AMS1117-3.3V Detailed explanation of pin function specifications and circuit principle instructions

AMS1117-3.3 V Detailed explanation of pin function specifications and circuit principle instructions

The AMS1117-3.3V is a low-dropout (LDO) voltage regulator from the manufacturer Advanced Monolithic Systems (AMS). It is commonly used to provide a stable 3.3V output from a higher input voltage. The AMS1117 family includes several different output voltages (e.g., 1.8V, 3.3V, 5V), and the "3.3V" variant specifically outputs a regulated 3.3V voltage.

AMS1117-3.3V Pin Function Specifications

Package Type and Pinout

The AMS1117-3.3V typically comes in the SOT-223 or TO-220 package. Below is a detailed description of the pinout and the function of each pin in both common packages.

Pinout for AMS1117-3.3V in SOT-223 (5 Pins): Pin Number Pin Name Pin Function 1 Adj Adjustable pin for external voltage reference (not used for fixed voltage versions like AMS1117-3.3V). 2 Vout Output voltage (3.3V for AMS1117-3.3V). This is where the regulated output is taken. 3 GND Ground pin. The regulator's ground connection. 4 Vin Input voltage. This pin connects to the higher input voltage (e.g., 5V, 12V, etc.). 5 NC (No Connection) This pin does not have a function in the SOT-223 package. It is left unconnected. Pinout for AMS1117-3.3V in TO-220 (3 Pins): Pin Number Pin Name Pin Function 1 Vin Input voltage (connects to a higher voltage source). 2 GND Ground pin. 3 Vout Output voltage (3.3V).

Circuit Principle Instructions

The AMS1117-3.3V works by regulating the input voltage (e.g., 5V, 12V) down to a stable 3.3V output voltage. It is classified as an LDO (Low Dropout Regulator), meaning it can operate with a small voltage difference between input and output. This is especially useful in applications where a stable 3.3V is needed, and the available input voltage is only slightly higher.

Basic Operating Principles:

Input Voltage: The input voltage (Vin) needs to be at least 3.3V + dropout voltage. For the AMS1117, the dropout voltage is typically around 1.1V. Therefore, the input voltage should ideally be at least 4.4V to achieve a stable 3.3V output.

Voltage Regulation: The AMS1117-3.3V uses an internal feedback mechanism to ensure that the output voltage remains stable at 3.3V, regardless of fluctuations in the input voltage (as long as it is above the dropout voltage) or the current drawn by the load.

Ground Pin: The ground (GND) pin provides the reference for the voltage regulation and ensures proper operation.

capacitor s: To stabilize the output and improve transient response, external capacitors are often used on the input and output pins. A typical recommendation is to place a 10µF capacitor on the input and a 10µF capacitor on the output.

AMS1117-3.3V Pin Function FAQ (20 Questions)

What is the input voltage range for AMS1117-3.3V? The AMS1117-3.3V requires an input voltage of at least 4.4V to output a stable 3.3V. What is the output voltage of AMS1117-3.3V? The AMS1117-3.3V provides a regulated 3.3V output. What type of package does AMS1117-3.3V come in? The AMS1117-3.3V is typically available in SOT-223 and TO-220 packages. Can I use AMS1117-3.3V for 5V input? Yes, the AMS1117-3.3V can be used with a 5V input to output 3.3V, as long as the input voltage is higher than the dropout voltage of 1.1V. What is the dropout voltage of AMS1117-3.3V? The dropout voltage is typically 1.1V, meaning the input voltage needs to be at least 4.4V to get a stable 3.3V output. What should be the value of the input capacitor? A 10µF capacitor is recommended on the input pin to ensure stable operation. What is the output capacitor value recommendation? A 10µF capacitor is also recommended on the output pin to improve stability. How much current can AMS1117-3.3V supply? The AMS1117-3.3V can supply up to 800mA of current, depending on the heat dissipation and the package used. What is the typical quiescent current for AMS1117-3.3V? The quiescent current is typically around 5mA.

Can AMS1117-3.3V be used in battery-powered applications?

Yes, but keep in mind that the dropout voltage limits the use in low-voltage battery-powered devices.

Does AMS1117-3.3V need external resistors for voltage adjustment?

No, for the fixed 3.3V version, no external resistors are needed for voltage adjustment.

What is the thermal shutdown feature in AMS1117-3.3V?

The AMS1117-3.3V has a thermal shutdown feature that protects it from overheating. If the chip exceeds a certain temperature, it will shut down to prevent damage.

Does AMS1117-3.3V have overcurrent protection?

Yes, it has internal overcurrent protection to prevent damage in case of excessive current draw.

What are the typical applications for AMS1117-3.3V?

AMS1117-3.3V is commonly used in microcontroller circuits, sensor circuits, and other applications that require a stable 3.3V power supply.

Is AMS1117-3.3V suitable for low-noise applications?

Yes, it is suitable for low-noise applications due to its low dropout voltage and stable output.

Can AMS1117-3.3V work with high input voltages (e.g., 12V)?

Yes, the AMS1117-3.3V can work with higher input voltages like 12V, but the input voltage should be higher than the dropout voltage.

Is there an adjustable version of AMS1117?

Yes, the AMS1117 series includes adjustable versions, but the AMS1117-3.3V is a fixed voltage version.

What is the output voltage tolerance for AMS1117-3.3V?

The output voltage tolerance is typically ±1%, meaning the output will remain within 3.267V to 3.333V.

Can AMS1117-3.3V be used in automotive applications?

Yes, AMS1117-3.3V can be used in automotive applications, but care should be taken regarding input voltage variations.

What are the lead-free options for AMS1117-3.3V?

The AMS1117-3.3V is available in lead-free versions that comply with RoHS standards.

This detailed information covers the essential specifications, pinouts, and common questions for the AMS1117-3.3V voltage regulator.