The MC1455BDR2G from onsemi is a bipolar 555 timer capable of operating up to 500kHz in astable and monostable modes, in an SOIC-8 package for timing and oscillator applications.<\/p>\n
| \u5305\u88c5<\/td>\n | SOIC-8<\/td>\n<\/tr>\n<\/table>\n\u7279\u70b9<\/h2>\n\u5e94\u7528<\/h2>\nProduct Overview The MC1455BDR2G from onsemi is a bipolar 555 timer capable of operating up to 500kHz in astable and monostable modes, in an SOIC-8 package for timing and oscillator applications. Key Specifications Package SOIC-8 Features See datasheet for complete specifications Industry-standard package Applications Industrial control Consumer electronics Communication equipment Automotive electronics<\/p>","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[13,55],"tags":[],"chip_brand":[144],"class_list":["post-5549","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","category-transistors","chip_brand-on"],"acf":{"brief_explanation":"555 timer, bipolar, 500kHz, SOIC-8","date_code":"","package_case":"SOIC-8","in_stock":3424,"datasheet":"https:\/\/www.onsemi.com\/pub\/Collateral\/MC1455B-D.PDF","price":"$0.35 @ 1ku","product_introduction":"The MC1455BDR2G from onsemi is a bipolar 555 timer capable of operating up to 500kHz in astable and monostable modes, in an SOIC-8 package for timing and oscillator applications.","working_principle":"The MC1455BDR2G is a bipolar 555 timer IC from onsemi in SOIC-8, capable of operating in both monostable (one-shot) and astable (free-running) modes at frequencies up to 500kHz. The internal architecture consists of: (1) Three 5k-ohm resistors forming a voltage divider that sets VCC\/3 and 2VCC\/3 reference levels; (2) Two comparators (upper and lower) that compare the threshold and trigger inputs against these references; (3) An SR flip-flop that stores the output state; (4) A discharge transistor (open-collector on pin 7) that controls the timing capacitor. In monostable mode: A falling edge on TRIGGER (below VCC\/3) sets the flip-flop, output goes HIGH, and the discharge transistor turns OFF, allowing the external timing capacitor (CT) to charge through the timing resistor (RT). When the capacitor voltage reaches 2VCC\/3, the upper comparator resets the flip-flop, output goes LOW, and the discharge transistor turns ON, rapidly discharging CT. The pulse width = 1.1 x RT x CT. In astable mode: The capacitor charges through R1+R2 and discharges through R2 only, creating a free-running oscillator. The frequency = 1.44 \/ ((R1 + 2R2) x CT), with duty cycle = (R1+R2)\/(R1+2R2). The bipolar output can sink and source 200mA directly, driving relays, LEDs, and small motors. The CONTROL VOLTAGE pin allows external modulation of the timing reference, enabling pulse-width modulation. The -BDR2G suffix specifies SOIC-8, lead-free, tape-and-reel.","pin_description":"
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