{"id":6632,"date":"2026-06-18T15:46:25","date_gmt":"2026-06-18T15:46:25","guid":{"rendered":"https:\/\/materialparts.com\/tl494cn\/"},"modified":"2026-06-18T15:46:25","modified_gmt":"2026-06-18T15:46:25","slug":"tl494cn","status":"publish","type":"post","link":"https:\/\/materialparts.com\/zh\/tl494cn\/","title":{"rendered":"TL494CN"},"content":{"rendered":"

\u4ea7\u54c1\u6982\u89c8<\/h2>\n

The TL494CN from Texas Instruments is a fixed-frequency pulse-width-modulation (PWM) control circuit for switching power supplies. With dual error amplifiers, adjustable dead-time, and push-pull or single-ended output, it is the standard controller for PC power supplies and ATX PSU designs. Packaged in 16-PDIP.<\/p>\n

\u4e3b\u8981\u89c4\u683c<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n
\u63a7\u5236\u6a21\u5f0f<\/td>\nVoltage-mode PWM<\/td>\n<\/tr>\n
\u5f00\u5173\u9891\u7387<\/td>\n1Hz to 300kHz<\/td>\n<\/tr>\n
\u7535\u6e90\u7535\u538b<\/td>\n7V to 40V<\/td>\n<\/tr>\n
Reference Voltage<\/td>\n5V +\/-5%<\/td>\n<\/tr>\n
Error Amplifiers<\/td>\n2 (independent)<\/td>\n<\/tr>\n
\u8f93\u51fa\u7535\u6d41<\/td>\n200mA per output<\/td>\n<\/tr>\n
Output Config<\/td>\nPush-pull or single-ended<\/td>\n<\/tr>\n
Dead Time Control<\/td>\n0 to 45% adjustable<\/td>\n<\/tr>\n
\u5305\u88c5<\/td>\n16-PDIP<\/td>\n<\/tr>\n
\u5de5\u4f5c\u6e29\u5ea6<\/td>\n0 to +70 C<\/td>\n<\/tr>\n<\/table>\n

\u7279\u70b9<\/h2>\n
    \n
  • Dual error amplifiers for voltage and current feedback<\/li>\n
  • Adjustable dead-time control (0-45%)<\/li>\n
  • Push-pull or single-ended output configuration<\/li>\n
  • Internal 5V reference (5%)<\/li>\n
  • Output transistor can source or sink 200mA<\/li>\n
  • Under-voltage lockout<\/li>\n<\/ul>\n

    \u5e94\u7528<\/h2>\n
      \n
    • ATX and PC power supply controllers<\/li>\n
    • Half-bridge and push-pull converters<\/li>\n
    • DC-DC converter regulation<\/li>\n
    • Battery charger control circuits<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"

