MIC3809

MIC3808/3809 www.DataSheet4U.com MIC3808/3809 Micrel Push-Pull PWM Controller General Description The MIC3808 and MIC3809 are a family of complementary output push-pull PWM control ICs that feature high speed and low power consumption. The MIC3808/9 are ideal for telecom level (36V to 75V) isolated step down dc/dc conversion applications where high output current, small size, and high efficiency are required. The dual-ended push-pull architecture of the MIC3808/9 allows more efficient utilization of the transformer than singleended topologies, allowing smaller size dc/dc solutions. Additionally, the out-of-phase push-pull topology allows a higher effective duty cycle, reducing input and output ripple as well as stress on the external components. The dead-time between the two outputs is adjustable between 60ns to 200ns, limiting the duty cycle of each output stage to less than 50%. The MIC3808/9 are built on a low-power, high-speed BiCMOS process. The 130µA start-up current and 1mA run-current reduce the size of the start-up circuitry and allow high efficiency even at light loads. The high-speed internal 4MHz error amplifier allows MIC3808/9 operation up to 1MHz. The MIC3808 has a turn-on threshold of 12.5V whereas the MIC3809 has a lower turn-on threshold of 4.3V. Both devices are available in SOP-8 and MSOP-8 package options with an operating range of –40°C to +85°C. Data sheets and support documentation can be found on Micrel’s web site at: www.micrel.com. Features ...