MCP1755 Low Dropout Regulator (LDO)

Last modified by Microchip on 2023/11/09 08:59

The MCP1755/S is a 16V, high PSRR Low Dropout (LDO) voltage regulator with short-circuit current fold-back. This regulator provides up to 300 mA of output current and accepts a continuous input voltage from 3.6V to 16V, making it ideal for automotive and commercial 12V DC systems. Delivering 80 dB of ripple rejection at 1 kHz, this device is for AC-sensitive applications such as GFCI and AFCI circuit breakers. The current fold-back feature gradually reduces the device current down to 30 mA under short-circuit conditions to protect against damage. When the short is removed, the device will recover and continue operating.

Available on Microchip Direct

Dropout voltage is defined as the input-to-output voltage differential at which the output voltage drops 2% below the nominal value that was measured with a VR + 1.0 V differential applied, where VR is the nominal output voltage

MCP1755/S LDO Features

  • Maximum Input Voltage: 16 V
  • Output Voltage Range 1.8 V – 5 V
  • Output Current: 300 mA for all output voltages
  • Typical Quiescent Current: 68 μA
  • Typical Dropout Voltage at Maximum Iout: 300 mV
  • Packages: 3-pin SOT-23A, 3-pin SOT-89, 5-pin SOT-89, 8-pin 2 × 3 DFN
  •  High noise rejection, typical PSRR 80 dB at 1 kHz
  • High output accuracy, 0.85% typical output range
  • Standard output voltage options: 1.8 V, 2.5 V, 2.8 V, 3.0 V, 3.3 V, 4.0 V, 5.0 V
  • Tight output tolerance of ±2.0 % over entire operating temperature range
  • Stable with minimum 1.0 μF output capacitance
  • Power good output
  • Shutdown input
  • Short-circuit protection with true output current fold-back
  • Over-temperature protection

Package Options

SOT-223-58-lead 2 x 3 DFN
8-lead 2 x 3 DFN 

MCP1755 block diagram

MCP1755 Applications

Voltage Regulator

MCP1755/S is most commonly used as a voltage regulator for battery-powered applications. In this application example, the input voltage (VIN) ranges from 3.6 V to 4.8 V (Maximum VIN). The typical output voltage (VOUT) is 1.8 V and it can supply a maximum of 50 mA.

MCP1755 voltage regulator

MCP1755S LDO is available as a fixed-voltage device.

Current Voltage Reference

The MCP1755/S can be used as a low quiescent current voltage reference. For example, in PIC® Microcontroller applications, the initial accuracy of the reference can be calibrated using production test equipment or by using a ratio measurement. In the application example, a bridge sensor is used for calibration. When the initial accuracy is calibrated, the thermal stability and line regulation tolerance are the only errors introduced by the MCP1755/S. The low-cost, low quiescent current and small ceramic output capacitor are all advantages when using the MCP1755/S as a voltage reference.

MCP1755 application ratio