High-Side Switch Controller with Current Limiting

The MAX14922 is a high-side, n-channel FET controller for implementing industrial high-side switches for switching ground-connected loads. The MAX14922 device controls an external nMOS power transistor, allowing low RON high-side switch applications from a +9V to +70V supply range.

Fast inductive load turn-off can be achieved with use of a high-voltage TVS diode enabling up to -70V (max) voltage clamping. Ground-connected TVS diodes allow clamping of exceptionally high inductive energies. Load current is limited to a user-defined value through a sense resistor. External FET overload protection is achieved using an auto-retry timing feature, as defined by a user-selected capacitor (CBLANK at tBLANK input) or optionally using an external timing control. The MAX14922 features an on-chip comparator enabling monitoring of the high-side switch output or the supply input voltage with a user-selected threshold. An integrated charge pump enables high speed switching rates when using low RON FETs in the 20kHz to 50kHz range. The MAX14922 is available in a 3mm x 3mm, 16-TQFN package. The MAX14922 device is specified over the -40°C to +125°C operating temperature range.Applications

* Industrial Digital Outputs * High-Side Switches * Motor Holding Brakes * Relay and Solenoid Drivers

* +9V to +70V Operating Supply Range

* 5V / 50mA Integrated Linear Regulator

* -40°C to +125°C Ambient Temperature Operating Range

* 16-TQFN Package, 3mm x 3mm, 0.5mm Pin Pitch

* Robust Design Features

* Ultra High-Speed Inductive Load Turn-Off by Clamping to -70V

* Supply Independent Inductive Clamping

* Support of Low RON FETs Having Qg (Total) = 50nC

* External FET Turn-On Propagation Delay < 20μs

* Active Current Limit Control During Overcurrent

* Fault Monitoring Diagnostic Features

* Overcurrent Detect Output

* High Supply-Voltage Indication

* Flexible Supply or Load Voltage Monitor

* Undervoltage Lockout

* Thermal Warning and Shutdown Protection

* Device Ready Indication