Datasheet MAX1698, MAX1698A (Maxim) - 5

High-Efficiency Step-Up Current Regulator for LEDs MAX1698/MAX1698A Pin Description PIN NAME FUNCTION
1 VCC IC Supply Voltage Input. Power for internal circuitry. Input range is 2.7V to 5.5V. Active-Low Shutdown Input. In shutdown, the MOSFET turns off, but a current path still exists between the 2 SHDN input and output. The minimum forward voltage of the LED array must exceed the maximum VBATT to ensure that the LEDs are off in shutdown. 1.25V Reference Output. Capable of sourcing 150µA for external loads. This pin is internally compensated. 3 REF Do not connect any bypass capacitors at REF. 4 ADJ Adjust Input. Allows dynamic adjustment of the output current. FB regulates to 300mV when ADJ = REF. 5, 7 GND Ground 6 FB Feedback Input. Connect to the external LED current-sense feedback resistor. 8 PGND Power Ground 9 CS FET Current-Sense Input 10 EXT Gate Driver Output CS MAX1698 SHDN UNDERVOLTAGE VCC LOCKOUT/ SHUTDOWN V TRIG CC MAX tON Q EXT ADJ TRIG PGND MIN tOFF Q FB 1.25V SOFT-START REF GND REFERENCE Figure 1. Functional Diagram
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