UC3845J
  • Share:

Unitrode UC3845J

Manufacturer No:
UC3845J
Manufacturer:
Unitrode
Package:
Bulk
Description:
UC3845 CURRENT MODE PWM CONTROLL
Delivery:
Payment:
iso14001
iso45001
iso9001
iso13485

Product Introduction

Overview

The UC3845J is a current-mode PWM (Pulse Width Modulation) controller integrated circuit produced by Unitrode, now part of Texas Instruments. This component is specifically designed for off-line and DC-to-DC converter applications, requiring minimal external components. It features a trimmed oscillator for precise duty cycle control, a temperature-compensated reference, a high-gain error amplifier, and a current sensing comparator. The UC3845J is widely used in power supply systems due to its robust and efficient design.

Key Specifications

Parameter Symbol Value Unit
Supply Voltage VCC 30 V
Output Current IO ±1 A
Analog Inputs (Pin 2, 3) V(ANA) -0.3 to 6.3 V
Error Amp Output Sink Current ISINK (E.A) 10 mA
Power Dissipation at TA≤25°C (8DIP) PD 1200 mW
Storage Temperature Range TSTG -65 ~ +150 °C
Oscillation Frequency f 47 to 57 kHz
Maximum Duty Cycle D(Max) 47 to 50% %
Start-Up Current IST 0.45 to 1 mA
Operating Supply Current ICC(OPR) 14 to 17 mA

Key Features

  • Trimmed oscillator for precise duty cycle control
  • Temperature-compensated reference
  • High-gain error amplifier
  • Current sensing comparator
  • High current totem-pole output for driving a Power MOSFET
  • Low start-up current
  • Maximum duty cycle clamp
  • Under-voltage lockout (UVLO) with hysteresis
  • Operating frequency up to 500 kHz

Applications

The UC3845J is primarily used in off-line and DC-to-DC converter applications. It is suitable for a variety of power supply systems, including:

  • Switch-mode power supplies
  • DC-to-DC converters
  • High-frequency power supplies
  • Power factor correction circuits

Q & A

  1. What is the primary function of the UC3845J?

    The UC3845J is a current-mode PWM controller designed for off-line and DC-to-DC converter applications.

  2. What is the maximum supply voltage for the UC3845J?

    The maximum supply voltage is 30V.

  3. What is the typical operating frequency range of the UC3845J?

    The typical operating frequency range is 47 to 57 kHz.

  4. Does the UC3845J have under-voltage lockout (UVLO) protection?
  5. What is the maximum duty cycle for the UC3845J?

    The maximum duty cycle is 47 to 50%.

  6. What type of output does the UC3845J have?

    The UC3845J has a high current totem-pole output for driving a Power MOSFET.

  7. What are the typical start-up and operating supply currents for the UC3845J?

    The start-up current is 0.45 to 1 mA, and the operating supply current is 14 to 17 mA.

  8. What is the storage temperature range for the UC3845J?

    The storage temperature range is -65°C to +150°C.

  9. Can the UC3845J operate at 100% duty cycle?

    No, the UC3845J can operate with a maximum duty cycle of 50%.

  10. What are some common applications of the UC3845J?

    Common applications include switch-mode power supplies, DC-to-DC converters, high-frequency power supplies, and power factor correction circuits.

Product Attributes

Output Type:Transistor Driver
Function:Step-Up, Step-Down, Step-Up/Step-Down
Output Configuration:Positive
Topology:- 
Number of Outputs:1
Output Phases:1
Voltage - Supply (Vcc/Vdd):12V ~ 28V
Frequency - Switching:100kHz
Duty Cycle (Max):48%
Synchronous Rectifier:No
Clock Sync:No
Serial Interfaces:- 
Control Features:Frequency Control
Operating Temperature:0°C ~ 70°C (TA)
Mounting Type:Through Hole
Package / Case:8-CDIP (0.300", 7.62mm)
Supplier Device Package:8-CDIP
0 Remaining View Similar

In Stock

-
360

Please send RFQ , we will respond immediately.

Same Series
DD15S20LV50/AA
DD15S20LV50/AA
CONN D-SUB HD RCPT 15P SLDR CUP
CBC46W4S10G0X/AA
CBC46W4S10G0X/AA
CONN D-SUB RCPT 46POS CRIMP
DD15S20WT2S/AA
DD15S20WT2S/AA
CONN D-SUB HD RCPT 15P SLDR CUP
DD15S20Z00/AA
DD15S20Z00/AA
CONN D-SUB HD RCPT 15P SLDR CUP
PCD50M98S0T2X
PCD50M98S0T2X
DSUB 50M STR CONTACT J/S TIN
CBC13W3S10HE3S/AA
CBC13W3S10HE3S/AA
CONN D-SUB RCPT 13POS CRIMP
DD26S2S0V3X/AA
DD26S2S0V3X/AA
CONN D-SUB HD RCPT 26P SLDR CUP
DD26S2S50V3X/AA
DD26S2S50V3X/AA
CONN D-SUB HD RCPT 26P SLDR CUP
DD26S20WTX
DD26S20WTX
CONN D-SUB HD RCPT 26P SLDR CUP
DD26S20WE30
DD26S20WE30
CONN D-SUB HD RCPT 26P SLDR CUP
DD26S20WT0
DD26S20WT0
CONN D-SUB HD RCPT 26P SLDR CUP
DD26S20L0X
DD26S20L0X
CONN D-SUB HD RCPT 26P SLDR CUP

