DC-DC Converter Control Circuits MC34063A
● OUTPUT SWITCH CURRENT IN EXCESS OF
1.5A
●
2% REFERENCE ACCURACY
●
LOW QUIESCENT CURRENT:2.5mA(TYP.)
●
OPERATING FROM 3V TO 40V
●
REQUENCY OPERATION TO 100KHz
●
ACTIVE CURRENT LIMITING
DESCRIPTION
The MC34063A series is a monolithic control
circuit delivering the main functions for DC-DC
voltage converting. ORDERING INFORMATION
The device contains an intermal temperature
compensated reference, comparator, duty cycle
controlled oscillator with an active current limit
circuit driver and high current output switch.
Output voltage is adjustable through two external
resistors with a 2% reference accuracy.
Employing a minimum number of external
components the MC34063A devices series is
designed for Step-Down, Step-Up and
Voltage-lnverting applications.
BLOCK DIAGRAM
HTC
1
MC34063AN 8 DIP
Device Package
MC34063AD 8 SOP
Ipk Oscillator
s
R
8
3
6
4
5
72
1
Q
+
Vcc
Drive
Collector
Ipk Sense Switch
Emitter
Switch
Collector
GND
-
1.25V
Reference
Regulator
Comparator
lnverting
input
Comparator
Q2
Q1
Timing
Capacitor
1
2
3
4
8
7
6
5
Switch
Emitter
Timing
Capacitor
Ground
Ipk Sense
Vcc
Comparator
- Input
Drive
Collector
Switch
Collector
8 SOP/ 8 DIP PIN Configulation
DC-DC Converter Control Circuits MC34063A
ABSOLUTE MAXIMUM RATINGS
PARAMETER VALUE UNIT
Power Supply Voltage
Comparator input Voltage Range
Switch Collector Voltage
Switch Emitter Voltage (VSWC=40V)
Switch Collector to Emitter Voltage
Driver Collector Voltage
Driver Collector Current
Switch Current
Power Dissipation at Tamb=25℃(for Plastic Package )
(for SOIC Package )
Operating Ambient Temperature Range
Storage Temperature Range
Absolute Maximum Rating are those values beyond which damage to the device may occur.
Functional operation under these condition is not implied.
THERMAL DATA
PARAMETER UNIT
Thermal Resistance Junction-ambient
(
*
)
Max
(
*
)
This Value de
p
ends from thermal desi
g
n of PCB on which the device is mounted.
CONNECTION DIAGRAM (to
p
view) PIN CONNECTIONS
PIN NO SYMBOL NAME AND FUNCTION
SWC Switch Collector
SWE Switch Emitter
TC Timing Capactor
GND Ground
CII Comparator lnverting lnput
Vcc Voltage Supply
SC11080 IPK IPK Sense
DRC Voltage Driver Collector
HTC
SO-8
160 ℃/w
2
5
6
7
8
1
2
3
4
SYMBOL
Rthi-amb
DIP-8
100
Ptot
Top
Tstg
SYMBOL
VCE
Vdc
Idc
Isw
Vcc
Vir
VSWC
VSWE
℃
1.25 W
0.625
100 ㎃
-40 to 150 ℃
0 to 70 ℃
℃
1.5 A
40 V
40 V
50 V
-0.3 to 40 V
40 V
40 V
1
4
8
5
SWC
GND
SWE
TC
CII
VCC
IPK
DRC
DC-DC Converter Control Circuits MC34063A
ELECTRICAL CHARACTERISTICS( Refer to the test circuits, VCC=5V, Ta=TLOW to THIGH, unless
otherwise specified, see note 2)
OSCILLATOR
Frequency V
pin5
= 0 V ,C
T
= 1nF ,T
a
= 25oC
Charge Current V
CC
= 5 to 40V ,T
a
= 25oC
Discharge Current V
CC
= 5 to 40V ,T
a
= 25oC
Discharge to Charge Current Ratio Pin 7= V
CC
,T
a
= 25oC
Current Limit Sense Voltage I
chg
= I
dischg
,T
a
= 25oC
OUTPUT SWITCH
Saturation Voltage, ISW= 1A ,Pins 1,8 connected
Darlington connection
Saturation Voltage ISW= 1A ,R
p
in8= 82Ω to VCC,
Forced β ~ 20
DC Current Gain I
SW
= 1A, V
CE
= 5V, T
a
= 25oC
Collector Off-State Current VCE= 40V
COMPARATOR
Threshold Voltage T
a
= 25oC
Ta= TLOW to THIGH
Threshold Voltage Line Regulation VCC= 3 to 40V
Input Bias Current VIN= 0V
TOTAL DEVICE
Supply Current VCC= 5 to 40V, CT=1㎋
Pin7= VCC ,V
p
in5>Vth, Pin2=GN
D
Remaining pins open
for MC34063A
Start-up Voltage(note 4) T
a
= 25oC ,C
T
=1㎌ ,Pin5= 0V
for MC34063A
Notes:
1) Maximum package power dissipation limit must be observed.
