UC3843 Status: ACTIVE

Current-Mode PWM Controller

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Datasheet

Current Mode PWM Controller (Rev. C) (uc3843.pdf, 728 KB)
14 Jun 2007 Download

	UC1843	UC2843	UC3843
Topology	Boost, Flyback, Forward	Boost, Flyback, Forward	Boost, Buck, Flyback, Forward
Control Method	Current Mode	Current Mode	Current Mode
Duty Cycle(Max)(%)	100	100	100
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/Package	14CFP,20LCCC,8CDIP	14SOIC,8PDIP,8SOIC	14SOIC,8PDIP,8SOIC
Regulated Outputs(#)	1	1	1
	Samples	Samples	Samples
	Inventory	Inventory	Inventory

Other qualified versions of UC3843

Version	Part Number	Definition
Military	UC1843	QML certified for Military and Defense Applications

Customers Who Evaluated This Product Also Evaluated

UC3843A: Current Mode PWM Controller
UCC2808A-2: Low-Power Current-Mode Push-Pull PWM
TLV431B: Low-Voltage Adjustable Precision Shunt Regulator
TPS54331: 3A, 28V Input Step Down SWIFT(tm) DC/DC Converter with Eco-mode(tm)
MC34063A: 1.5-A Boost/Buck/Inverting Switching Regulator

Product Information

Features

Optimized For Off-line and DC-to-DC Converters
Low Start-Up Current (<1 mA)
Automatic Feed ForwardCompensation
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
500-kHz Operation
Low R_O Error Amp

Description

The UC1842/3/4/5 family of control devices provides the necessary features to implement off-line or dc-to-dc fixed frequency current mode control schemes with a minimal external parts count. Internally implemented circuits include under-voltage lockout featuring start up current less than 1 mA, a precision reference trimmed for accuracy at the error amp input, logic to insure latched operation, a PWM comparator which 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 in the off state.

Differences between members of this family are the under-voltage lockout thresholds and maximum duty cycle ranges. The UC1842 and UC1844 have UVLO thresholds of 16 V_ON and 10 V_OFF, ideally suited to off-line applications. The corresponding thresholds for the UC1843 and UC1845 are 8.4 V and 7.6 V. The UC1842 and UC1843 can operate to duty cycles approaching 100%. A range of zero to 50% is obtained by the UC1844 and UC1845 by the addition of an internal toggle flip flop which blanks the output off every other clock cycle.

Pricing / Packaging / CAD Design Tools / Samples

			Price	Packaging			CAD Design Tools		Samples
Device	Status	Temp (^oC)	Price \| Quantity	Package \| Pins	Top Side Marking	Package QTY \| Package Carrier	Symbols	Footprints	Samples
UC3843D	ACTIVE	0 to 70	0.80 \| 1ku	SOIC (D) \| 14	View	50 \| TUBE
UC3843D8	ACTIVE	0 to 70	0.80 \| 1ku	SOIC (D) \| 8	View	75 \| TUBE
UC3843D8G4	ACTIVE	0 to 70	0.80 \| 1ku	SOIC (D) \| 8	View	75 \| TUBE
UC3843D8TR	ACTIVE	0 to 70	0.90 \| 1ku	SOIC (D) \| 8	View	2500 \| LARGE T&R	Purchase Samples
UC3843D8TRG4	ACTIVE	0 to 70	0.90 \| 1ku	SOIC (D) \| 8	View	2500 \| LARGE T&R	Purchase Samples
UC3843DG4	ACTIVE	0 to 70	0.80 \| 1ku	SOIC (D) \| 14	View	50 \| TUBE
UC3843DTR	ACTIVE	0 to 70	0.90 \| 1ku	SOIC (D) \| 14	View	2500 \| LARGE T&R	Purchase Samples
UC3843DTRG4	ACTIVE	0 to 70	0.90 \| 1ku	SOIC (D) \| 14	View	2500 \| LARGE T&R	Purchase Samples
UC3843N	ACTIVE	0 to 70	0.80 \| 1ku	PDIP (P) \| 8	View	50 \| TUBE
UC3843NG4	ACTIVE	0 to 70	0.80 \| 1ku	PDIP (P) \| 8	View	50 \| TUBE
UC3843P	OBSOLETE	0 to 70		PDIP (P) \| 8	View			Not Available
UC3843QTR	OBSOLETE	0 to 70		PLCC (FN) \| 20	View			Not Available

