Datasheet LT1936 (Analog Devices) - 6

LT1936
PIN FUNCTIONS BOOST (Pin 1):
The BOOST pin is used to provide a drive
FB (Pin 6):
The LT1936 regulates its feedback pin to voltage, higher than the input voltage, to the internal bipolar 1.200V. Connect the feedback resistor divider tap to this NPN power switch. pin. Set the output voltage according to VOUT = 1.200V (1 + R1/R2). A good value for R2 is 10k.
VIN (Pin 2):
The VIN pin supplies current to the LT1936’s internal regulator and to the internal power switch. This
VC (Pin 7):
The VC pin is used to compensate the LT1936 pin must be locally bypassed. control loop by tying an external RC network from this pin to ground. The COMP pin provides access to an internal
SW (Pin 3):
The SW pin is the output of the internal power RC network that can be used instead of the external switch. Connect this pin to the inductor, catch diode and components. boost capacitor.
COMP (Pin 8):
To use the internal compensation network,
GND (Pin 4):
Tie the GND pin to a local ground plane tie the COMP pin to the V below the LT1936 and the circuit components. Return the C pin. Otherwise, tie COMP to ground or leave it fl oating. feedback divider to this pin.
SHDN Exposed Pad (Pin 9):
The Exposed Pad must be soldered
(Pin 5):
The SHDN pin is used to put the LT1936 in to the PCB and electrically connected to ground. Use a shutdown mode. Tie to ground to shut down the LT1936. large ground plane and thermal vias to optimize thermal Tie to 2.3V or more for normal operation. If the shutdown performance. feature is not used, tie this pin to the VIN pin. SHDN also provides a soft-start function; see the Applications Infor- mation. Do not drive SHDN more than 5V above VIN.
BLOCK DIAGRAM
VIN V 2 IN C2 INT REG AND UVLO D2 ∑ BOOST ON OFF 1 SLOPE R R3 COMP Q SHDN 5 C3 S Q DRIVER Q1 C4 L1 OSC SW 3 VOUT C1 D1 FREQUENCY FOLDBACK R1 FB 6 VC gm R2 CC RC 150pF 1.200V 50k VC COMP GND 7 4 1936 BD 8 R4 C5 1936fd 6