MC1489AD ON Semiconductor, MC1489AD Datasheet - Page 6

• Manufacturer Part Number: MC1489AD
• Manufacturer: ON Semiconductor

Specifications of MC1489AD

• Interface Circuit Standard 1: EIA-232-D
• Number Of Receivers: 4
• Number Of Transmitters: Not Required
• Number Of Transceivers: Not Required
• Data Transmission Topology: Point-to-Point
• Receiver Signal Type: Single-Ended
• Transmitter Signal Type: Not Required
• Single Supply Voltage (typ): 5V
• Single Supply Voltage (min): 4.5V
• Single Supply Voltage (max): 5.5V
• Dual Supply Voltage (typ): Not RequiredV
• Dual Supply Voltage (min): Not RequiredV
• Dual Supply Voltage (max): Not RequiredV
• Supply Current: 26mA
• Power Supply Requirement: Single
• Operating Temp Range: 0C to 75C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 14
• Package Type: SOIC
• Lead Free Status / Rohs Status: Not Compliant

General Information
the EIA−232D specification detailing the requirements for
the interface between data processing equipment and data
communications equipment. This standard specifies not
only the number and type of interface leads, but also the
voltage levels to be used. The MC1488 quad driver and its
companion circuit, the MC1489 quad receiver, provide a
complete interface system between DTL or TTL logic levels
and the EIA−232D defined levels. The EIA−232D
requirements as applied to receivers are discussed herein.
3000 W and 7000 W for input voltages between 3.0 and 25 V
in magnitude; and any voltage on the receiver input in an
open circuit condition must be less than 2.0 V in magnitude.
The MC1489 circuits meet these requirements with a
maximum open circuit voltage of one V
−25 V as a Logic “1” and inputs between 3.0 and 25 V as a
Logic “0.” On some interchange leads, an open circuit of
power “OFF” condition (300 W or more to ground) shall be
decoded as an “OFF” condition or Logic “1.” For this
reason, the input hysteresis thresholds of the MC1489
circuits are all above ground. Thus an open or grounded
input will cause the same output as a negative or Logic “1”
input.
Device Characteristics
from the second stage to the input stage providing input
hysteresis for noise rejection. The MC1489 input has typical
The Electronic Industries Association (EIA) has released
The required input impedance is defined as between
The receiver shall detect a voltage between − 3.0 and
The MC1489 interface receivers have internal feedback
6
5
4
3
2
1
10
Capacitance from Response Control Pin to GND
Figure 10. Typical Turn On Threshold versus
10 pF
100 pF
PW, INPUT PULSE WIDTH (ns)
100
300 pF
500 pF
1000
BE
.
APPLICATIONS INFORMATION
MC1489
http://onsemi.com
10,000
6
turn−on voltage of 1.25 V and turn−off of 1.0 V for a typical
hysteresis of 250 mV. The MC1489A has typical turn−on of
1.95 V and turn−off of 0.8 V for typically 1.15 V of
hysteresis.
node in addition to the input and output pins, thereby
allowing the designer to vary the input threshold voltage
levels. A resistor can be connected between this node and an
external power supply. Figures 4, 6 and 7 illustrate the input
threshold voltage shift possible through this technique.
high frequency, high energy noise pulses. Figures 10 and 11
show typical noise pulse rejection for external capacitors of
various sizes.
combined or used individually for many combinations of
interfacing applications. The MC1489 circuits are
particularly useful for interfacing between MOS circuits and
DTL/TTL logic systems. In this application, the input
threshold voltages are adjusted (with the appropriate supply
and resistor values) to fall in the center of the MOS voltage
logic levels (see Figure 12).
as long as the designer realizes that he may not drive this
node with a low impedance source to a voltage greater than
one diode above ground or less than one diode below
ground. This feature is demonstrated in Figure 13 where two
receivers are slaved to the same line that must still meet the
EIA−232D impedance requirement.
Each receiver section has an external response control
This response node can also be used for the filtering of
These two operations on the response node can be
The response node may also be used as the receiver input
6
5
4
3
2
1
10
Capacitance from Response Control Pin to GND
Figure 11. Typical Turn On Threshold versus
12 pF
100 pF 300 pF
PW, INPUT PULSE WIDTH (ns)
100
500 pF
1000
MC1489A
10,000