Texas Instruments UC3724N, UC3724DWTR, UC3724DW, UC2724N, UC2724J Datasheet

UC1724
UC2724
UC3724

04/99

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.

Isolated Drive Transmitter

BLOCK DIAGRAM

UDG-92037

Note: Pin numbers refer to DIL-8 packages.

2

UC1724
UC2724
UC3724

CONNECTION DIAGRAMS

DIL-8 (Top View)
J Or N Package

SOIC-16 (Top View)
DW Package

ELECTRICAL CHARACTERISTICS: Unless otherwise stated, V

CC

= 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 V

IN

Rising 7.75 9.5 V

Threshold Hysteresis 0.4 1.0 1.5 V

Retriggerable One-Shot

Initial Accuracy T

J

= 25°C 1.54 1.9 2.25 µs

Temperature Stability Over Operating T

J

1.0 2.9 µs

Voltage Stability V

IN

= 10 to 35V 0.2 0.5 %/V

Operating Frequency L

LOAD

= 1.4mH 100 150 200 kHz
Minimum Pulse Width RT = 2k CT = 300pF 100 500 1200 ns
Operating Frequency RT = 2k C

T = 300pF L

LOAD

= 1.4mH 500 750 1100 kHz

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 (V

IN

+

0.3)V

P

HI, 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 cur-

rents are positive into, negative out of part.

Note 2: Consult Unitrode Integrated Circuit Databook for ther-

mal limitations and considerations of package.

Note 3: Pin numbers refer to DIL-8 packages.

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<TA<125°C

Operating Temperature Range (UC3724). . . . . . 0°C<TA<70°C

Note 4: Range over which the device is functional and

parameter limits are guaranteed.

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

ORDERING INFORMATION