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UC3856 Status: ACTIVE

Improved Current Mode PWM Controller


      
         
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Datasheet

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 UC1856 UC2856 UC3856
TopologyBoost, Flyback, Forward, Full-Bridge, Half-Bridge, Push-Pull  Boost, Flyback, Forward, Full-Bridge, Half-Bridge, Push-Pull  Boost, Buck, Flyback, Forward, Full-Bridge, Half-Bridge, Push-Pull  
Control MethodCurrent Mode  Current Mode  Current Mode  
Duty Cycle(Max)(%)50  50  50  
PWM Outputs(#)2  2  2  
Frequency(Max)(kHz)1000  1000  1000  
UVLO Thresholds On/Off(V)7.7/7  7.7/7  7.7/7  
Pin/Package16CDIP, 20LCCC  16PDIP, 16SOIC  16PDIP, 16SOIC, 20PLCC  
Regulated Outputs(#)2  2  2  
 SamplesSamplesSamples
 InventoryInventoryInventory

Other qualified versions of UC3856

Version Part Number Definition
Military UC1856 QML certified for Military and Defense Applications

Customers Who Evaluated This Product Also Evaluated

  • UC3846: Current Mode PWM Controller
  • UC2856: Improved Current Mode PWM Controller
  • UCC25600: 8-Pin High-Performance Resonant Mode Controller
  • TPS62290: 2.25MHz 1A Step-Down Converter in 2x2mm SON Package

Product Information

Features

  • Pin-for-Pin Compatible With the UC3846
  • 65ns Typical Delay From Shutdown to Outputs, and 50ns Typical Delay From Sync to Outputs
  • Improved Current Sense Amplifier With Reduced Noise Sensitivity
  • Differential Current Sense with 3V Common Mode Range
  • Trimmed Oscillator Discharge Current for Accurate Deadband Control
  • Accurate 1V Shutdown Threshold
  • High Current Dual Totem Pole Outputs (1.5A peak)
  • TTL Compatible Oscillator SYNC Pin Thresholds
  • 4kV ESD Protection

Description

The UC3856 is a high performance version of the popular UC3846 series of current mode controllers, and is intended for both design upgrades and new applications where speed and accuracy are important. All input to output delays have been minimized, and the current sense output is slew rate limited to reduce noise sensitivity. Fast 1.5A peak output stages have been added to allow rapid switching of power FETs.

A low impedance TTL compatible sync output has been implemented with a tri-state function when used as a sync input.

Internal chip grounding has been improved to minimize internal \x93noise\x94 caused when driving large capacitive loads. This, in conjunction with the improved differential current sense amplifier results in enhanced noise immunity.

View All Description in Datasheet

    

Pricing / Packaging / CAD Design Tools / Samples

PricePackagingCAD Design ToolsSamples
DeviceStatusTemp (oC)Price | QuantityPackage | PinsTop Side MarkingPackage QTY | Package CarrierSymbolsFootprintsSamples
UC3856DWACTIVE0 to 701.90 | 1kuSOIC (DW) | 16 View 40 | TUBE Download CAD Format for this Symbol Download CAD Format for this Footprint
UC3856DWG4ACTIVE0 to 701.90 | 1kuSOIC (DW) | 16 View 40 | TUBE Download CAD Format for this Symbol Download CAD Format for this Footprint
UC3856DWTRACTIVE0 to 701.70 | 1kuSOIC (DW) | 16 View 2000 | LARGE T&R Download CAD Format for this Symbol Download CAD Format for this FootprintPurchase Samples
UC3856DWTRG4ACTIVE0 to 701.70 | 1kuSOIC (DW) | 16 View 2000 | LARGE T&R Download CAD Format for this Symbol Download CAD Format for this FootprintPurchase Samples
UC3856NACTIVE0 to 701.90 | 1kuPDIP (N) | 16 View 25 | TUBE Download CAD Format for this Symbol Download CAD Format for this Footprint
UC3856NG4ACTIVE0 to 701.90 | 1kuPDIP (N) | 16 View 25 | TUBE Download CAD Format for this Symbol Download CAD Format for this Footprint
UC3856QACTIVE0 to 702.25 | 1kuPLCC (FN) | 20 View 46 | TUBE Download CAD Format for this Symbol Download CAD Format for this FootprintPurchase Samples
UC3856QG3ACTIVE0 to 702.25 | 1kuPLCC (FN) | 20 View 46 | TUBE Download CAD Format for this Symbol Download CAD Format for this FootprintPurchase Samples

* 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 WeeksUC3856DW
AmericasArrow >1k
Rochester Electronics 80
EuropeAvnet-SILICA 115
WorldwideDigiKey 55
TI Lead Time*: 20 WeeksUC3856DWG4
WorldwideDigiKey  Available
TI Lead Time*: 20 WeeksUC3856DWTR
WorldwideDigiKey  Available
TI Lead Time*: 20 WeeksUC3856DWTRG4
WorldwideDigiKey  Available
TI Lead Time*: 20 WeeksUC3856N
AmericasAvnet 156
Newark 36
Rochester Electronics >1k
AsiaFarnell Asia 36
WorldwideDigiKey 75
Mouser Electronics 92
TI Lead Time*: 20 WeeksUC3856NG4
AmericasRochester Electronics 875
AsiaFarnell Asia 99
EuropeFarnell 56
WorldwideDigiKey  Available
TI Lead Time*: 4 WeeksUC3856Q
AmericasArrow 26
Rochester Electronics >1k
WorldwideMouser Electronics 40
TI Lead Time*: 4 WeeksUC3856QG3
None Reported
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** 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
UC3856DW RoHS Compliant Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEARViewView
UC3856DWG4 RoHS Compliant Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEARViewView
UC3856DWTR RoHS Compliant Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEARViewView
UC3856DWTRG4 RoHS Compliant Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEARViewView
UC3856N RoHS Compliant Green (RoHS & no Sb/Br) CU NIPDAU N/A for Pkg TypeViewView
UC3856NG4 RoHS Compliant Green (RoHS & no Sb/Br) CU NIPDAU N/A for Pkg TypeViewView
UC3856Q RoHS Compliant Green (RoHS & no Sb/Br) CU SN Level-2-260C-1 YEARViewView
UC3856QG3 RoHS Compliant Green (RoHS & no Sb/Br) CU SN Level-2-260C-1 YEARViewView

* 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 UC3856 Help

Datasheet

Application Notes

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Customers Who Evaluated This Product Also Evaluated...
Part # Name Product Family Comments
UC3846 Current Mode PWM Controller AC/DC AND DC/DC POWER SUPPLIES-PWM POWER SUPPLY CONTROLLERS TI customers also evaluated this product.
UC2856 Improved Current Mode PWM Controller AC/DC AND DC/DC POWER SUPPLIES-PWM POWER SUPPLY CONTROLLERS TI customers also evaluated this product.
UCC25600 8-Pin High-Performance Resonant Mode Controller AC/DC AND DC/DC POWER SUPPLIES-PWM POWER SUPPLY CONTROLLERS TI customers also evaluated this product.
TPS62290 2.25MHz 1A Step-Down Converter in 2x2mm SON Package DC/DC CONVERTERS (INTEGRATED SWITCH)-STEP-DOWN REGULATORS TI customers also evaluated this product.

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