* 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

	TI Inventory Status			Reported Distributor Inventory
UC3843D	As of 8:48 AM GMT, 20 Nov 2008			As of 8:48 AM GMT, 20 Nov 2008
	In Stock	In Progress QTY \| Date	Lead Time	Region	Company	In Stock	Purchase
	0*	>10k \| 17 Dec	4 Weeks	Americas	DigiKey	471
					Mouser Electronics	242
					Rochester Electronics	>1k
				Asia	WPI	900
				Europe	Arrow Northern Europe	400
UC3843D8	As of 8:48 AM GMT, 20 Nov 2008			As of 8:48 AM GMT, 20 Nov 2008
	In Stock	In Progress QTY \| Date	Lead Time	Region	Company	In Stock	Purchase
	0*	>10k \| 18 Dec	4 Weeks	Americas	DigiKey	>1k
				Americas	Mouser Electronics	371
				Europe	Avnet-SILICA	525
					Farnell	>1k
					Spoerle	375
UC3843D8G4	As of 8:48 AM GMT, 20 Nov 2008			As of 8:48 AM GMT, 20 Nov 2008
	In Stock	In Progress QTY \| Date	Lead Time	Region	Company	In Stock	Purchase
	0*	>10k \| 18 Dec	4 Weeks	Americas	Mouser Electronics	108
UC3843D8TR	As of 8:48 AM GMT, 20 Nov 2008			As of 8:48 AM GMT, 20 Nov 2008
	In Stock	In Progress QTY \| Date	Lead Time	Region	Company	In Stock	Purchase
	0*	>10k \| 17 Dec	4 Weeks	Americas	Rochester Electronics	>1k
	0*		4 Weeks	Asia	WPI	>1k
UC3843D8TRG4	As of 8:48 AM GMT, 20 Nov 2008			As of 8:48 AM GMT, 20 Nov 2008
	In Stock	In Progress QTY \| Date	Lead Time	Region	Company	In Stock	Purchase
	0*	>10k \| 17 Dec	4 Weeks	None Reported View Distributors
UC3843DG4	As of 8:48 AM GMT, 20 Nov 2008			As of 8:48 AM GMT, 20 Nov 2008
	In Stock	In Progress QTY \| Date	Lead Time	Region	Company	In Stock	Purchase
	0*	>10k \| 17 Dec	4 Weeks	Americas	Mouser Electronics	25
				Europe	EBV Elektronik	250
				Europe	Farnell	182
UC3843DTR	As of 8:48 AM GMT, 20 Nov 2008			As of 8:48 AM GMT, 20 Nov 2008
	In Stock	In Progress QTY \| Date	Lead Time	Region	Company	In Stock	Purchase
	0*	>10k \| 17 Dec	4 Weeks	Americas	Rochester Electronics	>1k
UC3843DTRG4	As of 8:48 AM GMT, 20 Nov 2008			As of 8:48 AM GMT, 20 Nov 2008
	In Stock	In Progress QTY \| Date	Lead Time	Region	Company	In Stock	Purchase
	0*	>10k \| 17 Dec	4 Weeks	None Reported View Distributors
UC3843N	As of 8:48 AM GMT, 20 Nov 2008			As of 8:48 AM GMT, 20 Nov 2008
	In Stock	In Progress QTY \| Date	Lead Time	Region	Company	In Stock	Purchase
	0*	7526 \| 2 Jan	8 Weeks	Americas	DigiKey	945
		3102 \| 5 Jan			Mouser Electronics	165
					Newark	143
					Rochester Electronics	>1k
				Europe	Abacus Polar	>1k
					Avnet-SILICA	950
					Spoerle	100
UC3843NG4	As of 8:48 AM GMT, 20 Nov 2008			As of 8:48 AM GMT, 20 Nov 2008
	In Stock	In Progress QTY \| Date	Lead Time	Region	Company	In Stock	Purchase
	0*	7526 \| 2 Jan	8 Weeks	Americas	Avnet	349
		3102 \| 5 Jan		Americas	Mouser Electronics	249
				Europe	EBV Elektronik	950
View all Distributors

