UC2842AQ

Manufacturer Part NumberUC2842AQ
ManufacturerTexas Instruments
UC2842AQ datasheet
 


Specifications of UC2842AQ

TopologyBoostControl MethodCurrent
Duty Cycle(max)(%)100Frequency(max)(khz)500
Uvlo Thresholds On/off(v)16/10Pin/package14SOIC, 8SOIC
Regulated Outputs(#)1Operating Temperature Range(c)-40 to 125
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D
Extended Temperature Performance of
–40 C to 125 C
D
Optimized for Off-line and DC to DC
Converters
D
Low Start Up Current (<0.5 mA)
D
Trimmed Oscillator Discharge Current
D
Automatic Feed Forward Compensation
D
Pulse-by-Pulse Current Limiting
D
Enhanced Load Response Characteristics
D
Under-Voltage Lockout With Hysteresis
D
Double Pulse Suppression
D
High Current Totem Pole Output
D
Internally Trimmed Bandgap Reference
D
500 kHz Operation
D
Low R
Error Amp
O
description
The UC2842A/3A/4A/5A family of control ICs is a pin for pin compatible improved version of the UC2842/3/4/5
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 0.5 mA. Oscillator discharge is trimmed
to 8.3 mA. During under voltage lockout, the output stage can sink at least 10 mA at less than 1.2 V for V
5 V.
The difference between members of this family are shown in the table below.
PART NUMBER
UC2842A
UC2843A
UC2844A
UC2845A
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 Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ
CURRENT-MODE PWM CONTROLLER
COMP
I
SENSE
R
COMP
I
SENSE
R
UVLO ON
UVLO OFF
MAXIMUM DUTY CYCLE
16 V
10 V
8.5 V
7.9 V
16 V
10 V
8.5 V
7.9 V
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
SGLS164 – APRIL 2003
D 8-PIN PACKAGE
(TOP VIEW)
V
1
8
REF
V
V
2
7
FB
CC
OUTPUT
3
6
/C
GND
4
5
T
T
D 14-PIN PACKAGE
(TOP VIEW)
V
1
14
REF
NC
NC
2
13
V
V
3
12
FB
CC
NC
V
4
11
C
OUTPUT
5
10
NC
GND
6
9
/C
PWR GND
7
8
T
T
CC
<100%
<100%
<50%
<50%
Copyright
2003, Texas Instruments Incorporated
over
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UC2842AQ Summary of contents

  • Page 1

    ... 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 Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ CURRENT-MODE PWM CONTROLLER COMP I SENSE ...

  • Page 2

    ... UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ CURRENT-MODE PWM CONTROLLER SGLS164 – APRIL 2003 T A SOIC-8 – D8 SOIC-8 – D8 SOIC-14 – D SOIC-14 – D SOIC-8 – D8 SOIC-8 – D8 SOIC-14 – D SOIC-14 – 125 C – 125 C SOIC-8 – D8 SOIC-8 – D8 SOIC-14 – D SOIC-14 – D SOIC-8 – ...

  • Page 3

    ... Ordering Information UC 284 UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ CURRENT-MODE PWM CONTROLLER D R TAPE and REEL INDICATOR PACKAGE D = Plastic SOIC, 14 pin D8 = Plastic SOIC, 8 pin AUTOMOTIVE TEMPERATURE RANGE INDICATOR IMPROVED PERFORMANCE INDICATOR PRODUCT OPTION 2 through 5 POST OFFICE BOX 655303 DALLAS, TEXAS 75265 SGLS164 – APRIL 2003 ...

  • Page 4

    ... UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ CURRENT-MODE PWM CONTROLLER SGLS164 – APRIL 2003 absolute maximum ratings over operating free-air temperature range (unless otherwise noted) V voltage (low impedance source voltage (I mA ...

  • Page 5

    ... Fall time UVLO saturation Undervoltage Lockout Section Start threshold Start threshold Minimum operation voltage after turn on Minimum operation voltage after turn on UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ CURRENT-MODE PWM CONTROLLER = 15 V (see Note 1 TEST CONDITIONS COMP = 2 See Note 2 ...

  • Page 6

    ... UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ CURRENT-MODE PWM CONTROLLER SGLS164 – APRIL 2003 electrical characteristics –40_C to 125_C (unless otherwise stated PARAMETER PWM Section Maximum duty cycle Maximum duty cycle Minimum duty cycle Total Standby Current Start-up current Operating supply current V CC internal zener voltage NOTES: 1 ...

  • Page 7

    ... UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ PARAMETER MEASUREMENT INFORMATION Figure 2. Under Voltage Lockout Peak Current (Is) is Determined By The Formula: Ismax 1. small RC filter may be required to supress switch transients. Figure 3. Current Sense Circuit POST OFFICE BOX 655303 DALLAS, TEXAS 75265 CURRENT-MODE PWM CONTROLLER SGLS164 – APRIL 2003 During UVLO, the Output is low ...

  • Page 8

    ... UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ CURRENT-MODE PWM CONTROLLER SGLS164 – APRIL 2003 PARAMETER MEASUREMENT INFORMATION Output Saturation Characteristics Figure 4 Oscillator Frequency vs Timing Resistance 8 Error Amplifier Open-Loop Frequency Response PLICATION INFORMATION Figure 6. Oscillator POST OFFICE BOX 655303 DALLAS, TEXAS 75265 Figure 5 Maximum Duty Cycle vs Timing Resistor ...

  • Page 9

    ... The transistor and 5k potentiometer are used to sample the oscillator waveform and apply an adjustable ramp to pin 3. Figure 7. Open-Loop Laboratory Text Fixture UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ CURRENT-MODE PWM CONTROLLER APPLICATION INFORMATION A fraction of the oscillator ramp can be resistively summed with the current sense signal to provide slope compensation for converters requiring duty cycles over 50% ...

  • Page 10

    ... UC2842AQ, UC2843AQ, UC2844AQ, UC2845AQ CURRENT-MODE PWM CONTROLLER SGLS164 – APRIL 2003 Power Supply Specifications 1. Input Voltage 2. Line Isolation 3. Switching Frequency 4. Efficiency, Full Load 5. Output Voltage: A. +5V, 5 Load B. +12V, 3%; 0.1A to 0.3A Load Ripple voltage: 100 mV P-P Max C. –12V, 3%; 0.1A to 0.3A Load Ripple voltage: 100 mV P-P Max ...

  • Page 11

    ... PACKAGING INFORMATION Orderable Device (1) Package Type Package Status UC2842AQD ACTIVE SOIC UC2842AQD8 ACTIVE SOIC UC2842AQD8R ACTIVE SOIC UC2842AQDR ACTIVE SOIC UC2843AQD ACTIVE SOIC UC2843AQD8 ACTIVE SOIC UC2843AQD8G4 ACTIVE SOIC UC2843AQD8R ACTIVE SOIC UC2843AQD8RG4 ACTIVE SOIC UC2843AQDR ACTIVE SOIC UC2845AQD ...

  • Page 12

    Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): ...

  • Page 13

    ... TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Type Drawing UC2842AQD8R SOIC UC2843AQD8R SOIC UC2845AQD8R SOIC PACKAGE MATERIALS INFORMATION Pins SPQ Reel Reel Diameter Width (mm) W1 (mm 2500 330.0 12 2500 330.0 12 2500 330.0 12.4 Pack Materials-Page 1 ...

  • Page 14

    ... Device Package Type UC2842AQD8R SOIC UC2843AQD8R SOIC UC2845AQD8R SOIC PACKAGE MATERIALS INFORMATION Package Drawing Pins SPQ Length (mm 2500 D 8 2500 D 8 2500 Pack Materials-Page 2 9-Dec-2010 Width (mm) Height (mm) 367.0 367.0 35.0 367.0 367.0 35.0 367.0 367.0 35.0 ...

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  • Page 19

    ... 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’ ...