TheUC3843BNG(购买请点击) series are high performance fixedfrequency current mode controllers. They are specifically designed forOff−Line and DC−DC converter applications designer acost−effective solution with minimal external components. Theseintegrated circuits trimmed oscillator for precise duty cyclecontrol, compensated reference, high gain erroramplifier, current sensing comparator, and a high current totem poleoutput ideally suited for driving a power MOSFET.
Also included are protective features consisting of input andreference undervoltage lockouts each with hysteresis, cycle−by−cyclecurrent limiting, programmable output deadtime, and a latch for singlepulse meteringUC3843BNG(购买请点击).
These devices are available in an 8−pin dual−in−line and surfacemount (SOIC−8) plastic package as well as the 14−pin plastic surfacemount (SOIC−14). The SOIC−14 package has separate power andground pins for the totem pole output stage.
The UC3843BNG(购买请点击) has UVLO thresholds of 16 V (on) and 10 V (off),ideally suited for off−line converters. The UCX843B is tailored forlower voltage applications having UVLO thresholds of 8.5 V (on) and7.6 V (off).
Features
Trimmed Oscillator for Precise Frequency Control;
Oscillator Frequency Guaranteed at 250 kHz;
Current Mode Operation to 500 kHz;
Automatic Feed Forward CompensationUC3843BNG(购买请点击);
Latching PWM for Cycle−By−Cycle Current Limiting;
Internally Trimmed Reference with Undervoltage LockoutUC3843BNG(购买请点击);
High Current Totem Pole Output;
Undervoltage Lockout with Hysteresis;
Low Startup and Operating Current;
Pb−Free Packages are Available。
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