MC14C89 ONSEMI [ON Semiconductor], MC14C89 Datasheet - Page 5

• Manufacturer Part Number: MC14C89
• Description: QUAD LOW POWER LINE RECEIVERS
• Manufacturer: ONSEMI [ON Semiconductor]

Description
direct replacements for the MC1489A and MC1489. Both
devices meet all EIA–232 specifications and also the faster
EIA–562 and CCITT V.28 specifications. Noise pulse
rejection circuitry eliminates the need for most response
control filter capacitors but does not exclude the possibility as
filtering is still possible at the Response Control (RC) pins.
Also, the Response Control pins allow for a user defined
selection of the threshold voltages. The MC14C89AB and
MC14C89B are manufactured with a bipolar technology
using low power techniques and consume at most 700
plus load currents with a +5.0 V supply.
Outputs
inputs, the load current, the bias of the Response Control
pins, and the supply voltage. Table 1 applies to each receiver,
regardless of how many other receivers within the package
are supplying load current.
Receiver Inputs and Response Control
accordance with Table 1. The nominal V IL and V IH
thresholds are 0.95 V and 1.90 V respectively for the
MC14C89AB. For the MC14C89B, the nominal V IL and V IH
thresholds are 0.95 and 1.30, respectively. The inputs are
able to withstand 30 V referenced to ground. Should the
input voltage exceed ground by more than 30 V, excessive
currents will flow at the input pin. Open input pins will
generate a logic high output, but good design practices
dictate that inputs should never be left open.
through a resistor string. The RC pins provide for adjustment
of the threshold voltages of the IC while preserving the
amount of hysteresis. Figure 10 shows a typical application
to adjust the threshold voltages. The RC pins also provide
access to an internal resistor string which permits low pass
filtering of the input signal within the IC. Like the input pins,
the RC pins should not be taken above or below ground by
more than 30 V or excessive currents will flow at these pins.
The dependence of the low level threshold voltage (V IL ) upon
R RC and V bat can be described by the following equation:
then adding the hysteresis for each device (0.35 for the
V
MOTOROLA ANALOG IC DEVICE DATA
The MC14C89AB and MC14C89B are designed to be
The output low or high voltage depends on the state of the
The receiver inputs determine the state of the outputs in
The Response Control (RC) pins are coupled to the inputs
V IH can be found by calculating for V IL using equation (1)
IL
]
5.32 k
V 0.09
*The asterisk denotes A, B, C, or D.
W
)
Table 1. Function Table
*
Input*
505
6.67
H
L
V
bat
W
Receivers
R
RC
10 6
R
RC
W
2
(1.6)
Output*
505
H
L
)
W
2.02 k
APPLICATIONS INFORMATION
W
MC14C89B, AB
m
(1)
A,
MC14C89B or 0.95 V for the MC14C89AB). Figure 7 plots
equation (1) for two values of V bat and a range of R RC .
capacitor chosen can be calculated by the equation,
where f
of the low pass filter.
input noise rejection. The inputs have the ability to ignore
pulses which exceed the V IH and V IL thresholds but are less
than 1.0
1.0
amplitude. Figure 8 is a graph showing typical input noise
rejection as a function of pulse amplitude and pulse duration.
Figure 8 reflects data taken for an input with an unconnected
RC pin and applied to the MC14C89AB and MC14C89B.
Operating Temperature Range
–40 C to +85 C, and the devices are designed to meet the
EIA–232–E, EIA–562 and CCITT V.28 specifications over
this temperature range. The timing characteristics are
guaranteed to meet the specifications at +25 C. The
maximum ambient operating temperature is listed as +85 C.
However, a lower ambient may be required depending on
system use (i.e., specifically how many receivers within a
package are used), and at what current levels they are
operating. The maximum power which may be dissipated
within the package is determined by:
and summed for each of the four receivers, while the last
term is common to the entire package.
where: R JA =
where: V CC =
V OH , V OL =
If an RC pin is to be used for low pass filtering, the
Another feature of the MC14C89AB and MC14C89B is
The ambient operating temperature range is listed as
As indicated, the first term (in brackets) must be calculated
m
T J(max) =
s, the noise pulse may still be ignored depending on its
Figure 9. Application to Adjust Thresholds
–3 dB
m
I CC =
C
P D =
s in duration. As the duration of the pulse exceeds
T A =
RC
represents the desired –3 dB role–off frequency
P D
Input Pin
thermal resistance (typ., 100 C/W for the
DIP and 125 C/W for the SOIC packages);
maximum operating junction temperature
(150 C); and
ambient temperature.
{[(V CC – V OH )
[(V OL )
positive supply voltage;
measured or estimated from Figure 2
and 3;
measured quiescent supply current.
]
(max)
2.02 k

+
I OL ]} each receiver + (V CC
W
+
–
T
R RC
V bat
1
2
Response Control Pin
J(max)
p

f
R
*
I OH ] or
q
JA
3dB
– T
A

I CC )
5
(2)