NCP1562BDR2G

The NCP1562x is a family of voltage mode controllers designed for dc--dc converters requiring high--efficiency and low parts count. These controllers incorporate two in phase outputs with an overlap delay to prevent simultaneous conduction and facilitates soft switching. The main output is designed for driving a forward converter primary MOSFET. The secondary output is designed for driving an active clamp circuit MOSFET, a synchronous rectifier on the secondary side, or an asymmetric half bridge circuit. The NCP1562 family reduces component count and system size by incorporating high accuracy on critical specifications such as maximum duty cycle limit, undervoltage detector and overcurrent threshold. Two distinctive features of the NCP1562 are soft--stop and a cycle skip current limit with a time threshold. Soft--stop circuitry powers down the converter in a controlled manner if a severe fault is detected. The cycle skip detector enables a soft--stop sequence if a continuous overcurrent condition is present. Additional features found in the NCP1562 include line feed-- forward, frequency synchronization up to 1.0 MHz, cycle--by--cycle current limit with leading edge blanking (LEB), independent under and overvoltage detectors, adjustable output overlap delay, programmable maximum duty cycle, internal startup circuit and soft--start.

Applications

• Telecommunications Power Converters
• Low Output Voltage Converters using Control Driven Synchronous Rectifier
• Industrial Power Converters
• 42 V Automotive System
• ATX Power Supplies

Key features

• Dual Control Outputs with Adjustable Overlap Delay
• >2.0 A Output Drive Capability
• Soft--Stop Powers Down Converter in a Controlled Manner Cycle--by--Cycle Current Limit
• Cycle Skip Initiated if Continuous Current Limit Condition Exists
• Voltage Mode Operation with Input Voltage Feedforward
• Fixed Frequency Operation up to 1.0 MHz
• Bidirectional Frequency Synchronization
• Independent Line Undervoltage and Overvoltage Detectors
• Accurate Programmable Maximum Duty Cycle Limit
• Programmable Maximum Volt--Second Product
• Programmable Soft--Start
• Internal 100 V Startup Circuit
• Precision 5.0 V Reference
• These are Pb--Free Devices