DS14C238
Single Supply TIA/EIA-232 4 x 4 Driver/Receiver
General Description
The DS14C238 is a four driver, four receiver device which
conforms to the TIA/EIA-232-E standard and CCITT V.28
recommendations. This device eliminates
12V supplies by
employing an internal DC-DC converter to generate the nec-
essary output levels from a single +5V supply. Driver slew
rate control and receiver noise filtering have also been inter-
nalized to eliminate the need for external slew rate control
and noise filtering capacitors.
Features
n
Conforms to TIA/EIA-232-E and CCITT V.28
n
Internal DC-DC converter
n
Operates with single +5V supply
n
Low power requirement -- I
CC
10 mA max
n
Internal driver slew rate control
n
Receiver noise filtering
n
Operates above 120 kbits/sec
n
Direct replacement for MAX238
Connection Diagram
01128201
Order Number DS14C238WM, DS14C238WMX
See NS Package Number M24B
Functional Diagram
01128202
July 2002
DS14C238
Single
Supply
TIA/EIA-23
24x4
Driver/Receiver
2002 National Semiconductor Corporation
DS011282
www.national.com
Absolute Maximum Ratings
(Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage (V
CC
)
-0.3V to +6V
V+ Pin
(V
CC
-0.3V) to +15V
V- Pin
+0.3V to -15V
Driver Input Voltage
-0.3V to (V
CC
+0.3V)
Driver Output Voltage
(V+ +0.3V) to (V-
-0.3V)
Receiver Input Voltage
30V
Receiver Output Voltage
-0.3V to (V
CC
+0.3V)
Junction Temperature
+150C
Maximum Package Power Dissipation
@
+25C (Note 6)
WM Package
1400 mW
Storage Temp. Range
-65C to +150C
Lead Temp.
(Soldering, 4 Seconds)
+260C
Short Circuit Duration (D
OUT
)
Continuous
ESD Rating
(HBM, 1.5 k
, 100 pF)
2.0 kV
Recommended Operating
Conditions
Min
Max
Units
Supply Voltage, V
CC
4.5
5.5
V
Operating Free Air Temp. (T
A
)
DS14C238
0
+70
C
Electrical Characteristics
(Note 2)
Over recommended operating conditions, unless otherwise specified.
Symbol
Parameter
Conditions
Min
Typ
Max
Units
DEVICE CHARACTERISTICS
V+
Positive Power Supply
R
L
= 3 k
, C1C4 = 1.0 F, D
IN
= 0.8V
9.0
V
V-
Negative Power Supply
R
L
= 3 k
, C1C4 = 1.0 F, D
IN
= 2.0V
-8.0
V
I
CC
Supply Current (V
CC
)
No Load
7.0
10
mA
DRIVER CHARACTERISTICS
V
IH
High Level Input Voltage
2.0
V
CC
V
V
IL
Low Level Input Voltage
GND
0.8
V
I
IH
High Level Input Current
V
IN
2.0V
-10
+10
A
I
IL
Low Level Input Current
V
IN
0.8V
-10
+10
A
V
OH
High Level Output Voltage
R
L
= 3 k
5.0
7.4
V
V
OL
Low Level Output Voltage
-6.3
-5.0
V
I
OS
+
Output High Short
V
O
= 0V, V
IN
= 0.8V
(Note 3)
-30
-15
-5.0
mA
Circuit Current
I
OS
-
Output Low Short
V
O
= 0V, V
IN
= 2.0V
5.0
12
30
mA
Circuit Current
R
O
Output Resistance
-2V
V
O
+2V, V
CC
= GND = 0V
300
RECEIVER CHARACTERISTICS
V
TH
Input High Threshold Voltage
1.9
2.4
V
V
TL
Input Low Threshold Voltage
0.8
1.5
V
V
HY
Hysteresis
0.2
0.4
1.0
V
R
IN
Input Resistance
3.0
4.5
7.0
k
I
IN
Input Current
V
IN
= +15V
2.14
3.8
5.0
mA
V
IN
= +3V
0.43
0.6
+1.0
mA
V
IN
= -3V
-1.0
-0.6
-0.43
mA
V
IN
= -15V
-5.0
-3.8
-2.14
mA
V
OH
High Level Output Voltage
V
IN
= -3V, I
O
= -3.2 mA
3.5
4.5
V
V
IN
= -3V, I
O
= -20 A
4.0
4.9
V
V
OL
Low Level Output Voltage
V
IN
= +3V, I
O
= +2.0 mA
0.25
0.4
V
DS14C238
www.national.com
2
Switching Characteristics
(Note 4)
Over recommended operating conditions, unless otherwise specified.
