Hello Guys! Hope you’re well today. I welcome you on board. Thank you for clicking this read. In this post today, I’ll walk you through the Introduction to AMS1117.
The AMS1117 is a common voltage regulator that comes with both fixed and customizable voltages. It is a 3-pin device mainly used to drive load under 1A. The output voltage ranges from 1.5V to 5V. When it works at maximum current, it results in a low dropout voltage of 1.3A.
I suggest you read this post all the way through, as I’ll be discussing Pinout, datasheet, features, and applications of this tiny device AMS1117.
Let’s jump right in.
Introduction to AMS1117
- The AMS1117 is a common voltage regulator mainly used for high-efficiency linear regulation and post-regulation switching supplies.
- This 3-pin device is also used as a battery charger and comes with an output voltage range from 1.5V to 5V. It returns a low dropout voltage of 1.3A when it operates at maximum current.
- The AMS1117 series of voltage regulators comes with both fixed and adjustable voltages and are constructed to support up to 1A current. The dropout voltage is 1.3V which decreases at low load currents.
- The current limit is applied to the power source circuitry and regulator to compensate the stress when this regulator comes across the overload situations.
- AMS1117 is available in three packages i.e. surface mount SOT-223 package, TO-252 (DPAK) plastic package, and 8L SOIC package.
- Moreover, this device is compatible with three-terminal regulators like SCSI and is widely used in battery-powered instrumentation.
- This regulator is also used in some cases to obtain a negative voltage.
Before installing this device into your project, it’s wise to go through the datasheet of the component that gives an overview of the main characteristics and power ratings of the device.
The following image shows the pinout diagram of AMS1117.
The AMS1117 comes with three pins as below:
This pin is used to adjust the output voltage. In the case of a fixed voltage regulator, it acts as a ground.
2: Output Voltage/Vout
The regulated output voltage configured by the Adjust pin is achieved from this pin.
3: Input Voltage (Vin)
This pin gets the input voltage that is then regulated and produced at the output voltage.
The following are the features of AMS1117.
- Low Drop-Out (LDO) Voltage regulator
- 3- terminal Fixed/Adjustable Linear voltage regulator
- Fixed Voltage type: 1.5V, 1.8V, 2.5V, 2.85V, 3.3V and 5V
- Adjustable Voltage range: 1.25V to 13.8V
- Built-in thermal and current limiting protection.
- Output current = 1000mA
- Operating junction temperature = 125°C
- Maximum Drop-out Voltage = 1.3V
- Available in three packages: SOT-223, SO-8 Package and TO-252
- Used in Arduino boards to regulate 5V and 3.3V, AMS1117 is similar to other linear voltage regulators like LM317, 7805. It is commonly famous for small form factor and is available in SMD package.
- They all, however, are configured for a maximum current of 1A. It is widely applied in active SCSI terminators and power management for a notebook.
- Depending on the output voltage and package, this linear voltage regulator is categorized into many types.
- If a fixed voltage is applied at the Vin pin of the regulator we’ll get a regulated output voltage at the Vout pin. The Adj/Ground pin is grounded in this case.
- We need to add a capacitor at the regulated output voltage to remove any noise from the regulator. The circuit diagram of the fixed voltage regulator is given below.
- In an adjustable type voltage regulator, two external resistors are included to identify the regulator’s output voltage.
- You can see from the circuit diagram below, two resistors R1 and R2 are added to identify the regulator’s output voltage.
- The capacitors are added to remove any noise from the circuit.
The following is the formula to determine the output voltage that is based on two resistors R1 and R2. To find out the desired output voltage, we can choose the R1 and R2 (must be less than 1k) of our own choice.
Vout = Vref * (1 + R2/R1) + Iadj * R2
For an Adjustable type voltage regulator we need two external resistors to decide the output voltage of the Regulator.
- A reference circuit diagram for adjustable voltage is shown below, where the resistors R1 and R2 decides the output voltage of the regulator.
- The capacitor CAdj is an optional component that can be added to improve ripple rejection if required. The other two capacitors are to filter the input and output noise respectively.
- Used in current limiting circuits
- Employed in motor control circuits
- Incorporated in reverse polarity circuits
- Employed in variable power supply
- Used for voltage regulations
- Employed in Desktop PC systems
That’s all for today. I hope you like this article. If you have any questions you can approach me in the section below, I’d love to help you according to the best of my knowledge. Feel free to keep us updated with your valuable suggestions and feedback, they help us produce quality content. Thank you for reading this article.