MAX8627 Maxim Integrated Products, MAX8627 Datasheet - Page 12

• Manufacturer Part Number: MAX8627
• Description: Synchronous Boost Converter
• Manufacturer: Maxim Integrated Products

Low V
Boost Converter with True Shutdown
ILIM sets the current limit when the output reaches
regulation. It is different from the startup current limit
used during soft-start to control inrush current. For the
maximum current limit of 3.5A, connect ILIM to GND.
To set the current limit (I
ILIM to a resistor-divider from POUT to GND as shown
in
does not change with voltage setting on ILIM.
Set R3 between 30kΩ and 300kΩ, then calculate the
value of R4 as follows:
12
Figure
______________________________________________________________________________________
R
1. Note, however, that the idle-mode threshold
4
=
R x
3
BATT
⎛
⎜
⎝
(
I
LIM
Setting the Current Limit
+
LIM
0 64
, 20µA IQ, 1MHz Synchronous
.
V
) lower than 3.5A, connect
POUT
A
)
×
0 2865
.
Ω
−
1
⎞
⎟
⎠
Good PC board layout is important to achieve optimal
performance from the MAX8627. Poor design can
cause excessive conducted and/or radiated noise.
Conductors carrying discontinuous currents and any
high-current path should be made as short and wide as
possible. Keep the feedback network (R1 and R2) very
close to the IC, preferably within 0.2in of the FB and
GND pins. Nodes with high dV/dt (switching nodes)
should be kept as small as possible and routed away
from FB. Connect the input and output capacitors as
close as possible to the IC. Refer to the MAX8627
evaluation kit for a PC board layout example.
PROCESS: BiCMOS
PC Board Layout and Routing
Chip Information