Symbol
Parameter
Conditions
Min
Typ
Max
Units
DRIVER CHARACTERISTICS
t
PLH
Propagation Delay LOW to HIGH
R
L
= 3 k
0.7
4.0
s
t
PHL
Propagation Delay HIGH to LOW
C
L
= 50 pF
0.6
4.0
s
t
sk
Skew |t
PLH
t
PHL
|
(Figures 1, 2)
0.1
1.0
s
SR1
Output Slew Rate
R
L
= 3k
to 7 k, C
L
= 50 pF
4.0
15
30
V/s
SR2
Output Slew Rate
R
L
= 3 k
, C
L
= 2500 pF
3.0
5.0
V/s
RECEIVER CHARACTERISTICS
t
PLH
Propagation Delay LOW to HIGH
Input Pulse Width
>
10 s
2.0
6.5
s
t
PHL
Propagation Delay HIGH to LOW
C
L
= 50 pF
2.8
6.5
s
t
SK
Skew | t
PLH
t
PHL
|
(Figures 3, 4)
0.8
2.0
s
t
NW
Noise Pulse Width Rejected
(Figures 3, 4)
2.5
1.0
s
Note 1: "Absolute Maximum Ratings" are those values beyond which the safety of the device cannot be guaranteed. They are not meant to imply that the devices
should be operated at these limits. The tables of "Electrical Characteristics" specify conditions for device operation.
Note 2: Current into device pins is defined as positive. Current out of device pins is defined as negative. All voltages are referenced to ground unless otherwise
specified.
Note 3: I
OS
+ and I
OS
- values are for one output at a time. If more than one output is shorted simultaneously, the device power dissipation may be exceeded.
Note 4: Receiver AC input waveform for test purposes: t
r
= t
f
= 200 ns, V
IH
= 3V, V
IL
= -3V, f = 64 kHz (128 kbits/sec). Driver AC input waveform for test purposes:
t
r
= t
f
10 ns, V
IH
= 3V, V
IL
= 0V, f = 64 kHz (128 kbits/sec).
Note 5: All typicals are given for V
CC
= 5.0V and T
A
= +25C.
Note 6: Ratings apply to ambient temperature at +25C. Above this temperature derate: WM package 13.5 mW/C.
Parameter Measurement Information
01128204
FIGURE 1. Driver Load Circuit
01128205
FIGURE 2. Driver Switching Waveform
01128206
FIGURE 3. Receiver Load Circuit
DS14C238
www.national.com
3
Parameter Measurement Information
(Continued)
Pin Descriptions
V
CC
(pin 9) -- Power supply pin for the device,
+5V (
10%).
V+ (pin 11) -- Positive supply for TIA/EIA-232-E drivers. Recommended external capacitor: C4 = 1.0 F (6.3V). This supply is not
intended to be loaded externally.
V- (pin 15) -- Negative supply for TIA/EIA-232-E drivers. Recommended external capacitor: C3 = 1.0 F (16V). This supply is not
intended to be loaded externally.
C1+, C1- (pins 10 and 12) -- External capacitor connection pins. Recommended capacitor 1.0 F (6.3V).
C2+, C2- (pins 13 and 14) -- External Capacitor connection pins. Recommended capacitor 1.0 F (16V).
D
IN
14 (pins 5, 18, 19, and 21) -- Driver input pins are TTL/CMOS compatible. Inputs of unused drivers may be left open, an
internal pull-up resistor (500 k
minimum, typically 5 M) pulls input to V
CC
. Output will be LOW for open inputs.
D
OUT
14 (pins 2, 1, 24, and 20) -- Driver output pins conform to TIA/EIA-232-E levels.
R
IN1
14 (pins 3, 7, 23, and 16) -- Receiver input pins accept TIA/EIA-232-E input voltages (
15V). Receivers feature a noise
filter and guaranteed hysteresis of 200 mV. Unused receiver input pins may be left open. Internal input resistor (5 k
) pulls input
LOW, providing a failsafe HIGH output.
R
OUT
14 (pins 4, 6, 22, and 17) -- Receiver output pins are TTL/CMOS compatible. Receiver output HIGH voltage is specified
for both CMOS and TTL load conditions.
GND (pin 8) -- Ground Pin.
01128207
FIGURE 4. Receiver Propagation Delays and Noise Rejection
DS14C238
www.national.com
4
Physical Dimensions
inches (millimeters) unless otherwise noted
Order Number DS14C238WM, DS14C238WMX
NS Package Number M24B
LIFE SUPPORT POLICY
NATIONAL'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL
COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are devices or
systems which, (a) are intended for surgical implant
into the body, or (b) support or sustain life, and
whose failure to perform when properly used in
accordance with instructions for use provided in the
labeling, can be reasonably expected to result in a
significant injury to the user.
2. A critical component is any component of a life
support device or system whose failure to perform
can be reasonably expected to cause the failure of
the life support device or system, or to affect its
safety or effectiveness.
National Semiconductor
Corporation
Americas
Email: support@nsc.com
National Semiconductor
Europe
Fax: +49 (0) 180-530 85 86
Email: europe.support@nsc.com
Deutsch Tel: +49 (0) 69 9508 6208
English
Tel: +44 (0) 870 24 0 2171
Franais Tel: +33 (0) 1 41 91 8790
National Semiconductor
Asia Pacific Customer
Response Group
Tel: 65-2544466
Fax: 65-2504466
Email: ap.support@nsc.com
National Semiconductor
Japan Ltd.
Tel: 81-3-5639-7560
Fax: 81-3-5639-7507
www.national.com
DS14C238
Single
Supply
TIA/EIA-23
24x4
Driver/Receiver
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.
PDF 
ZIP