NCP1117ST18T3G

NCP1117ST18T3G is ON Semiconductor’s fixed 1.8 V low‑dropout regulator (LDO) in a SOT‑223 package, part of the NCP1117 family. It provides up to about 1 A of output current with a typical dropout of ~1 V and accepts input voltages up to around 15 V. The “ST18” designation identifies the fixed 1.8 V output version.
Key points:
- Pinout (front view, left to right): Ground/Adj, Vout, Vin; the tab is usually tied to Vin.
- Requires external capacitors for stability: typically a 10 µF low‑ESR on the output and a input bypass capacitor (often ~10 µF).
- Use cases: generates a 1.8 V rail for microcontrollers, memory, and other digital ICs.
- Thermal/Protection: can deliver up to ~1 A with proper heat sinking; include precautions against reverse discharge (e.g., a diode from output to input if Vin can fall below Vout).
In short, a compact, fixed 1.8 V LDO suitable for small 1.8 V rails with modest thermal budgets.

Equivalents (1.8 V, 1 A LDO, pin-compatible):
- LM1117-1.8 (Texas Instruments / National)
- LD1117V18 (STMicroelectronics)
- AMS1117-1.8 (Analog Devices / others)
- AP1117-1.8 (Diodes Inc)
- KA1117-1.8 (various vendors)

NCP1117ST18T3G is a 1.8 V fixed output LDO regulator. Key features:
- Fixed output: 1.8 V at up to 1 A
- Low dropout: ~1.2 V at 1 A
- Input voltage range up to about 20 V
- Requires output capacitor (min ~10 µF, low ESR) for stability; input cap recommended
- Output tolerance typically ±2% (at 25°C)
- Quiescent current ~5 mA
- Built-in current limit and thermal shutdown protection
- Wide operating temperature: -40°C to +125°C
- RoHS/compliant; available in common packages (SOT-223 and TO-263/T3G variants)

- Pin count: 3 pins (in a SOT-223 package; tab exists).
- Pinout (front view, left to right): 1 = GND, 2 = VOUT, 3 = VIN. Tab = VIN.
- Function: Fixed 1.8 V low-dropout regulator (LDO), typically capable of up to about 1 A.

- Manufacturer: ON Semiconductor (ON).
- What kind of company: An American multinational semiconductor company that designs and manufactures a broad range of energy-efficient electronics, including analog, power management, sensors, and logic ICs.

Applications of NCP1117ST18T3G (1.8V fixed-output LDO):
- Generate 1.8V core/logic rails for digital ICs
- Post-regulator for microcontrollers, CPUs, FPGAs, ASICs, and memories
- Local 1.8V supply in battery-powered and portable devices from higher input voltages
- Power rails for consumer electronics (set-top boxes, IoT, wearables)
- Embedded systems and telecom/network equipment
- Prototyping/development boards requiring a stable 1.8V rail
Note: Ensure proper input/output capacitors and thermal considerations per datasheet.

SOT‑223 (3‑pin) surface‑mount package.