Overview
The UC2845AD8TRG4 is a current-mode PWM controller produced by Texas Instruments. This device is part of the UCx84xA family, which is optimized for use in off-line and DC-DC converters. It features a low start-up current of less than 0.5 mA and includes undervoltage lockout (UVLO) protection to ensure controlled operation during power-up and power-down sequences. The UC2845AD8TRG4 is available in various packages, including SOIC, PDIP, and PLCC, making it versatile for different design requirements.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Supply Voltage (VCC) | - | - | 30 | V |
| Output Current (IOUT) | - | - | ±1 A | A |
| Operating Free-Air Temperature | -40 | - | 125 | °C |
| Oscillator Frequency | 47 | 52 | 57 | kHz |
| Reference Voltage (VREF) | 4.95 | 5 | 5.05 | V |
| UVLO Start Threshold | 7.8 | 8.4 | 9 | V |
| UVLO Minimum Operation Voltage | 7 | 7.6 | 8.2 | V |
| Maximum Duty Cycle | - | - | <50% | % |
Key Features
- Optimized for off-line and DC-DC converters
- Low start-up current of less than 0.5 mA
- Undervoltage lockout (UVLO) protection
- Trimmed oscillator discharge current
- Error amplifier with an open-loop gain of 80 dB
- Current sense input for peak current limiting
- High output drive capability
- Thermal shutdown protection
Applications
The UC2845AD8TRG4 is suitable for a variety of power supply applications, including:
- Off-line power supplies
- DC-DC converters
- Switch-mode power supplies
- High-efficiency power conversion systems
Q & A
- What is the typical start-up current of the UC2845AD8TRG4?
The typical start-up current is less than 0.5 mA.
- What is the operating temperature range for the UC2845AD8TRG4?
The operating temperature range is from -40°C to 125°C.
- What is the UVLO start threshold for the UC2845AD8TRG4?
The UVLO start threshold is between 7.8 V and 9 V.
- What is the maximum duty cycle for the UC2845AD8TRG4?
The maximum duty cycle is less than 50%.
- What is the oscillator frequency range for the UC2845AD8TRG4?
The oscillator frequency range is between 47 kHz and 57 kHz.
- What is the reference voltage (VREF) for the UC2845AD8TRG4?
The reference voltage (VREF) is between 4.95 V and 5.05 V.
- Does the UC2845AD8TRG4 have thermal shutdown protection?
Yes, the UC2845AD8TRG4 includes thermal shutdown protection.
- What are the common applications for the UC2845AD8TRG4?
Common applications include off-line power supplies, DC-DC converters, and switch-mode power supplies.
- What is the error amplifier's open-loop gain?
The error amplifier has an open-loop gain of 80 dB.
- Can the UC2845AD8TRG4 be used in high-efficiency power conversion systems?
Yes, the UC2845AD8TRG4 is suitable for high-efficiency power conversion systems.
