The UC3844B, UC3845B series is a high-performance fixed-frequency current-mode controller. They are designed for off-line and DC-to-DC converter application designers to provide cost-effective solutions with minimal external components. These ICs feature an oscillator, temperature compensation reference, high-gain error amplifier, current-sense comparator, and a high-current totem pole output that is ideal for driving power MOSFETs. Also included are protection features and components of input and reference undervoltage lockout with hysteresis, cycle-by-cycle current limiting, latching to single-pulse measurements and flip-flop blanks, output shutdown of all other oscillation cycles, enabling output dead time for programming, from 50% to 70%. The devices are available in 8-pin dual-in-line and surface-mount (SO-8) plastic packages and 14-pin plastic surface-mount (SO-14). The SO-14 package has separate power and ground pins for the totem pole output stage. The UCX844B has a 16 V UVLO threshold (top) and 10 V (off), making it ideal for off-line converters. The UCX845B is designed for low-voltage applications with (ON) and 7.6 V (off) and 8.5 V UVLO thresholds
Precise frequency control of side vibrations
The oscillator frequency is guaranteed to be at 250 kHz
The current mode operates to a 500 kHz output switching frequency
Output dead time adjustable range from 50% to 70%
Automatic feedforward compensation
The latching PWM current limit is a cycle-by-cycle current limit
Internally fine-tuned numbering is separated from undervoltage
High current totem pole output
Separation from hysteresis undervoltage
Low start-up and operating current
Lead-free packages are available
Centennial Electronic Technology (Shenzhen) Co., Ltd
Address: 13H, Block A, Huaqiang Plaza, Huaqiang Road, Futian District, Shenzhen
Phone: 0755-83591082
Fax: 0755-83591083
Q Q：1051085817
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