Overview
The UC3845BD1R2G is a high-performance fixed frequency current mode controller produced by onsemi. It is part of the UC3844B and UC3845B series, designed specifically for off-line and dc-to-dc converter applications. These integrated circuits offer a cost-effective solution with minimal external components, making them ideal for a variety of power management needs.
The device features an oscillator, a temperature-compensated reference, a high-gain error amplifier, a current sensing comparator, and a high current totem pole output. This configuration is well-suited for driving power MOSFETs and includes protective features such as input and reference undervoltage lockouts, cycle-by-cycle current limiting, and adjustable output deadtimes.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Oscillator Frequency | 250 kHz | kHz |
| Output Switching Frequency | Up to 500 kHz | kHz |
| Output Deadtime Adjustable | 50% to 70% | % |
| Undervoltage Lockout (UVLO) Thresholds | 8.5 V (on), 7.6 V (off) | V |
| Maximum Power Supply Voltage | 36 V | V |
| Output Current (Source or Sink) | 1.0 A | A |
| Operating Ambient Temperature | 0 to +70°C | °C |
| Package Type | SOIC-8 |
Key Features
- Trimmed Oscillator for Precise Frequency Control
- Current Mode Operation to 500 kHz Output Switching Frequency
- Output Deadtime Adjustable from 50% to 70%
- Automatic Feed Forward Compensation
- Latching PWM for Cycle-By-Cycle Current Limiting
- Internally Trimmed Reference with Undervoltage Lockout
- High Current Totem Pole Output
- Undervoltage Lockout with Hysteresis
- Low Startup and Operating Current
- Pb-Free Packages are Available and RoHS Compliant
Applications
The UC3845BD1R2G is designed for various power management applications, including:
- Off-line converters
- Dc-to-dc converters
- Power supplies requiring high efficiency and reliability
- Switch-mode power supplies
- Other applications requiring precise current mode control
Q & A
- What is the primary function of the UC3845BD1R2G?
The UC3845BD1R2G is a high-performance fixed frequency current mode controller designed for off-line and dc-to-dc converter applications.
- What is the oscillator frequency of the UC3845BD1R2G?
The oscillator frequency is guaranteed at 250 kHz.
- What is the maximum output switching frequency of the UC3845BD1R2G?
The maximum output switching frequency is up to 500 kHz.
- What are the undervoltage lockout (UVLO) thresholds for the UC3845BD1R2G?
The UVLO thresholds are 8.5 V (on) and 7.6 V (off).
- What is the maximum power supply voltage for the UC3845BD1R2G?
The maximum power supply voltage is 36 V.
- What is the output current capability of the UC3845BD1R2G?
The output current capability is 1.0 A (source or sink).
- What are the operating temperature ranges for the UC3845BD1R2G?
The operating ambient temperature range is 0 to +70°C.
- In what package types is the UC3845BD1R2G available?
The UC3845BD1R2G is available in SOIC-8 and SOIC-14 packages.
- Does the UC3845BD1R2G have protective features?
Yes, it includes protective features such as input and reference undervoltage lockouts, cycle-by-cycle current limiting, and adjustable output deadtimes.
- Is the UC3845BD1R2G Pb-free and RoHS compliant?
Yes, the UC3845BD1R2G is Pb-free and RoHS compliant.
