Advanced Analog Technology AZ3843
The AZ3842/3/4/5 are high performance fixed frequency current-mode PWM controller series. These integrated circuits are optimized for off-line and DC-DC converter applications with minimum external components. They feature under-voltage lockout (UVLO) circuit for low start-up current, trimmed oscillator for precise duty cycle control, current sense comparator providing maximum current limiting and a totem pole output stage for increasing output current.FEATURES
● Robust VREF Line/Load Regulation Low Line Regulation : 4mV Low Load Regulation : 4mV High Stability of Reference Voltage over a Full Temperature Range: 0.2mV/ oC Operating Frequency up to 500KHz High PWM Frequency Stability over a Full Temperature Range: 2.5% High PWM Frequency Stability under a Full Supply Voltage Range: 0.2% Accurate Over-temperature Protection with Hysteresis UVLO with Hysteresis CURRENT MODE PWM CONTROLLERGENERAL DESCRIPTION
In addition, these ICs also feature accurate protection against over-temperature, over-current and maximal output power. The AZ3842 and AZ3844 have UVLO thresholds of 15.5V(on) and 10V(off); The corresponding thresholds for AZ3843 and AZ3845 are 8.4 V(on) and 7.8V(off). The AZ3842 and AZ3843 can operate approaching 100% duty cycle; AZ3844 and AZ3845 can operate from zero to 50% duty cycle. These ICs are available in 3 packages: SOIC-8, DIP-8 and SOIC-14.●
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APPLICATIONS
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● Off-line Converter DC-DC Converter Voltage Adapter CRT Monitor Power Supply Desktop Power Supply DVD/STB Power Supply SOIC-8 DIP-8 SOIC-14 Figure 1.