Overview
The UC3845ADM, produced by Microsemi Corporation, is a high-performance current mode PWM (Pulse Width Modulation) controller. This integrated circuit is specifically designed for off-line and DC-DC converter applications, offering a cost-effective solution with minimal external components. The UC3845ADM is part of the UC3844B and UC3845B series, known for their fixed frequency operation and robust protective features.
Key Specifications
| Parameter | Value |
|---|---|
| Manufacturer | Microsemi Corporation |
| Package Type | 8-Pin SOIC |
| Switching Frequency | 500 kHz |
| Supply Voltage Range | 7.6 V to 30 V |
| Output Current | Up to 1 A |
| Operating Temperature | 0°C to 70°C |
| UVLO (Undervoltage Lockout) | 8.4 V / 7.6 V |
| Duty Cycle | Up to 50% |
| RoHS Compliance | Yes |
Key Features
- Fixed frequency operation
- Current mode control with cycle-by-cycle current limiting
- Temperature compensated reference
- High gain error amplifier
- Current sensing comparator and PWM latch
- Protective features including input and reference undervoltage lockouts, and output deadtime programming
- High current totem pole output for driving power MOSFETs
Applications
The UC3845ADM is suitable for a variety of power conversion applications, including:
- Off-line power supplies
- DC-DC converters
- Step-up and step-down converters
- Synchronous rectifier applications
Q & A
- What is the switching frequency of the UC3845ADM?
The switching frequency of the UC3845ADM is 500 kHz. - What is the supply voltage range for the UC3845ADM?
The supply voltage range is from 7.6 V to 30 V. - What is the maximum output current of the UC3845ADM?
The maximum output current is up to 1 A. - What are the operating temperature ranges for the UC3845ADM?
The operating temperature range is from 0°C to 70°C. - Does the UC3845ADM have undervoltage lockout (UVLO) protection?
Yes, it has UVLO protection with thresholds of 8.4 V and 7.6 V. - What type of package does the UC3845ADM come in?
The UC3845ADM comes in an 8-Pin SOIC package. - Is the UC3845ADM RoHS compliant?
Yes, the UC3845ADM is RoHS compliant. - What are some key protective features of the UC3845ADM?
The key protective features include input and reference undervoltage lockouts, cycle-by-cycle current limiting, and output deadtime programming. - What types of converters can the UC3845ADM be used in?
The UC3845ADM can be used in off-line power supplies, DC-DC converters, step-up and step-down converters, and synchronous rectifier applications. - How does the UC3845ADM control the output switch conduction?
The output switch conduction is initiated by the oscillator and terminated when the peak inductor current reaches the threshold level established by the error amplifier output.
