{"id":6464,"date":"2026-06-16T04:02:05","date_gmt":"2026-06-16T04:02:05","guid":{"rendered":"https:\/\/materialparts.com\/lm5155xss\/"},"modified":"2026-06-16T04:02:05","modified_gmt":"2026-06-16T04:02:05","slug":"lm5155xss","status":"publish","type":"post","link":"https:\/\/materialparts.com\/ar\/lm5155xss\/","title":{"rendered":"LM5155XSS"},"content":{"rendered":"

\u0646\u0638\u0631\u0629 \u0639\u0627\u0645\u0629 \u0639\u0644\u0649 \u0627\u0644\u0645\u0646\u062a\u062c<\/h2>\n

The LM5155XSS is a 2.2MHz automotive-grade boost\/flyback\/SEPIC controller from Texas Instruments with 3.5V to 65V input range and 100V\/2A gate driver. The spread-spectrum option (X suffix) reduces EMI. With 1\u00b5A shutdown current, \u00b11% reference accuracy, programmable soft start, and slope compensation, it supports high-power non-isolated and isolated power supply designs in a WQFN-16 (4x4mm) package.<\/p>\n

\u0627\u0644\u0645\u0648\u0627\u0635\u0641\u0627\u062a \u0627\u0644\u0631\u0626\u064a\u0633\u064a\u0629<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
\u0627\u0644\u0637\u0648\u0628\u0648\u0644\u0648\u062c\u064a\u0627<\/td>\nBoost \/ Flyback \/ SEPIC Controller<\/td>\n<\/tr>\n
\u062c\u0647\u062f \u0627\u0644\u0625\u062f\u062e\u0627\u0644<\/td>\n3.5V to 65V<\/td>\n<\/tr>\n
Gate Drive Voltage<\/td>\n100V maximum \/ 2A peak<\/td>\n<\/tr>\n
\u062a\u0631\u062f\u062f \u0627\u0644\u062a\u062d\u0648\u064a\u0644<\/td>\n100kHz to 2.2MHz (resistor programmable)<\/td>\n<\/tr>\n
Spread Spectrum<\/td>\nYes (X suffix, \u00b17% frequency dithering)<\/td>\n<\/tr>\n
Reference Voltage<\/td>\n1V (\u00b11% over temperature)<\/td>\n<\/tr>\n
Quiescent Current (ON)<\/td>\n500\u00b5A typical<\/td>\n<\/tr>\n
\u062a\u064a\u0627\u0631 \u0625\u064a\u0642\u0627\u0641 \u0627\u0644\u062a\u0634\u063a\u064a\u0644<\/td>\n1\u00b5A typical<\/td>\n<\/tr>\n
Duty Cycle<\/td>\nUp to 92%<\/td>\n<\/tr>\n
\u0648\u0636\u0639 \u0627\u0644\u062a\u062d\u0643\u0645<\/td>\nCurrent mode (peak)<\/td>\n<\/tr>\n
Slope Compensation<\/td>\nInternal, programmable with Rslope<\/td>\n<\/tr>\n
Soft Start<\/td>\nProgrammable (external capacitor)<\/td>\n<\/tr>\n
VCC LDO<\/td>\n7.2V internal, bypassable for external bias<\/td>\n<\/tr>\n
Enable\/UVLO<\/td>\nAdjustable with hysteresis<\/td>\n<\/tr>\n
Protection<\/td>\nOCP, OVP, thermal shutdown<\/td>\n<\/tr>\n
\u0627\u0644\u062d\u0632\u0645\u0629<\/td>\nWQFN-16 (4.0 x 4.0mm)<\/td>\n<\/tr>\n
\u062f\u0631\u062c\u0629 \u062d\u0631\u0627\u0631\u0629 \u0627\u0644\u062a\u0634\u063a\u064a\u0644<\/td>\n-40 \u062f\u0631\u062c\u0629 \u0645\u0626\u0648\u064a\u0629 \u0625\u0644\u0649 +125 \u062f\u0631\u062c\u0629 \u0645\u0626\u0648\u064a\u0629<\/td>\n<\/tr>\n
\u0627\u0644\u0645\u0624\u0647\u0644\u0627\u062a<\/td>\nAEC-Q100<\/td>\n<\/tr>\n<\/table>\n

