MAX1771 12V or Adjustable, High-Efficiency, Low IQ, Step-Up DC-DC ControllerTypical Operating Characteristics (continued) (Circuit of Figure 2a, TA = +25°C, unless otherwise noted.) ENTERING/EXITING SHUTDOWN A 0V B 5V 0V 2ms/div IOUT = 500mA, VIN = 5V A: SHDN, 5V/div B: VOUT, 5V/div Pin DescriptionPINNAMEFUNCTION 1 EXT Gate Drive for External N-Channel Power Transistor 2 V+ Power-Supply Input. Also acts as a voltage-sense point when in bootstrapped mode. Feedback Input for Adjustable-Output Operation. Connect to ground for fixed-output operation. 3 FB Use a resistor divider network to adjust the output voltage. See Setting the Output Voltage section. Active-High TTL/CMOS Logic-Level Shutdown Input. In shutdown mode, VOUT is a diode drop 4 SHDN below V+ (due to the DC path from V+ to the output) and the supply current drops to 5µA maximum. Connect to ground for normal operation. 1.5V Reference Output that can source 100µA for external loads. Bypass to GND with 0.1µF. 5 REF The reference is disabled in shutdown. 6 AGND Analog Ground 7 GND High-Current Ground Return for the Output Driver Positive Input to the Current-Sense Amplifier. Connect the current-sense resistor between CS 8 CS and GND. 6 Maxim Integrated