Variable Over-Current Detection Load Switch

This over-current latch load switch provides over-current protection, thermal shutdown protection, soft-start function, and low power OFF function. The Overcurrent protection function is activated when the load is shorted. This protection function is effective in preventing damage due to sudden and unexpected incidents. It is also equipped with an error flag notification pin which indicates thermal shutdown and over-current condition. The project can help to protect the connected device from overcurrent, monitoring of various power lines, and power management. The board operates from 12V DC to 24V DC. The power LED indicates the output. Screw terminals provided for an easy connection of input and output supply. For the Fault function, additional 5V VCC DC input is required, otherwise, the VCC is not required. The circuit is normally enabled, and you can connect enable pin to GND to disable the output. Output is latching type; power is OFF when a fault condition occurs and sequence can be reversed with power OFF or Disable/Enable Pin.

Features

• Operating Supply 12V DC to 24V
• Operating Current 3mA + 5mA LED = 8mA Approx
• Load Current 3Amps
• Output Load Voltage 12V-24V DC
• Output On Resistance 45mOhms
• Over Current Threshold 3.35A (Adjustable 3.35A to 10Amps, Read Note)
• Over Current Protection Function (Latch OFF)
• Thermal Shutdown Protection Function (TSD)
• Low Voltage Output OFF Function (UVLO) Threshold 6V
• Standby Current 5uA + LED Current
• Operating Temperature -40C to +85C
• Error Flag Notification Output, Normally High ( VCC=5V)
• PCB Dimensions 40.64 x 39.69mm
• 4 X 3MM Mounting Holes

Connections and Other Details

• CN1: Pin 1 = +12V to +24V DC Output, Pin 2 = GND
• CN2: Pin 1 = Enable (Default Enabled, Connect to GND = Disable), Pin 2 = VCC 5V DC Flag Pull-Up Supply, Pin 3 = Flag Output (Default High, Low= When Fault Condition Occurs), Pin 4 = GND
• CN3: Pin 1 = +12V to +24V DC Input, Pin 2 = GND
• D1: Output Power LED
• R2: Current Limit Adjust, Refer Figure
• PR1 + R7: Optional for Adjustable Current Limit
• R1: Soft Start Delay 50mS (Refer Figure to change Delay)

Thermal Shutdown Function

(Thermal Shutdown Detection TTSD, Thermal Shutdown Hysteresis TTSDHYS) This IC has a built-in TSD function. When the temperature of the IC reaches Thermal Shutdown Detection (TTSD) = 175 °C (Typ) or more, the output is turned off, and the FLAG outputs Low. Hysteresis (TTSDHYS) is installed for thermal shutdown function, and output automatically returns to normal when chip temperature becomes 160 °C (Typ) or less. The condition for Latch-Off is when Variable Overcurrent Detection (IOCD2) is reached and the temperature of IC reaches Thermal Shutdown Detection (TTSD) = 175 °C (Typ) or more. The condition for Latch-off Release is the switching of EN voltage (VEN) or IN voltage (VIN).

Schematic

Parts List

Connections

Load Current Adjustment

Softstart Delay Adjust

Gerber View

Photos

Video

BV1HAL45EFJ Datasheet

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