UC2843A-Q1

Manufacturer Part NumberUC2843A-Q1
ManufacturerTexas Instruments
UC2843A-Q1 datasheet
 


Specifications of UC2843A-Q1

TopologyBoostControl MethodCurrent
Duty Cycle(max)(%)100Frequency(max)(khz)500
Uvlo Thresholds On/off(v)8.5/7.9Pin/package8SOIC
Vin(min)(v)8.5Vin(max)(v)30
Regulated Outputs(#)1Operating Temperature Range(c)-40 to 125
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CURRENT-MODE PWM CONTROLLER
FEATURES
1
Qualified for Automotive Applications
Extended Temperature Performance of
–40 C to 125 C
Optimized for Off-Line and DC-to-DC
Converters
Low Start-Up Current (<0.5 mA)
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
500-kHz Operation
Low R
Error Amp
O
DESCRIPTION/ORDERING INFORMATION
The UC2843A control IC is a pin-for-pin compatible improved version of the UC2843. Providing the necessary
features to control current mode switched mode power supplies, this device has the following improved features.
Start up current is specified to be less than 0.5 mA. Oscillator discharge is trimmed to 8.3 mA. During
undervoltage lockout, the output stage can sink at least 10 mA at less than 1.2 V for V
PART NUMBER
UC2843A
T
A
–40 C to 125 C
SOIC-8 – D8
(1) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI
web site at www.ti.com.
(2) Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are available at
www.ti.com/sc/package.
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
UVLO ON
UVLO OFF
8.5 V
7.9 V
ORDERING INFORMATION
(2)
PACKAGE
ORDERABLE PART NUMBER
Reel of 2500
UC2843AQD8RQ1
UC2843A-Q1
SGLS384 – MAY 2008
D PACKAGE
(TOP VIEW)
COMP
V
1
8
REF
V
V
2
7
FB
CC
I
OUTPUT
3
6
SENSE
R
/C
GND
4
5
T
T
over 5 V.
CC
MAXIMUM DUTY
CYCLE
<100%
(1)
TOP-SIDE MARKING
UC2843AQ
Copyright © 2008, Texas Instruments Incorporated

UC2843A-Q1 Summary of contents

  • Page 1

    ... Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. UVLO ON UVLO OFF 8.5 V 7.9 V ORDERING INFORMATION (2) PACKAGE ORDERABLE PART NUMBER Reel of 2500 UC2843AQD8RQ1 UC2843A-Q1 SGLS384 – MAY 2008 D PACKAGE (TOP VIEW) COMP REF ...

  • Page 2

    ... Submit Documentation Feedback FUNCTIONAL BLOCK DIAGRAM UVLO 5-V S/R REF V REF Good Logic Current Sense Comparator (1) (2) for additional information on enhanced plastic packaging. Product Folder Link(s): UC2843A-Q1 www.ti.com V REF Internal Bias Output 6 S GND 5 PWM R Latch VALUE ...

  • Page 3

    ... T (min)). V (max) and V REF J J REF . This contributes approximately 300 A of current to the measurement. The total REF ≤ V ≤ 0.8 V. SENSE Product Folder Link(s): UC2843A-Q1 UC2843A-Q1 SGLS384 – MAY 2008 MIN TYP MAX UNIT 4.95 5.0 5. 0.2 ...

  • Page 4

    ... TEST CONDITIONS = 20 mA OUT = 200 mA OUT = –20 mA OUT = –200 mA OUT = OUT = Product Folder Link(s): UC2843A-Q1 www.ti.com MIN TYP MAX UNIT 0.1 0 2 13.5 50 150 ns 50 150 ns 0.7 1.2 V 7.8 8 ...

  • Page 5

    ... CC <17 mA < 0.5 mA Figure 2. Undervoltage Lockout Error Amp COMP 1 Current 3 Sense GND 5 S Figure 3. Current Sense Circuit Product Folder Link(s): UC2843A-Q1 UC2843A-Q1 SGLS384 – MAY 2008 0 OFF ON During UVLO, the output is low Current Sense Comparator Submit Documentation Feedback V CC ...

  • Page 6

    ... Submit Documentation Feedback Error Amplifier Open-Loop Frequency Response Source Sat (V – Product Folder Link(s): UC2843A-Q1 www.ti.com 100 1k 10k 100k 1M 10M Frequency – Hz Figure 5. Copyright © 2008, Texas Instruments Incorporated 0 -45 -90 -135 ...

  • Page 7

    ... Figure 6. Oscillator R T UC2843A COMP REF OUTPUT 3 6 SENSE GND Product Folder Link(s): UC2843A-Q1 UC2843A-Q1 SGLS384 – MAY 2008 Maximum Duty Cycle vs Timing Resistor V REF V CC 0.1 µF 0.1 µ OUTPUT GND Submit Documentation Feedback 7 ...

  • Page 8

    ... W 22 µ USD1120 R13 470 pF Figure 9. Off-Line Flyback Regulator Product Folder Link(s): UC2843A-Q1 www.ti.com (Note 2) (Note 2) USD945 C11 C10 4700 µF 4700 µ USF1002 C12 2200 µF N12 ...

  • Page 9

    ... TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold Customer on an annual basis. OTHER QUALIFIED VERSIONS OF UC2843A-Q1 : Catalog: UC2843A • ...

  • Page 10

    ...

  • Page 11

    ... Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’ ...