LM1117. Available in fixed voltage options such as 1.8V, 2.5V, 3.3V, 5V, and also in the adjustable version. Design for efficient voltage regulation with low dropout voltage, especially under heavy loads. Commonly use in electronic circuits that require low-voltage regulation, including power supplies for microcontrollers and battery-powered devices such as notebook computers, tablets, and handheld devices.

NCP1117

Manufacturer: ON Semiconductor

Offer similar voltage regulation performance and can handle up to 800mA of output current. Characterized by low dropout voltage and low quiescent current. Available in adjustable and fixed voltage versions, it is ideal for low-power systems, communication devices, and LED drivers. Frequently use in portable electronics and power management circuits and offers compatibility with AMS1117 voltage regulation.

NCV1117

Manufacturer: ON Semiconductor

A high-reliability version of the NCP1117, design specifically for automotive and industrial applications. Comes in both adjustable and fixed voltage options and operates over a wide temperature range, making it suitable for high-reliability systems, such as automotive electronics. Perfect for applications requiring stable voltage regulation under harsh conditions, including automotive power supplies and industrial equipment.

SPX1117

Manufacturer: Exar Corporation

Available in a variety of output voltages, including 1.8V, 2.5V, 3.3V, and 5V. Design for applications requiring low dropout voltage and high efficiency. With its SOT-223 package, it is ideal for space-constrained applications. Commonly use in power supplies for portable devices, notebook computers, and low-voltage circuits and is suitable for point-of-load regulation and other compact power systems.

TLV1117

Manufacturer: Texas Instruments

A low-voltage, low-dropout regulator design for small packages such as the SOT-23. It offers a low dropout voltage and is available in 1.2V, 1.8V, 2.5V, 3.3V, and 5V output voltages. Highly efficient for low-current applications, making it ideal for battery-operated devices and high-efficiency systems where require low voltage drop. Typically use for powering microcontrollers, analog circuits, and other low-power components.

When choosing a replacement or equivalent, it is important to consider factors such as the output current, dropout voltage, and specific voltage requirements for your application. All the replacements listed here offer similar functionality, with slight variations that may cater to specific applications, such as automotive, industrial, or low-voltage systems.

2. AMS1117 Voltage Regulator Manufacturer

The voltage regulator produce by several manufacturers, ensuring broad availability and reliability across various industries. The primary manufacturers include:

1. AMS is the original manufacturer of the AMS1117’s series. They are known for producing a range of reliable voltage regulators and analog ICs. AMS's versions of the circuit widely use in applications requiring low-dropout voltage regulation.

2. EVVO is another manufacturer that offers equivalents, providing regulators with similar performance characteristics to the original AMS design.

3. UMW manufactures the AMS1117 and similar products, offering high-quality voltage regulators for various applications, including consumer electronics and industrial devices.

3. Features of the AMS1117 Regulator

Can deliver up to 800mA of current, which is suitable for powering a wide range of devices, including microcontrollers and other low-power systems.

The circuit can operate with a maximum input-output voltage differential of 1.3V at full load. As the load current decreases, the dropout voltage also reduces, making the device highly efficient.

Current Limiting and Thermal Shutdown: These features help protect the regulator and the circuit from overload conditions, ensuring stable operation even under heavy load or thermal stress.

Wide Output Voltage Range: With both adjustable and fixed output options, the AMS1117 caters to various voltage requirements.

Adjustable Version (AMS1117-ADJ)

This version allows you to set the output voltage using external resistors. The adjustable version is useful when need specific or non-standard voltage levels. By adjusting the resistor values in the voltage divider configuration, you can obtain a wide range of output voltages, making it ideal for flexible power supply applications.

Fixed Voltage Versions

AMS1117-1.2: Provides a stable 1.2V output, commonly use for low-power logic circuits and microcontrollers.

AMS1117-1.25: Offers a 1.25V output, suitable for circuits that need precise voltage regulation for specific components.

AMS1117-1.5: Provides 1.5V, often use in analog devices, sensors, and low-voltage electronics.

AMS1117-1.8: Delivers a 1.8V output, often use for communication systems and LED drivers.

AMS1117-2.5: Use in applications where require 2.5V, such as powering analog systems and embedded devices.

AMS1117-2.85: Provides 2.85V output, suitable for powering devices that require specific voltages between 2.5V and 3.3V.

AMS1117-3.3: One of the most common versions, use for 3.3V logic circuits, microcontrollers, and wireless devices.

AMS1117-5.0: This version ideal for 5V logic circuits, USB power supplies, and general-purpose applications.

AMS1117 Package Types

Available in two common package types, making it adaptable to various design requirements. Each package type offers specific advantages size, thermal performance, and mounting options.

SOT-223 Package

A compact, surface-mount package that widely use in applications where space is limited. Typically use for low to moderate-power devices and offers good thermal dissipation and electrical performance.

