The L6920DTR from STMicroelectronics is a high-efficiency synchronous step-up (boost) DC-DC converter that operates from input voltages as low as 0.6V with guaranteed startup at 1V. It integrates a 120 m\u03a9 N-channel switch and 120 m\u03a9 P-channel synchronous rectifier, requiring only three external components to deliver fixed 3.3V or 5V output, or adjustable output from 2V to 5.2V.<\/p>\n
Product Overview The L6920DTR from STMicroelectronics is a high-efficiency synchronous step-up (boost) DC-DC converter that operates from input voltages as low as 0.6V with guaranteed startup at 1V. It integrates a 120 m\u03a9 N-channel switch and 120 m\u03a9 P-channel synchronous rectifier, requiring only three external components to deliver fixed 3.3V or 5V output, or adjustable […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[31,13],"tags":[],"chip_brand":[142],"class_list":["post-6509","post","type-post","status-publish","format-standard","hentry","category-dc-dc-converters","category-integrated-circuits-ics","chip_brand-st"],"acf":{"brief_explanation":"Synchronous boost DC-DC, 0.6-5.5Vin, 3.3V\/5V\/adj out, 120m\u03a9 switches, 1A limit, TSSOP-8","date_code":"","package_case":"TSSOP-8","in_stock":2800,"datasheet":"https:\/\/www.st.com\/resource\/en\/datasheet\/l6920.pdf","price":"$1.35","product_introduction":"The L6920DTR from STMicroelectronics is a monolithic synchronous step-up converter designed for battery-powered applications where high efficiency and minimal component count are essential. The device integrates both the N-channel active switch and P-channel synchronous rectifier, eliminating the need for an external Schottky diode and reducing component count to just three: an inductor, an input capacitor, and an output capacitor. The 0.6V minimum operating voltage enables operation from a nearly depleted single battery cell, while the 1V guaranteed startup ensures reliable initialization. The variable frequency PFM control scheme maintains high efficiency across the entire load range, from light load (\u00b5A range) to full load (hundreds of mA). The DTR suffix indicates TSSOP-8 tape and reel packaging.","working_principle":"The L6920DTR uses a pulse-frequency modulation (PFM) control scheme where the switching frequency varies with load current to maintain high efficiency across the full load range. When the output voltage drops below the regulation threshold, the N-channel MOSFET turns on and energy is stored in the external inductor (TON phase). After a maximum on time of 5 \u00b5s (or when the current limit of 1A is reached), the N-channel switch turns off and the P-channel synchronous rectifier turns on, transferring the inductor energy to the output (TOFF phase). The synchronous rectifier remains on until the inductor current drops to zero (discontinuous conduction mode) or the output voltage exceeds the regulation threshold. At light loads, the switching frequency naturally decreases, minimizing gate drive and switching losses. The integrated low-battery comparator monitors the input voltage through the LBI pin and asserts the open-drain LBO output when the voltage drops below the 1.23V threshold.","pin_description":"
| Pin<\/th> | Name<\/th> | Function<\/th><\/tr> | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1<\/td> | FB<\/td> | Output voltage feedback (GND=5V, OUT=3.3V, or external divider)<\/td><\/tr> | ||||||||||||
| 2<\/td> | LBI<\/td> | Low battery detect input (threshold=1.23V)<\/td><\/tr> | ||||||||||||
| 3<\/td> | LBO<\/td> | Low battery detect output (open-drain, active-low)<\/td><\/tr> | ||||||||||||
| 4<\/td> | REF<\/td> | 1.23V reference voltage output (bypass with 100nF)<\/td><\/tr> | ||||||||||||
| 5<\/td> | SHDN<\/td> | Shutdown control (low=shutdown, high=operating)<\/td><\/tr> | ||||||||||||
| 6<\/td> | GND<\/td> | Ground<\/td><\/tr> | ||||||||||||
| 7<\/td> | LX<\/td> | Inductor connection (switch node)<\/td><\/tr> | ||||||||||||
| 8<\/td> | OUT<\/td> | Power output and sense connection<\/td><\/tr><\/table>","application_scenarios":"The L6920DTR excels in single-cell alkaline or NiMH battery applications where the 1V startup and 0.6V operating capability extract maximum energy from the battery. In GPS receivers, it provides a stable 3.3V supply from a single Li-ion cell. For digital cameras, the 5V output option powers CCD\/CMOS sensor circuits from a 3.6V lithium battery. The low battery detection feature eliminates the need for a separate voltage monitor IC, reducing BOM count. In PDA and handheld devices, the 0.1 \u00b5A shutdown current preserves battery life during long idle periods.","alternative_models":"
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