Specifications
| Attribute | Value |
| Package | Tube |
| ProductStatus | Obsolete |
| OutputType | Transistor Driver |
| Function | Step-Up, Step-Up/Step-Down |
| OutputConfiguration | Positive, Isolation Capable |
| Topology | Boost, Flyback |
| NumberofOutputs | 1 |
| OutputPhases | 1 |
| Voltage-Supply(Vcc/Vdd) | 7.6V ~ 30V |
| Frequency-Switching | Up to 500kHz |
| DutyCycle(Max) | 96% |
| SynchronousRectifier | No |
| ClockSync | No |
| ControlFeatures | Frequency Control |
| OperatingTemperature | 0°C ~ 70°C (TA) |
| MountingType | Through Hole |
| Package/Case | 8-DIP (0.300, 7.62mm) |
Overview
Description
The UC3843BN is a high-performance current-mode PWM controller typically used in DC-DC converters and offline power supplies. It features a fixed operating frequency, high-speed oscillator, and a wide input voltage range, which make it versatile for various applications. The device provides efficient power management by allowing precise control of power levels and minimizing standby power consumption.
Key features include an output drive capability for MOSFETs, low start-up current, and built-in protection mechanisms such as overcurrent protection, undervoltage lockout, and thermal shutdown. The UC3843BN operates at a fixed frequency set by an external resistor and capacitor, allowing for customizable operation depending on the application requirements.
This controller is especially popular in applications requiring high efficiency and compact size, such as battery chargers, industrial power supplies, and consumer electronics. Its robust design and ease of use make it a reliable choice for engineers working on switching power supply designs.
Key features include an output drive capability for MOSFETs, low start-up current, and built-in protection mechanisms such as overcurrent protection, undervoltage lockout, and thermal shutdown. The UC3843BN operates at a fixed frequency set by an external resistor and capacitor, allowing for customizable operation depending on the application requirements.
This controller is especially popular in applications requiring high efficiency and compact size, such as battery chargers, industrial power supplies, and consumer electronics. Its robust design and ease of use make it a reliable choice for engineers working on switching power supply designs.
Equivalent
The UC3843BN is a current-mode PWM controller commonly used in power supply applications. Equivalent products include:
1. UC3842/UC3844 (varying duty cycle)
2. NCP3843 (functionally similar from ON Semiconductor)
3. MC3843 (Motorola/Freescale's variant)
4. LM3843 (from Texas Instruments)
5. KA3843 (from Fairchild/ON Semiconductor)
These alternatives provide similar functionality and can be used in similar applications, but always verify pin compatibility and exact specifications before substituting.
1. UC3842/UC3844 (varying duty cycle)
2. NCP3843 (functionally similar from ON Semiconductor)
3. MC3843 (Motorola/Freescale's variant)
4. LM3843 (from Texas Instruments)
5. KA3843 (from Fairchild/ON Semiconductor)
These alternatives provide similar functionality and can be used in similar applications, but always verify pin compatibility and exact specifications before substituting.
Features
The UC3843BN is a high-performance current mode PWM controller commonly used in off-line and DC-to-DC converter applications. Key features include:
1. Wide Input Voltage Range: Operates over a broad range of voltages, enhancing its versatility in various applications.
2. Low Start-up Current: Minimizes power consumption during start-up, improving efficiency.
3. High Gain Current Amplifier: Provides precise control over output current, ensuring stable performance.
4. Under-Voltage Lockout (UVLO): Protects the system by shutting down the device if the input voltage falls below a specified threshold.
5. Totem-Pole Output: Ensures fast switching speeds and reduces switching losses.
6. Internal Oscillator: Offers a programmable frequency, typically up to 500 kHz, allowing for design flexibility.
7. Soft Start Capability: Gradually increases the output to prevent current spikes during power-up.
8. Error Amplifier: Provides feedback signal processing to maintain accurate output voltage.
These features make the UC3843BN suitable for a wide range of power supply applications, including power adapters, battery chargers, and LED drivers.
1. Wide Input Voltage Range: Operates over a broad range of voltages, enhancing its versatility in various applications.
2. Low Start-up Current: Minimizes power consumption during start-up, improving efficiency.
3. High Gain Current Amplifier: Provides precise control over output current, ensuring stable performance.
4. Under-Voltage Lockout (UVLO): Protects the system by shutting down the device if the input voltage falls below a specified threshold.
