Input / GND - These are the power input terminals for the driver. The terminal block provides a power (VIN) and ground (GND) connection to allow the user to attach the EVM to a cable harness.

EN (J7) - This is the jumper used to enable the LED driver (EN pin). The driver will be enabled when the EN pin is high and disabled when it is low (GND).

VIO (J6) - This pin provides power for the I²C lines (Clock & Data) and for the EN pin. It is recommended that this pin is connected to the VIN pin. If desired, it can be connected to the 3.3V line provided by the USB interface connector. In this configuration, communication via the I²C interface may not be possible if the supply voltage to the LED driver is below approximately 3 V.

D1-CON (J21 pin2 and pin3), D2-CON (J22 pin2 and pin3), D3-CON (J23 pin2 and pin3) and D4-CON (J24 pin2 and pin3) - are the jumpers used to connect the on-board flash LEDs to the LED output of the driver.

STR1(J15) and STR2(J17) - These two pins provide external methods for initiating a flash events. The STRX pin is connected to ground via a 300-kΩ resistor internal to the LM3645. To externally drive this pin, either connect a control signal directly to the STRX pin of the connector or place a jumper between connector pins STRX and PWMX. Pin PWMX can be configured as a time-adjustable voltage pulse.

TORCH/TX (J19) - This pin provides an external method for initiating a torch event. The TORCH/TX pin is connected to ground via a 300-kΩ resistor internal to the LM3645. To externally drive this pin, either connect a control signal directly to the TORCH/TX pin of the connector or place a jumper between connector pins TORCH/TX and PWM0. Pin PWM0 can be configured as ON or OFF. Removing the jumper, and setting the TORCH/TX pin to TX mode, this pin is used to initiate a TX-interrupt event. To externally drive this pin, either connect a control signal directly to the TX pin of the connector or place a jumper between connector pins TX and PWM0.

TEMP1(J28) and TEMP(J29) - These two pins provides temperature sensing and current scale back function. The TEMP function can be utilized via the externally connected NTC thermistor.

SDA(J9) and SCL (J10) - These connections allow the user to externally control the I²C lines.

OUT（J30,) - These provide access to the regulated output of the driver. The user can measure VOUT with reference to GND。

VINL/VIN (J5) - The user can monitor the Inductor Current and Input Current waveforms by omitting this jumper and using separate wires from the power supply to the VINL and VIN pins. This will remove the Input Capacitors from the Inductor and eliminate their filtering effect to the Inductor Current.

J31, J32, J33 and J34: LED Current measurements -The LM3645EVM provides a way to accurately measure the LED current through both LEDs on board. Resistors R1,R2, R3 and R4 (0.5 Ω) are placed between the cathode of LED1, LED2, LED3 and LED4 respectively, and Ground. The user can first measure the resistor values accurately, by applying a known current through connector DxF and Ground and measuring the voltage between DxS and GNDS. Then, during normal flash or torch operation, the voltage measured across the resistor divided by the resistor value will equal the current through the resistor (and the LED).