PT4832A

Due to market price fluctuations, if you need to purchase or consult the price. You can contact us or emial to us:   sales@allicdata.com

DC-DC converters are devices that transform DC power from one voltage level to another in order to match the requirements of a particular load. PT4832A is a three-terminal high-efficiency DC-DC converter. This article will discuss the application field and the working principle of PT4832A.

Application Field

The application range of PT4832A is very wide. It is suitable for the applications that require high conversion efficiency and tight line/load regulation. Examples are house electric appliance, personal communication device, IT product, and LED lighting. This device is especially designed for the applications with other AC/DC sources, such as adapter/charger and solar panel.

The PT4832A is specifically designed to be integrated into paper currency detector to provide its internal power supply. The device provides stable 5/3.3V power with high efficiency to the currency detector, allowing it to perform the highly accurate detection required for counting the money efficiently.

It also serves as a battery charger in commercial hand-held/portable devices. In this application, the battery voltage is converted from 3.3V to 5V, and the charge process is automatically monitored and controlled, ensuring the battery to be securely and efficiently charged.

Working Principle

PT4832A is a step-up DC-DC converter. Its circuit structure is based on the non-synchronous switched-mode boost converter, which boosts the input voltage from ground to a certain level of output. A simplified circuit diagram is given in Figure 1.

The main components used for different functional blocks are listed as follows:

• Transistor Q1: energy storage element.
• Transistor Q2: main switch.
• Diode D1: current limiting element.
• Diode D2: output rectifier.
• Capacitor C1: output filter.
• Inductor L1: current regulating element.

Initially, the power is supplied to the input terminal of PT4832A and the two transistors (Q1 and Q2) are switched off. When the input voltage reaches its threshold level, Q2 is turned on suddenly. It then pulls the drain voltage of Q1 to ground level, charging the inductor with full current. Subsequently, when Q2 is turned off, the voltage across the inductor begins to increase, thus storing energy in the inductor and causing energy to flow from drain to source of Q1. Since the output voltage is proportional to the voltage across the inductor, it is amplified in the step-up mode.

When the output voltage reaches its peak, Q2 is turned on again. This produces negative voltage of current in the inductor and energy is transferred from source to drain. Afterwards, the diode D2 will enable the current to return to the load. C1 is used to reduce the ripple of the output voltage.

To further optimize the performance and provide advanced features, PT4832A incorporates several additional elements, such as external voltage reference, comparator, reference current generator, and oscillator. These peripheral devices enable the device to reach various control parameters such as output voltage accuracy, current protection etc.

Conclusion

The PT4832A is a three-terminal high-efficiency DC-DC converter suitable for a wide range of applications. It is based on the non-synchronous switched-mode boost converter and amplifies the input voltage in the step-up mode. Peripheral devices such as voltage reference and oscillator are included to provide advanced features. It is thus ideal for those applications that require high conversion efficiency and tight line/load regulation, such as paper currency detector and battery charger.

The specific data is subject to PDF, and the above content is for reference