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Max619 regulated 5v charge-pump dc-dc converter, Chip topography – Rainbow Electronics MAX619 User Manual

Page 7

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MAX619

Regulated 5V Charge-Pump

DC-DC Converter

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7

Layout Considerations

The MAX619’s high oscillator frequency makes good
layout important. A good layout ensures stability and
helps maintain the output voltage under heavy loads.
For best performance, use very short connections to
the capacitors.

Paralleling Devices

Two MAX619s can be placed in parallel to increase
output drive capability. The IN, OUT, and GND pins
can be paralleled, but C1 and C2 pins cannot. The
input bypass capacitor and output filter capacitor are,
to some extent, shared when two circuits are paral-
leled. If the circuits are physically close together, it
may be possible to use a single bypass and a single
output capacitor, each with twice the value of the single
circuit. If the MAX619s cannot be placed close togeth-
er, use separate bypass and output capacitors. The
amount of output ripple observed will determine
whether single input bypass and output filter capacitors
can be used.

___________________Chip Topography

C1+

C1-

SHDN

GND

0.115”

(2.921mm)

IN

OUT

C2+

C2-

0.072”

(1.828mm)

TRANSISTOR COUNT: 599;
SUBSTRATE CONNECTED TO GND.

MAX619

IN

OUT

GND

INPUT

5V, 40mA

MAX619

IN

OUT

GND

Figure 3. Paralleling Two MAX619s