DS75154
Quad Line Receiver

General Description

The DS75154 is a quad monolithic line receiver designed to
satisfy the requirements of the standard interface between
data terminal equipment and data communication equipment
as defined by EIA Standard RS-232C. Other applications are
in relatively short, single-line, point-to-point data transmis-
sion systems and for level translators. Operation is normally
from a single 5V supply; however, a built-in option allows op-
eration from a 12V supply without the use of additional com-
ponents. The output is compatible with most TTL and LS cir-
cuits when either supply voltage is used.

In normal operation, the threshold-control terminals are con-
nected to the V

CC1

terminal, pin 15, even if power is being

supplied via the alternate V

CC2

terminal, pin 16. This pro-

vides a wide hysteresis loop which is the difference between
the positive-going and negative-going threshold voltages. In
this mode, if the input voltage goes to zero, the output volt-
age will remain at the low or high level as determined by the
previous input.

For fail-safe operation, the threshold-control terminals are
open. This reduces the hysteresis loop by causing the

negative-going threshold voltage to be above zero. The
positive-going threshold voltage remains above zero as it is
unaffected by the disposition of the threshold terminals. In
the fail-safe mode, if the input voltage goes to zero or an
open-circuit condition, the output will go to the high level re-
gardless of the previous input condition.

Features

Input resistance, 3 k

to 7 k

over full RS-232C voltage

range

Input threshold adjustable to meet "fail-safe"
requirements without using external components

Inverting output compatible with TTL or LS

Built-in hysteresis for increased noise immunity

Output with active pull-up for symmetrical switching
speeds

Standard supply voltage -- 5V or 12V

Schematic Diagram

DS005795-1

Note: When using V

CC1

(pin 15), V

CC2

(pin 16) may be left open or shorted to V

CC1

. When using V

CC2

, V

CC1

must be left open or connected to the

threshold control pins.

May 1998

DS75154

Quad

Line

Receiver

DS005795

www.national.com

Absolute Maximum Ratings

(Note 2)

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.

Normal Supply Voltage (Pin 15),

CC1

)

Alternate Supply Voltage (Pin 16),

CC2

)

14V

Input Voltage

25V

Storage Temperature Range

-65°C to +150°C

Maximum Power Dissipation (Note 1) at 25°C

SO Package

650 mW

Lead Temperature (Soldering, 4

seconds)

260°C

Operating Conditions

Min

Max

Units

Supply Voltage (Pin 15), (V

CC1

)

4.5

5.5

Alternate Supply Voltage

(Pin 16), (V

CC2

)

10.8

13.2

Input Voltage

Temperature, (T

)

+70

°C

Note 1: Derate molded DIP package 10.9 mW/°C above 25°C; derate SO
package 8.01 mW/°C above 25°C.

Electrical Characteristics

(Notes 3, 4, 5)

Symbol

Parameter

Conditions

Min

Typ

Max

Units

High-Level Input Voltage

(

Figure 1)

Low-Level Input Voltage

(

Figure 1)

-3

T+

Positive-Going Threshold Voltage

(

Figure 1)

Normal Operation

0.8

2.2

Fail-Safe Operation

0.8

2.2

T-

Negative-Going Threshold Voltage

(

Figure 1)

Normal Operation

-3

-1.1

Fail-Safe Operation

0.8

1.4

T+

-V

T-

Hysteresis

(

Figure 1)

Normal Operation

0.8

3.3

Fail-Safe Operation

0.8

2.2

High-Level Output Voltage

=-400 µA, (Figure 1)

2.4

3.5

Low-Level Output Voltage

=16 mA, (Figure 1)

0.23

0.4

Input Resistance

(

Figure 2)

=-25V to -14V

=-14V to -3V

=-3V to +3V

=3V to 14V

=14V to 25V

I(OPEN)

Open-Circuit Input Voltage

=0, (Figure 3)

0.2

Short-Circuit Output Current

CC1

=5.5V, V

=-5V, (Figure 4)

-10

-20

-40

(Note 6)

CC1

Supply Current From V

CC1

=5.5V, T

=25°C, (Figure 5)

CC2

Supply Current From V

CC2

=13.2V, T

=25°C, (Figure 5)

Switching Characteristics

CC1

=5V, T

=25°C)

Symbol

Parameter

Conditions

Min

Typ

Max

Units

PLH

Propagation Delay Time, Low-to-High

=50 pF, R

=390

, (

Figure 6)

Level Output

PHL

Propagation Delay Time, High-to-Low

=50 pF, R

=390

, (

Figure 6)

Level Output

TLH

Transition Time, Low-to-High Level

=50 pF, R

=390

, (

Figure 6)

Output

THL

Transition Time, High-to-Low Level

=50 pF, R

=390

, (

Figure 6)

Output

Note 2: "Absolute Maximum Ratings" are those values beyond which the safety of the device cannot be guaranteed. Except for "Operating Temperature Range" they
are not meant to imply that the devices should be operated at these limits. The table of "Electrical Characteristics" provides conditions for actual device operation.

Note 3: Unless otherwise specified min/max limits apply across the 0°C to +70°C range for the DS75154. All typical values are for T

=25°C and V

CC1

=5V.

Note 4: All currents into device pins shown as positive, out of device pins as negative, all voltages referenced to ground unless otherwise noted. All values shown
as max or min on absolute value basis.

www.national.com

DC Test Circuits and Truth Tables

DS005795-3

Test

Measure

CC1

CC2

(Pin 15)

(Pin 16)

Open-Circuit Input

Open

4.5V

Open

(Fail-Safe)

Open

10.8V

T+

min,

0.8V

Open

5.5V

Open

T-

(Fail-Safe)

0.8V

Open

13.2V

T+

min (Normal)

(Note 7)

Pin 15

5.5V and T

Open

(Note 7)

Pin 15

13.2V

max,

-3V

Pin 15

5.5V and T

Open

T-

min (Normal)

-3V

Pin 15

13.2V

min, V

T+

max,

Open

4.5V

Open

T-

max (Fail-Safe)

Open

10.8V

min, V

T+

max,

Pin 15

4.5V and T

Open

(Normal)

Pin 15

10.8V

T-

max (Normal)

(Note 8)

Pin 15

5.5V and T

Open

(Note 8)

Pin 15

13.2V

Note 7: Momentarily apply -5V, then 0.8V.

Note 8: Momentarily apply 5V, then ground.

FIGURE 1. V

, V

T+

, V

T-

, V

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