The MP3430 is a monolithic step-up converter that integrates a power switch and a biased avalanche photodiode (APD) current monitor. The device can double the output voltage through the APD optical receivers. The MP3430 can provide up to 90V output. The MP3430 uses a current-mode, fixedfrequency architecture to regulate the output voltage, which provides a fast transient response and cycle-by-cycle current limiting. The MP3430 features two accurate APD current monitoring outputs with 1:10 and 1:2 ratios, respectively. Resistor-adjustable current limiting protects the APD from optical power transients. The MP3430 includes over-current and thermaloverload protection to prevent damage in the event of an output overload. The MP3430 is available in a small 3mm×3mm QFN16 package.2.7V-to-5.5V Input Voltage 100V/1? NFET with 0.9A Limit Up to 90V Output Voltage 50ns APD Current Monitoring Response Speed 1.3MHz Fixed Switching Frequency Internal Compensation and Soft-Start High-Side APD Current Monitor with less than ±5% Tolerance 1:10 and 1:2 Ratio Outputs for APD Current Monitoring Thermal-Shutdown Protection Programmable APD Over-Current Limit and Protection 3×3mm QFN16 Package