Datasheet LT8304, LT8304-1 (Analog Devices) - 7

LT8304/LT8304-1
PIN FUNCTIONS EN/UVLO (Pin 1):
Enable/Undervoltage Lockout. The
SW (Pin 5):
Drain of the Internal DMOS Power Switch. EN/UVLO pin is used to enable the LT8304. Pull the pin Minimize trace area at this pin to reduce EMI and voltage below 0.2V to shut down the LT8304. This pin has an ac- spikes. curate 1.214V threshold and can be used to program a VIN
R
undervoltage lockout (UVLO) threshold using a resistor
FB (Pin 6):
Input Pin for External Feedback Resistor. Connect a resistor from this pin to the transformer primary divider from VIN to ground. A 2.5µA current hysteresis SW pin. The ratio of the R allows the programming of V FB resistor to the RREF resistor, IN UVLO hysteresis. If neither times the internal voltage reference, determines the output function is used, tie this pin directly to VIN. voltage (plus the effect of any non-unity transformer turns
INTVCC (Pin 2):
Internal 3V Linear Regulator Output. The ratio). Minimize trace area at this pin. INTVCC pin is supplied from VIN and powers the internal
R
control circuitry and gate driver. Do not overdrive the
REF (Pin 7):
Input Pin for External Ground Referred Ref- erence Resistor. The resistor at this pin should be in the INTVCC pin with any external supply, such as a third winding range of 10k, but for convenience in selecting a resistor supply. Locally bypass this pin to ground with a minimum divider ratio, the value may range from 9.09k to 11.0k. 1µF ceramic capacitor.
TC (Pin 8):
Output Voltage Temperature Compensation. The
VIN (Pin 3):
Input Supply. The VIN pin supplies current to voltage at this pin is proportional to absolute temperature the internal circuitry and serves as a reference voltage for (PTAT) with temperature coefficient equal to 3.35mV/°C, the feedback circuitry connected to the RFB pin. Locally i.e., equal to 1V at room temperature 25°C. The TC pin bypass this pin to ground with a capacitor. voltage can be used to estimate the LT8304 junction tem-
GND (Pin 4, Exposed Pad Pin 9):
Ground. The exposed perature. Connect a resistor from this pin to the RREF pin pad provides both electrical contact to ground and good to compensate the output diode temperature coefficient. thermal contact to the printed circuit board. Solder the exposed pad directly to the ground plane. 8304fa For more information www.linear.com/LT8304 7 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Typical Application Related Parts Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Revision History Typical Application Related Parts