Features: • Separate High Current Source and Sink Outputs Ideally Suited for Driving Bipolar Power Transistors: 1.0 A
Source, 1.5 A Sink
• Unique Overload and Short Circuit Protection
• Thermal Protection
• Oscillator with Sync Input
• Current Mode Operation to 500 kHz Output Switching Frequency
• Output Deadtime Adjustable from 50% to 70%
• Automatic Feed Forward Compensation
• Latching PWM for CycleByCycle Current Limiting
• Input and Reference Undervoltage Lockouts with Hysteresis
• Low Startup and Operating Current
Pinout
Specifications
|
Rating |
Symbol |
Value |
Unit |
| Total Power Supply and Zener Current |
(ICC + IZ) |
30 |
mA |
Sink Ground Voltage
with Respect to Gnd (Pin 9) |
VSink(neg) |
5.0 |
V |
Output Supply Voltage
with Respect to Sink Gnd (Pins 4, 5, 12, 13)
|
VC |
20 |
V |
Output Current (Note 1)
Source
Sink |
IO(Source)
IO(Sink) |
1.0
1.5 |
A |
| Output Energy (Capacitive Load per Cycle) |
W |
5.0 |
J |
| Current Sense and Voltage Feedback Inputs |
Vin |
0.3 to 5.5 |
V |
Sync Input
High State Voltage
Low State Reverse Current |
VIH
IIL |
5.5
20 |
V
mA |
| Load Detect Input Current |
Iin |
20 to +10 |
mA |
| Error Amplifier Output Sink Current |
IEA (Sink) |
10 |
mA |
Power Dissipation and Thermal Characteristics
Maximum Power Dissipation at TA = 25
Thermal Resistance, JunctiontoAir
Thermal Resistance, JunctiontoCase |
PD
RJA
RJC |
2.5
80
15 |
W
/W
/W |
| Operating Junction Temperature |
TJ |
150 |
|
| Operating Ambient Temperature |
TA |
25 to +85 |
|
NOTE: 1. Maximum package power dissipation limits must be observed.DescriptionThe MC44602 is an enhanced high performance fixed frequency current mode controller that is specifically designed for offline and high voltage dctodc converter applications. This device has the unique ability of changing operating modes if the converter output is overloaded or shorted, offering the designer additional protection for increased system reliability. The MC44602 has several distinguishing features when compared to conventional current mode controllers. These features consist of a foldback amplifier for overload detection, valid load and demag comparators with a fault latch for short circuit detection, thermal shutdown, and separate high current source and sink outputs that are ideally suited for driving a high voltage bipolar power transistor, such as the MJE18002, MJE18004, or MJE18006.
Standard features of MC44602 include an oscillator with a sync input, a temperature compensated reference, high gain error amplifier, and a current sensing comparator. Protective features consist of input and reference undervoltage lockouts each with hysteresis, cyclebycycle current limiting, a latch for single pulse metering, and a flipflop which blanks the output off every other oscillator cycle, allowing output deadtimes to be programmed from 50% to 70%. MC44602 is manufactured in a 16 pin dualinline heat tab package for improved thermal conduction.
MC44602 Data Sheet
