UC2843ADTR
Current-mode PWM controllers for power management in compact SOIC packages
Manufacturer： ['rochester', 'ti', 'unitrode']
series introduction
# Introduction to the UC2843ADTR Product Series
## 1. Overview
The UC2843ADTR is a member of a highly versatile and widely - used integrated circuit product series designed for switch - mode power supply (SMPS) applications. It is a fixed - frequency current - mode PWM controller that offers a comprehensive set of features to simplify the design and enhance the performance of power supply systems.
## 2. Key Features
### 2.1 Fixed - Frequency Operation
The UC2843ADTR operates at a fixed frequency, which is typically set by an external resistor and capacitor. This fixed - frequency characteristic provides stability to the power supply, making it easier to design the associated passive components such as inductors and capacitors. It also helps in reducing electromagnetic interference (EMI) as the switching frequency is well - defined, allowing for more effective filtering.
### 2.2 Current - Mode Control
One of the standout features of this series is the current - mode control scheme. In current - mode control, the inductor current is sensed and used as a control variable in addition to the output voltage. This provides several advantages, including improved line regulation, faster transient response, and inherent peak - current limiting. By directly controlling the inductor current, the UC2843ADTR can quickly respond to changes in the input voltage or load current, ensuring a stable output voltage.
### 2.3 Adjustable Output Voltage
The output voltage of the power supply can be easily adjusted using an external resistor divider network. This flexibility allows designers to tailor the power supply to meet the specific voltage requirements of different applications, whether it's a low - voltage microcontroller power supply or a higher - voltage industrial equipment power source.
### 2.4 Under - Voltage Lockout (UVLO)
The UC2843ADTR is equipped with an under - voltage lockout feature. This ensures that the device does not start operating until the supply voltage reaches a predefined threshold. Once the supply voltage drops below this threshold, the device shuts down, protecting the power supply and the connected load from potential damage due to insufficient power.
### 2.5 Soft - Start Function
A soft - start feature is integrated into the UC2843ADTR. During startup, the duty cycle of the PWM signal gradually increases, which helps in reducing the inrush current. This is particularly important in power supply applications where large inrush currents can cause stress on components and potentially damage them. The soft - start function also helps in preventing overshoots in the output voltage during startup.
### 2.6 Over - Current Protection
The current - mode control mechanism in the UC2843ADTR inherently provides over - current protection. When the inductor current exceeds a certain limit, the PWM duty cycle is reduced or the output is shut off to prevent damage to the power switch and other components in the power supply. This protection feature enhances the reliability of the power supply system.
## 3. Package and Pinout
The UC2843ADTR comes in a small - outline integrated circuit (SOIC) package, which is a surface - mount package. This package is suitable for high - density printed circuit board (PCB) designs, making it ideal for modern electronic devices where space is at a premium.
The pinout of the UC2843ADTR is designed to provide easy access to its various functions. Key pins include the power supply pins (VCC), the ground pin (GND), the feedback pin (FB) for regulating the output voltage, the current - sense input pin (CS) for current - mode control, and the output pin (OUT) that drives the power switch in the SMPS.
## 4. Applications
### 4.1 Consumer Electronics
In consumer electronics such as mobile phone chargers, laptops
Images for reference
14-SOIC
14-TSSOPa
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