NCV8851-1: Automotive Average Current Mode 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
  • 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
  • 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)
Benefits
  • Fast transient response and simple compensator design
  • Tight tolerance on programmable output voltage
  • Allows for direct regulation from car battery through load dump conditions
  • Supplies internal supply for gate drivers
  • Disables start-up in undervoltage conditions
  • Lowers inrush current and avoids output overshoot during start-up
  • Very low sleep current
  • Protects against switch cross-conduction (shoot-through)
  • Allows for design flexibility
  • Allows for frequency synchronization and spread spectrum operation
  • Limits current to protect devices
  • Protects components in case of a short-circuit and recovers
  • Thermally protects IC
Applications
  • Automotive systems requiring high current
  • Pre-regulated supply for low-voltage SMPSs and LDOs
End Products
  • Automotive systems
Simulation Models (1)
Document TitleDocument ID/SizeRevisionRevision Date
NCV8851 average PSPICE model for AC simulations for loop stability (Bode plot)NCV8851AC_PSPICE (467kB)0Jul, 2014
Data Sheets (1)
Document TitleDocument ID/SizeRevisionRevision Date
Automotive Grade Synchronous Buck ControllerNCV8851-1/D (177kB)2
Evaluation Board Documents (5)
Document TitleDocument ID/SizeRevisionRevision Date
NCV8851-1GEVB Bill of Materials ROHS CompliantNCV8851-1GEVB_BOM_ROHS.PDF (67.0kB)3
NCV8851-1GEVB Evaluation Board User's ManualEVBUM2119/D (482kB)2
NCV8851-1GEVB Gerber Layout Files (Zip Format)NCV8851-1GEVB_GERBER.ZIP (37.0kB)1
NCV8851-1GEVB SchematicNCV8851-1GEVB_SCHEMATIC.PDF (65.0kB)3
NCV8851-1GEVB Test ProcedureNCV8851-1GEVB_TEST_PROCEDURE.PDF (177.0kB)0
Package Drawings (1)
Document TitleDocument ID/SizeRevision
TSSOP-20 WB948E-02 (39.7kB)D
Evaluation/Development Tool Information
ProductStatusComplianceShort Description
NCV8851-1GEVBActivePb-freeAdjustable Output Synchronous Buck Controller Evaluation Board
Order Information
ProductStatusCompliancePackageMSL*ContainerBudgetary Price/Unit
NCV8851-1DBR2GActiveAEC Qualified PPAP Capable Pb-freeTSSOP-20948E-023Tape and Reel2500$1.3
Specifications
ProductTopologyPhasesControl ModeVCC Min (V)VCC Max (V)fSW Typ (kHz)tres Typ (ns)
NCV8851-1DBR2GStep-DownCurrent Mode4.540Up to 500
Automotive Grade Synchronous Buck Controller (177kB) NCV8851-1
NCV8851 average PSPICE model for AC simulations for loop stability (Bode plot) NCV8851-1
NCV8851-1GEVB BOM ROHS NCV8851-1GEVB
EVBUM2119/D - 482 KB NCV8851-1GEVB
NCV8851-1GEVB GERBER NCV8851-1GEVB
NCV8851-1GEVB SCHEMATIC NCV8851-1GEVB
NCV8851-1GEVB TEST PROCEDURE NCV8851-1GEVB
TSSOP-20 WB NLSX3018