ADM7150ACPZ-5.0-R7 Integrated Circuits (ICs)

ADM7150ACPZ-5.0-R7 Application Field and Working Principle

PMIC - Voltage Regulators - Linear

ADM7150ACPZ-5.0-R7 is a low-dropout linear voltage regulator (LDO) compliant to the Standard Microsystems Corporation Pin Assignment Standard. It provides the precision, performance and output current capability to supply the most advanced microprocessors and microcontrollers, including those designed to operate at 3.3 V and below.

Specifically, the ADM7150ACPZ-5.0-R7 features high-current output capability, low noise and high power supply rejection ratio (PSRR). The device contains current limiting, thermal shutdown and reverse-battery protection. With its ultra-low dropout voltage of 180 mV, the device can supply up to 500 mA of output current with an input voltage of 5.0 V.

Application Fields

The ADM7150ACPZ-5.0-R7 is useful in a variety of applications, such as microprocessor/microcontroller applications, portable equipment, cellular phones, digital cameras, PDAs, smart phones, industrial equipment, automotive systems and batteries.

Working Principle

The basic principle used to build an ADM7150ACPZ-5.0-R7 is the same as any other linear regulator. The typical schematic of a regulator using this device is shown in Figure 1. The circuit can be divided into two parts: a voltage reference and the error amplifier.

The voltage reference consists of two precision resistors connected between two terminals, VREF+, and VREF-. The reference voltage is generated by an internal voltage reference and is monitored with an external precision resistor divider connected between the device\'s VREF+ and VREF- terminals.

The error amplifier is a non-inverting circuit with a gain of one that compares the output voltage of the device, VOUT, to the voltage reference. If the output voltage, VOUT, is higher than the reference voltage, VREF, the error amplifier pulls the feedback pin, FB, low and triggers the internal comparator to open the pass transistor.

The pass transistor is the device by which the input current, IIN, is regulated. If the output voltage, VOUT, is lower than the reference voltage, VREF, the error amplifier releases the feedback pin, FB, and the pass transistor is closed again. This loop is repeated every time the output voltage, VOUT, changes, regulating the input current, IIN, accordingly.

The ADM7150ACPZ-5.0-R7 is able to maintain a constant output voltage, VOUT, with a maximum input current of 500 mA. The supply rejection ratio is typically –100 dB and the output voltage noise is typically 0.15 µV RMS.