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Load-Dump/Reverse-Voltage Protection Circuits

Protect Power-Supply Inputs from Automotive Voltage Transients, Including Load Dump

Product Details

The MAX16126/MAX16127 load-dump/reverse-voltage protection circuits protect power supplies from damaging input voltage conditions, including overvoltage, reverse-voltage, and high-voltage transient pulses. Using a built-in charge pump, the devices control two external back-to-back n-channel MOSFETs that turn off and isolate downstream power supplies during damaging input conditions, such as an automotive load-dump pulse or a reverse-battery condition. Operation is guaranteed down to 3V to ensure proper operation during automotive cold-crank conditions. These devices feature a flag output (active-low FLAG) that asserts during fault conditions.

For reverse-voltage protection, external back-to-back MOSFETs outperform the traditional reverse-battery diode, minimizing the voltage drop and power dissipation during normal operation.

The MAX16126/MAX16127 use external resistors to adjust the overvoltage and undervoltage comparator thresholds for maximum flexibility.

The MAX16127 provides limiter-mode fault management for overvoltage and thermal shutdown conditions; whereas the MAX16126 provides switch-mode fault management for overvoltage and thermal shutdown conditions. In the limiter mode, the output voltage is limited and active-low FLAG is asserted low during a fault. In the switch mode, the external MOSFETs are switched off and active-low FLAG is asserted low after a fault. The switch mode is available in four options: latch mode, 1 autoretry mode, 3 autoretry mode, and always autoretry mode.

The MAX16126/MAX16127 are available in 12-pin TQFN packages. These devices operate over the automotive temperature range (-40°C to +125°C).

Key Features

  • Increases Protection of Sensitive Electronic Components in Harsh Environments
    • -36V to +90V Wide Input-Voltage Protection Range
    • Fast Gate Shutoff During Fault Conditions with Complete Load Isolation
    • Thermal-Shutdown Protection
    • Active-Low FLAG Output Identifies Fault Condition
  • AEC-Q100 Automotive Qualified
    • Operates Down to +3V, Riding Out Cold-Crank Conditions
    • -40°C to +125°C Operating Temperature Range
  • Integration Reduces Solution Size
    • Internal Charge-Pump Circuit Enhances External n-Channel MOSFETs
    • Adjustable Undervoltage/Overvoltage Thresholds
    • 3mm x 3mm, 12-Pin TQFN Package
  • Reduced Power Dissipation Compared to Discrete Solutions
    • Minimal Operating Voltage Drop for Reverse- Voltage Protection
    • 350µA (max) Supply Current and 100µA (max) Shutdown Current at 30V Input

Applications/Uses

  • Automotive
  • Avionics
  • Industrial
  • Telecom/Server/Networking
Parametric specs for Overvoltage Protection Controllers
# Channels 1
VIN (V) (min) 3
VIN (V) (max) 90
Over Voltage Trip Level (V) Adjustable
Under Voltage Lockout (V) Adjustable
VGATE (V) 9
Over Volt. Flag Open-Drain
Oper. Temp. (°C) -40 to +125
Package/Pins TQFN/12
Budgetary
Price (See Notes)
$1.12 @1k
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Simplified Block Diagram

MAX16126, MAX16127: Functional Diagram MAX16126, MAX16127: Functional Diagram Zoom icon

Technical Docs

Design & Development

Click any title below to view the detail page where available.

Description

The MAX16126/MAX16127 evaluation kits (EV kits) demonstrate high overvoltage protection of the MAX16126/MAX16127 devices for automotive applications that must survive load-dump and high-voltage transient conditions. The fully assembled and tested surface-mount EV kit board provides two circuits: One full-featured solution and one minimum parts-count circuit. The full-featured solution exercises all the features of the devices and allows -60V to +90V protection beyond the 3V to 30V operating range. The minimum parts-count solution provides a cost-effective option using a small 3A, dual MOSFET and reduced 0 to +60V voltage range.