* Our information is updated daily, so please check back with us soon if this does not meet your needs. You may also contact your TI Authorized Distributor , including those listed above, for real time stock information.

** 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 Content				DPPM / MTBF / FIT Rate
Device	Eco Plan*	Lead / Ball Finish	MSL Rating / Peak Reflow	Details	Details
UC3843D	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	View	View
UC3843D8	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	View	View
UC3843D8G4	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	View	View
UC3843D8TR	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	View	View
UC3843D8TRG4	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	View	View
UC3843DG4	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	View	View
UC3843DTR	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	View	View
UC3843DTRG4	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	View	View
UC3843N	Green (RoHS & no Sb/Br)	CU NIPDAU	N/A for Pkg Type	View	View
UC3843NG4	Green (RoHS & no Sb/Br)	CU NIPDAU	N/A for Pkg Type	View	View
UC3843P					View

* 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

Datasheets

Current Mode PWM Controller (Rev. C) (uc3843.pdf, 728 KB)
14 Jun 2007 Download

Application Notes

Understanding Buck-Boost Power Stages in Switchmode Power Supplies (Rev. A) (slva059a.htm, 8 KB)
28 May 2002 Abstract
UCC38C42 Family of High-Speed BiCMOS Current-Mode PWM Controllers (slua257.htm, 8 KB)
07 Feb 2002 Abstract
Conditioning a Switch-mode Power Supply Current Signal Using TI Op Amps (sloa044.htm, 8 KB)
23 Mar 2000 Abstract
DN-42A Design Considerations for Transitioning from UC3842 to the New UCC3802 (slua084.htm, 8 KB)
05 Sep 1999 Abstract
DN-65 Considerations in Powering BiCMOS ICs (slua081.htm, 8 KB)
05 Sep 1999 Abstract
DN-43 Simple Techniques to Generate a Negative Voltage Bias Supply (slua042.htm, 8 KB)
05 Sep 1999 Abstract
U-100A UC3842/3/4/5 Provides Low-Cost Current-Mode Control (slua143.htm, 9 KB)
05 Sep 1999 Abstract
U-111, Practical Considerations in Current Mode Power Supplies (slua110.htm, 8 KB)
05 Sep 1999 Abstract
DN-40 The Effects of Oscillator Discharge Current Variations on Maximum Duty (slua173.htm, 8 KB)
05 Sep 1999 Abstract
DN-27 UC1842/UC1842A Family - Summary of Functional Differences (slua163.htm, 8 KB)
05 Sep 1999 Abstract
DN-26 UC3842A Low-Cost Start-up and Fault Protection Circuit (slua162.htm, 8 KB)
05 Sep 1999 Abstract
Understanding Boost Power Stages In Switchmode Power Supplies (slva061.htm, 8 KB)
04 Mar 1999 Abstract
Understanding Buck Power Stages In Switchmode Power Supplies (slva057.htm, 8 KB)
04 Mar 1999 Abstract

View Application Notes for PWM Power Supply Controllers

User Guides

View User Guides for PWM Power Supply Controllers

More Literature

Standard Linear Products Cross-Reference (Rev. D) (slyt017d.pdf, 1169 KB)
05 May 2006 Download

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UC3843 Status: ACTIVE

Current-Mode PWM Controller

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