1/13September 2003
■INPUT RESISTANCE –3k to 7kΩ
■INPUT SIGNAL RANGE – ± 30V
■INPUT THRESHOLD HYSTERESIS BUILT-IN
■RESPONSE CONTROL:
a) LOGIC THRESHOLD SHIFTING
b) INPUT NOISE FILTERING
DESCRIPTION
The MC1489 monolithic quad line receivers are
designed to interface data terminal equipment
with data communications equipment in
conformance with the specifications of EIA
Standard N° RS232C.
SCHEMATIC DIAGRAM
MC1489
MC1489A
QUAD LINE RECEIVERS
DIP
SOP
MC1489/MC1489A
2/13
PIN CONFIGURATION (top view)
ORDERING CODES
ABSOLUTE MAXIMUM RATINGS
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is
not implied.
DIP14 SO14 SO14 (TAPE & REEL)
MC1489P MC1489D1 MC1489D1013TR
MC1489AP MC1489AD1013TR
Symbol Parameter Value Unit
VSPower Supply Voltage 10 V
VIInput Voltage Range ±30 V
IOL Output Load Current 20 mA
PTOT Power Dissipation 1W
T
amb Operating Ambient Temperature 0to75 °C
T
stg Storage Temperature Range -65 to 150 °C
MC1489/MC1489A
3/13
ELECTRICAL CHARACTERISTICS
Response Control Pin in Open; VS=5V,T
amb = 0 to 75°C, unless otherwise specified.
SWITCHING CHARACTERISTICS
VS=5V,T
amb = 25°C, (see Figure 1)
TEST CIRCUITS
Figure 1 : Switching Response
Symbol Parameter Test Conditions Min. Typ. Max. Unit
IIH Positive Input Current VIH =25V 3.6 8.3 mA
V
IH = 3 V 0.43
IIL Negative Input Current VIL = - 25 V -3.6 -8.3 mA
VIL = - 3 V -0.43
VIH Input Turn-On Threshold
Voltage Tamb = 25°C, VOL ≤0.45 V
IL=10mA for MC1489 1 1.5 V
for MC1489A 1.75 1.95 2.25
VIL Input Turn-Off Threshold
Voltage Tamb = 25°C, VOL ≥2.5VI
L=-0.5mA 0.75 1.25 V
VOH Output Voltage High VIH =0.75V,I
L=-0.5mA 2.5 4 5 V
I
L= 0.5 mA Input Open Circuit 2.5 4 5
VOL Output Voltage Low VIL =3V, I
L= 10 mA 0.2 0.45 V
IOS Output Short Circuit
Current -3 -4 mA
ISPower Supply Current All gates "ON", IO=0mA,V
IH = 5 V 16 26 mA
PCPower Consumption VIH = 5 V 80 130 mW
Symbol Parameter Test Conditions Min. Typ. Max. Unit
tPLH Propagation Delay Time RL= 3.9 KΩ25 85 ns
tTHL Rise Time RL= 3.9 KΩ120 175 ns
tPHL Propagation Delay Time RL=390Ω25 50 ns
tTHL Fall Time RL=390Ω10 20 ns
MC1489/MC1489A
4/13
Figure 2 : Response Control Node
Figure 3 : Input Current
Figure 4 : Output Short-Circuit Current
C: capacitor is for noise filtering
MC1489/MC1489A
5/13
Figure 5 : Output Voltage and Input Threshold Voltage
Figure 6 : Power Supply Currents
MC1489/MC1489A
6/13
TYPICAL APPLICATIONS:
Figure 7 : RS232C Data Transmission
TYPICAL CHARACTERISTICS VS=5V,T
amb = 25°C, unless otherwise specified
Figure 8 : Input Current vs Input Voltage Figure 9 : MC1489 Input Threshold Voltage
Adjustment
MC1489/MC1489A
7/13
Figure 10 : MC1489A Input Threshold Voltage
Adjustment
Figure 11 : Input Threshold vs Temperature
Figure 12 : Input Threshold vs Power Supply
Voltage
MC1489/MC1489A
8/13
APPLICATION INFORMATION
The Electronic Industries Association (EIA) has released the RS-232C 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 RS-232C defined levels. The RS-232C
requirements as applied to receivers are discussed herein.