      Product Overview The TL494CN from Texas Instruments is a fixed-frequency pulse-width-modulation (PWM) control circuit for switching power supplies. With dual error amplifiers, adjustable dead-time, and push-pull or single-ended output, it is the standard controller for PC power supplies and ATX PSU designs. Packaged in 16-PDIP. Key Specifications Control Mode Voltage-mode PWM Switching Frequency 1Hz to […]<\/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":[13,29],"tags":[],"chip_brand":[],"class_list":["post-6632","post","type-post","status-publish","format-standard","hentry","category-integrated-circuits-ics","category-power-management-ics-pmic"],"acf":{"brief_explanation":"Voltage-mode PWM controller, dual error amps, 300kHz, push-pull\/single-ended, 16-PDIP","date_code":"","package_case":"16-PDIP","in_stock":8595,"datasheet":"https:\/\/www.ti.com\/lit\/ds\/symlink\/tl494.pdf","price":"$0.50 @ 1ku","product_introduction":"The TL494CN from Texas Instruments is the industry-standard voltage-mode PWM controller used in millions of PC power supplies worldwide. It contains all the building blocks for a switching power supply: an oscillator with frequency set by RT and CT, two error amplifiers for voltage and current feedback, an adjustable dead-time control comparator, a pulse-steering flip-flop for push-pull operation, and two totem-pole output transistors rated at 200mA each. The output configuration pin (pin 13) selects between push-pull (two alternating outputs) and single-ended (parallel outputs). The dead-time control pin (pin 4) provides 0-45% dead-time adjustment, essential for push-pull and half-bridge converters to prevent shoot-through. The internal 5V reference powers the error amplifiers and can supply external circuits. The TL494 has been the backbone of ATX power supply design since the 1990s.","working_principle":"The TL494 oscillator generates a sawtooth waveform at the CT pin with frequency determined by RT and CT values (f = 1\/(RT x CT)). This sawtooth is compared against three signals in the PWM comparator: the dead-time control voltage (pin 4), the output of error amplifier 1, and the output of error amplifier 2. The PWM comparator outputs a pulse whose width is determined by the lowest of these three control signals. In push-pull mode, the pulse-steering flip-flop alternates the output between the two output transistors (Q1 and Q2) on each oscillator cycle, producing a 50% maximum duty cycle per output. In single-ended mode, both outputs switch in parallel for up to 100% duty cycle. The dead-time control adds a minimum off-time that prevents both output transistors from being on simultaneously in push-pull configurations, ensuring safe operation of the external power switches.","pin_description":"
      Pin<\/th>Name<\/th>Function<\/th><\/tr>
      1<\/td>1IN+<\/td>Error amp 1 non-inverting input<\/td><\/tr>
      2<\/td>1IN-<\/td>Error amp 1 inverting input<\/td><\/tr>
      3<\/td>FEEDBACK<\/td>Feedback \/ PWM compensation<\/td><\/tr>
      4<\/td>DTC<\/td>Dead-time control (0-45% dead time)<\/td><\/tr>
      5<\/td>CT<\/td>Oscillator timing capacitor<\/td><\/tr>
      6<\/td>RT<\/td>Oscillator timing resistor<\/td><\/tr>
      7<\/td>GND<\/td>Ground<\/td><\/tr>
      8<\/td>C1<\/td>Output transistor 1 collector<\/td><\/tr>
      9<\/td>E1<\/td>Output transistor 1 emitter<\/td><\/tr>
      10<\/td>E2<\/td>Output transistor 2 emitter<\/td><\/tr>
      11<\/td>C2<\/td>Output transistor 2 collector<\/td><\/tr>
      12<\/td>VCC<\/td>Supply voltage (7-40V)<\/td><\/tr>
      13<\/td>OUT CTRL<\/td>Output control (GND=push-pull, REF=single-ended)<\/td><\/tr>
      14<\/td>REF<\/td>5V reference output<\/td><\/tr>
      15<\/td>2IN-<\/td>Error amp 2 inverting input<\/td><\/tr>
      16<\/td>2IN+<\/td>Error amp 2 non-inverting input<\/td><\/tr><\/table>","application_scenarios":"
      • ATX PC power supply controller with dual error amplifiers for voltage and current regulation<\/li>
      • Half-bridge and push-pull converter control with adjustable dead-time<\/li>
      • DC-DC converter regulation with voltage-mode PWM and 200mA output drive<\/li>
      • Battery charger control circuits using dual error amplifiers for CV\/CC regulation<\/li><\/ul>","alternative_models":"
        Model<\/th>Manufacturer<\/th>Key Difference<\/th><\/tr>
        UC3842BN<\/td>TI<\/td>Current-mode, single output, higher performance<\/td><\/tr>
        KA7500B<\/td> Fairchild<\/td>TL494 equivalent, second source<\/td><\/tr>
        SG3525A<\/td>ST<\/td>Push-pull PWM, totem-pole outputs<\/td><\/tr>
        LM5025<\/td>TI<\/td>Active clamp forward controller, modern<\/td><\/tr><\/table>"},"_links":{"self":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/6632","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/comments?post=6632"}],"version-history":[{"count":0,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/posts\/6632\/revisions"}],"wp:attachment":[{"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/media?parent=6632"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/categories?post=6632"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/tags?post=6632"},{"taxonomy":"chip_brand","embeddable":true,"href":"https:\/\/materialparts.com\/zh\/wp-json\/wp\/v2\/chip_brand?post=6632"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}