Overview
The CAT32, produced by onsemi, is a DC/DC step-up converter designed to drive multiple white light-emitting diodes (LEDs) connected in series. This device is ideal for applications requiring regulated LED current and high efficiency, particularly in battery-powered devices. The CAT32 operates at a constant switching frequency of 1.2 MHz, allowing the use of small external inductors and ceramic capacitors.
Key Specifications
| Parameter | Rating/Range | Unit |
|---|---|---|
| VIN, LED, SHDN Voltage | 2 to 7 | V |
| SW Voltage | 20 | V |
| RSET Voltage | 1 | V |
| Storage Temperature Range | −65 to +150 | °C |
| Junction Temperature | 125 | °C |
| Lead Soldering Temperature (10 secs) | 300 | °C |
| ESD Rating – Human Body Model | 2000 | V |
| Quiescent Current | 0.5 to 0.7 | mA |
| Ground Current in Shutdown | 0.05 to 1 | μA |
| LED Current Adjust Range | 5 to 40 | mA |
| Switching Frequency | 0.8 to 1.6 | MHz |
| Switch Current Limit | 400 to 780 | mA |
| Switch Resistance | 0.5 to 1.2 | Ω |
| Efficiency | 83% | % |
Key Features
- Low Quiescent Ground Current: Typical 0.5 mA.
- High Efficiency: Over 80%.
- Adjustable Output Current: Up to 40 mA.
- High Frequency Operation: 1.2 MHz.
- Input Voltage Range: 2 V to 7 V.
- Low Resistance Power Switch: 0.5 Ω.
- Drives up to 4 White LEDs in Series.
- Shutdown Current: Less than 1 μA.
- Load Fault Protection: Against open-circuit conditions.
- Low Profile Package: TSOT-23 6-lead, 1 mm max height.
- Pb-Free, Halogen Free/BFR Free, and RoHS Compliant.
Applications
- Color LCD and Keypad Backlighting
- Cellular Phones
- Handheld Terminals
- Digital Cameras
- PDAs/Games
- Portable MP3 Players
Q & A
- What is the primary function of the CAT32 device?
The CAT32 is a DC/DC step-up converter designed to drive multiple white LEDs connected in series, providing regulated output current.
- What is the switching frequency of the CAT32?
The CAT32 operates at a constant switching frequency of 1.2 MHz.
- How is the LED current adjusted in the CAT32?
The LED current is adjusted using an external resistor (RSET) connected to the RSET pin. The current through this resistor sets the regulated current in the LEDs.
- What is the maximum number of LEDs the CAT32 can drive in series?
The CAT32 can drive up to 4 white LEDs in series.
- How can LED dimming be achieved with the CAT32?
LED dimming can be achieved using a DC voltage, a logic signal, or a pulse width modulation (PWM) signal on the SHDN pin or by adjusting the RSET pin.
- What is the typical quiescent current of the CAT32?
The typical quiescent current is 0.5 mA.
- What is the shutdown current of the CAT32?
The shutdown current is less than 1 μA.
- Does the CAT32 have any protection features?
Yes, the CAT32 includes overcurrent limiting protection and load fault protection against open-circuit conditions.
- What is the package type and dimensions of the CAT32?
The CAT32 is available in a low-profile (1 mm max height) TSOT-23 6-lead package.
- Is the CAT32 compliant with environmental standards?
Yes, the CAT32 is Pb-Free, Halogen Free/BFR Free, and RoHS Compliant.
