MC34063AD Datasheet, PDF (3/9 Pages) Tiger Electronic Co.,Ltd – DC-to-DC Converter Control Circuits

MC34063A
ELECTRICAL CHARACTERISTICS
(Unless otherwise specified: Vcc=5.0V, Ta=0~70°C)
CHARACTERISTICS
SYMBOL MIN TYP MAX UNIT
O S C I L L AT O R
Frequency (Vpin5=0V, Vcc=5.0V)
fosc
24 33 42 kHz
Charge current (Vcc=5.0~40V, Vpin3=L)
Ichg
24 31 42 µA
Discharge current (Vcc=5.0~40V, Vpin3=H)
Idischg 140 199 260 µA
Discharge to charge current ratio
(V_PIN7=V_CC, Ta=25°C)
Current limit sense voltage
(Ichg=Idischg, Ta=25°C)
Idischg/Ichg 5.2 6.2 7.5
Vipk(sense) 250 300 350 mV
OUTPUT SWITCH (Note 3)
Saturation voltage, Darlington connection(Note 4)
(ISW=0.8A, pins 1,8 connected)
Saturation voltage, Darlington connection
(ISW=0.8A, Rpin 8=82Ω to Vcc)
VCE(sat)
VCE(sat)
0.9 1.3 V
0.45 0.7 V
D C c u r r e n t g a i n ( I S W = 0 . 8 A , VCE= 5 . 0 V, Ta = 2 5 °C )
hFE
50 120
Collector off-state current (VCE=40V)
Ic(off)
2 100 µA
C O M PA R AT O R
Threshold voltage (Ta=25°C, Vcc=5.0V)
Threshold voltage line regulation (Vcc=5.0~40V)
Vth
Regline
1.23 1.25 1.27 V
4.0 5.0 mV
Input bias current(Vin=0V)
IIB
-40 -400 nA
TOTAL DEVICE
S u p p l y c u r r e n t ( V c c = 5 . 0 ~ 4 0 V, V p i n 5 = H )
Icc
2.36 4.0 mA
Notes: 3. Low duty cycle pulse techniques are used during test to maintain junction temperature
as close to ambient temperature as possible.
4. If the output switch is driven into hard saturation (non-Darlington configuration) at low
switch currents (≤ 300 mA) and high driver currents (≥ 30 mA), it may take up to 2.0 µs for it to
come out of saturation. This condition will shorten the off time at frequencies≥ 30 kHz, and is
magnified at high temperatures. This condition does not occur with a Darlington configuration,
since the output switch cannot saturate. If a non-Darlington configuration is used, the following
output drive condition is recommended:
Forced βof output switch : Ic output/ (Ic drive –7.0mA)* ≥10
*The 100Ω resistor in the emitter of the driver device requires about 7.0 mA before the output
switch conducts.