AC/DC and DC/DC Power Supplies - PWM Power Supply Controllers - UC3844A

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Datasheet

Current Mode PWM Controller (Rev. B) (PDF 3638 KB)
04 Sep 2009

Functional Block Diagram

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	UC1844A	UC1844A-EP	UC2844A	UC3844A
Topology	Boost, Flyback, Forward		Boost, Buck, Flyback, Forward	Boost, Buck, Flyback, Forward
Control Method	Current Mode	Current Mode	Current Mode	Current Mode
Duty Cycle(Max)(%)	50	50	50	50
PWM Outputs(#)	1	1	1	1
Frequency(Max)(kHz)	450	500	450	450
UVLO Thresholds On/Off(V)	16/10	16/10	16/10	16/10
Pin/Package	20LCCC, 8CDIP	8SOIC	14SOIC, 8PDIP, 8SOIC	14SOIC, 8PDIP, 8SOIC
Regulated Outputs(#)	1	1	1	1
	Samples	Samples	Samples	Samples
	Inventory	Inventory	Inventory	Inventory

Other qualified versions of UC3844A

Version	Part Number	Definition
Enhanced Product	UC1844A-EP	Supports Defense, Aerospace and Medical Applications
Military	UC1844A	QML certified for Military and Defense Applications
Space	UC1844A-SP	Radiation tolerant, ceramic packaging and qualified for use in Space-based application

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 V_CC over 5V.

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
UC3844AD	ACTIVE	0 to 70	0.85 \| 1ku	SOIC (D) \| 14	View	50 \| TUBE
UC3844AD8	ACTIVE	0 to 70	0.85 \| 1ku	SOIC (D) \| 8	View	75 \| TUBE
UC3844AD8G4	ACTIVE	0 to 70	0.85 \| 1ku	SOIC (D) \| 8	View	75 \| TUBE
UC3844AD8TR	ACTIVE	0 to 70	0.90 \| 1ku	SOIC (D) \| 8	View	2500 \| LARGE T&R	Purchase Samples
UC3844AD8TRG4	ACTIVE	0 to 70	0.90 \| 1ku	SOIC (D) \| 8	View	2500 \| LARGE T&R	Purchase Samples
UC3844ADG4	ACTIVE	0 to 70	0.85 \| 1ku	SOIC (D) \| 14	View	50 \| TUBE
UC3844ADTR	ACTIVE	0 to 70	0.90 \| 1ku	SOIC (D) \| 14	View	2500 \| LARGE T&R	Purchase Samples
UC3844ADTRG4	ACTIVE	0 to 70	0.90 \| 1ku	SOIC (D) \| 14	View	2500 \| LARGE T&R	Purchase Samples
UC3844AN	ACTIVE	0 to 70	0.85 \| 1ku	PDIP (P) \| 8	View	50 \| TUBE
UC3844ANG4	ACTIVE	0 to 70	0.85 \| 1ku	PDIP (P) \| 8	View	50 \| TUBE

* 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
Region	Company	In Stock	Purchase
TI Lead Time*: 20 WeeksUC3844AD
Americas	Newark	340
Americas	Rochester Electronics	>1k
Asia	Farnell Asia	412
Europe	Farnell	262
TI Lead Time*: 20 WeeksUC3844AD8
Americas	Arrow	3
	Avnet	>1k
	Newark	156
	Rochester Electronics	>1k
Asia	Farnell Asia	156
Europe	Arrow Southern Europe	300
Worldwide	Mouser Electronics	552
TI Lead Time*: 20 WeeksUC3844AD8G4
Europe	EBV Elektronik	>1k
TI Lead Time*: 20 WeeksUC3844AD8TR
Americas	Rochester Electronics	>1k
Europe	Avnet-SILICA	>1k
TI Lead Time*: 20 WeeksUC3844AD8TRG4
None Reported View Distributors
TI Lead Time*: 20 WeeksUC3844ADG4
None Reported View Distributors
TI Lead Time*: 20 WeeksUC3844ADTR
Americas	Rochester Electronics	>1k
TI Lead Time*: 20 WeeksUC3844ADTRG4
None Reported View Distributors
TI Lead Time*: 20 WeeksUC3844AN
Americas	Arrow	33
	Newark	142
	Rochester Electronics	83
Asia	Farnell Asia	292
Asia	WPI	43
Europe	Arrow Northern Europe	150
Europe	Spoerle	350
Worldwide	Mouser Electronics	77
TI Lead Time*: 20 WeeksUC3844ANG4
Europe	EBV Elektronik	>1k
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
UC3844AD	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	View	View
UC3844AD8	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	View	View
UC3844AD8G4	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	View	View
UC3844AD8TR	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	View	View
UC3844AD8TRG4	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	View	View
UC3844ADG4	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	View	View
UC3844ADTR	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	View	View
UC3844ADTRG4	Green (RoHS & no Sb/Br)	CU NIPDAU	Level-1-260C-UNLIM	View	View
UC3844AN	Green (RoHS & no Sb/Br)	CU NIPDAU	N/A for Pkg Type	View	View
UC3844ANG4	Green (RoHS & no Sb/Br)	CU NIPDAU	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 UC3844A

Datasheet

Current Mode PWM Controller (Rev. B) (PDF, 3638 KB)
04 Sep 2009

Application Notes

Conditioning a Switch-mode Power Supply Current Signal Using TI Op Amps (HTM, 8 KB) 6732 views
23 Mar 2000 Read Abstract
Understanding Buck-Boost Power Stages in Switchmode Power Supplies (Rev. A) (HTM, 8 KB) 23248 views
28 May 2002 Read Abstract
UCC38C42 Family of High-Speed BiCMOS Current-Mode PWM Controllers (HTM, 8 KB) 11113 views
07 Feb 2002 Read Abstract
U-111, Practical Considerations in Current Mode Power Supplies (HTM, 8 KB) 11960 views
05 Sep 1999 Read Abstract
DN-40 The Effects of Oscillator Discharge Current Variations on Maximum Duty (HTM, 8 KB) 3184 views
05 Sep 1999 Read Abstract
DN-26 UC3842A Low-Cost Start-up and Fault Protection Circuit (HTM, 8 KB) 7378 views
05 Sep 1999 Read Abstract
DN-27 UC1842/UC1842A Family - Summary of Functional Differences (HTM, 8 KB) 3785 views
05 Sep 1999 Read Abstract
DN-29 UC3842A Family - Frequency Foldback Technique Provides Protection (HTM, 8 KB) 3569 views
05 Sep 1999 Read Abstract
DN-30 Programmable Electronic Circuit Breaker (HTM, 8 KB) 3068 views
05 Sep 1999 Read Abstract
DN-42A Design Considerations for Transitioning from UC3842 to the New UCC3802 (HTM, 8 KB) 5737 views
05 Sep 1999 Read Abstract

View Application Notes for PWM Power Supply Controllers

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UC3844A Status: ACTIVE

Current Mode PWM Controller

Most Popular Links

Datasheet

Functional Block Diagram

Other qualified versions of UC3844A

Product Information

Features

Description

Pricing / Packaging / CAD Design Tools / Samples

Inventory

Quality & Lead (Pb)-Free Data

Technical Documents

Datasheet

Application Notes

Support and Community

Customer Tags

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