## Overview of the ACT6330 The **ACT6330** is a high-performance, high-efficiency fixed-frequency PWM step-up (Boost) DC/DC converter. It is primarily designed for driving series LEDs or powering small displays where a constant current or voltage is required from a low-voltage input. --- ### Key Technical Specifications | Feature | Specification | | :--- | :--- | | **Input Voltage Range** | 2.6V to 5.5V | | **Output Voltage Range** | Up to 12V (Internal MOSFET rating) | | **Switching Frequency** | 1.1 MHz | | **Switch Current Limit** | ~1.3A | | **Efficiency** | Up to 90% | | **Package Type** | SOT23-6 | --- ### Internal Electronic Components The ACT6330 integrates several critical functional blocks within its silicon: 1. **Power MOSFET:** An internal N-channel MOSFET acts as the primary switch. Its low $R_{DS(ON)}$ minimizes power loss during conduction. 2. **PWM Controller:** A 1.1 MHz oscillator drives the logic, allowing for the use of small external inductors and capacitors. 3. **Error Amplifier:** Compares the feedback voltage ($V_{FB}$) against an internal reference (typically 0.6V) to regulate the output. 4. **Protection Circuitry:** * **Over Voltage Protection (OVP):** Prevents the device from damaging itself if the load (e.g., an LED string) becomes an open circuit. * **Thermal Shutdown:** Shuts the device down if the internal junction temperature exceeds safety limits. * **Cycle-by-Cycle Current Limit:** Protects the inductor and the IC from saturation or short circuits. --- ### Required External Components To function as a complete boost converter, the ACT6330 requires the following external parts: * **Inductor (L):** Usually 4.7µH to 10µH. It stores energy during the "ON" phase and releases it during the "OFF" phase. * **Schottky Diode (D):** Provides a fast-switching path for the current when the internal switch is off. * **Input/Output Capacitors ($C_{IN}, C_{OUT}$):** Ceramic capacitors (1µH to 4.7µH) are used to filter noise and stabilize voltage. * **Feedback Resistors ($R_1, R_2$):** Used to set the output voltage level based on the formula: `Vout = 0.6V * (1 + R1/R2)` --- ### Pin Configuration (SOT23-6) | Pin # | Name | Description | | :--- | :--- | :--- | | 1 | **SW** | Switch Pin. Connected to the inductor and Schottky diode. | | 2 | **GND** | Ground. | | 3 | **FB** | Feedback pin to regulate output. | | 4 | **EN** | Enable pin. High = Active; Low = Shutdown. | | 5 | **OV** | Over Voltage sense pin (on some variants). | | 6 | **VIN** | Power Supply Input. |