The MC33063A and MC34063A devices are easy-to-use ICs containing all the primary circuitry needed for building simple DC-DC converters. These devices primarily consist of an internal temperature-compensated reference, a comparator, an oscillator, a PWM controller with active current limiting, a driver, and a high-current output switch. Thus, the devices require minimal external components to build converters in the boost, buck, and inverting topologies.
The MC33063A device is characterized for operation from –40°C to 85°C, while the MC34063A device is characterized for operation from 0°C to 70°C.
PART NUMBER | PACKAGE (PIN) | BODY SIZE |
---|---|---|
MC3x063A | SOIC (8) | 4.90 mm × 3.91 mm |
SON (8) | 4.00 mm × 4.00 mm | |
PDIP (8) | 9.81 mm × 6.35 mm |
Changes from M Revision (January 2011) to N Revision
PIN | TYPE | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
Switch Collector | 1 | I/O | High-current internal switch collector input. |
Switch Emitter | 2 | I/O | High-current internal switch emitter output. |
Timing Capacitor | 3 | — | Attach a timing capacitor to change the switching frequency. |
GND | 4 | — | Ground |
Comparator Inverting Input | 5 | I | Attach to a resistor divider network to create a feedback loop. |
VCC | 6 | I | Logic supply voltage. Tie to VIN. |
IPK | 7 | I | Current-limit sense input. |
Driver Collector | 8 | I/O | Darlington pair driving transistor collector input. |
MIN | MAX | UNIT | |||
---|---|---|---|---|---|
VCC | Supply voltage | 40 | V | ||
VIR | Comparator inverting input voltage range | –0.3 | 40 | V | |
VC(switch) | Switch collector voltage | 40 | V | ||
VE(switch) | Switch emitter voltage | VPIN1 = 40 V | 40 | V | |
VCE(switch) | Switch collector to switch emitter voltage | 40 | V | ||
VC(driver) | Driver collector voltage | 40 | V | ||
IC(driver) | Driver collector current | 100 | mA | ||
ISW | Switch current | 1.5 | A | ||
TJ | Operating virtual junction temperature | 150 | °C | ||
Tstg | Storage temperature range | –65 | 150 | °C |
VALUE | UNIT | |||
---|---|---|---|---|
V(ESD) | Electrostatic discharge | Human body model (HBM), per ANSI/ESDA/JEDEC JS-001, all pins(1) | 2500 | V |
Charged device model (CDM), per JEDEC specification JESD22-C101, all pins(2) | 1500 |
MIN | MAX | UNIT | |||
---|---|---|---|---|---|
VCC | Supply voltage | 3 | 40 | V | |
TA | Operating free-air temperature | MC33063A | –40 | 85 | °C |
MC34063A | 0 | 70 |
THERMAL METRIC(1) | MC33063A | UNIT | |||
---|---|---|---|---|---|
D | DRJ | P | |||
8 PINS | |||||
RθJA | Junction-to-ambient thermal resistance | 97 | 41 | 85 | °C/W |
PARAMETER | TEST CONDITIONS | TA | MIN | TYP | MAX | UNIT | |
---|---|---|---|---|---|---|---|
fosc | Oscillator frequency | VPIN5 = 0 V, CT = 1 nF | 25°C | 24 | 33 | 42 | kHz |
Ichg | Charge current | VCC = 5 V to 40 V | 25°C | 24 | 35 | 42 | μA |
Idischg | Discharge current | VCC = 5 V to 40 V | 25°C | 140 | 220 | 260 | μA |
Idischg/Ichg | Discharge-to-charge current ratio | VPIN7 = VCC | 25°C | 5.2 | 6.5 | 7.5 | — |
VIpk | Current-limit sense voltage | Idischg = Ichg | 25°C | 250 | 300 | 350 | mV |
PARAMETER | TEST CONDITIONS | TA | MIN | TYP | MAX | UNIT | |
---|---|---|---|---|---|---|---|
VCE(sat) | Saturation voltage – Darlington connection |
ISW = 1 A, pins 1 and 8 connected | Full range | 1 | 1.3 | V | |
VCE(sat) | Saturation voltage – non-Darlington connection(2) |
ISW = 1 A, RPIN8 = 82 Ω to VCC, forced β ∼ 20 |
Full range | 0.45 | 0.7 | V | |
hFE | DC current gain | ISW = 1 A, VCE = 5 V | 25°C | 50 | 75 | — | |
IC(off) | Collector off-state current | VCE = 40 V | Full range | 0.01 | 100 | μA |
PARAMETER | TEST CONDITIONS | TA | MIN | TYP | MAX | UNIT | |
---|---|---|---|---|---|---|---|
Vth | Threshold voltage | 25°C | 1.225 | 1.25 | 1.275 | V | |
Full range | 1.21 | 1.29 | |||||
ΔVth | Threshold-voltage line regulation | VCC = 5 V to 40 V | Full range | 1.4 | 5 | mV | |
IIB | Input bias current | VIN = 0 V | Full range | –20 | –400 | nA |
PARAMETER | TEST CONDITIONS | TA | MIN | MAX | UNIT | |
---|---|---|---|---|---|---|
ICC | Supply current | VCC = 5 V to 40 V, CT = 1 nF, VPIN7 = VCC, VPIN5 > Vth, VPIN2 = GND, All other pins open |
Full range | 4 | mA |
The MC33063A and MC34063A devices are easy-to-use ICs containing all the primary circuitry needed for building simple DC-DC converters. These devices primarily consist of an internal temperature-compensated reference, a comparator, an oscillator, a PWM controller with active current limiting, a driver, and a high-current output switch. Thus, the devices require minimal external components to build converters in the boost, buck, and inverting topologies.
