LT8309 PIN FUNCTIONS GATE (Pin 1): N-Channel MOSFET Gate Driver Output. VCC (Pin 4): Input Voltage. This pin supplies current to the Switches between INTVCC and GND. Driven to GND during internal start-up circuitry and to the INTVCC LDO. This pin undervoltage lockout of INTVCC. must be locally bypassed with a capacitor. GND (Pin 2): Ground. DRAIN (Pin 5): Current Sense Pin. This pin senses INTV the voltage across the drain-to-source of the external CC (Pin 3): Regulated Supply for Internal Loads, and GATE Driver. Supplied from V N-channel MOSFET. A series resistor is needed to set the CC and regulates to 7V (typical). INTV offset voltage and needs to be at least 800Ω. The offset CC must be bypassed with a 4.7µF capacitor placed close to the pin. is equal to: 20mV • ⎛ ⎞ ⎜1 R − ⎟ ⎝ 2000 ⎠ BLOCK DIAGRAM 4 VCC 1.25V + 10µA 10µA – INTVCC 3 VBIAS DRAIN 5 + – VBIAS INTVCC LOGIC GATE 1 GND 2 8309 BD Rev. B 6 For more information www.analog.com Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Typical Applications Package Description Revision History Typical Application Related Parts