LM5041
LM5041 is Cascaded PWM Controller manufactured by National Semiconductor.
Description
The LM5041 PWM controller contains all of the features necessary to implement either current-fed or voltage-fed push-pull or bridge power converters. These “Cascaded” topologies are well suited for multiple output and higher power applications. The LM5041’s four control outputs include: the buck stage controls (HD and LD) and the pushpull control outputs (PUSH and PULL). Push-pull outputs are driven at 50% nominal duty cycle at one half of the switching frequency of the buck stage and can be configured for either a guaranteed overlap time (for current-fed applications) or a guaranteed both-off time (for voltage-fed applications). Push-pull stage MOSFETs can be driven directly from the internal gate drivers while the buck stage requires an external driver such as the LM5102. The LM5041 includes a high-voltage start-up regulator that operates over a wide input range of 15V to 100V. The PWM controller is designed for high-speed capability including an oscillator frequency range up to 1 MHz and total propagation delays of less than 100ns. Additional features include: line Under-Voltage Lockout (UVLO), soft-start, an error amplifier, precision voltage reference, and thermal shutdown.
Features n Internal Start-up Bias Regulator n Programmable Line Under-Voltage Lockout (UVLO) with Adjustable Hysteresis n Current Mode Control n Internal Error Amplifier with Reference n Dual Mode Over-Current Protection n Leading Edge Blanking n Programmable Push-Pull Overlap or Dead Time n Internal 1.5A Push-Pull Gate Drivers n Programmable Soft-start n Programmable Oscillator with Sync Capability n Precision Reference n Thermal Shutdown
Applications n n n n Telemunication Power Converters Industrial Power Converters Multi-Output Power Converters +42V Automotive Systems
Packages n TSSOP-16 n LLP-16 (5x5 mm) Thermally Enhanced
Typical Application Circuit
Simplified Cascaded Push-Pull Power Converter
© 2003 National Semiconductor Corporation
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