Overview
The UC3842BDR2 is a high-performance fixed frequency current mode controller produced by onsemi. It is specifically designed for off-line and DC-DC converter applications, offering a cost-effective solution with minimal external components. This integrated circuit 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 suitable for driving a power MOSFET.
Key Specifications
| Characteristic | Symbol | Min | Typ | Max | 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 | μJ |
| Reference Output Voltage (IO = 1.0 mA, TJ = 25°C) | Vref | 4.95 | 5.0 | 5.05 | V |
| Line Regulation (VCC = 12 V to 25 V) | Regline | - | - | 2.0 | mV |
| Load Regulation (IO = 1.0 mA to 20 mA) | Regload | - | - | 3.0 | mV |
| Temperature Stability | TS | - | - | 0.2 | mV/°C |
| Output Voltage Low State (ISink = 20 mA) | VOL | - | - | 1.1 | V |
| Output Voltage High State (ISource = 20 mA) | VOH | - | - | 6.2 | V |
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
- Protective features including input and reference undervoltage lockouts with hysteresis, cycle-by-cycle current limiting, programmable output deadtime, and a latch for single pulse metering
- Available in 8-pin dual-in-line and surface mount (SOIC-8) packages, as well as 14-pin surface mount (SOIC-14) package with separate power and ground connections
Applications
- Off-line converters
- DC-DC converters
- Power supply systems requiring high efficiency and reliability
- Switch-mode power supplies
- High-performance power management systems
Q & A
- What is the primary function of the UC3842BDR2?
The UC3842BDR2 is a high-performance fixed frequency current mode controller designed for off-line and DC-DC converter applications.
- What are the key protective features of the UC3842BDR2?
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.
- What is the maximum output current of the UC3842BDR2?
The maximum output current is 1.0 A.
- What is the reference output voltage of the UC3842BDR2?
The reference output voltage is typically 5.0 V, with a range of 4.95 V to 5.05 V.
- What are the available package options for the UC3842BDR2?
The device is available in 8-pin dual-in-line and surface mount (SOIC-8) packages, as well as a 14-pin surface mount (SOIC-14) package.
- What is the purpose of the trimmed oscillator in the UC3842BDR2?
The trimmed oscillator provides precise duty cycle control.
- How is the oscillator frequency programmed in the UC3842BDR2?
The oscillator frequency is programmed by the values chosen for the timing components RT and CT.
- What is the maximum power dissipation of the UC3842BDR2 at TA = 25°C?
The maximum power dissipation varies by package, but for the SOIC-14 package, it is specified in the datasheet.
- What is the temperature stability of the reference output voltage?
The temperature stability is typically 0.2 mV/°C.
- Can the UC3842BDR2 be used in high-temperature environments?
Yes, the device operates over a temperature range that includes up to +105°C for some versions.
