LD1117 Voltage Regulator: Datasheet, Pinout, Circuit

LD1117 Pinout

LD1117 Symbol

LD1117 Footprint

LD1117 3D Model

The LD1117 is a low drop voltage regulator able to provide up to 800 mA of output current, available even in an adjustable version (VREF = 1.25 V). Concerning fixed versions, are offered the following output voltages: 1.2 V, 1.8 V, 2.5 V, 2.85 V, 3.3 V and 5.0 V. The device is supplied in SOT-223, DPAK, SO-8 and TO-220.

• Low dropout voltage (1 V typ.) 

• 2.85 V device performances are suitable for SCSI-2 active termination 

• Output current up to 800 mA 

• Fixed output voltage of: 1.2 V, 1.8 V, 2.5 V, 3.3 V, 5.0 V 

• Adjustable version availability (VREF = 1.25 V) 

• Internal current and thermal limit 

• Available in ± 1 % (at 25 °C) and 2 % in full temperature range 

• Supply voltage rejection: 75 dB (typ.)

LD1117 Block Diagram

• Used for Positive voltage regulations

• Battery Operated applications.

• Variable power supply

• Current limiting circuits

• Reverse polarity circuits

• Commonly used in Desktop PC, DVD and other consumer products

• Used in motor control circuits

LD1117 Application circuit (for 1.2 V)

LD1117 Application circuit (for other fixed output voltages)

The Alternatives for LD1117:

• KIA78xxP

• LM1117

The LD1117 is a Linear Voltage Regulator similar to the well-known LM317. Since it is accessible as a DCY Package, it is noted for its tiny form factor (SMD Component). The LD1117 is available in a variety of configurations, including fixed output voltages of 1.8V, 2.5V, 3.3V, or 5V, as well as a variable voltage regulator with a 1.25V reference value. The LD1117 is extremely similar to the LM1117, but it has a much lower voltage drop, making it ideal for battery-powered applications.

So, if you're looking for a low-voltage SMD component voltage regulator, this IC can be the correct fit for you.

Using the LD1117 is rather straightforward. If the voltage regulator is a fixed voltage regulator, simply supply power to the IC through the Vin pin, and the regulated output can be found on the Vout pin. In this situation, the Adj/Ground pin is only used as a ground pin and is grounded. A capacitor can also be added to the output side of the circuit to filter out noise.

To determine the output voltage of an adjustable type voltage regulator, two external resistors are required. The output voltage of the regulator is determined by the resistors R1 and R2, as illustrated in the reference circuit diagram below. The CAdj capacitor is an optional component that can be used to increase ripple rejection. The input and output noise is filtered by the other two capacitors.

LD1117 Package

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