UC3724N
UC1724
UC2724
UC3724
Isolated Drive Transmitter
FEATURES
∙500mA Output Drive, Source or Sink
∙8 to 35V Operation
∙Transmits Logic Signal Instantly
∙Programmable Operating Frequency
∙Under-Voltage Lockout
∙Able To Pass DC Information Across Transformer
∙Up To 600kHz Operation
DESCRIPTION
The UC1724 family of Isolated Drive Transmitters, along with the UC1725 Isolated Drivers, provide a unique solution to driving isolated power MOSFET gates. They are particularly suited to drive the high-side devices on a high-voltage H-bridge. The UC1724 devices transmit drive logic, and drive power, to the isolated gate circuit using a low cost pulse transformer.
This drive system utilizes a duty-cycle modulation technique that gives instantaneous response to the drive control transistions, and reliably passes steady-state, or DC, conditions. High frequency operation, up to 600kHz, allows the cost and size of the coupling transformer to be minimized.
These devices will operate over an 8 to 35 Volt supply range. The dual high current totem pole outputs are disabled by an uder-voltage lockout circuit to prevent spurious responses during startup or low voltage conditions.
These devices are available in 8 pin plastic or ceramic dual-inline packages, as well as 16 pin SOIC package.
BLOCK DIAGRAM
Note: Pin numbers refer to DIL-8 packages.
UDG-92037
04/99
ABSOLUTE MAXIMUM RATINGS
Supply Voltage VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40V Source/Sink Current (Pulsed) . . . . . . . . . . . . . . . . . . . . . . . . 1A
Source/Sink Current (Continuous) . . . . . . . . . . . . . . . . . . . 0.5A
Ouput Voltage (Pins 4, 6). . . . . . . . . . . . . . . –0.3 to (VIN +0.3)V PHI, RT, and CT inputs (Pins 1, 7, and 8) . . . . . . . . . –0.3 to 6V
Operating Junction Temperature (Note 2) . . . . . . . . . . . . 150°C Storage Temperature Range . . . . . . . . . . . . . . –65°C to 150°C Lead Temperature (Soldering, 10 Seconds) . . . . . . . . . . 300°C
Note 1: All voltages are with respect to GND (Pin 2); all currents are positive into, negative out of part.
Note 2: Consult Unitrode Integrated Circuit Databook for thermal limitations and considerations of package.
Note 3: Pin numbers refer to DIL-8 packages.
UC1724
UC2724
UC3724
CONNECTION DIAGRAMS
DIL-8 (Top View)
J Or N Package
RECOMMENDED OPERATION CONDITIONS
Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +9V to +35V Sink/Source Load Current (each output) . . . . . . . . . 0 to 500mA Timing Resistor. . . . . . . . . . . . . . . . . . . . . . . . . . . 2kW to 10kW Timing Capacitor . . . . . . . . . . . . . . . . . . . . . . . . . 300pF to 3nF Operating Temperature Range (UC1724) . . . –55°C<T A<125°C Operating Temperature Range (UC3724) . . . . . . 0°C<T A<70°C
Note 4: Range over which the device is functional and parameter limits are guaranteed.
ORDERING INFORMATION
|
TEMPERATURE RANGE |
PACKAGE |
UC1724J |
–55°C to +125°C |
CDIP |
UC2724DW |
–25°C to +85°C |
SOIC-Wide |
UC2724N |
|
PDIP |
UC3724DW |
0°C to +70°C |
SOIC-Wide |
UC3724N |
|
PDIP |
SOIC-16 (Top View)
DW Package
ELECTRICAL CHARACTERISTICS: Unless otherwise stated, VCC = 20V, RT = 4.3kΩ, CT = 1000pF, no load on any output and these specifications apply for: –55oC < TA < 125oC for the UC1724, –25oC < TA < 85oC for the UC2724, and
0oC < TA < 70oC for the UC3724. TA=TJ.
PARAMETER |
TEST CONDITIONS |
MIN |
TYP |
MAX |
UNITS |
Under-Voltage Lockout |
|
|
|
|
|
Start-Up Threshold |
VIN Rising |
|
7.75 |
9.5 |
V |
Threshold Hysteresis |
|
0.4 |
1.0 |
1.5 |
V |
Retriggerable One-Shot |
|
|
|
|
|
Initial Accuracy |
TJ = 25°C |
1.54 |
1.9 |
2.25 |
μs |
Temperature Stability |
Over Operating TJ |
1.0 |
|
2.9 |
μs |
Voltage Stability |
VIN = 10 to 35V |
|
0.2 |
0.5 |
%/V |
Operating Frequency |
LLOAD = 1.4mH |
100 |
150 |
200 |
kHz |
Minimum Pulse Width |
RT = 2k CT = 300pF |
100 |
500 |
1200 |
ns |
Operating Frequency |
RT = 2k CT = 300pF LLOAD = 1.4mH |
500 |
750 |
1100 |
kHz |
2
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