Overview
The FAN5333ASX, produced by onsemi, is a general-purpose LED driver that features fixed frequency mode operation and an integrated FET switch. This device is designed to drive flash LEDs in serial connections, making it suitable for high output power applications. It operates at high switching frequencies to minimize switching noise, particularly beneficial in hand-held communications equipment. The device also boasts minimal quiescent current in both normal and shutdown modes to extend battery life. The operation mode can be controlled via a logic level shutdown circuitry.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Input Voltage (VIN) | 1.8 | - | 5.5 | V |
| Switching Frequency | 1.2 | 1.5 | 1.8 | MHz |
| Peak Switch Current | 1.1 | - | 1.5 | A |
| Output Power Capability | - | - | 1.5 | W |
| Quiescent Current (Normal Mode) | - | - | 0.6 | mA |
| Quiescent Current (Shutdown Mode) | - | - | 0.1 | μA |
| Feedback Voltage (FAN5333A) | 110 | - | 121 | mV |
| Feedback Voltage (FAN5333B) | 315 | - | 331 | mV |
| Thermal Shutdown Temperature | - | - | 150 | °C |
| Package Type | - | - | SOT23-5 | - |
Key Features
- Fixed frequency mode operation at 1.5 MHz to minimize switching noise.
- Integrated FET switch with low ON-resistance for high efficiency and low power dissipation.
- Adjustable output voltage and cycle-by-cycle current limit circuit to keep the peak current below 1.5 A.
- Low shutdown current (<1 μA) to extend battery life.
- Over-voltage protection and thermal shutdown at 150°C.
- Internal compensation and feedback voltage options (110 mV for FAN5333A, 315 mV for FAN5333B).
- Pb-free and halide-free packaging.
Applications
- Cell phones and handheld communications equipment.
- PDAs and other portable devices.
- Display bias and LED bias applications.
- Flash LED drivers.
Q & A
- What is the primary function of the FAN5333ASX?
The FAN5333ASX is a general-purpose LED driver designed to drive flash LEDs in serial connections with high output power and minimal switching noise.
- What is the switching frequency of the FAN5333ASX?
The switching frequency is between 1.2 MHz and 1.8 MHz.
- How is the output current set in the FAN5333ASX?
The output current is set by a resistor divider connected between the FB pin and ground, using the internal reference voltage (VREF) of 110 mV for FAN5333A or 315 mV for FAN5333B.
- What is the maximum peak switch current of the FAN5333ASX?
The maximum peak switch current is 1.5 A.
- How does the FAN5333ASX manage thermal protection?
The device features thermal shutdown at 150°C, which resets when the die cools to 130°C.
- What are the recommended operating conditions for the input voltage?
The input voltage (VIN) should be between 1.8 V and 5.5 V.
- What is the quiescent current in shutdown mode?
The quiescent current in shutdown mode is less than 1 μA.
- What type of package does the FAN5333ASX come in?
The device is packaged in a 5-lead SOT23 package.
- How can the LED current be dimmed using the FAN5333ASX?
The LED current can be dimmed using PWM signals, DC voltage, or filtered PWM signals through the FB pin and external circuitry.
- What are some of the key applications for the FAN5333ASX?
Key applications include cell phones, PDAs, handheld equipment, display bias, and flash LED drivers.
