The U3V40Fx family of boost (step-up) voltage regulators are high-efficiency synchronous switching regulators that generate higher output voltages from input voltages as low as 1.3 V. (Note: minimum start-up voltage is 2.7 V; see the connections section for details.) The regulators actively limit the instantaneous input currents to 9.5 A, and the input current can typically be as high as 4.5 A for several seconds before the thermal protection activates. Input currents of around 3.5 A can typically be maintained for many minutes without triggering thermal shutdown, though the actual performance depends on the input and output voltages as well as external factors such as ambient temperature and airflow. For boost regulators, the output current equals the input current times the efficiency divided by the boost ratio of VOUT to VIN, so the more you are boosting, the lower the maximum output current will be (see the maximum continuous output current section below for performance graphs).
These regulators feature a variety of built-in protections, including cycle-by-cycle input current limiting, soft-start, programmable under-voltage lockout, output over-voltage protection, and over-temperature shutdown.
Warning: This boost regulator uses the typical topology that connects the input to the output through an inductor and diode, with nothing to completely break that current path. Therefore, the input voltage will go through to the output even when the regulator is disabled, and exposure to short circuits or other excessive loads will damage the regulator.
Features and specifications
* Input voltage: 1.3 V to 12 V (Note: minimum start-up voltage is 2.7 V; see the connections section for details.)
* Output voltage: 12 V with 4% accuracy
* Typical efficiency of 85% to 95%, depending on input voltage, output voltage, and load (see the efficiency graph below)
* Switching frequency: ~600 kHz under heavy loads
* Power-save mode with ultrasonic operation that increases light load efficiency by reducing switching frequency, but keeps it above the audible range (20 kHz)
* Typical no-load quiescent currents under 2 mA (see the quiescent current graph below)
* 9.5 A switch allows for:
– Instantaneous input currents up to 9.5 A
– Input currents up to 4 A for several seconds
– Input currents up to 3.5 A for prolonged durations
* Integrated protections:
– Over-temperature shutdown
– Soft-start feature limits inrush current and gradually ramps output voltage
– Output over-voltage protection (typically at 16.5V)
– Cycle-by-cycle input current limiting to 9.5 A
* Compact size: 0.6" × 0.6" × 0.22" (15.2 × 15.2 × 5.6 mm)
* Weight: 1.5 g