Datasheet

MAX8627
Low V
BATT
, 20µA IQ, 1MHz Synchronous
Boost Converter with True Shutdown
12
Maxim Integrated
Setting the Current Limit
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
LIM
) lower than 3.5A, connect
ILIM to a resistor-divider from POUT to GND as shown
in Figure 1. Note, however, that the idle-mode threshold
does not change with voltage setting on ILIM.
Set R3 between 30kΩ and 300kΩ, then calculate the
value of R4 as follows:
PC Board Layout and Routing
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.
Chip Information
PROCESS: BiCMOS
RRx
V
IA
POUT
LIM
43
0 64 0 2865
1=
+
()
×Ω
−
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⎝
⎜
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⎠
⎟
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