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! FEATURES
" 3V to 30V Input Voltage Operation.
" Internal 1.6A Peak Current Switch.
" Internal ±1.8% Reference.
" Low Quiescent Current at 1.6mA.
" Frequency Operation from 100Hz to 100KHz.
" Current Limiting.
! APPLICATIONS
" Saver for Cellular phones
" DC-DC Converter Module
MC34063A
DC/DC CONVERTER CONTROL CIRCUIT
SPEC NO: DS34063A-00
! DESCRIPTION
The MC34063A by Analog Integrations
Corporation, an improved second source over the
industrial standard MC34063A, is a monolithic
control circuit containing the primary functions
required for DC/DC converters. The device
consists of an internal temperature compensated
reference, comparator, controlled duty cycle
oscillator with an active current limit circuit, driver
and high current output switch. This device is
specifically designed to be incorporated in step-
down, step-up and voltage-inverting applications
with a minimum number of external components.
The ±1.8% internal reference and low quiescent
current of 1.6mA are among the improvements of
the device over the competition.
! TYPICAL APPLICATION CIRCUIT
200µH
VOUT
*RS
VIN
+
C1 100µF
8
DRI
7
IPK
6
VCC
5
FB
1
SC
2
SE
3
TC
4
GND
CT
MC34063A
L
D1 +
1N5819
CO
8.6V SAVER
*:Io=0.3/RS
RB
33K
RA
5.6K
Saver Circuit for Cellular Phone
! ORDERING INFORMATION
MC34063A XX
PACKAGE TYPE
N: PLASTIC DIP
S: SMALL OUTLINE
TEMPERATURE
C: 0°C~+70°C
ORDER NUMBER
PIN CONFIGURATION
MC34063ACN
(PLASTIC DIP)
MC34063ACS
(PLASTIC SO)
TOP VIEW
SC 1
SE 2
TC 3
GND 4
8 DRI
7 IPK
6 VCC
5 FB
ANALOG INTEGRATIONS CORPORATION
www.analog.com.tw
4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. TEL: (8863)577-2500 FAX:(8863)577-2510
1
! BLOCK DIAGRAM
SC 1
Q2
Q1
SE 2
80
QS
R
MC34063A
DC/DC CONVERTER CONTROL CIRCUIT
SPEC NO: DS34063A-00
8 DRI
7 IPK
TC 3
GND 4
CT IS
Oscillator
1.25V
Reference
Voltage
Comparator
+
-
6
VCC
5 FB
! PIN DESCRIPTIONS
PIN 1: SC - 1.6A switch collector
PIN 2: SE - Darlington switch emitter
PIN 3: TC - Oscillator timing capacitor
PIN 4: GND - Power GND
! APPLICATION INFORMATION
• DESIGN FORMULA TABLE
CALCULATION
t ON
t OFF
(tON + tOFF) MAX
STEP-DOWN
VOUT + VF
V - V - VIN(MIN) SAT OUT
1
FMIN
CT 4x10-5tON
IC (SWITCH)
2IOUT(MAX)
RS
L(MIN)
Co
0.33/IC(SWITCH)
V - V - V tIN(MIN)
SAT OUT
ON(MAX)
IC(SWITCH)
I ( t + tC ( SWITCH) ON
OFF)
8 VRIPPLE( P - P )
PIN 5: FB - Feedback comparator inverting input
PIN 6: VCC - Power supply input
PIN 7: IPK
PIN 8: DRI
- Highside current sense input,
VCC - VIPK=300mV
- Drive collector
STEP-UP
V + V VOUT
F - IN(MIN)
V - VIN(MIN)
SAT
1
FMIN
4 x 10-5tON
2IOUT(MAX)
(
t ON + t OFF )
t OFF
0.33/ IC (SWITCH)
V - V tIN(MIN)
SAT
ON(MAX)
IC(SWITCH)
I tOUT ON
VRIPPLE(P - P)
VOLTAGE-INVERTING
VOUT + VF
VIN - VSAT
1
FMIN
4 x 10-5tON
2IOUT(MAX)
(
t ON + t OFF )
t OFF
0.33/ IC (SWITCH)
V - V tIN(MIN)
SAT
ON(MAX)
IC(SWITCH)
I tOUT ON
VRIPPLE(P - P)
ANALOG INTEGRATIONS CORPORATION
www.analog.com.tw
4F, 9 Industry E. 9th Road, Science-based Industrial Park , Hsinchu, Taiwan, R.O.C. TEL: (8863)577-2500 FAX:(8863)577-2510
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