Part Number: NCP1117ST50T3G

Manufacturer: onsemi

Description: IC REG LINEAR 5V 1A SOT223

Shipped from: Shenzhen/HK Warehouse

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Technical Specifications of NCP1117ST50T3G

Datasheet  NCP1117ST50T3G datasheet
Category Integrated Circuits (ICs)
Family PMIC – Voltage Regulators – Linear
Manufacturer ON Semiconductor
Packaging Tape & Reel (TR)
Part Status Active
Regulator Topology Positive Fixed
Voltage – Output 5V
Current – Output 1A
Voltage – Dropout (Typical) 1.07V @ 800mA
Number of Regulators 1
Voltage – Input Up to 20V
Current – Limit (Min) 1A
Operating Temperature 0°C ~ 125°C
Mounting Type Surface Mount
Package / Case TO-261-4, TO-261AA
Supplier Device Package SOT-223

NCP1117 Description

The NCP1117 series of low dropout positive voltage regulators have a maximum dropout voltage of 1.2 V at 800 mA over temperature and can deliver output currents greater than 1.0 A. This series has nine fixed output voltages with no minimum load required to maintain regulation: 1.5 V, 1.8 V, 1.9 V, 2.0 V, 2.5 V, 2.85 V, 3.3 V, 5.0 V, and 12 V. A variant with a configurable output that can be configured to operate between 1.25 V and 18.8 V using two external resistors is also supplied. On-chip trimming provides an accurate adjustment of the reference/output voltage to within 1.0%. Some internal protection measures include limiting the output current, compensating for the safe working area, and shutting down when the temperature gets too high. The NCP1117 series can function with input voltages of up to 20 V. Devices are offered in DPAK and SOT223 packages.


  • Output current greater than 1.0 A. maximum dropout voltage of 1.2 V at 800 Ma above temperature.
  • 5, 1.8, 1.9, 2.0, 2.5, 2.85, 3.3, 5.0, and 12-volt fixed output voltages.
  • Option for Adjustable Output Voltage.
  • Trimmed to a reference/output voltage of 1.0%.
  • Protection against the current limit, safe operation, and thermal shutdown.
  • To 20 V Input Operation.
  • AEC-Q100 qualified and PPAP capable; NCV Prefix for Automotive and Other Applications Needing Special Site and Control Change Requirements.
  • These Devices Are Pb-Free.

Applications Information

Compared to the traditional industry standard three-terminal adjustable regulators, the NCP1117 offers a considerable dropout voltage reduction, improved output voltage precision, and temperature stability. These devices offer output current limiting, safe operating area compensation, and thermal shutdown safety, making them perfect for powering various consumer and business products. The older LM317 and its derived device types are pin compatible with the NCP1117 family.

● Output Voltage

Voltage regulators that can be adjusted are floating devices. The nominal 1.25 V reference voltage between the output and adjustment pins is created and maintained by them. Resistor R1 programs the reference voltage to a continuous current source, and this current travels through R2 to the ground to calibrate the output voltage. Typically, a programmed current level greater than the minimum 5.0 mA required for regulation is chosen.

The adjusted pin current, Iadj, produces a minor output voltage error that is typically unnoticeable because it is substantially smaller and consistent than the designed load current. For the fixed output devices, R1 and R2 are built into the device, and the ground current Ignd varies depending on the output voltage from 3.0 mA to 5.0 mA.

● External Capacitors

If the device is more than a few inches from the power source, an input bypass capacitor Cin might be necessary for regulator stability. This capacitor will greatly improve the output transient response and lessen the circuit’s sensitivity when supplied by a complicated source impedance. The regulator’s input and ground terminals should be across the input bypass capacitor’s mounting location, using the minimum track length possible.

Capacitor Cout helps the regulator adjust the frequency, and its use is necessary to ensure the output is stable.  It is necessary to have a minimum capacitance of 4.7 F and equivalent series resistance (ESR) between 33 m (typ) and 2.2.

As long as it satisfies the minimum capacitance value and ESR limitations over the circuit’s whole working temperature range, the capacitor type can be ceramic, tantalum, or aluminum electrolytic. Higher output capacitance values can lower output noise while improving loop stability and transient response.

● Protection Diodes

When utilized in typical regulator applications, the two internal low-impedance diode pathways of the NCP1117 family are often unprotected. The first path, which connects Vout and Vin, has a peak surge current resistance of around 15 A. Vin cannot produce a current surge of this size during normal cycling. Device damage is only conceivable when Vin is shorted or crowbarred to the ground, and Cout exceeds 50 F. The device must be protected by diode D1 in these circumstances. The second link, which connects Cadj and Vout, has a peak surge current resistance of roughly 150 mA. If the output is shorted or crowbarred to ground and Cadj is larger than 1.0 F, protection diode D2 is necessary.

If Vin is shorted to ground and Cadj is above 50 degrees Fahrenheit, a combination of protection diodes D1 and D2 may be necessary. The internal diodes’ stated peak current capacity is 100 s at a junction temperature of 25 °C. These numbers should be used as a general guide because they could change.

● Load Regulation

Although the NCP1117 series can deliver excellent load regulation, since these are three terminal devices, only a limited amount of remote load sensing is feasible. To get the best load regulation performance possible, two requirements must be met. The top side of programming resistor R1 should be attached to the regulator housing as closely as is practical. By doing this, the voltage drop brought on by the wire resistance RW + being connected in series with the reference voltage across R1 will be reduced.

The ground end of R2 must be directly linked to the load per the second requirement. This enables real Kelvin sensing, in which the regulator makes up for the voltage loss brought on by the wiring resistance RW.


To sum up, the NCP1117 series of low dropout positive voltage regulators offers a remarkable selection of features that make them the perfect option for powering a variety of consumer and commercial equipment. Compared to the traditional industry-standard three-terminal adjustable regulators, these regulators perform better, with a maximum dropout voltage of 1.2 V at 800 mA over temperature and an output current surpassing 1.0 A. Additionally, the series provides nine fixed output voltages as well as an adjustable output version that can be programmed from 1.25 V to 18.8 V, giving it a flexible option for a variety of applications.

Additionally, the regulators have built-in safety features including output current limiting, safe operating area compensation, thermal shutdown, and no minimum load requirement for control maintenance. They come in SOT-223 and DPAK packages and have an operating voltage range of up to 20 V. Pin compatibility with the earlier LM317. Its descendant device types are another benefit of the NCP1117 series.

It is important to remember that the device needs input bypass capacitors, frequency compensation capacitors to assure output stability, and protective diodes in some circumstances. In order to benefit from this cutting-edge technology, we advise getting in touch with ICRFQ, your trusted electronic component supplier, as soon as possible if you’re interested in obtaining the NCP1117 or learning more about its characteristics.

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