MC34063A
t
on-off
.OUTPUT SWITCH ON-OFF TIME(μS)
1000
500
200
100
50
20
10
5.0
2.0
1.0
DC-TO-DC Converter Control Circuits
TYPICAL PERFORMANCE CHARACTERISTICS
V
CC
=5.0V
Pin7=V
CC
Pin5=GND
T
A
=25°C
t
on
V
OSC,
OSOCILLATOR VOLTAGE(V)
200 mV / DIV
V
CC
=5.0V Pins1,5,8=Open
Pin7=V
CC
C
T
=1.0μF
Pin2=GND T
A
=25°C
10μS / DIV
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6
V
CC
=5.0V
Pin7=V
cc
Pins 2
,3,5=GND
T
A
= 25ºC
Forcedβ = 20
Darlington Connection
t
off
0.01 0.02 0.05 0.1 0.2 0.5
1.0 2.0
5.0
10
C
T
,OSCILLATOR TIMING CAPACITOR(nF)
Figure 3. Timing Capacitor Waveform
Figure 2. Output Switch On−Off Time vs.
Oscillator Timing Capacitor
1.8
V
CE
(sat),SATURATION VOTAGE(V)
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1.0
0
0.2
0.4 0.6 0.8 1.0 1.2 1.4 1.6
V
CC
=5.0V
P
ins
1,7,8=V
cc
P
ins
3,5=GND
T
A
= 25ºC
V
CE
(sat),SATURATION VOTAGE(V)
I
E
, EMITTER CURRENT(A)
Figure 4. Emitter Follower Configuration Output
Saturation Voltage vs. Emitter Current
I
C
, COLLECTOR CURRENT(A)
Figure 5. Common Emitter Configuration Output Switch
Saturation Voltage vs. Collector Current
400
3.6
V
cc
=5.0V
I
chg
=I
dischg
V
IPK
(sense),CURRENT LIMIT
I
CC
,SUPPLY CURRENT(mA)
380
360
3.2
2.8
2.4
2.0
1.6
1.2
0.8
0.4
0
0
5.0 10
15
20
25 30
35
40
C
T
=1.0nF
Pin7=V
cc
Pin2=GND
SENSE VOLTAGE(V)
340
320
300
280
260
240
220
200
-55
-25
0
25
50
75
100 125
T
A
,AMBIENT TEMPERATURE(°C)
Figure 6. Current Limit Sense Voltage vs.
Temperature
V
CC
,S UPPLY VOLTAGE(V)
Figure 7. Standby Supply Current vs. Supply Voltage
5
WINGS [ WING SHING COMPUTER COMPONENTS ]