View Details

Features

  • Dual Circuits
    • Full-Featured Solution (-60V to +90V)
    • Minimum Parts-Count Solution (0 to +60V)
  • Robust Reverse-Battery Protection (Circuit 1)
  • Positive Input Supply Voltage Protection Range Extended Beyond +90V (Circuit 1)
  • Adjustable Undervoltage and Overvoltage Thresholds
  • Adjustable Undervoltage Set for 8V
  • Adjustable Overvoltage Threshold Set for 32.1V
  • Enable Input/Flag Output
  • Proven PCB Layout
  • Fully Assembled and Tested

Description

The MAX16126/MAX16127 evaluation kits (EV kits) demonstrate high overvoltage protection of the MAX16126/MAX16127 devices for automotive applications that must survive load-dump and high-voltage transient conditions. The fully assembled and tested surface-mount EV kit board provides two circuits: One full-featured solution and one minimum parts-count circuit. The full-featured solution exercises all the features of the devices and allows -60V to +90V protection beyond the 3V to 30V operating range. The minimum parts-count solution provides a cost-effective option using a small 3A, dual MOSFET and reduced 0 to +60V voltage range.

View Details

Features

  • Dual Circuits
    • Full-Featured Solution (-60V to +90V)
    • Minimum Parts-Count Solution (0 to +60V)
  • Robust Reverse-Battery Protection (Circuit 1)
  • Positive Input Supply Voltage Protection Range Extended Beyond +90V (Circuit 1)
  • Adjustable Undervoltage and Overvoltage Thresholds
  • Adjustable Undervoltage Set for 8V
  • Adjustable Overvoltage Threshold Set for 32.1V
  • Enable Input/Flag Output
  • Proven PCB Layout
  • Fully Assembled and Tested

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Support & Training

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Parameters

Parametric specs for Overvoltage Protection Controllers
# Channels 1
VIN (V) (min) 3
VIN (V) (max) 90
Over Voltage Trip Level (V) Adjustable
Under Voltage Lockout (V) Adjustable
VGATE (V) 9
Over Volt. Flag Open-Drain
Oper. Temp. (°C) -40 to +125
Package/Pins TQFN/12
Budgetary
Price (See Notes)
$1.12 @1k

Key Features

  • Increases Protection of Sensitive Electronic Components in Harsh Environments
    • -36V to +90V Wide Input-Voltage Protection Range
    • Fast Gate Shutoff During Fault Conditions with Complete Load Isolation
    • Thermal-Shutdown Protection
    • Active-Low FLAG Output Identifies Fault Condition
  • AEC-Q100 Automotive Qualified
    • Operates Down to +3V, Riding Out Cold-Crank Conditions
    • -40°C to +125°C Operating Temperature Range
  • Integration Reduces Solution Size
    • Internal Charge-Pump Circuit Enhances External n-Channel MOSFETs
    • Adjustable Undervoltage/Overvoltage Thresholds
    • 3mm x 3mm, 12-Pin TQFN Package
  • Reduced Power Dissipation Compared to Discrete Solutions
    • Minimal Operating Voltage Drop for Reverse- Voltage Protection
    • 350µA (max) Supply Current and 100µA (max) Shutdown Current at 30V Input

Applications/Uses

  • Automotive
  • Avionics
  • Industrial
  • Telecom/Server/Networking

Description

The MAX16126/MAX16127 load-dump/reverse-voltage protection circuits protect power supplies from damaging input voltage conditions, including overvoltage, reverse-voltage, and high-voltage transient pulses. Using a built-in charge pump, the devices control two external back-to-back n-channel MOSFETs that turn off and isolate downstream power supplies during damaging input conditions, such as an automotive load-dump pulse or a reverse-battery condition. Operation is guaranteed down to 3V to ensure proper operation during automotive cold-crank conditions. These devices feature a flag output (active-low FLAG) that asserts during fault conditions.

For reverse-voltage protection, external back-to-back MOSFETs outperform the traditional reverse-battery diode, minimizing the voltage drop and power dissipation during normal operation.

The MAX16126/MAX16127 use external resistors to adjust the overvoltage and undervoltage comparator thresholds for maximum flexibility.

The MAX16127 provides limiter-mode fault management for overvoltage and thermal shutdown conditions; whereas the MAX16126 provides switch-mode fault management for overvoltage and thermal shutdown conditions. In the limiter mode, the output voltage is limited and active-low FLAG is asserted low during a fault. In the switch mode, the external MOSFETs are switched off and active-low FLAG is asserted low after a fault. The switch mode is available in four options: latch mode, 1 autoretry mode, 3 autoretry mode, and always autoretry mode.

The MAX16126/MAX16127 are available in 12-pin TQFN packages. These devices operate over the automotive temperature range (-40°C to +125°C).

Simplified Block Diagram

MAX16126, MAX16127: Functional Diagram MAX16126, MAX16127: Functional Diagram Zoom icon

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal