Datasheet Texas Instruments UC3843QTR

ManufacturerTexas Instruments
SeriesUC3843
Part NumberUC3843QTR
Datasheet Texas Instruments UC3843QTR

Current-Mode PWM Controller 20-PLCC 0 to 70

Datasheets

UCx84x Current-Mode PWM Controllers datasheet
PDF, 3.8 Mb, Revision: E, File published: Jan 6, 2017
Extract from the document

Prices

Status

Lifecycle StatusObsolete (Manufacturer has discontinued the production of the device)
Manufacture's Sample AvailabilityNo

Packaging

Pin20
Package TypeFN
Industry STD TermPLCC
JEDEC CodeS-PQCC-J
Width (mm)8.96
Length (mm)8.96
Thickness (mm)4.06
Pitch (mm)1.27
Max Height (mm)4.57
Mechanical DataDownload

Parametrics

Approx. Price (US$)0.42 | 1ku
Control MethodPeak Current Mode
Duty Cycle(Max)(%)100
Frequency(Max)(kHz)500
Frequency(Min)(kHz)26
Gate Drive(Typ)(A)1
Operating Temperature Range(C)0 to 70
Package GroupPDIP
SOIC
RatingCatalog
Special FeaturesError Amplifier
Multi-topology
TopologyBoost
Buck
Buck-Boost
Flyback
Forward
UVLO Thresholds On/Off(V)8.4/7.6
Vin(Max)(V)400
Vin(Min)(V)9

Eco Plan

RoHSNot Compliant
Pb FreeNo

Application Notes

  • DN-43 Simple Techniques to Generate a Negative Voltage Bias Supply
    PDF, 38 Kb, File published: Sep 5, 1999
    A low-power negative supply voltage can be developed from a positive input supply using some very common PWM control ICs. Typical applications include generating a -5V to -12V supply for analog function ICs (OP amps), RS-232 communication circuits, and MOSFET or IGBT gate drives at power levels below a few watts. This design note describes a low-power negative output voltage +5 to ?5V inverter usi
  • U-100A UC3842/3/4/5 Provides Low-Cost Current-Mode Control
    PDF, 507 Kb, File published: Sep 5, 1999
    The fundamental challenge of power supply design is to realize simultaneously two conflicting objectives: good electrical performance and low cost. The UC3842/3/4/5 control ICs are integrated pulse-width modulators (PWMs). These inexpensive IC controllers provide all the performance advantages of current-mode operation. In addition the UC3842 series is optimized for efficient power-sequencing of
  • DN-40 The Effects of Oscillator Discharge Current Variations on Maximum Duty
    PDF, 39 Kb, File published: Sep 5, 1999
    This design note details programming frequency and maximum duty cycle using the UC3842 and UC3842-A PWM oscillator ICs. Simplified equations are used to develop obtainable ranges for parameters over IC tolerances.
  • DN-27 UC1842/UC1842A Family - Summary of Functional Differences
    PDF, 21 Kb, File published: Sep 5, 1999
    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 device has been improved for higher frequency off-line power supplies. This new A series of controllers UC1842A/43A/44A/45A is superior to its predecessors in startup current requirements
  • DN-26 UC3842A Low-Cost Start-up and Fault Protection Circuit
    PDF, 155 Kb, File published: Sep 5, 1999
    The UC1842/3/4/5 family of control ICs can implement off-line or DC-to-DC fixed-frequency current-mode control schemes with a minimal external parts count. This design note describes a circuit with low startup current (less than 0.5mA) MOSFET-compatible undervoltage lockout thresholds programmable restart-delay HICCUP fault protection auxiliary 5V precision reference and overvoltage/overtemper
  • DN-65 Considerations in Powering BiCMOS ICs
    PDF, 100 Kb, File published: Sep 5, 1999
    Bipolar linear integrated circuits have been with us for years in the form of PWM and PFC controllers supervisory circuits and other circuits. Since these devices have traditionally used relatively high-voltage (35V) bipolar processes powering was not a concern. In addition many of these ICs contained high-current protection zeners to keep higher voltages from damaging the devices. With a numb
  • Understanding Buck Power Stages In Switchmode Power Supplies
    PDF, 173 Kb, File published: Mar 4, 1999
    A switching power supply consists of the power stage and the control circuit. The power stage performs the basic power conversion from the input voltage to the output voltage and includes switches and the output filter. This report addresses the buck power stage only and does not cover control circuits. Detailed steady-state and small-signal analysis of the buck power stage operating in continuous
  • Understanding Boost Power Stages In Switchmode Power Supplies
    PDF, 149 Kb, File published: Mar 4, 1999
    A switching power supply consists of the power stage and the control circuit. The power stage performs the basic power conversion from the input voltage to the output voltage and includes switches and the output filter. This report addresses the boost power stage only and does not cover control circuits. The report includes detailed steady-stage and small-signal analysis of the boost power stage o
  • UCC38C42 Family of High-Speed BiCMOS Current-Mode PWM Controllers
    PDF, 280 Kb, File published: Feb 7, 2002
    Since their introduction in the mid 1980?s the bipolar UC3842 family of Pulse width modulation (PWM)controllers has grown to become the most widely-used control strategy in the power supply industry. [1] The reasons for success are quite clear the devices feature an elegantly simple yet very effective control architecture they use only 8 pins they can drive MOSFET gates directly and they offer
  • U-111 Practical Considerations in Current Mode Power Supplies
    PDF, 787 Kb, File published: Sep 5, 1999
    This application note explains the numerous PWM functions and ways to maximize their usefulness. It covers practical circuit design considerations such as slope compensation gate drive circuitry external control functions synchronization and paralleling current-mode controlled modules. Circuit diagrams and simplified equations are included.
  • DN-42A Design Considerations for Transitioning from UC3842 to the New UCC3802
    PDF, 42 Kb, File published: Sep 5, 1999
    The UCC3802 offers numerous advantages that allow the power supply design engineer to meet requirements for lower power for battery-operated equipment higher switching frequencies for reduced magnetics size higher levels of circuit integration for improved reliability and lower cost. The UCC3802 family of devices is pin-out compatible with the UC3842 and UC3842A families; however it is not plu
  • Conditioning a Switch-mode Power Supply Current Signal Using TI Op Amps
    PDF, 61 Kb, File published: Mar 23, 2000
    The switch-mode power supply primary current is often sensed using a power resistor. Using an op amp to amplify the current-sense signal can reduce cost and improve noise performance and efficiency. This report reviews the advantages of using an op amp circuit and analyzes the design criteria needed to choose the proper op amp.
  • Understanding Buck-Boost Power Stages in Switchmode Power Supplies (Rev. A)
    PDF, 363 Kb, Revision: A, File published: May 28, 2002

Model Line

Manufacturer's Classification

  • Semiconductors > Power Management > Offline and Isolated DC/DC Controllers and Converters > PWM and Resonant Controller