Load-Dump/Reverse-Voltage Protection Circuits
Protect Power-Supply Inputs from Automotive Voltage Transients, Including Load Dump
DescriptionThe 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).
- 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
|Part Number||# Channels||VIN|
|Over Voltage Trip Level|
|Under Voltage Lockout|
|Over Volt. Flag||Oper. Temp.|
|MAX16126||1||3||90||Adjustable||Adjustable||9||Open-Drain||-40 to +125|
Technical DocumentsWhite Paper 7328 How Automotive Displays Can Comply with Functional Safety Requirements
|Device||Fab Process||Technology||Sample size||Rejects||FIT at 25°C||FIT at 55°C||Material Composition|