Microchip Technology ADM00352 Data Sheet
2011-2013 Microchip Technology Inc.
DS20005004C-page 15
MCP16301/H
To calculate the shunt resistance, the maximum I
BOOST
and I
Z
current are used at the minimum input voltage
).
EQUATION 4-2:
SHUNT RESISTANCE
V
Z
and I
Z
can be found on the Zener diode
manufacturer’s data sheet (typical I
Z
= 1 mA).
FIGURE 4-4:
Series Regulator Boost Supply.
Series regulator applications use a Zener diode to drop
the excess voltage. The series regulator bias source
can be input or output voltage derived, as shown in
the excess voltage. The series regulator bias source
can be input or output voltage derived, as shown in
. For proper circuit operation, the boost
supply must remain between 3.0V and 5.5V at all
times.
times.
R
SH
V
INMIN
V
Z
–
I
Boost
I
Z
+
------------------------------
=
C
B
V
OUT
V
IN
C
IN
C
OUT
SW
BOOST
GND
EN
FB
L
R
TOP
R
BOT
V
IN
Boost Diode
FW Diode
12V
15V to 36V
C
B
V
IN
C
IN
SW
BOOST
GND
EN
FB
L
V
IN
Boost Diode
FW Diode
2V
12V
VZ = 7.5V
VZ = 7.5V
V
OUT
R
TOP
R
BOT
C
OUT
MCP16301/H
MCP16301/H