TO-252 (DPAK) Package

The TO252 packing, also known as D-PAK, is a larger, surface-mount package that provides better thermal management and suite for applications where require higher power dissipation. Often use for higher current applications compared to the SOT-223. Its larger footprint allows for better heat sinking and more robust power delivery.

4. Pin Configuration of AMS1117

Come in two versions: fixed and adjustable. Understanding the pin configuration is essential when incorporating the device into your circuit.

Fixed Voltage Version Pin Connections:

1.Pin 1 (Ground): Connect to the circuit ground. This pin provides the reference for the output voltage.

2.Pin 2 (VOUT): This is the output voltage pin, where you will connect the load that requires the regulated voltage.

3.Pin 3 (VIN): Connect to the input voltage, which should be at least 1V higher than the output voltage for proper regulation.

Adjustable Version Pin Connections:

1.Pin 1 (Adjust): This pin use to set the output voltage by connecting two external resistors in a voltage divider configuration.

2.Pin 2 (VOUT): This is the output voltage pin, similar to the fixed version.

3.Pin 3 (VIN): Connect the input voltage here. For proper operation, the input voltage must be higher than the output voltage.

5. Working Principles

A low-dropout (LDO) voltage regulator that ensures stable output voltage even when the input voltage is only slightly higher than the output voltage. It works by using a feedback loop that continuously compares the output voltage (VOUT) to an internal reference voltage, typically 1.25V. Based on this comparison, the regulator adjusts the internal pass transistor, which controls the flow of current, to maintain the desired output.

The key feature of the AMS1117 is its low dropout voltage, typically around 1.3V, which means it can effectively regulate the output voltage even when the difference between the input and output is minimal. This makes it ideal for applications such as battery-powered devices, where energy efficiency is necessary.

The regulator has both adjustable and fixed versions. The adjustable version (AMS1117-ADJ) allows users to set the output voltage using external resistors, while the fixed versions are pre-set to common voltages such as 1.2V, 3.3V, and 5V.

Additionally, the circuits includes safety features such as current limiting, which protects against excessive current, and thermal shutdown, which prevents overheating. These features ensure that the regulator operates safely and reliably in a variety of electronic applications.

6. Applications

Widely use in various applications as its ability to provide stable voltage with low dropout. Some of the common applications include:

1. High Efficiency Linear Regulators: Use as a linear regulator in systems requiring efficient voltage regulation while maintaining low power loss, especially in low-voltage circuits.

2. Post Regulators for Switching Supplies: In switch-mode power supplies (SMPS), the component acts as a post regulator, ensuring the output voltage remains stable after the switching conversion process.

3. 5V to 3.3V Linear Regulator: Commonly use to convert 5V to 3.3V for powering devices like microcontrollers and logic circuits that require a regulated 3.3V supply.

4. Battery Chargers: Use in battery charging circuits to provide the correct voltage levels for charging lithium-ion batteries or other rechargeable battery types.

5. Active SCSI Terminators: The regulator use in Small Computer System Interface (SCSI) systems, providing stable voltage to active terminators and ensuring proper communication across devices.

6. Power Management for Notebooks: In notebook and portable computing devices, managing the power supply to ensure stable voltage for internal components such as processors and memory.

7. Battery Powered Instrumentation: Ideal for battery-powered instruments, offering efficient voltage regulation to ensure the device operates reliably for extended periods without excessive power loss.

These applications benefit from the AMS1117’s low dropout voltage, current-limiting features, and the ability to provide stable output even with minimal input-to-output voltage difference.

7. Application of AMS1117 Voltage Regulator Circuitry

The voltage regulator commonly use in various circuits that require stable voltage regulation. Here are some typical AMS1117 circuitry applications:

5V to 3.3V Voltage Regulator Circuit

In many microcontroller projects, require a 5V to 3.3V voltage conversion, especially when using components such as Arduino or Raspberry Pi. The AMS1117-3.3 can step down the 5V input to a stable 3.3V output. The circuit consists of the AMS1117-3.3 regulator, input and output capacitors (10µF recommended), and a 5V power source.

Battery Charger Circuit

Use in battery charging circuits to provide a stable voltage suitable for charging lithium-ion or other rechargeable batteries. The regulator ensures that the charging voltage is stable and consistent, preventing damage to the battery.

Active SCSI Terminator Circuit

In SCSI systems, can use the circuit to provide power to active terminators, ensuring stable communication between devices on the SCSI bus. Active terminators require a regulated supply, and the component ensures that the voltage remains constant.

Power Supply for Portable Instruments

For battery-powered instrumentation, such as handheld measurement devices, can use the regulator to convert higher battery voltages (e.g., 5V or 12V) to lower, stable voltages required by the circuits, such as 3.3V or 5V.

Post-Regulator in Switching Power Supply

In switching power supplies (SMPS), the circuit acts as a post-regulator to ensure that the output voltage remains stable after the switching process. This configuration is common in more complex power supplies where switching regulators are use for efficiency, and the circuit fine-tunes the output.

