Rainbow Electronics MAX15032 - Manual (Page 6)

MAX15032
500kHz, 36V Output, 600mW PWM
Step-Up DC-DC Converter
6 _______________________________________________________________________________________
Pin Description
PIN NAME FUNCTION
1 LX
Drain of Internal 40V n-Channel DMOS. Connect inductor/diode to LX. Minimize trace area at LX to
reduce switching noise emission.
2 GND
Signal Ground. Connect directly to the local ground plane. Connect GND to PGND at a single point,
typically near the output capacitor return terminal.
3 FB
Feedback Regulation Point. Connect to the center tap of a resistive divider from the output (V OUT ) to
GND to set the output voltage. The FB voltage regulates to 1.245V (typ).
4 SHDN
Active-Low Shutdown Control Input. A logic-low voltage on SHDN shuts down the device and reduces
the supply current to 0.5µA (max). Connect SHDN to IN for always-on operation. Do not connect
SHDN to a voltage higher than V
IN .
5 IN Input Supply Voltage. Bypass IN to PGND with a 4.7µF minimum ceramic capacitor.
6 CN
Negative Terminal of the Charge-Pump Flying Capacitor for 2.7V to 5.5V Supply Voltage Operation.
Leave CN unconnected when the input voltage is in the +5.5V to +11V range.
7 CP
Positive Terminal of the Charge-Pump Flying Capacitor for 2.7V to 5.5V Supply Voltage Operation.
Connect to IN when the input voltage is in the +5.5V to +11V range.
8 PGND
Power Ground. Connect the input and output filter capacitors’ negative terminal to PGND. Connect
externally to GND at a single point, typically at the output capacitor return terminal.
— EP
Exposed Pad. Connect EP to a large copper plane at the GND potential to improve thermal
dissipation. Do not use as the main GND connection.
Functional Diagram
N
MAX15032
+A
-C
-A
+C
CLK
V REF
SHDN
V REF
LX
PGND
FB
GND
CN
CP
IN
SWITCH
CONTROL
LOGIC
SOFT-
START
OSCILLATOR
500kHz
CHARGE
PUMP
(DOUBLER)
BIAS AND
REFERENCE
THERMAL
SHUTDOWN
SWITCH
CURRENT
SENSE
UVLO