> Source: https://www.tinkered.ai/components/ams1117-3v3-module (Tinkered). Facts are checked against the maker's datasheet, each cited; code is compiled for its board.
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# AMS1117 3.3V Regulator Module

A thumb-sized AMS1117-3.3 breakout that turns a 5 V rail into a regulated 3.3 V, capacitors and power LED already fitted.

Source page: https://www.tinkered.ai/components/ams1117-3v3-module
Datasheet: http://www.advanced-monolithic.com/pdf/ds1117.pdf

## In short

The AMS1117-3.3 module is a small breakout around AMS's AMS1117-3.3 low-dropout regulator, a 1 A part whose dropout is 1.1 V typical and 1.3 V maximum at 0.8 A (AMS1117 datasheet, pp. 1, 3). Wire a 5 V supply to VIN, ground to GND, and take 3.3 V from OUT for your 3.3 V parts; the chip's absolute maximum input is 15 V (p. 2). The module already carries the output capacitor the regulator needs for stability (p. 4).

The AMS1117-3.3 module is one of the most common ways to get 3.3 V on a breadboard. It is a small blue board with a three-pin header, VIN, GND and OUT, carrying an AMS1117-3.3 regulator in a SOT-223 package, its input and output capacitors and a red power LED. Several makers build it to the same pattern; the regulator itself is Advanced Monolithic Systems' AMS1117.

The AMS1117 is a three-terminal low-dropout linear regulator rated for up to 1 A. The 3.3 V version holds 3.251 V to 3.349 V at 4.8 V in, its dropout is 1.1 V typical and 1.3 V maximum at 0.8 A, and it includes current limiting (900 mA minimum, 1.1 A typical) and thermal shutdown at a 165 °C junction (AMS1117 datasheet, pp. 2, 3, 4). In practice that means a 5 V USB rail or an Arduino's 5V pin is enough to run it.

Being linear, it turns the dropped voltage into heat: (VIN minus 3.3 V) times the load current. AMS guarantees its regulation specs up to 1.2 W of dissipation in the SOT-223 package (p. 3), which is about 700 mA from 5 V but only about 140 mA from 12 V. It is the right part for a few hundred milliamps of 3.3 V from 5 V; for big drops at high current, a buck converter wastes far less.

## Agent rules

Follow these when you wire this part or write code for it.

- Do: GND to the circuit's ground, shared with the board that talks to the 3.3 V part.
- Do: OUT feeds only 3.3 V parts: wire their VCC to OUT (or put OUT on a rail of its own and say which rail is 3.3 V). Never tie OUT to a rail another supply drives.
- Do: The supply goes to VIN, never to OUT: fed through OUT it regulates nothing.
- Do: Heat: the regulator burns (VIN − 3.3 V) x current.
- Do: A board's logic pins still talk to the 3.3 V part: a 5 V board's outputs into a 3.3 V-only input need a level shifter or a divider (say so).
- Do: From 5 V keep the load to about 700 mA: the SOT-223 package limits the regulator to 1.2 W
- Never: No VIN from a 3.3 V source; NO VIN above 12 V (15 V destroys it).
- Never: No OUT on a 5 V rail or a board's 5V pin.
- On an ESP32 DevKit V1: VIN is on VIN, which gives about 5 V only while the board is powered from USB.
- On a Raspberry Pi Pico: VIN is on VBUS, which gives about 5 V only while the board is powered from USB.

## Pinout

| Pin | Function | Type |
| --- | --- | --- |
| VIN | VIN (4.5-12 V in) · 3.3 V (max 12 V) | power in |
| OUT | OUT (3.3 V) | power out |
| GND | GND | power in |

## Wiring

### Arduino Uno

| AMS1117 3.3V Regulator Module | Arduino Uno | Note |
| --- | --- | --- |
| VIN | 5V |  |
| GND | GND |  |

### ESP32 DevKit V1

| AMS1117 3.3V Regulator Module | ESP32 DevKit V1 | Note |
| --- | --- | --- |
| VIN | VIN |  |
| GND | GND |  |

Warning: VIN is on VIN, which gives about 5 V only while the board is powered from USB.

### Raspberry Pi Pico

| AMS1117 3.3V Regulator Module | Raspberry Pi Pico | Note |
| --- | --- | --- |
| VIN | VBUS |  |
| GND | GND |  |

Warning: VIN is on VBUS, which gives about 5 V only while the board is powered from USB.

## Specifications

| Spec | Value | Source |
| --- | --- | --- |
| Output voltage (chip) | 3.3 V; 3.251 V to 3.349 V at VIN 4.8 V, 25 °C | AMS1117 datasheet (Advanced Monolithic Systems), p. 2 |
| Output current (chip) | Up to 1 A | AMS1117 datasheet, p. 1 |
| Dropout voltage | 1.1 V typical, 1.3 V max at 0.8 A | AMS1117 datasheet, p. 3 |
| Input voltage | 15 V absolute maximum | AMS1117 datasheet, p. 2 |
| Current limit | 900 mA min, 1100 mA typical, 1500 mA max | AMS1117 datasheet, p. 3 |
| Quiescent current | 5 mA typical, 11 mA max | AMS1117 datasheet, p. 3 |
| Dissipation for guaranteed regulation | 1.2 W in SOT-223 | AMS1117 datasheet, p. 3 (note 2) |
| SOT-223 thermal resistance | 90 °C/W, 46 °C/W to over 90 °C/W depending on copper area | AMS1117 datasheet, p. 2 |
| Thermal shutdown | Junction above 165 °C | AMS1117 datasheet, p. 4 |
| Module pins | VIN, GND, OUT (3.3 V) | Tinkered component registry |
| Maximum supply voltage | 12 V | Tinkered component registry |
| Dimensions | 8.8 × 7.6 × 17.9 mm | Tinkered component registry |
| Weight | 1 g | Tinkered component registry |
| Output voltage | 3.3 V | maker's datasheet, checked 29 Oct 2026 |
| Output current | 1 A, limited to 1.2 W in SOT-223 (about 700 mA from 5 V) | maker's datasheet, checked 29 Oct 2026 |

