Specifications
| Attribute | Value |
| Package / Case | Tape & Reel (TR),Cut Tape (CT),Bulk |
| Part Status | Active |
| Output Type | Transistor Driver |
| Function | Step-Up, Step-Down, Step-Up/Step-Down |
| Output Configuration | Positive, Isolation Capable |
| Topology | Boost, Buck, Flyback, Forward |
| Number of Outputs | 1 |
| Output Phases | 1 |
| Voltage - Supply (Vcc/Vdd) | 7.6V ~ 30V |
| Frequency - Switching | Up to 500kHz |
| Duty Cycle(Max) | 48% |
| Synchronous Rectifier | No |
| Clock Sync | No |
| Control Features | Frequency Control |
| Operating Temperature | 0°C ~ 70°C (TA) |
| Mounting Type | Surface Mount |
Overview
Description
The UC3845AD8TR is a high-performance, fixed-frequency, current-mode Pulse Width Modulation (PWM) controller integrated circuit. It is widely used in power supply applications to regulate voltage and current precisely. The "UC3845" is part of the UC384x family, with each variant offering different features tailored for specific applications.
Key features of the UC3845AD8TR include operating frequency up to 500 kHz, low start-up current, and high current output drive capability, making it suitable for driving power MOSFETs and IGBTs. The device operates at a fixed duty cycle and includes protection features such as overcurrent protection, undervoltage lockout, and thermal shutdown.
The "D8TR" denotes the specific package type and tape-and-reel packaging, indicating it comes in an 8-pin SOIC surface-mount package, ideal for compact PCB layouts. The UC3845AD8TR is commonly used in switched-mode power supplies (SMPS), DC-DC converters, and motor control applications, providing efficient power conversion and regulation.
Key features of the UC3845AD8TR include operating frequency up to 500 kHz, low start-up current, and high current output drive capability, making it suitable for driving power MOSFETs and IGBTs. The device operates at a fixed duty cycle and includes protection features such as overcurrent protection, undervoltage lockout, and thermal shutdown.
The "D8TR" denotes the specific package type and tape-and-reel packaging, indicating it comes in an 8-pin SOIC surface-mount package, ideal for compact PCB layouts. The UC3845AD8TR is commonly used in switched-mode power supplies (SMPS), DC-DC converters, and motor control applications, providing efficient power conversion and regulation.
Equivalent
The UC3845AD8TR is a high-performance current-mode PWM controller. Equivalent products include the SG1845, UC3842, UC3844, and TL3845. These components offer similar functionality for power supply applications, with attention to variations in operating frequency, current sense, and duty cycle limitations, so always check datasheets for compatibility in your specific application.
Features
The UC3845AD8TR is a high-performance current-mode PWM controller designed for off-line and DC-to-DC converter applications. Key features include:
1. High Performance: It operates at up to 500 kHz with low start-up and operating currents, making it suitable for efficient power supply designs.
2. Current-Mode Control: Provides inherent cycle-by-cycle current limiting, improved transient response, and simplified loop compensation.
3. Precision Reference: It has a trimmed oscillator for precise duty cycle control and an accurate internal reference voltage, ensuring stable operation.
4. Undervoltage Lockout (UVLO): Ensures the device remains off until the input voltage reaches a specified level, preventing erroneous operation at low voltages.
5. Short-Circuit Protection: Inherent protection against short circuits through cycle-by-cycle current limiting.
6. Soft Start Capability: Gradual increase in output voltage, minimizing inrush current at startup.
7. Package: Available in an 8-pin SOIC package, ensuring compact design and easy integration onto PCBs.
These features make the UC3845AD8TR a robust choice for power supply designs, offering reliability and efficiency.
1. High Performance: It operates at up to 500 kHz with low start-up and operating currents, making it suitable for efficient power supply designs.
2. Current-Mode Control: Provides inherent cycle-by-cycle current limiting, improved transient response, and simplified loop compensation.
3. Precision Reference: It has a trimmed oscillator for precise duty cycle control and an accurate internal reference voltage, ensuring stable operation.
4. Undervoltage Lockout (UVLO): Ensures the device remains off until the input voltage reaches a specified level, preventing erroneous operation at low voltages.
5. Short-Circuit Protection: Inherent protection against short circuits through cycle-by-cycle current limiting.
6. Soft Start Capability: Gradual increase in output voltage, minimizing inrush current at startup.
7. Package: Available in an 8-pin SOIC package, ensuring compact design and easy integration onto PCBs.
These features make the UC3845AD8TR a robust choice for power supply designs, offering reliability and efficiency.
Pinout
The UC3845AD8TR is a high-performance fixed-frequency current-mode PWM controller used primarily in off-line and DC-to-DC converter applications. It typically comes in an 8-pin package. Below is a brief overview of its pin count and functions:
1. Pin 1 (Compensation): Used for compensating the control loop to ensure system stability.
2. Pin 2 (Voltage Feedback): Receives the voltage feedback from the output to regulate the output voltage.
3. Pin 3 (Current Sense): Monitors the current through the power switch to provide over-current protection.
4. Pin 4 (RT/CT): Sets the oscillator frequency with an external resistor and capacitor.
5. Pin 5 (Ground): The ground reference point for the device.
6. Pin 6 (Output): Outputs the PWM signal to drive the power switch.
7. Pin 7 (VCC): Supplies the power to the IC.
8. Pin 8 (VREF): Provides a reference voltage output, typically 5V, to power other circuits in the system.
This IC is valued for its efficiency and reliability in power supply applications.
1. Pin 1 (Compensation): Used for compensating the control loop to ensure system stability.
2. Pin 2 (Voltage Feedback): Receives the voltage feedback from the output to regulate the output voltage.
3. Pin 3 (Current Sense): Monitors the current through the power switch to provide over-current protection.
4. Pin 4 (RT/CT): Sets the oscillator frequency with an external resistor and capacitor.
5. Pin 5 (Ground): The ground reference point for the device.
6. Pin 6 (Output): Outputs the PWM signal to drive the power switch.
7. Pin 7 (VCC): Supplies the power to the IC.
8. Pin 8 (VREF): Provides a reference voltage output, typically 5V, to power other circuits in the system.
This IC is valued for its efficiency and reliability in power supply applications.
Manufacturer
The UC3845AD8TR is manufactured by Texas Instruments (TI), a global semiconductor company. Texas Instruments specializes in the design and production of a wide range of electronic components and solutions, including analog and embedded processing products. The company is known for its innovations in the semiconductor industry and provides solutions that play a crucial role in modern electronics, touching various markets such as automotive, industrial, personal electronics, communications equipment, and enterprise systems. Their products are integral to the functioning of numerous electronic devices, making TI a pivotal player in advancing technology across different sectors.
Application
The UC3845AD8TR is a high-performance current-mode PWM controller typically used in power supply applications. Its application areas include switch-mode power supplies (SMPS), DC-DC converters, and off-line flyback converters. The device is well-suited for applications requiring high efficiency and precise control, such as industrial power supplies, battery chargers, and consumer electronics. Its features make it ideal for designs requiring low standby power and high-frequency operation, often found in lighting ballast controls and photovoltaic inverters.
Package
The UC3845AD8TR is a high-performance fixed-frequency current-mode PWM controller designed for off-line and DC-to-DC converter applications. It is typically packaged in an 8-pin SOIC (Small Outline Integrated Circuit), ideal for surface-mount technology applications.