\u0627\u0644\u0645\u064a\u0632\u0627\u062a<\/h2>\n
    \n
  • 3.5V to 65V wide input voltage range<\/li>\n
  • 100V\/2A gate driver for external N-FET<\/li>\n
  • Up to 2.2MHz switching frequency<\/li>\n
  • Spread-spectrum frequency dithering (\u00b17%) for EMI reduction<\/li>\n
  • \u00b11% reference voltage accuracy<\/li>\n
  • Current-mode control with programmable slope compensation<\/li>\n
  • 1\u00b5A shutdown current<\/li>\n
  • Adjustable UVLO with hysteresis<\/li>\n
  • Programmable soft start<\/li>\n
  • Output overvoltage and cycle-by-cycle overcurrent protection<\/li>\n
  • Internal 7.2V VCC LDO (bypassable)<\/li>\n
  • AEC-Q100 qualified<\/li>\n<\/ul>\n

    \u0627\u0644\u062a\u0637\u0628\u064a\u0642\u0627\u062a<\/h2>\n
      \n
    • Automotive LED headlight boost drivers<\/li>\n
    • Industrial PLC power supplies<\/li>\n
    • Telecom 48V isolated flyback<\/li>\n
    • SEPIC converters for battery-powered systems<\/li>\n
    • Boost converters for automotive ADAS<\/li>\n
    • Multi-output flyback for IGBT gate drivers<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

