{"product_id":"uc3842-sop8-current-mode-pwm-controller-ic-5pack","title":"UC3842 SOP-8 Current-Mode PWM Controller IC UC3842A UC3842B (5-Pack)","description":"\u003ch2\u003eUC3842 SOP-8 Current-Mode PWM Controller IC (5-Pack)\u003c\/h2\u003e\u003cp\u003eThe \u003cstrong\u003eUC3842\u003c\/strong\u003e is a high-performance fixed-frequency current-mode PWM controller in a \u003cstrong\u003eSOP-8\u003c\/strong\u003e surface-mount package. Operating up to \u003cstrong\u003e500kHz\u003c\/strong\u003e with a \u003cstrong\u003e1A totem-pole gate drive output\u003c\/strong\u003e, it is the industry-standard controller for flyback, forward, and boost SMPS designs. The UC3842A and UC3842B variants differ only in UVLO thresholds.\u003c\/p\u003e\u003ch3\u003eKey Specifications\u003c\/h3\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePart Number\u003c\/td\u003e\n\u003ctd\u003eUC3842 \/ UC3842A \/ UC3842B\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePackage\u003c\/td\u003e\n\u003ctd\u003eSOP-8 (SMD)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTopology\u003c\/td\u003e\n\u003ctd\u003eCurrent-mode PWM (fixed frequency)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax Oscillator Frequency\u003c\/td\u003e\n\u003ctd\u003e500kHz\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGate Drive Output\u003c\/td\u003e\n\u003ctd\u003e1A peak (totem-pole)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDuty Cycle\u003c\/td\u003e\n\u003ctd\u003e0 - 100% (UC3842) \/ 0 - 50% (UC3843)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUVLO Thresholds\u003c\/td\u003e\n\u003ctd\u003e16V on \/ 10V off (UC3842A: 16V\/10V, UC3842B: 16V\/10V)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReference Voltage\u003c\/td\u003e\n\u003ctd\u003e5V (2% accuracy)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCurrent Sense Input\u003c\/td\u003e\n\u003ctd\u003e1V threshold (cycle-by-cycle OCP)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temperature\u003c\/td\u003e\n\u003ctd\u003e0C to +70C (UC3842) \/ -40C to +85C (UC3842A)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eQuantity\u003c\/td\u003e\n\u003ctd\u003e5 pieces\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch3\u003eUC384x Family Comparison\u003c\/h3\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003cth\u003ePart\u003c\/th\u003e\n\u003cth\u003eMax Duty Cycle\u003c\/th\u003e\n\u003cth\u003eUVLO On\/Off\u003c\/th\u003e\n\u003cth\u003eTemp Range\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUC3842\u003c\/td\u003e\n\u003ctd\u003e100%\u003c\/td\u003e\n\u003ctd\u003e16V \/ 10V\u003c\/td\u003e\n\u003ctd\u003e0 to +70C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUC3843\u003c\/td\u003e\n\u003ctd\u003e50%\u003c\/td\u003e\n\u003ctd\u003e8.5V \/ 7.6V\u003c\/td\u003e\n\u003ctd\u003e0 to +70C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUC3844\u003c\/td\u003e\n\u003ctd\u003e50%\u003c\/td\u003e\n\u003ctd\u003e16V \/ 10V\u003c\/td\u003e\n\u003ctd\u003e0 to +70C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eUC3845\u003c\/td\u003e\n\u003ctd\u003e50%\u003c\/td\u003e\n\u003ctd\u003e8.5V \/ 7.6V\u003c\/td\u003e\n\u003ctd\u003e0 to +70C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch3\u003eWhy Choose UC3842?\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCurrent-Mode Control\u003c\/strong\u003e - Inherent cycle-by-cycle overcurrent protection and improved line regulation\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e500kHz Operation\u003c\/strong\u003e - Enables small transformer and filter components\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e1A Gate Drive\u003c\/strong\u003e - Directly drives power MOSFETs up to ~10nC gate charge without external buffer\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e5V Reference\u003c\/strong\u003e - Accurate 2% reference for feedback network design\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIndustry Standard\u003c\/strong\u003e - Extensive application notes and reference designs available\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eTypical Applications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eFlyback SMPS (offline, isolated)\u003c\/li\u003e\n\u003cli\u003eForward converter power supply\u003c\/li\u003e\n\u003cli\u003eBoost PFC pre-regulator\u003c\/li\u003e\n\u003cli\u003eDC-DC converter controller\u003c\/li\u003e\n\u003cli\u003eSMPS repair replacement (common in monitors, TVs, adapters)\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eQ: What is the difference between UC3842 and UC3843?\u003c\/strong\u003e UC3842 allows 0-100% duty cycle; UC3843 is limited to 0-50% (built-in duty cycle clamp). UC3843 is preferred for forward converters to prevent transformer saturation.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eQ: What MOSFET can UC3842 drive directly?\u003c\/strong\u003e MOSFETs with Qg up to ~10nC at the target switching frequency. For larger MOSFETs, add a totem-pole gate driver (TC4427, UCC27321) between UC3842 output and gate.\u003c\/p\u003e\u003ch3\u003ePackage Contents\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e5x UC3842 SOP-8 Current-Mode PWM Controller IC\u003c\/li\u003e\u003c\/ul\u003e","brand":"Keszoox","offers":[{"title":"Default Title","offer_id":46991505621227,"sku":"\u003cnone\u003e","price":6.28,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0677\/1005\/8731\/files\/uc3842-pwm-controller-sop8.webp?v=1761531261","url":"https:\/\/keszoox.com\/products\/uc3842-sop8-current-mode-pwm-controller-ic-5pack","provider":"Keszoox","version":"1.0","type":"link"}