UC3843 Status: ACTIVE

Current-Mode PWM Controller

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Datasheet

Current Mode PWM Controller (Rev. C) (PDF 726 KB) 70183 views
14 Jun 2007

	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

UCC3895: BiCMOS Advanced Phase Shift PWM Controller
UC2843: Current-Mode PWM Controller
UCC28600: 8-Pin Quasi Resonant Flyback Green Mode Controller
TPS3808G01: Low Quiescent Current, Programmable-Delay Supervisory Circuit
TPS5450: 5.5V to 36V, 5A, 500kHz Step Down SWIFT™ Converter
TPS40192: 4.5V to 18V Input, Low Pin Count, Synchronous Buck Controller with Power Good

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	0.90 \| 1ku	SOIC (D) \| 14	View	50 \| TUBE
UC3843D8	ACTIVE	0 to 70	0.90 \| 1ku	SOIC (D) \| 8	View	75 \| TUBE
UC3843D8G4	ACTIVE	0 to 70	0.90 \| 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	0.90 \| 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	0.90 \| 1ku	PDIP (P) \| 8	View	50 \| TUBE
UC3843NG4	ACTIVE	0 to 70	0.90 \| 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 8:08 AM GMT, 03 Jul 2009	As of 8:08 AM GMT, 03 Jul 2009
	Lead Time	Region	Company	In Stock	Purchase
	4 Weeks	Americas	DigiKey	446
			Mouser Electronics	237
			Rochester Electronics	>1k
		Asia	WPI	900
UC3843D8	As of 8:08 AM GMT, 03 Jul 2009	As of 8:08 AM GMT, 03 Jul 2009
	Lead Time	Region	Company	In Stock	Purchase
	4 Weeks	Americas	Arrow	922
		Americas	DigiKey	>1k
		Europe	Avnet-SILICA	75
		Europe	Spoerle	225
UC3843D8G4	As of 8:08 AM GMT, 03 Jul 2009	As of 8:08 AM GMT, 03 Jul 2009
	Lead Time	Region	Company	In Stock	Purchase
	4 Weeks	Americas	Avnet	190
			DigiKey	Available
			Mouser Electronics	95
		Europe	EBV Elektronik	75
UC3843D8TR	As of 8:08 AM GMT, 03 Jul 2009	As of 8:08 AM GMT, 03 Jul 2009
	Lead Time	Region	Company	In Stock	Purchase
	4 Weeks	Americas	DigiKey	Available
		Americas	Rochester Electronics	>1k
		Asia	WPI	>1k
UC3843D8TRG4	As of 8:08 AM GMT, 03 Jul 2009	As of 8:08 AM GMT, 03 Jul 2009
	Lead Time	Region	Company	In Stock	Purchase
	4 Weeks	Americas	DigiKey	Available
UC3843DG4	As of 8:08 AM GMT, 03 Jul 2009	As of 8:08 AM GMT, 03 Jul 2009
	Lead Time	Region	Company	In Stock	Purchase
	4 Weeks	Americas	DigiKey	Available
		Americas	Mouser Electronics	2
		Europe	Farnell	275
UC3843DTR	As of 8:08 AM GMT, 03 Jul 2009	As of 8:08 AM GMT, 03 Jul 2009
	Lead Time	Region	Company	In Stock	Purchase
	8 Weeks	Americas	DigiKey	Available
	8 Weeks	Americas	Rochester Electronics	>1k
UC3843DTRG4	As of 8:08 AM GMT, 03 Jul 2009	As of 8:08 AM GMT, 03 Jul 2009
	Lead Time	Region	Company	In Stock	Purchase
	8 Weeks	Americas	DigiKey	Available
UC3843N	As of 8:08 AM GMT, 03 Jul 2009	As of 8:08 AM GMT, 03 Jul 2009
	Lead Time	Region	Company	In Stock	Purchase
	4 Weeks	Americas	Avnet	>1k
			DigiKey	>1k
			Mouser Electronics	113
			Newark	110
			Rochester Electronics	>1k
		Europe	Abacus Polar	>1k
		Europe	Avnet-SILICA	200
UC3843NG4	As of 8:08 AM GMT, 03 Jul 2009	As of 8:08 AM GMT, 03 Jul 2009
	Lead Time	Region	Company	In Stock	Purchase
	4 Weeks	Americas	DigiKey	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 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

Most useful technical documents for UC3843

Datasheet

Current Mode PWM Controller (Rev. C) (PDF 726 KB) 70183 views
14 Jun 2007

Application Notes

Conditioning a Switch-mode Power Supply Current Signal Using TI Op Amps (HTM 8 KB) 5606 views
23 Mar 2000 Read Abstract
Understanding Buck-Boost Power Stages in Switchmode Power Supplies (Rev. A) (HTM 8 KB) 20316 views
28 May 2002 Read Abstract
Understanding Boost Power Stages In Switchmode Power Supplies (HTM 8 KB) 13737 views
04 Mar 1999 Read Abstract
Understanding Buck Power Stages In Switchmode Power Supplies (HTM 8 KB) 14352 views
04 Mar 1999 Read Abstract
UCC38C42 Family of High-Speed BiCMOS Current-Mode PWM Controllers (HTM 8 KB) 10063 views
07 Feb 2002 Read Abstract
DN-43 Simple Techniques to Generate a Negative Voltage Bias Supply (HTM 8 KB) 2051 views
05 Sep 1999 Read Abstract
U-111, Practical Considerations in Current Mode Power Supplies (HTM 8 KB) 10159 views
05 Sep 1999 Read Abstract
DN-40 The Effects of Oscillator Discharge Current Variations on Maximum Duty (HTM 8 KB) 2865 views
05 Sep 1999 Read Abstract
DN-26 UC3842A Low-Cost Start-up and Fault Protection Circuit (HTM 8 KB) 6608 views
05 Sep 1999 Read Abstract
DN-27 UC1842/UC1842A Family - Summary of Functional Differences (HTM 8 KB) 3425 views
05 Sep 1999 Read Abstract
U-100A UC3842/3/4/5 Provides Low-Cost Current-Mode Control (HTM 9 KB) 18847 views
05 Sep 1999 Read Abstract
DN-42A Design Considerations for Transitioning from UC3842 to the New UCC3802 (HTM 8 KB) 4970 views
05 Sep 1999 Read Abstract
DN-65 Considerations in Powering BiCMOS ICs (HTM 8 KB) 3031 views
05 Sep 1999 Read Abstract

View Application Notes for PWM Power Supply Controllers

Selection Guides

Standard Linear Products Cross-Reference (Rev. D) (PDF 1169 KB) 28683 views
05 May 2006

Customers Who Evaluated This Product Also Evaluated...
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UC3843 Status: ACTIVE

Current-Mode PWM Controller

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