{"product_id":"step-up-voltage-regulator","title":"Step-Up Voltage Regulator","description":"\u003cp\u003eThe 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.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eNote:\u003c\/strong\u003e minimum start-up voltage is 2.7 V; see the connections section for details.\u003c\/p\u003e\n\u003cp\u003eThe 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).\u003c\/p\u003e\n\u003cp\u003eThese 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.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWarning:\u003c\/strong\u003e 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.\u003c\/p\u003e\n\u003ch2\u003eFeatures and specifications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eTypical efficiency of 85% to 95%, depending on input voltage, output voltage, and load (see the efficiency graph below)\u003c\/li\u003e\n\u003cli\u003eSwitching frequency: ~600 kHz under heavy loads\u003c\/li\u003e\n\u003cli\u003ePower-save mode with ultrasonic operation that increases light load efficiency by reducing switching frequency, but keeps it above the audible range (20 kHz)\u003c\/li\u003e\n\u003cli\u003eTypical no-load quiescent currents under 2 mA (see the quiescent current graph below)\u003c\/li\u003e\n\u003cli\u003e9.5 A switch allows for:\u003c\/li\u003e\n\u003cul\u003e\n\u003cli\u003eInstantaneous input currents up to 9.5 A\u003c\/li\u003e\n\u003cli\u003eInput currents up to 4.5 A for several seconds\u003c\/li\u003e\n\u003cli\u003eInput currents up to 4 A for prolonged durations\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cli\u003eIntegrated protections:\u003c\/li\u003e\n\u003cul\u003e\n\u003cli\u003eOver-temperature shutdown\u003c\/li\u003e\n\u003cli\u003eSoft-start feature limits inrush current and gradually ramps output voltage\u003c\/li\u003e\n\u003cli\u003eOutput over-voltage protection\u003c\/li\u003e\n\u003cli\u003eCycle-by-cycle input current limiting to 9.5 A\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cli\u003eCompact size: 0.6″ × 0.6″ × 0.22″ (15.2 × 15.2 × 5.6 mm)\u003c\/li\u003e\n\u003cli\u003eWeight: 1.5 g\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eConnections\u003c\/h2\u003e\n\u003cp\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0174\/1800\/files\/0J11525.1200_480x480.jpg?v=1641307799\"\u003e\u003c\/p\u003e\n\u003cp\u003eThe input voltage, \u003cstrong\u003eVIN\u003c\/strong\u003e, must initially be at least 2.7 V and should not exceed the output voltage, VOUT. (If VIN is higher than VOUT, the higher input voltage will show up on the output, which is potentially dangerous for your connected load and could also damage the regulator.) Once the regulator is on, VIN can fall as low as 0.8 V and the regulator will continue to operate. However, for VIN voltages below 1.3 V, an external source must be used to supply the EN pin (with 1.3 V or more) to keep the regulator enabled.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eVOUT\u003c\/strong\u003e is the regulated output voltage. The regulator’s soft-start feature gradually ramps up the VOUT voltage on start-up to limit in-rush current draw. In testing that allowed it to start into moderately sized capacitive loads (a few hundred µF) without issue. However, the U3V40Fx regulators do not have short-circuit protection so they could be damaged if exposed to output shorts or loads that draw excessive in-rush currents. We do not recommend using them with super capacitors or constant current loads beyond their maximum continuous ratings.\u003c\/p\u003e\n\u003cp\u003eThe regulator is enabled by default: a 30 kΩ pull-up resistor on the board connects the \u003cstrong\u003eEN\u003c\/strong\u003e pin to VIN. The enable pin can be driven low (under 0.4 V) to disable the regulator and put the board into a low-power state. However, please note that due to their standard boost regulator topology, the U3V40Fx family of regulators has \u003cspan style=\"text-decoration: underline;\"\u003eno way of disconnecting power from the load\u003c\/span\u003e, so the input voltage will pass directly through to VOUT when the regulator is disabled. The quiescent current draw is typically under 2 mA with no load (see the quiescent current graph below).\u003c\/p\u003e\n\u003cp\u003eBy adding a resistor R between EN and GND, it is possible to set a precise low-VIN cutoff threshold. The following equations show the relationship between the cutoff voltage in volts and R in kΩ:\u003c\/p\u003e\n\u003cp\u003eR=\u003csup\u003e36.9\u003c\/sup\u003e\/\u003csub\u003eVcutoff –1.38\u003c\/sub\u003e\u003c\/p\u003e\n\u003ch2\u003eIncluded hardware\u003c\/h2\u003e\n\u003cp\u003eThe connections are labeled on the back side of the PCB and are arranged with a 0.1″ spacing along the edge of the board for compatibility with solderless breadboards, connectors, and other prototyping arrangements that use a 0.1″ grid. You can solder wires directly to the board or solder in either the 6×1 straight male header strip or the 6×1 right-angle male header strip that is included.\u003c\/p\u003e\n\u003cp\u003eThe connections for VIN and GND are duplicated allowing two header pins to be used for each connection. Note that each header pin is only rated for 3 A (6 A combined per pair), and solderless breadboards are usually not intended to handle more than a few amps.