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UC3845A Status: ACTIVE

Current Mode PWM Controller


      
         
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Datasheet

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Functional Block Diagram


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 UC1845A UC2845A UC3845A
TopologyBoost, Flyback, Forward  Boost, Flyback, Forward  Boost, Buck, Flyback, Forward  
Control MethodCurrent Mode  Current Mode  Current Mode  
Duty Cycle(Max)(%)50  50  50  
PWM Outputs(#)1  1  1  
Frequency(Max)(kHz)450  450  450  
UVLO Thresholds On/Off(V)8.4/7.6  8.4/7.6  8.4/7.6  
Pin/Package20LCCC, 8CDIP  14SOIC, 16SOIC, 8PDIP, 8SOIC  14SOIC, 8PDIP, 8SOIC  
Regulated Outputs(#)1  1  1  
 SamplesSamplesSamples
 InventoryInventoryInventory

Other qualified versions of UC3845A

Version Part Number Definition
Catalog UC3845AM TI's standard catalog product
Enhanced Product UC1845A-EP Supports Defense, Aerospace and Medical Applications
Military UC1845A QML certified for Military and Defense Applications
Space UC1845A-SP Radiation tolerant, ceramic packaging and qualified for use in Space-based application

Customers Who Evaluated This Product Also Evaluated

  • UC3843A: Current Mode PWM Controller
  • TPS5430: 5.5V to 36V, 3A, 500kHz Step Down SWIFT™ Converter
  • TLV431A: Low Voltage Adjustable Precision Shunt Regulator
  • TPS5430-Q1: Automotive Catalog 3-A Wide-Input-Range Step-Down SWIFT™ Converter

Product Information

Features

  • Optimized for Off-line and DC to DC Converters
  • Low Start Up Current (<0.5mA)
  • Trimmed Oscillator Discharge Current
  • Automatic Feed Forward Compensation
  • Pulse-by-Pulse Current Limiting
  • Enhanced Load Response Characteristics
  • Under-Voltage Lockout With Hysteresis
  • Double Pulse Suppression
  • High Current Totem Pole Output
  • Internally Trimmed Bandgap Reference
  • 500kHz Operation
  • Low RO Error Amp

Description

The UC1842A/3A/4A/5A family of control ICs is a pin for pin compatible improved version of the UC3842/3/4/5 family. Providing the necessary features to control current mode switched mode power supplies, this family has the following improved features. Start up current is guaranteed to be less than 0.5mA. Oscillator discharge is trimmed to 8.3mA. During under voltage lockout, the output stage can sink at least 10mA at less than 1.2V for VCC over 5V.

    

Pricing / Packaging / CAD Design Tools / Samples

PricePackagingCAD Design ToolsSamples
DeviceStatusTemp (oC)Price | QuantityPackage | PinsTop Side MarkingPackage QTY | Package CarrierSymbolsFootprintsSamples
UC3845ADACTIVE0 to 700.85 | 1kuSOIC (D) | 14 View 50 | TUBE Download CAD Format for this Symbol Download CAD Format for this Footprint
UC3845AD8ACTIVE0 to 700.85 | 1kuSOIC (D) | 8 View 75 | TUBE Download CAD Format for this Symbol Download CAD Format for this Footprint
UC3845AD8G4ACTIVE0 to 700.85 | 1kuSOIC (D) | 8 View 75 | TUBE Download CAD Format for this Symbol Download CAD Format for this Footprint
UC3845AD8TRACTIVE0 to 700.90 | 1kuSOIC (D) | 8 View 2500 | LARGE T&R Download CAD Format for this Symbol Download CAD Format for this FootprintPurchase Samples
UC3845AD8TRG4ACTIVE0 to 700.90 | 1kuSOIC (D) | 8 View 2500 | LARGE T&R Download CAD Format for this Symbol Download CAD Format for this FootprintPurchase Samples
UC3845ADG4ACTIVE0 to 700.85 | 1kuSOIC (D) | 14 View 50 | TUBE Download CAD Format for this Symbol Download CAD Format for this Footprint
UC3845ADTRACTIVE0 to 700.90 | 1kuSOIC (D) | 14 View 2500 | LARGE T&R Download CAD Format for this Symbol Download CAD Format for this FootprintPurchase Samples
UC3845ADTRG4ACTIVE0 to 700.90 | 1kuSOIC (D) | 14 View 2500 | LARGE T&R Download CAD Format for this Symbol Download CAD Format for this FootprintPurchase Samples
UC3845ANACTIVE0 to 700.85 | 1kuPDIP (P) | 8 View 50 | TUBE Download CAD Format for this Symbol Download CAD Format for this Footprint
UC3845ANG4ACTIVE0 to 700.85 | 1kuPDIP (P) | 8 View 50 | TUBE Download CAD Format for this Symbol Download CAD Format for this Footprint

* Suggested Resale Price per unit (USD) for BUDGETARY USE ONLY. For higher volume price quotes,prices in local currency or delivery quotes, please contact your local Texas Instruments Sales Office or Authorized Distributor.