The MC33063A device is characterized for operation from –40°C to 85°C, while the MC34063A device is characterized for operation from 0°C to 70°C.
Based on the application, the device can be configured in multiple different topologies. See the Application and Implementation section for how to configure the device in several different operating modes.
NOTE
Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.
The user must determine the following desired parameters:
Vsat = Saturation voltage of the output switch
VF = Forward voltage drop of the chosen output rectifier
The following power-supply parameters are set by the user:
Vin = Nominal input voltage
Vout = Desired output voltage
Iout = Desired output current
fmin = Minimum desired output switching frequency at the selected values of Vin and Iout
Vripple = Desired peak-to-peak output ripple voltage. The ripple voltage directly affects the line and load regulation and, thus, must be considered. In practice, the actual capacitor value should be larger than the calculated value, to account for the capacitor's equivalent series resistance and board layout.
CALCULATION | VOLTAGE INVERTING |
---|---|
ton/toff | ![]() |
(ton + toff) | ![]() |
toff | ![]() |
ton | ![]() |
CT | ![]() |
Ipk(switch) | ![]() |
RSC | ![]() |
L(min) | ![]() |
CO | ![]() |
Vout | ![]() See Figure 8 |
TEST | CONDITIONS | RESULTS |
---|---|---|
Line regulation | VIN = 4.5 V to 6 V, IO = 100 mA | 3 mV ± 0.12% |
Load regulation | VIN = 5 V, IO = 10 mA to 100 mA | 0.022 V ± 0.09% |
Output ripple | VIN = 5 V, IO = 100 mA | 500 mVPP |
Short-circuit current | VIN = 5 V, RL = 0.1 Ω | 910 mA |
Efficiency | VIN = 5 V, IO = 100 mA | 62.2% |
Output ripple with optional filter | VIN = 5 V, IO = 100 mA | 70 mVPP |
The user must determine the following desired parameters:
Vsat = Saturation voltage of the output switch
VF = Forward voltage drop of the chosen output rectifier
The following power-supply parameters are set by the user:
Vin = Nominal input voltage
Vout = Desired output voltage
Iout = Desired output current
fmin = Minimum desired output switching frequency at the selected values of Vin and Iout
Vripple = Desired peak-to-peak output ripple voltage. The ripple voltage directly affects the line and load regulation and, thus, must be considered. In practice, the actual capacitor value should be larger than the calculated value, to account for the capacitor's equivalent series resistance and board layout.
CALCULATION | STEP UP |
---|---|
ton/toff | ![]() |
(ton + toff) | ![]() |
toff | ![]() |
ton | ![]() |
CT | ![]() |
Ipk(switch) | ![]() |
RSC | ![]() |
L(min) | ![]() |
CO | ![]() |
Vout | ![]() See Figure 10 |
TEST | CONDITIONS | RESULTS |
---|---|---|
Line regulation | VIN = 8 V to 16 V, IO = 175 mA | 30 mV ± 0.05% |
Load regulation | VIN = 12 V, IO = 75 mA to 175 mA | 10 mV ± 0.017% |
Output ripple | VIN = 12 V, IO = 175 mA | 400 mVPP |
Efficiency | VIN = 12 V, IO = 175 mA | 87.7% |
Output ripple with optional filter | VIN = 12 V, IO = 175 mA | 40 mVPP |
The user must determine the following desired parameters:
Vsat = Saturation voltage of the output switch
VF = Forward voltage drop of the chosen output rectifier
The following power-supply parameters are set by the user:
Vin = Nominal input voltage
Vout = Desired output voltage
Iout = Desired output current
fmin = Minimum desired output switching frequency at the selected values of Vin and Iout
Vripple = Desired peak-to-peak output ripple voltage. The ripple voltage directly affects the line and load regulation and, thus, must be considered. In practice, the actual capacitor value should be larger than the calculated value, to account for the capacitor's equivalent series resistance and board layout.
CALCULATION | STEP DOWN |
---|---|
ton/toff | ![]() |
(ton + toff) | ![]() |
toff | ![]() |
ton | ![]() |
CT | ![]() |
Ipk(switch) | ![]() |
RSC | ![]() |
L(min) | ![]() |
CO | ![]() |
Vout | ![]() See Figure 11 |
TEST | CONDITIONS | RESULTS |
---|---|---|
Line regulation | VIN = 15 V to 25 V, IO = 500 mA | 12 mV ± 0.12% |
Load regulation | VIN = 25 V, IO = 50 mA to 500 mA | 3 mV ± 0.03% |
Output ripple | VIN = 25 V, IO = 500 mA | 120 mVPP |
Short-circuit current | VIN = 25 V, RL = 0.1 Ω | 1.1 A |
Efficiency | VIN = 25 V, IO = 500 mA | 83.7% |
Output ripple with optional filter | VIN = 25 V, IO = 500 mA | 40 mVPP |
This device accepts 3 V to 40 V on the input. It is recommended to have a 1000-µF decoupling capacitor on the input.