LTC4368

• Companion module for Active Learning labs on buck and boost power converters
• Illustrates important concepts related to buck and boost converters:
  • Continuous vs. Discontinuous Conduction Modes
  • Open loop operation
  • Voltage mode control
  • Current mode control
• Independently adjustable parameters: frequency, duty cycle, voltage/current mode
• Onboard current sense amplifiers and adjustable load minimize equipment requirements.

The ADALM-SR1 (Analog Devices Active Learning Module, Switching Regulator) board is a companion module for several switching regulator exercises covering buck and boost regulators:

• Boost and Buck converter elements and open-loop operation
• Buck Converters: closed loop operation
• Boost Converters: closed loop operation

The circuits required for these exercises exceed the complexity that can be constructed on a breadboard, so the ADALM-SR1 was designed as a flexible platform for experimenting with power electronics. Onboard current sense amplifiers, adjustable electronic load, and feedback signal injection circuitry eliminate the need for expensive equipment — the only additional equipment required is:

• 5V USB wall adapter
• Basic adjustable power supply for input power (0-12V, 2A)
• Multimeter
• ADALM2000 or basic oscilloscope (2 channels with trigger, >10MHz bandwidth)

Demonstration circuit 2418A is intended to demonstrate the performance of the LTC4368 100V undervoltage (UV), overvoltage (OV), and reverse protection controller with bidirectional circuit breaker.

The LTC4368 protects circuits from overcurrent in both directions and from input voltages that may be too high, too low, or negative. The LTC4368 controls the gate voltage of two back-to-back connected external MOSFETs to ensure that the load is connected to the input supply only when there are no voltage or current faults. The OV and UV protection levels are adjusted by resistive dividers at the OV and UV pins, respectively. Asserting a low signal at the SHDN pin disables the MOSFETs and places the controller in a low-current shutdown state. The FAULT pin is asserted when the controller is in shutdown mode or when the input voltage is outside of the UV or OV window, or the load current exceeds the protection level, or the input voltage is below undervoltage lockout (1.8V to 2.4V).

After a forward overcurrent fault, the LTC4368 will either latch off power or retry after a user adjustable delay. A reverse overcurrent fault waits for the output to fall 100mV below the input to reconnect power to the load.

The LTC4368 can withstand DC voltages between −40V and 100V and has an operating range of 2.5V to 60V.

The DC2418A includes the LTC4368 controller, two backto- back connected power MOSFETs, current sense resistor, three jumpers, and three LEDs to indicate the input and output voltages and the FAULT pin signal.

Demonstration circuit 2418A is intended to demonstrate the performance of the LTC4368 100V undervoltage (UV), overvoltage (OV), and reverse protection controller with bidirectional circuit breaker.

The LTC4368 protects circuits from overcurrent in both directions and from input voltages that may be too high, too low, or negative. The LTC4368 controls the gate voltage of two back-to-back connected external MOSFETs to ensure that the load is connected to the input supply only when there are no voltage or current faults. The OV and UV protection levels are adjusted by resistive dividers at the OV and UV pins, respectively. Asserting a low signal at the SHDN pin disables the MOSFETs and places the controller in a low-current shutdown state. The FAULT pin is asserted when the controller is in shutdown mode or when the input voltage is outside of the UV or OV window, or the load current exceeds the protection level, or the input voltage is below undervoltage lockout (1.8V to 2.4V).

After a forward overcurrent fault, the LTC4368 will either latch off power or retry after a user adjustable delay. A reverse overcurrent fault waits for the output to fall 100mV below the input to reconnect power to the load.

The LTC4368 can withstand DC voltages between −40V and 100V and has an operating range of 2.5V to 60V.

The DC2418A includes the LTC4368 controller, two backto- back connected power MOSFETs, current sense resistor, three jumpers, and three LEDs to indicate the input and output voltages and the FAULT pin signal.