onsemi NCV8856A Automotive Synchronous Buck Controller

onsemi NCV8856A Automotive Synchronous Buck Controller is an adjustable output device that drives dual N-channel MOSFETs and is ideal for high-power applications. Average current mode control provides speedy transient responses and tight regulation over wide input voltage/output load ranges. The IC incorporates an internal fixed 6.0V low-dropout linear regulator (LDO) that supplies charge to the switch mode power supply’s (SMPS) bottom gate driver, limiting the power lost to excess gate drive. NCV8856A is designed for operation over a 4.5V to 38V input voltage range and can convert ten-to-one voltage at 500kHz. Additional controller features include undervoltage lockout, overvoltage shutdown, internal soft−start, low quiescent current sleep mode, programmable frequency, SYNC function, average current limiting, cycle-by-cycle overcurrent protection, and thermalshutdown.

Features

Average current mode control
0.8V ±2% reference voltage
Wide input voltage range from 4.5V to 38V
Operates through load dump conditions
6.0V low-dropout linear regulator (LDO)
Input UVLO (undervoltage lockout)
Internal soft-start
6.2µA maximum quiescent current in sleep mode
Adaptive non-overlap circuitry
180ns minimum high-side gate off-time

170kHz to 500kHz programmable fixed frequency
External clock synchronization up to 600kHz
Average Current Limiting (ACL)
Cycle-by-Cycle Overcurrent Protection (OCP)
Thermal Shutdown (TSD)
Moisture Sensitivity Level (MSL) 1
TSSOP-20 package
Lead-free and RoHS compliant

Applications

Automotive systems requiring high current
Pre-regulated supplies for low-voltage SMPSs and LDOs

Specifications

Quiescent currents
- 6.2µA maximum in sleep mode, 4.25µA typical
- 4.24mA maximum for no switching, 3.25mA typical
- 5.30mA maximum for switching with no gate loads, 4.35mA typical
1mA to 20mA LDO current range
+150°C to +210°C thermal shutdown range
1°C to 20°C thermal shutdown hysteresis
3.9V to 4.5V undervoltage lockout range
50mV to 200mV undervoltage lockout hysteresis range
Switching regulator
- 0.784V to 0.816V reference voltage range
- 110ns to 250ns minimum GH off-time range
- 200ns minimum GH pulse width (maximum), 140ns typical
Oscillator
- 153kHz to 575kHz switching frequency range
- 0.9V to 1.3V ramp voltage amplitude range
Voltage error amplifier
- 70dB minimum DC gain, 73dB typical
- 8.0MHz minimum gain bandwidth, 10MHz typical
- 1.3mA to 2mA minimum charge current range, 3mA to 4mA typical
- 1.0µA maximum FB bias current, 0.1µA typical
Current sense amplifier
- 0V to 10.0V common mode range
- 1V/V typical amplifier gain
SYNC
- 0.1µA to 20µA pin bias current range
- 0.8V to 2.0V threshold voltage range

Current error amplifier
- 70dB minimum DC gain, 73dB typical
- 8.0MHz minimum gain bandwidth, 10MHz typical
- 1.3mA to 2mA minimum charge current range, 3mA to 4mA typical
- 1.0µA maximum FB bias current, 0.1µA typical
- 2.7V minimum clamping voltage, 3.3V typical
Current limit
- 72mV to 133mV average threshold range
- 115mV to 215mV cycle-by-cycle threshold voltage range
- 200ns typical cycle-by-cycle response time
- 20mV minimum cycle-by-cycle/average threshold difference range
6.0V LDO
- 5.8V to 6.2V output voltage range
- 220mV maximum dropout voltage
- 30mA to 120mA current limit range
Gate drivers
- 1A to 2A GH/GL source/sink current range
- 70ns maximum GH-to-GL/GL-to-GH delay time, 40ns typical
14ms typical soft-start time
ENABLE (EN)
- 0.8V to 2.0V input threshold range
- 10µA maximum input current, 3.0µA typical
- 20ms minimum disable time (maximum)
1.5kV Human Body Model (HBM) ESD capability
-40°C to +150°C operating junction temperature range

onsemi NCV8856A Automotive Synchronous Buck Controller

Features

Applications

Specifications

Functional Block Diagram

Application Schematic

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