Automotive Grade Synchronous Buck Controller

The NCV8851−1 is an adjustable output, synchronous buck controller, which drives dual N−channel MOSFETs, ideal for high power applications. Average current mode control is employed for very fast transient response and tight regulation over wide input voltage and output load ranges. The IC incorporates an internal fixed 6.0 V low−dropout linear regulator (LDO), which supplies charge to the switch mode power supply’s (SMPS) bottom gate driver, limiting the power lost to excess gate drive. The IC is designed for operation over a wide input voltage range (4.5 V to 40 V) and is capable of 10 to 1 voltage conversion at 500 kHz.
Additional controller features include undervoltage lockout, internal soft−start, low quiescent current sleep mode, programmable frequency, SYNC function, average current limiting, cycle−by−cycle overcurrent protection and thermal shutdown.

FEATUREs
• Average Current Mode Control
• 0.8 V ±2% Reference Voltage
• Wide Input Voltage Range of 4.5 V to 40 V
• Operates through Load Dump Conditions
• 6.0 V Low−dropout Linear Regulator (LDO)
• Input UVLO (Undervoltage Lockout)
• Internal Soft−start
• 1.0 μA Maximum Quiescent Current in Sleep Mode
• Adaptive Non−overlap Circuitry
• 180 ns Minimum High−side Gate Off−time
• Programmable Fixed Frequency – 170 kHz to 500 kHz
• External Clock Synchronization up to 600 kHz
• Average Current Limiting (ACL)
• Cycle−by−Cycle Overcurrent Protection (OCP)
• Thermal Shutdown (TSD)
• This is a Pb−Free Device

APPLICATIONs
• Automotive Systems Requiring High Current
• Pre−regulated Supply for Low−voltage SMPSs and LDOs