L4987CPT120

L4987CPT120 Application Field and Working Principle

The L4987CPT120 is an advanced monolithic step down switching regulator IC, a member of the ST L4987C family, specially designed for ultra-low power applications. It is ideal for demanding battery powered applications like personal healthcare devices as well as industrial remote monitoring and control systems. This device combines in a very small thermally enhanced 14...16L TSSOP leadless package a 20 V power MOSFET with a peak current up to 2A. It has a very low quiescent current of only 490nA in DC/DC conversion mode and a low shutdown current of only 2A. It is powered by either a low voltage regulated 5V supply or a 3.3V unregulated input.

The L4987CPT120 offers integrated loop compensation, adjustable operating frequency, over-temperature protection and short-circuit protection. It functions as a step-down switching regulator that generates a regulated output voltage from an input voltage as low as 2.5V. The power management features of this switching regulator are designed to ensure a high efficiency, low power dissipation, and stable output voltage. In addition, the device can be used for voltage translation in battery protected circuits.

Working Principle

The working principle of the L4987CPT120 device is based on the Pulse-Width Modulation (PWM) technique. This versatile IC can operate either in non-synchronous mode or in synchronous mode. In non-synchronous mode, the L4987CPT120 is configured as a non-switching regulator with a permanent ON state. In this mode, the input voltage is regulated to a constant regulated output voltage. In synchronous mode, the device functions as a pulse width modulated (PWM) step-down switching regulator. In this mode, the output voltage is regulated to a constant regulated output voltage. The output voltage is regulated by adjusting the duty cycle of the PWM output.

The L4987CPT120 is designed to operate from a wide input voltage range of 2.5V to 20V. As the input voltage decreases, the duty cycle of the PWM output is automatically adjusted to maintain the regulated output voltage at a constant value. The frequency of PWM switching is automatically and dynamically adjusted to ensure the best possible power conversion.The L4987CPT120 device also offers adjustable soft start, over-temperature protection and short-circuit protection.

Applications

The L4987CPT120 is ideal for portable and battery-powered applications. It can be used in a variety of applications such as personal healthcare devices, industrial remote monitoring and control systems, automotive on-board systems, and many other applications.

The L4987CPT120 device is also well suited for low power lighting, portable radio, and WiFi access point applications. It can also be used as an internal SMPS module in point-of-load applications. The device is designed to provide a low drop-out voltage and high switching frequency, and is capable of operating at high levels of efficiency with a wide range of input voltages and output currents.

The L4987CPT120 device is also suitable for OLED, LED, LCD and panel backlighting, battery chargers, and USB powered applications. It is also suitable for other applications that require a low power, high efficiency power solution.