Power Supply circuits diagram electronics projects

This low drop out regulator presented in this electronic schematic is a low drop out regulator with high efficiency designed for portable applications like : cellular telephones , handheld equipment and other portable equipments .
This low drop out regulator circuit use the ADP3367 which is a low drop out high precision voltage regulator that can supply up to 300 mA output current.
Using the ADP3367  voltage regulator we can make a fixed +5 volts power supply without other external components .
Using two external resistors we can adjust the output voltage of power supply from +1.3 V to +16 V  .

Fixed or adjustable mode can be selected via the SET input pin .
The ADP3367  accept a wide input voltage range from 2.5 V to 16.5 V .
The ADP3367 is to pin-compatible replacement with the MAX667 low dropout voltage regulator .
Main features of the ADP3367 voltage regulator are : Low Dropout, Low Power CMOS, Shutdown Mode: 0.2 mA Quiescent Current , 300 mA Output Current Guaranteed , Pin Compatible with MAX667 , Stable with 10 mF Load Capacitor , +2.5 V to +16.5 V Operating Range , Low Battery Detector , Fixed +5 V or Adjustable Output .
If we want to use another voltage than 5 volts we need to calculate the value of the resistors R1 and R2 .
To choose the value of resistors we can use these formula or we can chose a value for R1 and then calculate the R2 value ( the Vset value is 1.255volts ) .

This power supply is based on the Analog Devices regulator . The ADP1111 is a step-up/step-down switching regulator which can operates from an low voltage of 2 V to 12 V in step-up mode and up to 30 V in step-down mode.

The ADP1111 can be programmed to operate in step-up/stepdown or inverting applications using only three external components.

The ADP1111 offer three fixed output voltages fixed outputs of 3.3 V, 5 V and 12 V but can give another value of the output voltage using an adjustable version .  In step-up mode the ADP1111 can deliver 100 mA at 5 V from a 3 V input or it can deliver 200 mA at 5 V from a 12 V input in step-down mode.

Main features of the ADP1111 switching regulator are :2 V to 30 V Input Voltage Range , 72 kHz Frequency Operation , Utilizes Surface Mount Inductors , Few External Components Required , Operates in Step-Up/Step-Down or Inverting Mode ,Low Battery Detector , User Adjustable Current Limit , Internal 1 A Power Switch , Fixed or Adjustable Output Voltage .

The ADP1111 can be used in many applications  like  : 3 V to 5 V, 5 V to 12 V Step-Up Converters ; 9 V to 5 V, 12 V to 5 V Step-Down Converters , Laptop and Palmtop Computers , Cellular Telephones , Flash Memory , VPP Generators , Remote Controls , Peripherals and Add-On Cards , Battery Backup Supplies , Uninterruptible Supplies , Portable Instruments and many other .

The ADP1111 can be used in many other configurations for many other applications ( see the datasheet ) but the circuit presented in this schematic simple 20 V to 5 V Step-Down Converter .

This regulator circuit presented in this schematic is a simple low power regulator based on the ADP120 regulator chip manufactured by Analog Devices . The ADP120 linear regulator chip is ideal for low power applications like : mobile phones  , digital camera , portable audio devices  , portable and battery-powered equipment .

The schematic of these ADP120 linear regulator is very simple an require few external components .

Input voltage range of the ADP120 is between 2.3 V to 5.5 V and the maximum Output voltage range is between 1.2 V to 3.3 V .  The ADP120 is available in output voltages of 1.2 V , 1,5 V , 1,8 V , 2,5 V , 2,8 V , 3 V and 3.3 V.

The maximum output current delivered by ADP120 is around 100mA .

Other features of the ADP120 low power linear regulator are : low quiescent current IGND = 11 μA with zero load IGND = 22 μA with 100 mA load , low shutdown current: <1 μA  , low dropout voltage 60 mV @ 100 mA load , High PSRR 73 dB @ 1 kHz at VOUT = 1.2 V 70 dB @ 10 kHz at VOUT = 1.2 V , low noise: 40 μV rms at VOUT = 1.2 V , no noise bypass capacitor required , initial accuracy: ±1% , Stable with small 1 μF ceramic output capacitor , current-limit and thermal overload protection .