2) TLOW= 0oC, THIGH
= 70oC
3) If Darlington configuration is not used, care must be taken to avoid deep saturation of output switch.
The resulting switch-off time may be adversely affected.
In a Darlington configuration the following output driver condition is suggested:
Forced β of output current switch= ICOUTPUT
/(ICDRIVER
-1㎃*)≥10
* Current less due to a built in 1KΩ antileakage resistor.
4) Start-up Voltage is the minimum Power Supply Voltage at which the internal oscillator begains to work.
HTC
TEST CONDITIONS MIN. TYP. MAX. UNIT
FOSC 24 33 42 KHz
SYMBOL PARAMETER
㎂
Idischg 140 200 260 ㎂
Ichg 24 33 42
Vipk(sense) 250 300 350 ㎷
Idischg/Ichg 5.2 6.2 7.5
UNIT
VCE(sat) 1 1.3 V
SYMBOL PARAMETER TEST CONDITIONS MIN.
0.45 0.7
TYP. MAX.
0.01 100
V
hFE 50 120
VCE(sat)
㎂
SYMBOL PARAMETER TEST CONDITIONS MIN. TYP. MAX. UNIT
IC(off)
Vth 1.225 1.25 1.275
15
V
1.21 1.29 V
TEST CONDITIONS MIN.
㎷
IIB -5 -400 ㎁
Regline
TYP. MAX. UNIT
ICC 2.5 4 ㎃
SYMBOL PARAMETER
VSTART-UP 2.1 V
3
DC-DC Converter Control Circuits MC34063A
TYPICAL ELECTRICAL CHARACTERISTICS
Emitter Follower Configuration Output Saturation Out
p
ut Switch ON-OFF Time vs Oscillato
r
Voltage vs Emitter Current Timing Capacitor
Common Emitter Configuration Output Switch Darlington Configuration Collector Emitter
Saturation Voltage vs Collector Current Saturation Voltage (VCE
(
sat
)
) vs Temperature
Power Collector Emitter Ssturation Voltage Current Limit Sense Voltage Voltage (Vi
pk
) vs
(VCE(sat
)
) vs Temperature Temperature
HTC
4
IE(㎃)
400 800
1.45
VCE
(sat)
0 1200
(V)
1.40
1.50
1.55
1.65
1.60
1.70
1.75
0 400 800 1200 1C(㎃)
VCE
(sat)
(V)
1.0
0.8
0.6
0.4
0.2
Darlington Connection
VCC
=5V
Pin7=VCC
Pins2,3,5=GND
Ta=25℃
Forced β =20
VCC
=5V
Pin1,7,8=VCC
Pins3,5=GND
Ta=25℃
VCE
(sat)
350
550
500
450
400
600
80400 TJ(℃)
120-40
VCC
=5V
IC=1A
VCC
=5V
IC=1A
Ton
Toff
(㎲)
200
150
100
50
0.01
0
0.1 1CT(㎋)
VCC
=5V
Pin7=VCC
Pin5=GND
Ta=25℃
(㎷)
VCE
(sat)
(㎷)
1000
950
900
850
800
-40
750
040 80 120 TJ(℃)
Vipk
(㎷)
270
280
290
300
310
320
-40 040 80 120 TJ(℃)
MC34063A
VCC
=5V
Ichg
=Idischg
0
Ton
Toff
DC-DC Converter Control Circuits MC34063A
TYPIC
A
L ELECTRIC
A
L CH
A
R
A
CTERISTICS
(
Continued
)