Inventory

Reported Distributor Inventory as of 9:52 AM GMT, 22 Nov 2009
RegionCompanyIn StockPurchase
TI Lead Time*: 20 WeeksUC3845AD
AmericasRochester Electronics >1k
AsiaWPI 65
WorldwideDigiKey 399
Mouser Electronics 68
TI Lead Time*: 20 WeeksUC3845AD8
AmericasArrow >1k
Newark 181
Rochester Electronics 596
AsiaFarnell Asia 169
WPI 70
EuropeArrow Northern Europe 202
Avnet-SILICA >1k
EBV Elektronik 1
Spoerle 375
WorldwideDigiKey 683
TI Lead Time*: 20 WeeksUC3845AD8G4
EuropeEBV Elektronik >1k
WorldwideDigiKey  Available
TI Lead Time*: 20 WeeksUC3845AD8TR
AmericasRochester Electronics >1k
WorldwideDigiKey  Available
TI Lead Time*: 20 WeeksUC3845AD8TRG4
WorldwideDigiKey  Available
TI Lead Time*: 20 WeeksUC3845ADG4
AmericasAvnet 50
AsiaFarnell Asia 42
WorldwideDigiKey  Available
TI Lead Time*: 20 WeeksUC3845ADTR
AmericasRochester Electronics >1k
EuropeAvnet-SILICA >1k
WorldwideDigiKey  Available
TI Lead Time*: 20 WeeksUC3845ADTRG4
WorldwideDigiKey  Available
TI Lead Time*: 20 WeeksUC3845AN
AmericasArrow >1k
Avnet 833
Newark 72
AsiaFarnell Asia 118
WPI 12
EuropeAbacus Polar 150
Arrow Northern Europe 150
Arrow Southern Europe 100
Farnell 118
Spoerle 450
WorldwideDigiKey >1k
TI Lead Time*: 20 WeeksUC3845ANG4
AmericasRochester Electronics 75
WorldwideDigiKey  Available
View all Distributors  

** Lead time information is not available at this time. However, our information is updated daily so please check back with us soon. Please contact your preferred TI Authorized Distributor for additional information.

Quality & Lead (Pb)-Free Data

 Product ContentDPPM / MTBF / FIT Rate
DeviceEco Plan* Lead / Ball FinishMSL Rating / Peak ReflowDetailsDetails
UC3845AD RoHS Compliant Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIMViewView
UC3845AD8 RoHS Compliant Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIMViewView
UC3845AD8G4 RoHS Compliant Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIMViewView
UC3845AD8TR RoHS Compliant Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIMViewView
UC3845AD8TRG4 RoHS Compliant Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIMViewView
UC3845ADG4 RoHS Compliant Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIMViewView
UC3845ADTR RoHS Compliant Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIMViewView
UC3845ADTRG4 RoHS Compliant Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIMViewView
UC3845AN RoHS Compliant Green (RoHS & no Sb/Br) CU NIPDAU N/A for Pkg TypeViewView
UC3845ANG4 RoHS Compliant Green (RoHS & no Sb/Br) CU NIPDAU N/A for Pkg TypeViewView

* The planned eco-friendly classification: Pb-Free (RoHS) or Pb-Free (RoHS Exempt) or Green (RoHS & no Sb/Br) - please click on the Product Content Details "View" link in the table above for the latest availability information and additional product content details.

If the information you are requesting is not available online at this time, contact one of our Product Information Centers regarding the availability of this information.

Technical Documents

Most useful technical documents for UC3845A Help

Datasheet

Application Notes

View Application Notes for PWM Power Supply Controllers

Customers Who Evaluated This Product Also Evaluated...
Part # Name Product Family Comments
UC3843A Current Mode PWM Controller AC/DC AND DC/DC POWER SUPPLIES-PWM POWER SUPPLY CONTROLLERS TI customers also evaluated this product.
TPS5430 5.5V to 36V, 3A, 500kHz Step Down SWIFT™ Converter DC/DC CONVERTERS (INTEGRATED SWITCH)-STEP-DOWN REGULATORS TI customers also evaluated this product.
TLV431A Low Voltage Adjustable Precision Shunt Regulator VOLTAGE REFERENCE-SHUNT VOLTAGE REFERENCE TI customers also evaluated this product.
TPS5430-Q1 Automotive Catalog 3-A Wide-Input-Range Step-Down SWIFT™ Converter DC/DC CONVERTERS (INTEGRATED SWITCH)-STEP-DOWN REGULATORS TI customers also evaluated this product.

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