TL3843B

ACTIVE

30V, 0.2A high Performance 500KHz current mode PWM with 8.4V/7.6V UVLO, 100% duty cycle, 0C to 70C

Product details

Operating temperature range (°C) 0 to 70 Control mode Current Topology Boost, Flyback Rating Catalog Features Adjustable switching frequency, Error amplifier, Fixed frequency, Multi-topology Duty cycle (max) (%) 100
Operating temperature range (°C) 0 to 70 Control mode Current Topology Boost, Flyback Rating Catalog Features Adjustable switching frequency, Error amplifier, Fixed frequency, Multi-topology Duty cycle (max) (%) 100
PDIP (P) 8 92.5083 mm² 9.81 x 9.43 SOIC (D) 8 29.4 mm² 4.9 x 6 SOIC (D) 14 51.9 mm² 8.65 x 6
  • Low Start-Up Current (<0.5mA)
  • Trimmed Oscillator Discharge Current
  • Current Mode Operation to 500kHz
  • Automatic Feed-Forward Compensation
  • Latching PWM for Cycle-by-Cycle Current Limiting
  • Internally Trimmed Reference With Undervoltage Lockout
  • High-Current Totem-Pole Output Undervoltage Lockout With Hysteresis
  • Double-Pulse Suppression
  • Low Start-Up Current (<0.5mA)
  • Trimmed Oscillator Discharge Current
  • Current Mode Operation to 500kHz
  • Automatic Feed-Forward Compensation
  • Latching PWM for Cycle-by-Cycle Current Limiting
  • Internally Trimmed Reference With Undervoltage Lockout
  • High-Current Totem-Pole Output Undervoltage Lockout With Hysteresis
  • Double-Pulse Suppression

The TL284xB and TL384xB series of control integrated circuits provide the features that are necessary to implement off-line or dc-to-dc fixed-frequency current-mode control schemes, with a minimum number of external components. Internally implemented circuits include an undervoltage lockout (UVLO) and a precision reference that is trimmed for accuracy at the error amplifier input. Other internal circuits include logic to ensure latched operation, a pulse-width modulation (PWM) comparator that also provides current-limit control, and a totem-pole output stage designed to source or sink high-peak current. The output stage, suitable for driving N-channel MOSFETs, is low when the output stage is in the off state.

The TL284xB and TL384xB series are pin compatible with the standard TL284x and TL384x with the following improvements. The start-up current is specified to be 0.5mA (max), while the oscillator discharge current is trimmed to 8.3mA (typ). In addition, during undervoltage lockout conditions, the output has a maximum saturation voltage of 1.2V while sinking 10mA (VCC = 5V).

Major differences between members of these series are the UVLO thresholds and maximum duty-cycle ranges. Typical UVLO thresholds of 16V (on) and 10V (off) on the TLx842B and TLx844B devices make them ideally suited to off-line applications. The corresponding typical thresholds for the TLx843B and TLx845B devices are 8.4V (on) and 7.6V (off). The TLx842B and TLx843B devices can operate to duty cycles approaching 100%. A duty-cycle range of 0% to 50% is obtained by the TLx844B and TLx845B by the addition of an internal toggle flip-flop, which blanks the output off every other clock cycle. The TL284xB-series devices are characterized for operation from –40°C to 85°C. The TL384xB-series devices are characterized for operation from 0°C to 70°C.

The TL284xB and TL384xB series of control integrated circuits provide the features that are necessary to implement off-line or dc-to-dc fixed-frequency current-mode control schemes, with a minimum number of external components. Internally implemented circuits include an undervoltage lockout (UVLO) and a precision reference that is trimmed for accuracy at the error amplifier input. Other internal circuits include logic to ensure latched operation, a pulse-width modulation (PWM) comparator that also provides current-limit control, and a totem-pole output stage designed to source or sink high-peak current. The output stage, suitable for driving N-channel MOSFETs, is low when the output stage is in the off state.

The TL284xB and TL384xB series are pin compatible with the standard TL284x and TL384x with the following improvements. The start-up current is specified to be 0.5mA (max), while the oscillator discharge current is trimmed to 8.3mA (typ). In addition, during undervoltage lockout conditions, the output has a maximum saturation voltage of 1.2V while sinking 10mA (VCC = 5V).

Major differences between members of these series are the UVLO thresholds and maximum duty-cycle ranges. Typical UVLO thresholds of 16V (on) and 10V (off) on the TLx842B and TLx844B devices make them ideally suited to off-line applications. The corresponding typical thresholds for the TLx843B and TLx845B devices are 8.4V (on) and 7.6V (off). The TLx842B and TLx843B devices can operate to duty cycles approaching 100%. A duty-cycle range of 0% to 50% is obtained by the TLx844B and TLx845B by the addition of an internal toggle flip-flop, which blanks the output off every other clock cycle. The TL284xB-series devices are characterized for operation from –40°C to 85°C. The TL384xB-series devices are characterized for operation from 0°C to 70°C.

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Technical documentation

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* Data sheet TLx84xB High-Performance Current-Mode Pwm Controllers datasheet (Rev. C) PDF | HTML 11 Oct 2024
Selection guide Power Management Guide 2018 (Rev. R) 25 Jun 2018

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PDIP (P) 8 Ultra Librarian
SOIC (D) 8 Ultra Librarian
SOIC (D) 14 Ultra Librarian

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