UMW AMS1117 Overview
The UMW AMS1117 is a 1A positive low-dropout linear voltage regulator and one of the most recognised and widely adopted LDO regulators in the electronics industry. With a typical dropout voltage of only 1.2V at 1A, the AMS1117 efficiently converts higher input voltages to stable, precise output rails with minimal headroom requirement — making it ideal for powering microcontrollers, FPGAs, wireless modules, sensors, and other digital and analogue loads from 5V or 3.3V supply rails. UMW manufactures the AMS1117 across a full range of fixed output voltages — 1.2V, 1.5V, 1.8V, 2.5V, 3.3V, and 5.0V — as well as an adjustable (ADJ) version that allows any output voltage to be set via an external resistor divider, covering virtually every standard logic and analogue supply voltage in common use.
Output regulation accuracy is 2% for fixed-voltage versions and 1.5% for the adjustable version, providing sufficient precision for powering digital logic rails and analogue reference supplies in cost-sensitive designs. The UMW AMS1117 requires only small input and output bypass capacitors to maintain stability — a minimum of 10µF on the output is recommended to ensure loop stability and transient response — making it one of the easiest LDO regulators to design with. The device includes internal current limiting and thermal shutdown protection, safeguarding both the regulator and the downstream circuit under overload or short-circuit conditions. Operating across a temperature range of -40°C to 125°C, the UMW AMS1117 is suitable for both commercial and industrial temperature grade applications.
The UMW AMS1117 is available in three package options — SOT-223, TO-252, and SOT-89 — providing flexibility to accommodate different PCB layout styles, heatsinking requirements, and component height constraints. All three packages are pin-compatible with AMS1117 devices from other manufacturers, enabling a direct board-level substitution. ABL Semi stocks the UMW AMS1117 as a fully authentic, original UMW factory product across multiple voltage variants and packages, with flexible MOQ from prototype through to mass production and full compliance documentation for UK and European customers.
Key Specifications
| Parameter | Value |
|---|---|
| Device Type | Positive Low-Dropout (LDO) Linear Voltage Regulator |
| Maximum Output Current | 1A (continuous) |
| Typical Dropout Voltage | 1.2V @ 1A output |
| Fixed Output Voltage Options | 1.2V, 1.5V, 1.8V, 2.5V, 3.3V, 5.0V |
| Adjustable Output Version | Yes (ADJ) — output set via external resistor divider |
| Output Accuracy — Fixed Versions | ±2% |
| Output Accuracy — Adjustable Version | ±1.5% |
| Recommended Output Capacitor | ≥10µF (for stability) |
| Internal Protections | Current limiting, thermal shutdown |
| Operating Temperature Range | -40°C to +125°C |
| Package Options | SOT-223, TO-252, SOT-89 |
Applications
The UMW AMS1117 is one of the most versatile and widely applied LDO regulators in both consumer and industrial electronics, used wherever a stable, low-noise DC output is required from a higher-voltage supply. Primary application areas include microcontroller and microprocessor core voltage supplies, Raspberry Pi and Arduino power rails, Wi-Fi and Bluetooth module power inputs, USB device power regulation, and FPGA I/O voltage generation. The device is equally well-suited to industrial sensor power supplies, LED driver bias rails, battery-powered embedded systems, and low-cost power supply modules, where its combination of 1A current capacity, wide voltage option range, and small package footprint provides a practical and cost-effective regulation solution.
Pin-to-Pin Compatible Alternatives
The UMW AMS1117 shares the same pinout and package dimensions as AMS1117 devices manufactured by multiple suppliers worldwide, enabling a direct board-level drop-in substitution across SOT-223, TO-252, and SOT-89 footprints without any schematic or layout changes.
| Reference Part Number | Original Manufacturer | Why Choose UMW AMS1117 |
|---|---|---|
| AMS1117-3.3 | Advanced Analogic Technologies (AATI) | The original AMS1117 reference device; UMW’s version offers identical electrical characteristics and pinout in all three packages at a more competitive unit cost with flexible MOQ from ABL Semi |
| AP2114H-3.3TRG1 | Diodes Inc. | 1A LDO regulator in SOT-223 with comparable dropout; UMW AMS1117 provides a pin-compatible alternative across a wider range of fixed voltage options including 1.2V, 1.8V, and 2.5V variants |
| LD1117S33TR | STMicroelectronics | ST’s popular 1A LDO in SOT-223 and TO-252; UMW AMS1117 is a direct footprint replacement offering equivalent regulation performance with lower unit cost at volume from ABL Semi UK stock |
| MCP1827S-3302E/DB | Microchip | Low-dropout regulator in TO-252; UMW AMS1117 provides a broader family of compatible fixed-output variants plus an adjustable version, in three package options, at a lower price point |
| LM1117IMP-3.3 | Texas Instruments | TI’s LM1117 series in SOT-223 and TO-252; UMW AMS1117 is a pin-compatible alternative with equivalent 2% output accuracy and the same fixed and adjustable version availability across multiple voltages |
Frequently Asked Questions
Is UMW AMS1117 RoHS compliant?
Yes. The UMW AMS1117 is fully RoHS compliant. UMW manufactures the AMS1117 in accordance with EU RoHS Directive 2011/65/EU, ensuring the device is free from restricted hazardous substances including lead and mercury. ABL Semi can provide full compliance and trade documentation upon request to support UK and European regulatory and procurement requirements.
What are the pin-to-pin replacements for UMW AMS1117?
The UMW AMS1117 is a direct pin-compatible replacement for AMS1117 devices from Advanced Analogic Technologies, as well as functionally and footprint-equivalent alternatives to the STMicroelectronics LD1117, Texas Instruments LM1117, Diodes Inc. AP2114H, and Microchip MCP1827 in SOT-223, TO-252, and SOT-89 packages. Refer to the compatibility table above for a detailed comparison.
What is the minimum order quantity (MOQ) for UMW AMS1117?
ABL Semi offers flexible MOQ for UMW AMS1117, supporting both prototype quantities and mass production orders. Contact us for current stock and pricing.
What package options are available for UMW AMS1117?
The UMW AMS1117 is available in three package options: SOT-223 (the most common surface-mount package for 1A LDOs, with an exposed tab for heat dissipation), TO-252 (DPAK — a larger through-hole-compatible SMD package offering better thermal transfer to PCB copper), and SOT-89 (a smaller surface-mount package suited to compact PCB designs with lower power dissipation requirements). All three packages are pin-compatible with equivalent AMS1117 devices from other manufacturers. Contact ABL Semi to confirm stock availability for your required voltage variant and package combination.
What input voltage is required to use the UMW AMS1117 3.3V version, and how is power dissipation calculated?
For the AMS1117-3.3 fixed version, the minimum input voltage required is the output voltage plus the dropout voltage: 3.3V + 1.2V (typical) = approximately 4.5V minimum, though a practical minimum of 4.75V is recommended to account for dropout variation across temperature and load. Power dissipation in an LDO regulator is calculated as PD = (VIN − VOUT) × IOUT. For example, regulating from 5V to 3.3V at 1A produces 1.7W of heat — which must be safely dissipated through the package and PCB copper. In the SOT-223 package, adequate PCB copper area and, in higher-current designs, a heatsink or thermal via array are recommended to keep junction temperature within the device’s rated limits and maintain regulation accuracy.
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