The required input impedance is defined as between 3000Ωand 7000Ωfor input voltages between 3.0
and 25V in magnitude; and any voltage on the receiver input in an open circuit condition must be less than
2.0V in magnitude. The MC1489 circuits meet these requirements with a maximum open circuit voltage of
one VBE.
The receiver shall detect a voltage between - 3.0 and - 25V as a Logic "1" and inputs between + 3.0 and
+ 2.5V as a Logic "0". On some interchange leads, an open circuit of power "OFF" condition (300Ωor
more to ground) shall be decoded as an "OFF" condition or Logic "1". For the 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
The MC1489 interface receivers have internal feedback from the second stage to the input stage
providing input hysteresis for noise rejection. The MC1489 input has typical turn-on voltage of 1.25V and
turn-off of 1.0 V for a typical hysteresis of 250mV. The MC1489A has typical turn-on of 1.95V and turn-off
of 0.8V for typically 1.15V of hysteresis.
Each receiver section has an external response control 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 2, 4 and 5 illustrate the input threshold voltage
shift possible through this technique.
This response node can also be used for the filtering of the high-frequency, high-energy noise pulses.
Figures 9 and 10 show typical noise-pulse rejection for external capacitors of various sizes.
These two operations on the response node can be combined or used individually for may combinations
of interfacing applications. The MC1489 circuits are particularly useful for interfacing between MOS
circuits and MDTL/MTTL 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
11).
The response node may also be used as the receiver input 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 12 where two receivers are slaved
to the same line that must still meet the RS-232C impedance requirement.
Figure 13 : Typical Turn-on Threshold vs
Capacitance from Response Control Pin to GND Figure 14 : Typical Turn-on Threshold vs
Capacitance from Response Control Pin to GND
MC1489/MC1489A
9/13
Figure 15 : Typical Paralleling of Two MC1489/A Receivers to Meet RS-232C
MC1489/MC1489A
10/13
DIM. mm. inch
MIN. TYP MAX. MIN. TYP. MAX.
a1 0.51 0.020
B 1.39 1.65 0.055 0.065
b 0.5 0.020
b1 0.25 0.010
D 20 0.787
E 8.5 0.335
e 2.54 0.100
e3 15.24 0.600
F 7.1 0.280
I 5.1 0.201
L 3.3 0.130
Z 1.27 2.54 0.050 0.100
Plastic DIP-14 MECHANICAL DATA
P001A
MC1489/MC1489A
11/13
DIM. mm. inch
MIN. TYP MAX. MIN. TYP. MAX.
A 1.75 0.068
a1 0.1 0.2 0.003 0.007
a2 1.65 0.064
b 0.35 0.46 0.013 0.018
b1 0.19 0.25 0.007 0.010
C 0.5 0.019
c1 45˚ (typ. )
D 8.55 8.75 0.336 0.344
E 5.8 6.2 0.228 0.244
e 1.27 0.050
e3 7.62 0.300
F 3.8 4.0 0.149 0.157
G 4.6 5.3 0.181 0.208
L 0.5 1.27 0.019 0.050
M 0.68 0.026
S ˚ (max.)
SO-14 MECHANICAL DATA
PO13G
8
MC1489/MC1489A
12/13
DIM. mm. inch
MIN. TYP MAX. MIN. TYP. MAX.
A 330 12.992
C 12.8 13.2 0.504 0.519
D 20.2 0.795
N 60 2.362
T 22.4 0.882
Ao 6.4 6.6 0.252 0.260
Bo 9 9.2 0.354 0.362
Ko 2.1 2.3 0.082 0.090
Po 3.9 4.1 0.153 0.161
P 7.9 8.1 0.311 0.319
Tape & Reel SO-14 MECHANICAL DATA
MC1489/MC1489A
13/13
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