Similar Products

Part Number UC3845J UC3846J UC3845N UC3843J UC3844J UC3845D
Manufacturer Unitrode Texas Instruments Texas Instruments Unitrode Texas Instruments Fairchild Semiconductor
Product Status Active Active Active Active Active Obsolete
Output Type Transistor Driver Transistor Driver Transistor Driver Transistor Driver Transistor Driver Transistor Driver
Function Step-Up, Step-Down, Step-Up/Step-Down Step-Up, Step-Up/Step-Down Step-Up, Step-Down, Step-Up/Step-Down Step-Up, Step-Down, Step-Up/Step-Down Step-Up, Step-Down, Step-Up/Step-Down Step-Up, Step-Down, Step-Up/Step-Down
Output Configuration Positive Positive Positive, Isolation Capable Positive, Isolation Capable Positive, Isolation Capable Positive or Negative, Isolation Capable
Topology - Boost, Flyback, Forward Converter, Half-Bridge, Push-Pull Boost, Buck, Buck-Boost, Flyback, Forward Boost, Buck, Buck-Boost, Flyback, Forward Boost, Buck, Buck-Boost, Flyback, Forward Boost, Buck, Buck-Boost, Flyback, Forward
Number of Outputs 1 2 1 1 1 1
Output Phases 1 1 1 1 1 1
Voltage - Supply (Vcc/Vdd) 12V ~ 28V 6.95V ~ 40V 12V ~ 28V 12V ~ 28V 12V ~ 28V 7.6V ~ 30V
Frequency - Switching 100kHz 500kHz Up to 500kHz Up to 500kHz Up to 500kHz Up to 500kHz
Duty Cycle (Max) 48% 50% 48% 97% 48% 48%
Synchronous Rectifier No Yes No No No No
Clock Sync No Yes No No No No
Serial Interfaces - - - - - -
Control Features Frequency Control Current Limit, Enable, Frequency Control, Soft Start Frequency Control Frequency Control Frequency Control Frequency Control
Operating Temperature 0°C ~ 70°C (TA) 0°C ~ 70°C (TA) 0°C ~ 70°C (TA) 0°C ~ 70°C (TA) 0°C ~ 70°C (TA) 0°C ~ 70°C (TA)
Mounting Type Through Hole Through Hole Through Hole Through Hole Through Hole Surface Mount
Package / Case 8-CDIP (0.300", 7.62mm) 16-CDIP (0.300", 7.62mm) 8-DIP (0.300", 7.62mm) 8-CDIP (0.300", 7.62mm) 8-CDIP (0.300", 7.62mm) 14-SOIC (0.154", 3.90mm Width)
Supplier Device Package 8-CDIP 16-CDIP 8-PDIP 8-CDIP 8-CDIP 14-SOIC

Related Product By Categories

UC2856N
UC2856N
Unitrode
UC2856 IMPROVED CURRENT MODE PWM
LM3489MM
LM3489MM
Texas Instruments
IC REG CTRLR BUCK 8VSSOP
TL5001AQDRG4Q1
TL5001AQDRG4Q1
Texas Instruments
IC REG CTRLR BCK/BST/FLYBK 8SOIC
UC3842BD1013TR
UC3842BD1013TR
STMicroelectronics
IC REG CTRLR BST FLYBK ISO 8SOIC
NCV887100D1R2G
NCV887100D1R2G
onsemi
IC REG CTRLR BOOST/FLYBACK 8SOIC
TPS40210DGQ
TPS40210DGQ
Texas Instruments
IC REG CTRLR MULT TOP 10MSOP
TL5001CPS-P
TL5001CPS-P
Texas Instruments
CATALOG PART WITH CUSTOM BRAND
LM5117PSQE/NOPB
LM5117PSQE/NOPB
Texas Instruments
IC REG CTRLR BUCK 24WQFN
LM5117QPMH/NOPB
LM5117QPMH/NOPB
Texas Instruments
IC REG CTRLR BUCK 20TSSOP
UC3844BD
UC3844BD
onsemi
IC REG CTRLR PWM CM 14-SOIC
UC3844BVD1R2
UC3844BVD1R2
onsemi
IC REG CTRLR PWM CM 8-SOIC
TL5001CPSR/1
TL5001CPSR/1
Texas Instruments
IC REG CTRLR BCK/BOOST/FLYBK 8SO

Related Product By Brand

UCC3889NG4
UCC3889NG4
Unitrode
IC OFFLINE SWITCH FLYBACK 8DIP
UC3770BNG4
UC3770BNG4
Unitrode
IC BRIDGE DRIVER PAR 16DIP
UCC27424PE4
UCC27424PE4
Unitrode
IC MOSFET DRIVR DUAL HS 4A 8DIP
UCC28513DWR
UCC28513DWR
Unitrode
UCC28513 ADVANCED PFC/PWM COMBIN
UCC2946PWG4
UCC2946PWG4
Unitrode
IC SUPERVISOR 1 CHANNEL 8TSSOP
UC2843NNTR
UC2843NNTR
Unitrode
UC2843 SWITCHING CONTROLLER
UC1842J883B
UC1842J883B
Unitrode
SWITCHING CONTROLLER, CURRENT-MO
UCC28C42DGK
UCC28C42DGK
Unitrode
UCC28C42 BICMOS LOW CURRENT 8 PI
UCC28C45P
UCC28C45P
Unitrode
UCC28C45 BICMOS LOW-POWER CURREN
UC2825DW/81051
UC2825DW/81051
Unitrode
UC2825 SWITCHING CONTROLLER
UC1524AJ/80839
UC1524AJ/80839
Unitrode
UC1524AJ PWM CONTROLLER
UC3845ANG4
UC3845ANG4
Unitrode
UC3845A CURRENT MODE PWM CONTROL