Linear Regulator for Microcontroller Circuits

In many embedded systems, microcontrollers (e.g., PIC, AVR, ARM processors) require a low dropout voltage regulator to power them. The circuit is ideal for this, converting 5V to 3.3V or 1.8V depending on the microcontroller’s voltage requirements.

Voltage Regulation for Communication Modules

In communication systems, where modules such as Wi-Fi, Bluetooth, and LoRa need stable power, the circuit can provide regulated voltages. Use to step down higher voltages (e.g., 5V) to lower, stable voltages (e.g., 3.3V) required by these communication chips.

Key Circuit Components for AMS1117 Circuits

For AMS1117-based circuits, input and output capacitors are necessary for smooth voltage regulation. Typical values range from 10µF to 22µF (ceramic or electrolytic), depending on the application. For the AMS1117-ADJ, external resistors use to set the desired output voltage. Require a stable DC voltage source (e.g., battery, power adapter, or regulated DC supply). In high-current applications, heat sinks or thermal pads is necessary for better thermal dissipation.

AMS1117 Datasheet PDF

8. Frequently Asked Questions [FAQ]

1. What is compatible with AMS1117?

Compatible with a wide range of circuits requiring low-dropout voltage regulation, including microcontrollers, communication modules, and power management systems. It works well with common power supply voltages such as 5V and 12V, providing stable output voltages such as 3.3V and 5.0V. The adjustable version is also suitable for custom voltages, allowing compatibility with various devices and circuits in battery-powered or embedded systems.

2. What is the AMS1117 3.3V Power Supply Module?

The AMS1117-3V3 power supply module uses the AMS1117-3.3 regulator to convert higher input voltages, typically 5V, to a stable 3.3V output. Commonly use to power 3.3V logic devices, such as microcontrollers and wireless communication modules. These modules often come with capacitors for improved stability and reduced voltage ripple. Ideal for battery-operated systems and low-power electronics, where require efficient voltage regulation.

3. What is the minimum load of the AMS1117?

Typically require a minimum load of 10mA to maintain stable operation. Below this current, the output voltage will become unstable, and the regulator can’t perform as expected. The minimum load is necessary to ensure the proper functioning of the feedback loop and maintain regulation, especially under light load conditions. For most applications, the AMS1117 performs well with a typical load of 10mA to 800mA.

4. What is the standby current of the AMS1117?

The standby current of the AMS1117 is typically 5mA. This is the quiescent currents, which is the current consumed by the regulator itself when it is not supplying significant load current. The AMS1117’s low quiescent current makes it suitable for battery-powered systems, as it helps minimize power consumption during periods of low activity or standby operation. This feature is essential for devices requiring long battery life.

5. What is the input voltage range of the AMS1117?

The circuit operates with an input voltage range of 1.8V to 15V. However, to maintain proper voltage regulation, the input should be higher than the output by at least the dropout voltage (typically 1.3V). For instance, to output 3.3V, the input must be at least 4.6V (considering the dropout voltage). The input range makes it compatible with both low-voltage and higher-voltage power supplies, offering flexibility in various applications.

6. What is the fixed voltage of AMS1117?

Available in several options, including 1.2V, 1.25V, 1.5V, 1.8V, 2.5V, 3.3V, and 5V. These fixed versions design to provide stable and regulated output voltages for specific needs. The fixed voltage versions eliminate the need for external components to set the output, making them ideal for applications requiring a consistent, predetermined voltage, such as microcontrollers, sensors, and battery-powered systems.

7. How to connect AMS1117?

To connect the AMS1117, the VIN pin should connect to the input power source (e.g., 5V or 12V), the GND pin to the common ground, and the VOUT pin to the load or device that requires the regulated voltage. For the adjustable version (AMS1117-ADJ), external resistors use to set the desired output voltage. Recommend Capacitors (typically 10µF) at both the input and output to improve stability and reduce noise.

8. How does the AMS1117 convert 5V to 3.3V?

The AMS1117-3.3 converts 5V input to 3.3V output by regulating the voltage using its internal feedback mechanism. When 5V apply to the VIN pin, the regulator maintains a stable 3.3V at the VOUT pin by adjusting the pass transistor. The AMS1117 uses a low dropout voltage (typically 1.3V) to efficiently regulate the output, ensuring that the difference between the input and output remains minimal while maintaining a stable 3.3V.

Conclusion

The AMS1117 is an excellent voltage regulator for applications requiring stable voltage regulation in low-voltage systems. Its low dropout voltage, wide selection of output voltages, and ease of use make it a go-to solution for portable electronics, microcontroller projects, power management, and many other electronic designs. Whether you're converting 5V to 3.3V or managing the power needs of a battery-operated system, the AMS1117 delivers reliable and efficient performance at an affordable price point.

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