      Product Overview The LM5155XSS is a 2.2MHz automotive-grade boost\/flyback\/SEPIC controller from Texas Instruments with 3.5V to 65V input range and 100V\/2A gate driver. The spread-spectrum option (X suffix) reduces EMI. With 1\u00b5A shutdown current, \u00b11% reference accuracy, programmable soft start, and slope compensation, it supports high-power non-isolated and isolated power supply designs in a WQFN-16 […]<\/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":[138],"class_list":["post-6464","post","type-post","status-publish","format-standard","hentry","category-dc-dc-converters","category-integrated-circuits-ics","chip_brand-ti"],"acf":{"brief_explanation":"65V boost\/flyback\/SEPIC controller, 2.2MHz, spread-spectrum, 100V\/2A gate, \u00b11% Vref, WQFN-16","date_code":"","package_case":"WQFN-16 (4.0 x 4.0 x 0.8mm)","in_stock":4500,"datasheet":"https:\/\/www.ti.com\/lit\/ds\/symlink\/lm5155.pdf","price":"$1.55 @ 1ku","product_introduction":"The LM5155XSS is a high-performance non-synchronous boost\/flyback\/SEPIC controller from Texas Instruments designed for automotive and industrial power supply applications. It features a 3.5V to 65V input range and drives an external N-channel MOSFET with a 100V\/2A gate driver, supporting output voltages up to 100V. The X suffix denotes the spread-spectrum feature, which dithers the switching frequency by \u00b17% to reduce peak EMI emissions \u2014 critical for passing automotive CISPR 25 radiated emissions tests. The 2.2MHz maximum switching frequency allows small inductors and places switching harmonics above the AM radio band. Current-mode control with programmable slope compensation ensures stable operation across wide input\/output ranges. The \u00b11% reference accuracy provides tight output regulation. The 1\u00b5A shutdown current preserves battery life in always-connected automotive systems.","working_principle":"The LM5155XSS uses peak current-mode control. In each switching cycle, the oscillator sets the RS flip-flop, turning on the external N-channel MOSFET. Current ramps in the inductor (boost) or primary winding (flyback), sensed by the CS pin through an external sense resistor. When the sensed current reaches the error amplifier's command level (plus slope compensation), the flip-flop resets and the MOSFET turns off. The inductor current then flows through the output diode to the load. The error amplifier compares a fraction of the output voltage (via the FB pin) with the internal 1V reference, adjusting the peak current command to maintain regulation. Slope compensation (programmable via an external resistor from COMP to SLOPE) prevents sub-harmonic oscillation at duty cycles above 50%. The spread-spectrum feature modulates the oscillator frequency with a pseudo-random pattern, spreading the switching energy across a wider bandwidth and reducing peak EMI at any single frequency. The internal 7.2V VCC LDO can be bypassed by connecting an external supply to VCC for higher efficiency at high input voltages.","pin_description":"
      Pin<\/th>Name<\/th>Description<\/th><\/tr>
      1<\/td>VIN<\/td>Input supply (3.5V to 65V)<\/td><\/tr>
      2<\/td>EN\/UVLO<\/td>Enable\/UVLO adjust<\/td><\/tr>
      3<\/td>RT<\/td>Switching frequency programming resistor<\/td><\/tr>
      4<\/td>SS<\/td>Soft start capacitor<\/td><\/tr>
      5<\/td>COMP<\/td>Error amplifier output \/ loop compensation<\/td><\/tr>
      6<\/td>SLOPE<\/td>Slope compensation resistor<\/td><\/tr>
      7<\/td>FB<\/td>Feedback voltage (target 1V)<\/td><\/tr>
      8<\/td>AGND<\/td>Analog ground<\/td><\/tr>
      9<\/td>CS<\/td>Current sense input<\/td><\/tr>
      10<\/td>PGND<\/td>Power ground<\/td><\/tr>
      11<\/td>GATE<\/td>Gate driver output (to external N-FET)<\/td><\/tr>
      12<\/td>VCC<\/td>Internal 7.2V LDO output (bypass cap)<\/td><\/tr>
      13<\/td>OV<\/td>Output overvoltage sense<\/td><\/tr>
      14<\/td>NC<\/td>No connect<\/td><\/tr>
      15<\/td>NC<\/td>No connect<\/td><\/tr>
      16<\/td>PG<\/td>Power good output (open drain)<\/td><\/tr><\/table>","application_scenarios":"
      • Automotive LED Headlight Boost:<\/b> Boost the 12V battery to 48V at 2A for an LED headlight string. The 2.2MHz switching frequency places harmonics above the AM band, and the spread-spectrum feature reduces EMI peaks to pass CISPR 25 Class 5. The 100V gate driver supports the 48V output with margin. Current-mode control provides fast LED current regulation during automotive transients (ISO 7637 pulse testing).<\/li>
      • 48V Telecom Isolated Flyback:<\/b> Generate isolated \u00b112V at 1A from a 48V telecom bus using a flyback topology. The LM5155 drives the primary MOSFET; a coupled inductor provides isolation and multiple outputs. The \u00b11% reference ensures tight primary-side regulation. The 65V input rating accommodates the 48V \u00b120% input range (38V to 72V including transients).<\/li>
      • SEPIC for Wide Input Battery:<\/b> Build a SEPIC converter that accepts 6V to 36V (2S to 8S Li-ion) and delivers a regulated 12V at 2A. The SEPIC topology handles input voltages both above and below the output, unlike a boost converter. The spread-spectrum option reduces EMI that could interfere with sensitive RF circuits in the same enclosure.<\/li><\/ul>","alternative_models":"
        Model<\/th>Vin<\/th>Topologies<\/th>Key Difference<\/th><\/tr>
        LM5155SS<\/td>3.5-65V<\/td>Boost\/Flyback\/SEPIC<\/td>No spread spectrum<\/td><\/tr>
        LM5156<\/td>3.5-65V<\/td>Boost\/Flyback\/SEPIC<\/td>Higher gate drive, HV start-up<\/td><\/tr>
        LM5180<\/td>4-65V<\/td>Flyback (integrated FET)<\/td>Integrated 1.5A FET, lower power<\/td><\/tr>
        MAX17597<\/td>4.5-60V<\/td>Boost\/Flyback<\/td>ADI\/Maxim, no spread spectrum<\/td><\/tr><\/table>"},"_links":{"self":[{"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/posts\/6464","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/comments?post=6464"}],"version-history":[{"count":0,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/posts\/6464\/revisions"}],"wp:attachment":[{"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/media?parent=6464"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/categories?post=6464"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/tags?post=6464"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/materialparts.com\/ar\/wp-json\/wp\/v2\/chip_brand?post=6464"}],"curies":[{"name":"\u062f\u0628\u0644\u064a\u0648 \u0628\u064a","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}