MC1488

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RS232B). The addition of the diodes also permits the MC1488 to withstand faults with power-supplies of

less than the 9.0V stated above.

The maximum short-circuit current allowable under fault conditions is more than guaranteed by the

previously mentioned 10 mA output current limiting.

The MC1488 is an extremely versatile line driver with a mired of possible applications. Several features of

the drivers enhance this versatility:

1. Output Current Limiting - this enables the circuit designer to define the output voltage levels

independent of power-supplies and can be accomplished by diode clamping of the output pins.

2. Power-Supply Range - as can be seen from the schematic drawing of the drivers, the positive and

negative driving elements of the device are essentially independent and do not require matching

power-supplies. In fact, the positive supply can very from a minimum seven volts (required for driving the

negative pulldown section) to the maximum specified 15 V. The negative supply can vary from

approximately -2.5 V to the minimum specified - 15 V. The MC1488 will drive the output to within 2 V of the

positive or negative supplies as long as the current output limits are not exceeded. The combination of the

current-limiting and supply-voltage features allow a wide combination of possible outputs within the same

quad package.

Figure 12 : Slew-Rate Load VS Capacitance for

Figure 13 : Power Supply Protection to Meet Power-off Fault Conditions