UC1843 Status: ACTIVE

Current Mode PWM Controller

Alert me about changes<br/>to this product

Alert me about changes
to this product

Datasheet

Current Mode PWM Controller (Rev. C) (PDF 658 KB)
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 UC1843

Version	Part Number	Definition
Catalog	UC3843	TI's standard catalog product
Space	UC1843-SP	Radiation tolerant, ceramic packaging and qualified for use in Space-based application

Customers Who Evaluated This Product Also Evaluated

UC3843: Current-Mode PWM Controller
UC1843A: Current Mode PWM Controller

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)	DSCC #	Price \| Quantity	Package \| Pins	Top Side Marking	Package QTY \| Package Carrier	Symbols	Footprints	Samples
5962-8670402PA	ACTIVE	-55 to 125		5.63 \| 100u	CDIP (JG) \| 8	View	1 \| TUBE	Purchase Samples
5962-8670402XA	ACTIVE	-55 to 125		11.78 \| 100u	LCCC (FK) \| 20		1 \| TUBE	Purchase Samples
UC1843J	ACTIVE	-55 to 125		3.38 \| 100u	CDIP (JG) \| 8	View	1 \| TUBE	Contact TI Distributor or Sales Office
UC1843J883B	ACTIVE	-55 to 125	5962-8670402PA	5.63 \| 100u	CDIP (JG) \| 8	View	1 \| TUBE	Contact TI Distributor or Sales Office
UC1843L	ACTIVE	-55 to 125		8.53 \| 100u	LCCC (FK) \| 20		1 \| TUBE	Contact TI Distributor or Sales Office
UC1843L883B	ACTIVE	-55 to 125	5962-8670402XA	11.78 \| 100u	LCCC (FK) \| 20		1 \| TUBE	Contact TI Distributor or Sales Office
UC1843W	ACTIVE	-55 to 125		8.53 \| 100u	CFP (W) \| 14		1 \| TUBE		Purchase 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 9:51 AM GMT, 08 Nov 2009
Region	Company	In Stock	Purchase
TI Lead Time*: 8 Weeks5962-8670402PA
Americas	Arrow	>1k
Europe	Avnet-SILICA	41
Europe	EBV Elektronik	24
TI Lead Time*: 8 Weeks5962-8670402XA
Americas	Avnet	22
TI Lead Time*: 8 WeeksUC1843J
Americas	Arrow	>1k
Europe	Avnet-SILICA	>1k
	Compel	396
	EBV Elektronik	>1k
	Spoerle	328
TI Lead Time*: 8 WeeksUC1843J883B
Americas	Arrow	891
	Avnet	125
	Rochester Electronics	61
TI Lead Time*: 8 WeeksUC1843L
None Reported View Distributors
TI Lead Time*: 8 WeeksUC1843L883B
None Reported View Distributors
TI Lead Time*: 8 WeeksUC1843W
None Reported View Distributors
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
5962-8670402PA	TBD	A42	N/A for Pkg Type	View	View
5962-8670402XA	TBD	POST-PLATE	N/A for Pkg Type	View	View
UC1843J	TBD	A42	N/A for Pkg Type	View	View
UC1843J883B	TBD	A42	N/A for Pkg Type	View	View
UC1843L	TBD	POST-PLATE	N/A for Pkg Type	View	View
UC1843L883B	TBD	POST-PLATE	N/A for Pkg Type	View	View
UC1843W	TBD	A42	N/A for Pkg Type	View	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 UC1843

Datasheet

Current Mode PWM Controller (Rev. C) (PDF, 658 KB)
14 Jun 2007

Application Notes

Conditioning a Switch-mode Power Supply Current Signal Using TI Op Amps (HTM, 8 KB) 6605 views
23 Mar 2000 Read Abstract
Understanding Buck-Boost Power Stages in Switchmode Power Supplies (Rev. A) (HTM, 8 KB) 22918 views
28 May 2002 Read Abstract
UCC38C42 Family of High-Speed BiCMOS Current-Mode PWM Controllers (HTM, 8 KB) 10989 views
07 Feb 2002 Read Abstract
U-111, Practical Considerations in Current Mode Power Supplies (HTM, 8 KB) 11772 views
05 Sep 1999 Read Abstract
DN-40 The Effects of Oscillator Discharge Current Variations on Maximum Duty (HTM, 8 KB) 3158 views
05 Sep 1999 Read Abstract
DN-26 UC3842A Low-Cost Start-up and Fault Protection Circuit (HTM, 8 KB) 7275 views
05 Sep 1999 Read Abstract
DN-27 UC1842/UC1842A Family - Summary of Functional Differences (HTM, 8 KB) 3746 views
05 Sep 1999 Read Abstract
U-100A UC3842/3/4/5 Provides Low-Cost Current-Mode Control (HTM, 9 KB) 21153 views
05 Sep 1999 Read Abstract
DN-42A Design Considerations for Transitioning from UC3842 to the New UCC3802 (HTM, 8 KB) 5627 views
05 Sep 1999 Read Abstract
DN-65 Considerations in Powering BiCMOS ICs (HTM, 8 KB) 3336 views
05 Sep 1999 Read Abstract

View Application Notes for PWM Power Supply Controllers

Customers Who Evaluated This Product Also Evaluated...
Part #	Name	Product Family	Comments
UC3843	Current-Mode PWM Controller	AC/DC AND DC/DC POWER SUPPLIES-PWM POWER SUPPLY CONTROLLERS	TI customers also evaluated this product.
UC1843A	Current Mode PWM Controller	AC/DC AND DC/DC POWER SUPPLIES-PWM POWER SUPPLY CONTROLLERS	TI customers also evaluated this product.

Support and Community

Customer Tags

No Tags are Available for this Part Number

UC1843 Status: ACTIVE

Current Mode PWM Controller

Most Popular Links