Catalog
Enhanced Product Current-Mode Pwm Controller
Key Features
• Controlled BaselineOne Assembly/Test Site, One Fabrication SiteExtended Temperature Performance of –55°C to 125°CEnhanced Diminishing Manufacturing Sources (DMS) SupportEnhanced Product Change NotificationQualification Pedigree(1)Optimized for Off-line and DC-to-DC ConvertersLow Start Up Current (<0.5 mA)Trimmed Oscillator Discharge CurrentAutomatic Feed Forward CompensationPulse-by-Pulse Current LimitingEnhanced Load Response CharacteristicsUnder-Voltage Lockout With HysteresisDouble Pulse SuppressionHigh Current Totem Pole OutputInternally Trimmed Bandgap Reference500 kHz OperationLow RO Error Amp(1)Component qualification in accordance with JEDEC and industry standards to ensure reliable operation over an extended temperature range. This includes, but is not limited to, Highly Accelerated Stress Test (HAST) or biased 85/85, temperature cycle, autoclave or unbiased HAST, electromigration, bond intermetallic life, and mold compound life. Such qualification testing should not be viewed as justifying use of this component beyond specified performance and environmental limits.Controlled BaselineOne Assembly/Test Site, One Fabrication SiteExtended Temperature Performance of –55°C to 125°CEnhanced Diminishing Manufacturing Sources (DMS) SupportEnhanced Product Change NotificationQualification Pedigree(1)Optimized for Off-line and DC-to-DC ConvertersLow Start Up Current (<0.5 mA)Trimmed Oscillator Discharge CurrentAutomatic Feed Forward CompensationPulse-by-Pulse Current LimitingEnhanced Load Response CharacteristicsUnder-Voltage Lockout With HysteresisDouble Pulse SuppressionHigh Current Totem Pole OutputInternally Trimmed Bandgap Reference500 kHz OperationLow RO Error Amp(1)Component qualification in accordance with JEDEC and industry standards to ensure reliable operation over an extended temperature range. This includes, but is not limited to, Highly Accelerated Stress Test (HAST) or biased 85/85, temperature cycle, autoclave or unbiased HAST, electromigration, bond intermetallic life, and mold compound life. Such qualification testing should not be viewed as justifying use of this component beyond specified performance and environmental limits.
Description
AI
The UCx84x 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. The internally implemented circuits include an undervoltage lockout (UVLO), featuring a start-up current of less than 1mA, and a precision reference trimmed for accuracy at the error amplifier input. Other internal circuits include logic to provide latched operation, a pulse-width modulation (PWM) comparator that also provides current-limit control, and a totem-pole output stage that is designed to source or sink high-peak current. The output stage, designed for driving N-channel MOSFETs, is low when the output stage is in the off state.
The UCx84x family offers a variety of package options, temperature range options, choice of maximum duty cycle, and choice of turnon and turnoff thresholds and hysteresis ranges. Devices with higher turnon or turnoff hysteresis are good choices for off-line power supplies, while the devices with a narrower hysteresis range are designed for DC-DC applications. The UC184x devices are specified for operation from –55°C to 125°C, the UC284x series is specified for operation from –40°C to 85°C, and the UC384x series is specified for operation from 0°C to 70°C.
The UCx84x 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. The internally implemented circuits include an undervoltage lockout (UVLO), featuring a start-up current of less than 1mA, and a precision reference trimmed for accuracy at the error amplifier input. Other internal circuits include logic to provide latched operation, a pulse-width modulation (PWM) comparator that also provides current-limit control, and a totem-pole output stage that is designed to source or sink high-peak current. The output stage, designed for driving N-channel MOSFETs, is low when the output stage is in the off state.
The UCx84x family offers a variety of package options, temperature range options, choice of maximum duty cycle, and choice of turnon and turnoff thresholds and hysteresis ranges. Devices with higher turnon or turnoff hysteresis are good choices for off-line power supplies, while the devices with a narrower hysteresis range are designed for DC-DC applications. The UC184x devices are specified for operation from –55°C to 125°C, the UC284x series is specified for operation from –40°C to 85°C, and the UC384x series is specified for operation from 0°C to 70°C.