MIC2289-24YML-TR [Microchip]

The MIC2289 is a PWM (pulse width modulated), boost-switching regulator that is optimized for constant-current white LED driver applications. The MIC2289 features an internal Schottky diode and three levels of output overvoltage protection providing a small size and efficient DC/DC solution that requires only four external components.

To optimize efficiency, the feedback voltage is set to only 95mV. This reduces power dissipation in the current set resistor and allows the lowest total output voltage, hence minimal current draw from the battery.

The MIC2289 implements a constant frequency 1.2MHz PWM control scheme. The high frequency, PWM operation saves board space by reducing external component sizes. The added benefit of the constant frequency PWM scheme in caparison to variable frequency is much lower noise and input ripple injected to the input power source.

The MIC2289 clamps the output voltage in case of open LED conditions, protecting itself and the output capacitor. The MIC2289 is available with three output OVP options of 15V, 24V, and 34V. The different OVP options allows the use of the smallest possible output capacitor with the appropriate voltage rating for a given application.

The MIC2289 has a junction temperature range of -40°C to +125°C.

• 2.5V to 10V input voltage
• Output voltage up to 34V
• Internal Schottky diode
• 15V, 24V, 34V output OVP options
• 1.2MHz PWM operation
• Over 500mA switch current
• 95mV feedback voltage
• <1% line and load regulation
• <1µA shutdown current
• Overtemperature protection
• UVLO
• -40°C to +125°C junction temperature range