MAX8571 MAXIM [Maxim Integrated Products], MAX8571 Datasheet - Page 5

• Manufacturer Part Number: MAX8571
• Description: High-Efficiency LCD Boost with True Shutdown
• Manufacturer: MAXIM [Maxim Integrated Products]

(MAX8571, V
PIN
1
2
3
4
5
6
(MAX8570/
(MAX8572/
MAX8571/
MAX8574)
MAX8573/
MAX8575)
CC
NAME
SHDN
V
GND
I
OUT
V
OUT
OUT
= 3.6V, V
SW
FB
LX
CC
_______________________________________________________________________________________
OUT
Feedback for setting the output voltage. Connect FB to the center of a resistor voltage-divider from the
output to GND to set positive output voltages.
Output. The output voltage is preset to 15V. Connect a 1µF ceramic capacitor from OUT to GND. In
shutdown, OUT is pulled to GND by an internal 7.5MΩ resistor.
Ground
Shutdown Input. A logic low at SHDN places the part in low-power shutdown mode. Pull SHDN high or
connect to V
Inductor Switching Connection
Isolation Switch Output. Internally connected to the drain of a p-channel MOSFET used to isolate the
output from the input during shutdown. Connect a 4.7µF ceramic capacitor from SW to GND. If true
shutdown is not required, SW can be left open with the input supply connected directly to the inductor.
Input Voltage Supply. Connect a 2.7V to 5.5V input supply to V
V
CC
LOAD TRANSIENT
= 18V, Circuit of Figure 2, T
to GND.
100µs/div
CC
MAX8570/71/73/74/75 toc15
for normal operation.
Typical Operating Characteristics (continued)
100mV/div
(AC-COUPLED)
5mA/div
0
A
= +25°C, unless otherwise noted.)
High-Efficiency LCD Boost
V
FUNCTION
SHDN
V
OUT
I
LX
with True Shutdown
STARTUP AND SHUTDOWN WAVEFORMS
1.8Ω LOAD
SW TURN-ON
BOOST SOFT-START
CC
. Connect a 1µF ceramic capacitor from
400µs/div
MAX8570/71/73/74/75 toc16
Pin Description
5V/div
10V/div
0
200mA/div
0
5