ETC 34063A

34063A
DC-TO-DC CONVERTER CONTROL CIRCUITS
The 34063A is a monolithic control circuit containing the primary functions required for DC-to-DC converters.
These devices consist of an internal temperature compensated reference, comparator, controlled duty cycle
oscillator with an active current limit circuit, driver and high current output switch. This series was specifically
designed to be incorporated in Step-Down and Step-Up and Voltage-Inverting applications with a minimum number
of external components.
FEATURES
FUNCTIONAL BLOCK DIAGRAM
•
•
•
•
•
•
•
Operation from 3.0 V to 40 V Input
Low Standby Current
Current Limiting
Output Switch Current to 1.5 A
Output Voltage Adjustable
Frequency Operation to 100 kHz
Precision 2% Reference
MAXIMUM RATINGS
Rating
Power Supply Voltage
Comparator Input Voltage Range
Symbol
VCC
VIR
Switch Collector Voltage
Switch Emitter Voltage (Vpin 1 = 40 V)
Switch Collector to Emitter Voltage
Driver Collector Voltage
Driver Collector Current (Note 1)
Switch Current
Power Dissipation and Thermal Characteristics
Ceramic Package, U Suffix TA = +25°C
Thermal Resistance
Plastic Package, P Suffix TA = +25°C
Thermal Resistance
SOIC Package, D Suffix TA = +25°C
Thermal Resistance
Operating Junction Temperature
Operating Ambient Temperature Range
Storage Temperature Range
VC(switch)
VE(switch)
VCE(switch)
IC(driver)
IC(driver)
ISW
PD
RθJA
PD
RθJA
PD
RθJA
TJ
TA
Tstg
Value
40
-0.3 to
+40
40
40
40
40
100
1.5
Unit
Vdc
Vdc
Vdc
Vdc
Vdc
Vdc
mA
A
1.25
100
1.25
100
625
160
+150
0 to +70
-65to+150
W
°C/W
W
°C/W
mW
°C/W
°C
°C
°C
ORDERING INFORMATION
Device
Temperature
Range
34063AD 0° to +70°C
34063AP1
Pin connection
Package
SO-8
Plastic DIP
ELECTRICAL CHARACTERICISTICS
o
(VCC = 5.0 V, TA= 0 to +70 C unless otherwise specified.)
Characteristics
Symbol
OSCILLATOR
Frequency (VPin 5 = 0 V, CT = 1.0 nF, TA = 25°C)
fosc
Charge Current (VCC = 5.0 V to 40 V, TA = 25°C)
Ichg
Discharge Current (VCC = 5.0 V to 40 V, TA = 25°C)
Idischg
Discharge to Charge Current Ratio (Pin7 to Vcc, TA=25°C) Idischg/Ichg
Current Limit Sense Voltage (Ichg = Idischg, TA = 25°C)
Vlpk(sense)
OUTPUT SWITCH (Note 3)
Saturation Voltage, Darlington Connection (ISW = 1.0 A,
VCE(sat)
Pins 1, 8 connected)
VCE(sat)
Saturation Voltage (ISW = 1.0 A, RPin 8 = 82 Ω to VCC.
Forced β = 20)
=
DC Current Gain (ISW = 1.0 A, VCE 5.0 V, TA = 25°C) hFE
Collector Off-State Current (VCE = 40V)
IC(off)
COMPARATOR
Threshold Voltage (TA = 25°C)
Vth
(TA = TLOW to THIGH)
Threshold Voltage (TA = 25°C) **
Threshold Voltage Line Regulation (VCC = 3.0 V to 40 V)
Input Bias Current (Vin=0V)
Vth
V REG line
IIB
TOTAL DEVICE
Supply Current (VCC = 5 0 V to 40 V, CT = 1 0 nF, Vpin7 =
ICC
VCC. VPin5 > Vth, Pin 2 = Gnd, Remaining pins open)
Min
Typ
Max
Unit
24
24
140
5.2
250
33
33
200
6.2
300
42
42
260
7.5
350
kHz
µA
µA
—
mV
—
1.0
1.3
V
—
0.45
0.7
V
50
—
120
0.01
—
100
—
µA
1.225
1.21
1.2375
1.25
—
1.25
1.275
1.29
1.2625
V
V
—
1.4
-40
5.0
-400
mV
nA
2.5
4.0
mA
NOTES:
1. Maximum package power dissipation limits must be observed.
2.
Low duty cycle pulse techniques are used during test to maintain Junction temperature as close to ambient
temperature as possible
3.
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 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 β of output switch = IC, output/(Ic, driver -7.0 mA*) > 10
*The 100 Ω. resistor in the emitter of the driver device requires about 7.0 mA before the output switch conducts
**Possible version for shipment