CAT4101Table 5. PIN DESCRIPTIONSNamePinFunction EN/PWM 1 Device enable (active high) and PWM control. VIN 2 Device supply input, connect to battery or supply. GND 3 Ground reference. RSET 4 A resistor connected between this pin and ground sets the LED current. LED 5 Bottom LED cathode terminal. TAB – Connect TAB to the Ground plane. Pin Function VIN is the supply pin for the device. A small 0.1 mF ceramic high−impedance zero−current state whenever the device is bypass capacitor is optional for noisy environments. The placed in shutdown mode. maximum operating voltage is 6.0 V. Whenever the input RSET pin is connected to an external resistor to set the LED supply falls below the under−voltage threshold, the current current. The ground side of the external resistor should be sink will automatically be disabled. star connected to the GND of the PCB. The pin source EN/PWM is the enable and one wire dimming input for the current mirrors the current to the LED sink. The voltage at LED channel. Guaranteed levels of logic high and logic low this pin is regulated to 1.2 V. are set at 1.3 V and 0.4 V respectively. When EN/PWM is GND is the ground reference for the device. The pin must be initially taken high, the device becomes enabled and the connected to the ground plane on the PCB. LED current is set at a gain of 400 times the current in RSET. TAB is the exposed pad underneath the package. For best To place the device into zero current shutdown mode, the thermal performance, the tab should be soldered to the PCB EN/PWM pin must be held low for 5 ms typical. and connected to the ground plane. LED pin is connected to the bottom LED cathode and provides a regulated current sink. The pin enters a http://onsemi.com6