5. Totem-Pole Output: Ensures fast switching speeds and reduces switching losses.
6. Internal Oscillator: Offers a programmable frequency, typically up to 500 kHz, allowing for design flexibility.
7. Soft Start Capability: Gradually increases the output to prevent current spikes during power-up.
8. Error Amplifier: Provides feedback signal processing to maintain accurate output voltage.
These features make the UC3843BN suitable for a wide range of power supply applications, including power adapters, battery chargers, and LED drivers.
Pinout
The UC3843BN is a fixed-frequency current-mode PWM controller commonly used in power supply circuits. It has an 8-pin configuration with the following pin functions:
1. Compensation (COMP): Allows for the performance of the control loop to be fine-tuned with external components.
2. Voltage Feedback (VFB): Receives the voltage feedback signal to regulate the output voltage.
3. Current Sense (CS): Monitors the current through a resistor and provides input for overcurrent protection.
4. RT/CT: Sets the oscillator frequency by connecting a resistor (RT) and capacitor (CT) to this pin.
5. Ground (GND): The common return for the power and signal of the IC.
6. Output (OUTPUT): Drives the gate of the power transistor to control the switching.
7. VCC: Supplies the power to the IC.
8. VREF: Provides a stable 5V reference voltage output for the IC's internal circuitry.
This IC is ideal for off-line and DC-to-DC converter applications due to its robust performance and control capabilities.
1. Compensation (COMP): Allows for the performance of the control loop to be fine-tuned with external components.
2. Voltage Feedback (VFB): Receives the voltage feedback signal to regulate the output voltage.
3. Current Sense (CS): Monitors the current through a resistor and provides input for overcurrent protection.
4. RT/CT: Sets the oscillator frequency by connecting a resistor (RT) and capacitor (CT) to this pin.
5. Ground (GND): The common return for the power and signal of the IC.
6. Output (OUTPUT): Drives the gate of the power transistor to control the switching.
7. VCC: Supplies the power to the IC.
8. VREF: Provides a stable 5V reference voltage output for the IC's internal circuitry.
This IC is ideal for off-line and DC-to-DC converter applications due to its robust performance and control capabilities.
Manufacturer
The UC3843BN is manufactured by Texas Instruments (TI). Texas Instruments is a technology company known for designing and manufacturing semiconductors and various integrated circuits, which are widely used in electronic devices across multiple industries. TI is a significant player in the electronics sector, providing solutions that include chips for power management, signal processing, and microcontrollers, among others. The company is headquartered in Dallas, Texas, and is recognized for its contributions to advancing electronic technology and innovation.
Application
The UC3843BN is a high-performance fixed-frequency current-mode PWM controller commonly used in power supply applications. Its primary application areas include:
1. Switch-Mode Power Supplies (SMPS): Ideal for AC/DC and DC/DC converters, providing efficient power conversion.
2. Battery Chargers: Used in both standalone and integrated charging systems for managing power efficiently.
3. LED Drivers: Suitable for driving LED lighting systems with precise current control.
4. Motor Control: Utilized in small motor control applications due to its ability to manage power effectively and maintain efficiency.
5. Telecommunications Equipment: Powers various devices requiring stable and efficient power management solutions.
The UC3843BN's robust design and versatility make it suitable for a wide range of applications requiring reliable power control and efficiency.
1. Switch-Mode Power Supplies (SMPS): Ideal for AC/DC and DC/DC converters, providing efficient power conversion.
2. Battery Chargers: Used in both standalone and integrated charging systems for managing power efficiently.
3. LED Drivers: Suitable for driving LED lighting systems with precise current control.
4. Motor Control: Utilized in small motor control applications due to its ability to manage power effectively and maintain efficiency.
5. Telecommunications Equipment: Powers various devices requiring stable and efficient power management solutions.
The UC3843BN's robust design and versatility make it suitable for a wide range of applications requiring reliable power control and efficiency.
Package
The UC3843BN is a high-performance current-mode PWM controller typically used in power supply applications. It is available in an 8-pin DIP (Dual In-line Package) package type.
