{"product_id":"stepdown-dc-dc-converter-with-current-limit","title":"Stepdown DC-DC Converter with Current Limit","description":"\u003cp\u003e\u003cspan\u003eThe step-down DC-DC Converter project presented here provides \u003c\/span\u003e\u003cstrong\u003e3.3V @ 1A\u003c\/strong\u003e\u003cspan\u003e output from an input range of \u003c\/span\u003e\u003cstrong\u003e8V to 36V DC\u003c\/strong\u003e\u003cspan\u003e. The adjustable current limit is an important feature of the project, which prevents the device from accidental output short circuits avoiding excessive load damage. The internal limiting current (latched function) has a typical value of 2.5 A. The project is built around the \u003c\/span\u003e\u003cstrong\u003eL6902\u003c\/strong\u003e\u003cspan\u003e chip from ST. The L6902D is a complete and simple step-down switching regulator with an adjustable current limit. Based on a voltage mode structure it integrates a current error amplifier to have a constant voltage and constant current control.  By means of an onboard current sense resistor R1 and R2, current limit programming is very simple and accurate (±5%). Refer to the datasheet of the chip for R1 and R2 values about the current limit adjustment. The project can be used to charge \u003c\/span\u003e\u003cstrong\u003eNiMH\u003c\/strong\u003e\u003cspan\u003e and \u003c\/span\u003e\u003cstrong\u003eNiCad\u003c\/strong\u003e\u003cspan\u003e batteries due to its constant current feature. The project operates with a fixed switching frequency of \u003c\/span\u003e\u003cstrong\u003e250Khz\u003c\/strong\u003e\u003cspan\u003e. If the temperature of the chip goes higher than a fixed internal threshold (150°C with 20°C hysteresis), the power stage is turned off. Other protections besides thermal shutdown complete the device for a safe and reliable application: overvoltage protection, frequency foldback overcurrent protection, and protection vs. feedback disconnection.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003eConnections\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCN1:\u003cspan\u003e \u003c\/span\u003e\u003c\/strong\u003ePin 1 = 3.3V – 1Amp Output, Pin 2 = GND\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCN2: Pin 1 =\u003cspan\u003e \u003c\/span\u003e\u003c\/strong\u003e+ DC 8 to 36V Input, Pin 2 = GND\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eD2:\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003ePower LED Input Side\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eFeatures\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eOutput 3.3V DC, Current up to 1 A (Output voltage adjustable from 1.235 V to 34 V) Read Note\u003c\/li\u003e\n\u003cli\u003eOperating input voltage from 8 V to 36 V\u003c\/li\u003e\n\u003cli\u003ePrecise 3.3 V (±2%) reference voltage\u003c\/li\u003e\n\u003cli\u003e5 % output current accuracy\u003c\/li\u003e\n\u003cli\u003e250 kHz internally fixed frequency\u003c\/li\u003e\n\u003cli\u003e5 % output current accuracy\u003c\/li\u003e\n\u003cli\u003eVoltage feedforward\u003c\/li\u003e\n\u003cli\u003eZero load current operation\u003c\/li\u003e\n\u003cli\u003eAdjustable current limit\u003c\/li\u003e\n\u003cli\u003eProtection against feedback Disconnection\u003c\/li\u003e\n\u003cli\u003eThermal shutdown\u003c\/li\u003e\n\u003cli\u003ePCB Dimensions 34.93 x 20.48mm\u003c\/li\u003e\n\u003cli\u003e4 x 2.5mm Mounting Holes\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e","brand":"dotfry","offers":[{"title":"Default Title","offer_id":47242110927020,"sku":"G176","price":12.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0757\/6436\/7532\/files\/G176B.jpg?v=1789720780","url":"https:\/\/dotfry.com\/products\/stepdown-dc-dc-converter-with-current-limit","provider":"dotfry","version":"1.0","type":"link"}