Reference Voltage vs Temperature Bias Current vs Temperature
Supply Current vs Temperature Supply Current vs Input Voltage
HTC
5
Vref
(V)
1.240
1.245
1.250
1.255
1.260
1.265
-40 040 80 120 TJ(℃)
VCC
=5V
ICC
(㎃)
0
1
2
3
4
5
-40 040 80 120 TJ(℃)
VCC
=5V
CT=1㎋
1.5
2.0
2.5
3.0
3.5
4.0
010 20 40 Vin(V)
TJ= 25℃
CT= 1㎋
IBias
0
6
8
10
-40 040 80 120 TJ(℃)
VCC
=5V
CII
to GND
(㎁)
2
4
(㎃)
30
ICC
DC-DC Converter Control Circuits MC34063A
TYPICAL APPLICATION CIRCUIT
Step-Up Converter
DRC SWC
Ipk SWE
Vcc TC
VIN CII GND VOUT
12V 25V/175㎃
MC34063A
Step-Down Converter
DRC SWC
Ipk SWE
Vcc TC
VIN CII GND
25V
MC34063A
VOUT
5V/0.5A
HTC
6
C2
100㎌
+
R1
C3
1.5㎋
R3
Rsc
R2
D1
BYV10-40
C1
330㎌
+
L1
8
7
6
5
1
2
3
4
180Ω
0.22Ω
2.2KΩ 44KΩ
170μH
C2
100㎌
+
R1
C3
470㎊
Rsc
R2
BYV10-40
D1
C1
470㎌
+
220μH
L
8
7
6
5
1
2
3
4
0.33Ω
1.2KΩ 3.5KΩ
DC-DC Converter Control Circuits MC34063A
Step-Up With External NPN Switch
VOUT
VIN
Voltage Inverting Converter
DRC SWC
Ipk SWE
Vcc TC
VIN CII GND
4.5V to 5V
MC34063A
VOUT
-12V /100㎃
HTC
7
C2
100㎌
+
R2
C3
1.5㎋
R3
R1
D1
BYV10-40
C1
1000㎌
+
L1
8
7
6
5
1
2
3
4
0.22Ω
8.2KΩ 953Ω
-
+
Rsc
+
1
2
3
4
5
6
7
8
Q2
Q1
comparator
Ipk Oscillator
1.25V
Reference
Regulator
90μH
S Q
R
DC-DC Converter Control Circuits MC34063A
Step-Down With External NPN Switch
VOUT
VIN
Step-Down With External PNP Switch
VOUT
VIN
HTC
8
-
+
Rsc
+
2
3
4
5
6
Q2
Q1
comparator
Ipk Oscillator
1.25V
Reference
Regulator
1
8
7
-
+
Rsc
+
2
3
4
5
6
7
8
Q2
Q1
comparator
Ipk Oscillator
1.25V
Reference
Regulator
1
S Q
R
S Q
R
DC-DC Converter Control Circuits MC34063A
Voltage Inverting With External NPN Switch
VOUT
VIN
Voltage Inverting With External PNP Saturated Switch
VOUT
VIN
HTC
9
-
+
Rsc
5
6
7
8
Q2
Q1
comparator
Ipk Oscillator
1.25V
Reference
Regulator
1
+
-
+
Rsc
Q2
Q1
comparator
Ipk Oscillator
1.25V
Reference
Regulator
+
S Q
R
S Q
R
2
3
4
8
7
6
5
4
3
2
1
DC-DC Converter Control Circuits MC34063A
Dual Output Voltage
+12V
GND
-12V
VIN
Higher Output Power, Higher Input Voltage
+VOUT
-VOUT
VIN
HTC
10
Rsc
5
Q2
Q1
comparator
Ipk Oscillator
1.25V
Reference
Regulator
+
+
6
7
8
1
2
3
4
S Q
R
Rsc
2
3
4
6
Ipk Oscillator
1.25V
Reference
Regulator
7
1
8
5
+
+Isolated from input
S Q
R
comparator
-
+
-
+
