Overview
The UC3843BD1R2 is a high-performance, fixed-frequency current mode controller produced by onsemi. This integrated circuit is specifically designed for off-line and DC-DC converter applications, offering a cost-effective solution with minimal external components. It features a trimmed oscillator for precise duty cycle control, a temperature-compensated reference, a high-gain error amplifier, a current sensing comparator, and a high-current totem pole output ideal for driving power MOSFETs. The device includes protective features such as input and reference undervoltage lockouts with hysteresis, cycle-by-cycle current limiting, programmable output deadtime, and a latch for single pulse metering.
Key Specifications
| Parameter | Symbol | Value | Unit |
|---|---|---|---|
| Bias and Driver Voltages | VCC, VC | 30 | V |
| Total Power Supply and Zener Current | ICC + IZ | 30 | mA |
| Output Current, Source or Sink | IO | 1.0 | A |
| Output Energy (Capacitive Load per Cycle) | W | 5.0 | mJ |
| Current Sense, Voltage Feedback, Vref and Rt/Ct Inputs | Vin | −0.3 to +5.5 | V |
| Error Amp Output Sink Current | IO | 10 | mA |
| Operating Junction Temperature | TJ | −40 to +105 | °C |
| Operating Ambient Temperature | TA | −40 to +105 | °C |
| Storage Temperature Range | Tstg | −65 to +150 | °C |
| Maximum Power Dissipation @ TA = 25°C | PD | 100 mW (SOIC-8), 862 mW (SOIC-14) | mW |
| Thermal Resistance, Junction-to-Air | RθJA | 145 °C/W (SOIC-8), 100 °C/W (SOIC-14) | °C/W |
Key Features
- Trimmed oscillator for precise duty cycle control
- Temperature-compensated reference
- High-gain error amplifier
- Current sensing comparator
- High-current totem pole output for driving power MOSFETs
- Input and reference undervoltage lockouts with hysteresis
- Cycle-by-cycle current limiting
- Programmable output deadtime
- Latch for single pulse metering
- Available in 8-pin dual-in-line and surface mount (SOIC-8 and SOIC-14) packages
Applications
- Off-line and DC-DC converter applications
- Power supply systems requiring high efficiency and reliability
- Automotive and industrial power conversion systems
- High-performance power management in various electronic devices
Q & A
- What is the UC3843BD1R2 used for?
The UC3843BD1R2 is used in off-line and DC-DC converter applications, providing a cost-effective solution with minimal external components.
- What are the key features of the UC3843BD1R2?
Key features include a trimmed oscillator, temperature-compensated reference, high-gain error amplifier, current sensing comparator, and high-current totem pole output.
- What are the maximum ratings for the UC3843BD1R2?
The maximum ratings include bias and driver voltages up to 30V, total power supply and zener current up to 30mA, and output current up to 1A.
- What is the operating temperature range for the UC3843BD1R2?
The operating ambient temperature range is −40 to +105°C, and the storage temperature range is −65 to +150°C.
- What types of packages are available for the UC3843BD1R2?
The device is available in 8-pin dual-in-line and surface mount (SOIC-8 and SOIC-14) packages.
- What protective features does the UC3843BD1R2 have?
The device includes input and reference undervoltage lockouts with hysteresis, cycle-by-cycle current limiting, programmable output deadtime, and a latch for single pulse metering.
- How is the oscillator frequency programmed in the UC3843BD1R2?
The oscillator frequency is programmed by the values chosen for the timing components RT and CT.
- What is the purpose of the current sensing comparator in the UC3843BD1R2?
The current sensing comparator monitors the inductor current and controls the peak inductor current on a cycle-by-cycle basis.
- Can the UC3843BD1R2 be used in automotive applications?
- What is the thermal resistance of the UC3843BD1R2 in different packages?
The thermal resistance is 145 °C/W for the SOIC-8 package and 100 °C/W for the SOIC-14 package.
