ISL6142
Negative Voltage Hot Plug Controller
Key Features
- Operates from -20V to -80V (-100V Absolute Max Rating)
- Programmable Inrush Current
- Programmable Time-Out
- Programmable Current Limit
- Programmable Over-Voltage Protection
- Programmable Under-Voltage Protection
- 135 mV of hysteresis ~4.7V of hysteresis at the power supply
- VDD Under-Voltage Lock-Out (UVLO) ~ 16.5V
- IntelliTripTM Electronic Circuit Breaker distinguishes between severe and moderate faults
- Fast shutdown for short circuit faults with a single retry (fault current > 4X current limit value).
- FAULT pin reports the occurrence of an Over-Current Time-Out
- Disable input controls GATE shutdown and resets Over-Current fault latch
- Load Current Monitor Function
- ISOUT provides a scaled version of the load current
- A resistor from ISOUT to -VIN provides current to voltage conversion
- Power Good Control Output
- Output latched "good" when DRAIN and GATE voltage thresholds are met.
- PWRGD active low: ISL6142 (L version)
- PWRGD active high: ISL6152 (H version)
Description
The ISL6142/52 are 14 pin, negative voltage hot plug controllers that allow a board to be safely inserted and removed from a live backplane. Inrush current is limited to a programmable value by controlling the gate voltage of an external N-channel pass transistor. The pass transistor is turned off if the input voltage is less than the Under-Voltage threshold, or greater than the Over-Voltage threshold. The PWRGD/PWRGD outputs can be used to directly enable a power module. When the Gate and DRAIN voltages are both considered good the output is latched in the active state.
The IntelliTrip™ electronic circuit breaker and programmable current limit features protect the system against short circuits. When the Over-Current threshold is exceeded, the output current is limited for a time-out period before the circuit breaker trips and shuts down the FET. The time-out period is programmable with an external capacitor connected to the CT pin. If the fault disappears before the programmed time-out, normal operation resumes. In addition, the IntelliTrip™ electronic circuit breaker has a fast Hard Fault shutdown, with a threshold set at 4 times the Over-Current trip point. When activated, the GATE is immediately turned off and then slowly turned back on for a single retry.
The IS+, IS-, and ISOUT pins combine to provide a load current monitor feature that presents a scaled version of the load current at the ISOUT pin. Current to voltage conversion is accomplished by placing a resistor (R9) from ISOUT to the negative input (-48V).
Applications
- VoIP (Voice over Internet Protocol) Servers
- Telecom systems at -48V
- Negative Power Supply Control
- +24V Wireless Base Station Power