## Circuit notes

- Feed VIN from a supply above about 4.6 V so the 3.3 V output stays in regulation through the 1.3 V maximum dropout (AMS1117 datasheet, p. 3): a USB 5 V rail, an Arduino's 5V or VIN pin, a 4xAA pack or a 9 V battery. Never exceed the 15 V absolute maximum (p. 2).
- Keep the dissipation, (VIN minus 3.3 V) times the current, within the 1.2 W AMS guarantees for SOT-223 (p. 3): roughly 700 mA from 5 V, 200 mA from 9 V and 140 mA from 12 V. The module's small copper area sits at the high end of the 46 to 90 °C/W range (p. 2), so it runs hot near those limits.
- Share GND between the module, the supply and the microcontroller. OUT feeds only 3.3 V parts; never connect OUT to a rail another supply drives.
- The regulator powers 3.3 V parts but does not translate logic levels. A 5 V board's output into a 3.3 V-only input still needs a divider or a level shifter.
- The module's own capacitors cover the regulator's stability. AMS notes that 22 µF of tantalum on the output ensures stability in all conditions (p. 4); add bulk capacitance at a load with large current spikes, such as an ESP8266 or an nRF24L01.

## Common mistakes

- **Powering it from 3.3 V or a single Li-ion cell.** With up to 1.3 V of dropout at 0.8 A (AMS1117 datasheet, p. 3), the output falls well below 3.3 V from a 3.3 V or 3.7 V source. Feed it 5 V, or choose a lower-dropout regulator for a single cell.
- **Expecting a full 1 A from 12 V.** From 12 V the regulator burns 8.7 V times the current: 1 A would be 8.7 W, far above the 1.2 W AMS guarantees for SOT-223 (p. 3). Above about 140 mA from 12 V it overheats and the thermal shutdown cuts in; use a buck converter instead.
- **Wiring the supply to OUT.** VIN is the input and OUT the 3.3 V output. Feeding the supply into OUT bypasses the regulator, and a 5 V supply then reaches every 3.3 V part on the rail.
- **Assuming it level-shifts signals.** The module only supplies power. A 5 V microcontroller's TX or SPI lines still swing to 5 V and need a divider or level shifter before a 3.3 V-only input.
- **Forgetting a common ground.** If the module's GND is not tied to the microcontroller's GND, the 3.3 V part and the board have no shared reference and communication fails.

## Questions

### How do I wire an AMS1117 3.3 V module to an Arduino?

Connect the Arduino's 5V pin to VIN and GND to GND, then take 3.3 V from OUT to your 3.3 V module's VCC. At 5 V in, the AMS1117-3.3 has headroom over its 1.3 V maximum dropout (AMS1117 datasheet, p. 3) and can supply several hundred milliamps.

### What is the maximum input voltage of the AMS1117-3.3?

The chip's absolute maximum input is 15 V (AMS1117 datasheet, p. 2). Above about 9 V the heat limit, 1.2 W for guaranteed regulation in SOT-223 (p. 3), restricts the current far more than the voltage rating does.

### How much current can the AMS1117 3.3 V module supply?

The chip is rated for 1 A with a current limit of 900 mA minimum (AMS1117 datasheet, pp. 1, 3), but heat sets the real limit: about 700 mA from 5 V and about 140 mA from 12 V before passing the 1.2 W AMS guarantees for SOT-223 (p. 3).

### Can I run an ESP8266 or ESP-01 from an AMS1117 module?

Yes, from 5 V in. The module gives enough current for the Wi-Fi bursts, and its output stays at 3.3 V while the input is above about 4.6 V (AMS1117 datasheet, p. 3). Add a bulk capacitor beside the ESP for its current spikes.

### My AMS1117 module's output is low or it gets very hot. Why?

A low output means the input is too close to 3.3 V: it needs 1.1 V to 1.3 V of headroom at load (AMS1117 datasheet, p. 3). Heat means the dissipation, (VIN minus 3.3 V) times the current, is high; past 165 °C the thermal shutdown turns it off (p. 4). Lower the input voltage or the load, or use a buck converter.

### AMS1117 vs LM1117: are they interchangeable?

Mostly. Both are 1117-style LDOs with the same GND/ADJ, VOUT, VIN pinout. AMS's AMS1117 is rated for 1 A (AMS1117 datasheet, p. 1); TI's LM1117 for 800 mA and a 15 V recommended input (TI LM1117 datasheet, pp. 1, 4). The module saves you fitting the capacitors yourself.

## Related parts

- [Red LED](https://www.tinkered.ai/components/led-red.md): wired with it in its circuit
- [220Ω Resistor](https://www.tinkered.ai/components/resistor-220.md): wired with it in its circuit
- [MB102 Breadboard Power Module](https://www.tinkered.ai/components/mb102-power-module.md): same job: regulates a supply
- [LM1117 3.3V Regulator (TO-220)](https://www.tinkered.ai/components/lm1117t-3v3.md): same job: regulates a supply
- [LM2596 Buck Converter Module](https://www.tinkered.ai/components/lm2596-buck-module.md): same job: regulates a supply
- [MT3608 Boost Converter Module](https://www.tinkered.ai/components/mt3608-boost-module.md): same job: regulates a supply

## Try it

Tinkered can design a circuit with the AMS1117 3.3V Regulator Module, draw its schematic and check it. Free to start at https://www.tinkered.ai.