The onsemi UC2844BD1R2G is a high-performance fixed-frequency current-mode PWM controller designed for offline and DC-DC power converter applications. It integrates an oscillator, temperature-compensated reference, high-gain error amplifier, current-sense comparator, and a high-current totem-pole output stage suitable for directly driving a power MOSFET.
The UC2844B supports current-mode operation at output switching frequencies up to 500kHz and has a typical maximum duty cycle of approximately 48%. An internal flip-flop blanks the output on alternate oscillator cycles, providing programmable output deadtime from approximately 50% to 70%. Additional functions include cycle-by-cycle current limiting, latching PWM, automatic feed-forward compensation, and undervoltage lockout.
Designed for offline converter applications, the UC2844B has typical 16V turn-on and 10V turn-off UVLO thresholds, with a minimum operating voltage of approximately 11V. Startup supply current is specified at up to approximately 0.5mA, helping support efficient bootstrap startup circuits. The controller also integrates a precision 5V reference.
Its totem-pole output can source or sink peak currents up to 1A according to the absolute maximum ratings, providing strong gate-drive capability for power MOSFETs. The UC2844B industrial-temperature version operates over an ambient temperature range of -25°C to +85°C.
The UC2844BD1R2G is supplied in an 8-pin SOIC surface-mount package. This Pb-free and RoHS-compliant orderable version is supplied on tape and reel with 2,500 devices per reel, and onsemi currently lists it as an active product.
Key Features:
- Manufacturer: onsemi
- Part Number: UC2844BD1R2G
- Device Type: Current-Mode PWM Controller
- Control Mode: Current Mode
- Typical Topology: Flyback
- Number of Outputs: 1
- Output Type: MOSFET Driver
- Output Switching Frequency: Up to 500kHz
- Typical Oscillator Frequency: 52kHz under specified conditions
- Typical Maximum Duty Cycle: 48%
- Maximum Duty-Cycle Range: 47% to 50%
- UVLO Turn-On Threshold: 16V typ.
- UVLO Turn-Off Threshold: 10V typ.
- Minimum Operating Voltage: Approx. 11V
- VCC Max Parametric Rating: 30V
- Absolute Maximum Bias / Driver Voltage: 36V
- Reference Voltage: 5V
- Peak Output Source / Sink Current: Up to 1A
- Cycle-by-Cycle Current Limiting: Yes
- Feed-Forward Compensation: Yes
- UVLO with Hysteresis: Yes
- Startup Current: Up to approx. 0.5mA
- Operating Temperature: -25°C to +85°C
- Package: SOIC-8
- Mounting Type: Surface Mount
- Packaging: Tape & Reel
- Reel Quantity: 2,500 pcs
- Product Status: Active
- Pb-Free and RoHS Compliant.
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