\u003c\/p\u003e\n\u003ch2\u003eTypical efficiency\u003c\/h2\u003e\n\u003cp\u003eThe efficiency of a voltage regulator, defined as (Power out)\/(Power in), is an important measure of its performance, especially when battery life or heat are concerns. As shown in the graphs below, the U3V40Fx regulator has an efficiency of 85% to 95% for most combinations of input voltage, output voltage, and load.\u003c\/p\u003e\n\u003cp\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0174\/1800\/files\/0J11501.1200_480x480.png?v=1641307208\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0174\/1800\/files\/0J11502.1200_480x480.png?v=1641307631\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0174\/1800\/files\/0J11503.1200_480x480.png?v=1641307665\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0174\/1800\/files\/0J11504.1200_480x480.png?v=1641307713\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0174\/1800\/files\/0J11505.1200_480x480.png?v=1641307744\"\u003e\u003c\/p\u003e\n\u003ch2\u003eMaximum continuous output current\u003c\/h2\u003e\n\u003cp\u003eThe maximum achievable output current is approximately proportional to the ratio of the input voltage to the output voltage. Additionally, the maximum output current can depend on other factors, including the ambient temperature, air flow, and heat sinking. The graph below shows the typical maximum continuous output currents these regulators can deliver at room temperature with no forced airflow or heat sinking.\u003c\/p\u003e\n\u003cp\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0174\/1800\/files\/0J11506.1200_480x480.png?v=1641307229\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDuring normal operation, this product can get \u003cspan style=\"color: #ff2a00;\"\u003ehot\u003c\/span\u003e enough to burn you. Take care when handling this product or other components connected to it.\u003c\/strong\u003e\u003c\/p\u003e\n\u003ch2\u003eQuiescent current\u003c\/h2\u003e\n\u003cp\u003eThe quiescent current is the current the regulator uses just to power itself, and the graph below shows this for the different regulator versions as a function of the input voltage. The module’s EN input can be driven low to put the board into a low-power state where it typically draws about 35 µA per volt on VIN.\u003c\/p\u003e\n\u003cp\u003e\u003cimg alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0174\/1800\/files\/0J11507.1200_480x480.png?v=1641307249\"\u003e\u003c\/p\u003e\n\u003ch2\u003eLC Voltage Spikes\u003c\/h2\u003e\n\u003cp\u003eWhen connecting voltage to electronic circuits, the initial rush of current can cause damaging voltage spikes that are much higher than the input voltage. In our tests with this family of regulator connected with typical power leads (~30″ test clips), we found that input voltages up to 11 V did not generally cause spikes high enough to damage the regulator itself, but even lower input voltages did cause spikes that could still be problematic for boost regulators operating with the input voltage close to the set output voltage, since input voltages above the set output voltage will propagate to the output and could damage circuits being powered by the regulator. An electrolytic capacitor (33 μF is a good starting point) can be added close to the regulator between VIN and GND to help suppress these spikes.\u003c\/p\u003e\n\u003cp\u003eMore information about LC spikes can be found in the application note, \u003ca href=\"https:\/\/www.pololu.com\/docs\/0J16\" target=\"_blank\"\u003eUnderstanding Destructive LC Voltage Spikes.\u003c\/a\u003e\u003c\/p\u003e\n\u003ch2\u003eFile downloads\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/www.pololu.com\/file\/0J1844\/step-up-voltage-regulator-u3v40fx-dimensions.pdf\" target=\"_blank\"\u003eDimension diagram of the U3V40Fx Step-Up Voltage Regulator\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/www.pololu.com\/file\/0J1845\/step-up-voltage-regulator-u3v40fx.step\" target=\"_blank\"\u003e3D model of the U3V40Fx Step-Up Voltage Regulator\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/www.pololu.com\/file\/0J1846\/reg28a-drill.dxf\" target=\"_blank\"\u003eDrill guide for the Pololu U3V40Fx family of step-up voltage regulators\u003c\/a\u003e - This DXF drawing shows the locations of all of the board’s holes.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Pololu","offers":[{"title":"5V - U3V40F5","offer_id":39626615980115,"sku":"POL-4012","price":9.95,"currency_code":"EUR","in_stock":false},{"title":"6V - U3V40F6","offer_id":39626616012883,"sku":"POL-4013","price":9.95,"currency_code":"EUR","in_stock":false},{"title":"7.5V - U3V40F7","offer_id":39626616045651,"sku":"POL-4014","price":9.95,"currency_code":"EUR","in_stock":false},{"title":"9V - U3V40F9","offer_id":39626616078419,"sku":"POL-4015","price":9.95,"currency_code":"EUR","in_stock":false},{"title":"12V - U3V40F12","offer_id":39626616111187,"sku":"POL-4016","price":9.95,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0174\/1800\/products\/0J11490.1200.jpg?v=1641308425","url":"https:\/\/shop.pimoroni.com\/en-eu\/products\/step-up-voltage-regulator","provider":"Pimoroni Ltd","version":"1.0","type":"link"}