mc34063acs Analog Intergrations Corporation, mc34063acs Datasheet - Page 6

• Manufacturer Part Number: mc34063acs
• Description: Dc/dc Converter Control Circuit
• Manufacturer: Analog Intergrations Corporation

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ANALOG INTEGRATIONS CORPORATION
4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C.
chosen:
V
V
The following power supply characteristics must be
V
V
I
OUT
APPLICATION EXAMPLES
SAT
F
IN
OUT
= Saturation voltage of the output switch.
= Forward voltage drop of the ringback rectifier
-
-
-
Nominal input voltage.
Desired output voltage,
Desired output current.
Line Regulation
Load Regulation
Short Circuit Current
V
OUT
=1.25 (1 + RB/RA)
V
C1
IN
+
Fig. 2 Step-Down Converter with External PNP Saturation Switch
V
IN
RS
0.25
100 F
+
RS
C1
RS
6
7
5
8
DRI
IPK
VCC
FB
8
7
6
5
Fig. 1 Step-Down Converter
DRI
VCC
FB
IPK
V
V
V
MC34063A
MC34063A
IN
IN
IN
= 10V ~20V @ I
= 15V, @ I
=15V, @ R
RB
GND
GND
CS
SE
TC
TC
CS
SE
2
3
4
1
2
3
4
1
O
L
=10mA ~ 500mA
= 0.1
F
V
R2
MIN
RIPPLE (P-P)
www.analog.com.tw
TEL: [phone] FAX:[phone]
CT
470pF
O
CT
=500mA
R1
D1
D1
1N5821
DC/DC CONVERTER CONTROL CIRCUIT
-
-
200 H
Q1
Minimum desired output switching frequency
at the selected values for V
Desired peak-to-peak output ripple voltage.
In practice, the calculated value will need to
be increased due to the capacitor equivalent
series resistance and board layout. The
ripple voltage should be kept to a low value
since it will directly effect the line and load
regulation.
RA
1.2K
L
L
+
3.6K
RB
Co
C
470 F
+
O
V
5V/500mA
V
OUT
OUT
40mV
5mV
1.3A
SPEC NO: DS34063A-P2
MC34063A
IN
and I
OUT
.
6