Integrated Circuits
Data Sheet
26ET31C
QUAD DIFFERENTIAL LINE DRIVER
(Pin compatible with 26LS31 in applications which 26ET31C do not require an enable function.)
FEATURES
- Supply Voltage Range 4.75V to 30V
- Operation to 800KHz
- CMOS and TTL Compatible Inputs
- Outputs RS-422A Compatible
- High Impedance Buffered Inputs with Hysteresis
- Outputs short circuit protected
- 70mA peak SINK current
- Outputs Protected by Thermal Shut-Down
APPLICATIONS
- Optical Encoders
- Industrial Control
DESCRIPTION
These line drivers are similar to the popular 26LS31 device, but without the enable function. They provide the
additional supply voltage range necessary for use in many industrial control applications. Outputs are compatible
with RS-422A, but they allow use of supplies up to 30V. Output voltage swings up to VCC -2V are typical. The
outputs are protected against shorts to ground by a two-fold scheme of current limiting and thermal shutdown.
Thermal shutdown is accomplished by monitoring junction temperature and comparing this to a band gap
reference on chip.
Input hysteresis of about 0.5V provides good noise margin, even in noisy industrial control environments. Input to
output propagation delays of less than 200ns are typical for rising and falling edges of the input waveform,
measured to the zero crossing of the differential outputs.
ABSOLUTE MAXIMUM RATINGS
| Parameter |
Symbol |
Min. |
Max. |
Units |
Ref. |
| Operating Temperature Range |
TA |
-40 |
115 |
C |
Note 1. |
| Supply Voltage Range |
VCC |
4.75 |
30 |
V |
- |
ELECTRICAL CHARACTERISTICS
Unless otherwise specified, typical values given at VCC=12V, TA = 25°C, and EN- <0.8V.
| Parameters |
Symbol |
Min. |
Typ. |
Max. |
Units |
Test Conditions |
| Overtemp Operate Point (junction) |
TJOP |
- |
155 |
- |
°C |
Note 1. |
| Overtemp Release Point (junction) |
TJRP |
- |
105 |
- |
°C |
Note 1. |
| Supply Current |
Icc1
Icc2 |
7.0
9.0 |
11.0
13.0 |
17.0
20.0 |
mA |
Vcc = 5 V (Icc1)
Vcc = 30.0V (Icc2) |
| Input Positive-Going Threshold |
VT+ |
1.1 |
1.5 |
1.9 |
V |
- |
| Input Negative-Going Threshold |
VT |
0.7 |
1.0 |
1.4 |
V |
- |
| Low Level Input Current |
IIL |
- |
-0.13 |
-4.0 |
A |
VIN = 0V, VCC = 30V |
| High Level Input Current |
IIH |
- |
0 |
4.0 |
A |
VIN = 30V, VCC = 30V |
| Low Level Output |
VOL |
- |
375 |
500 |
mV |
IOL = 20mA, VCC = 5V |
| Low Level Output |
VOL |
- |
375 |
500 |
mV |
IOL = 20mA, VCC = 30V |
| High Level Output |
VOH |
2.5 |
2.8 |
- |
V |
IOH = -20mA, VCC = 5V |
| High Level Output |
VOH |
27.8 |
28.0 |
- |
V |
IOH = -20mA, VCC = 30V |
AC SWITCHING CHARACTERISTICS
Values given at VCC = 24V, TA = 25°C, CL = 100pF on all outputs.
| Parameters |
Symbol |
Min. |
Typ. |
Max. |
Units |
Test Conditions |
| Propagation delay, rising input 50% point to zero crossing of differential outputs |
TPLH |
- |
- |
150 |
285 |
ns |
| Propagation delay, falling input 50% point to zero crossing of differential outputs |
TPHL |
- |
- |
170 |
310 |
ns |
| Output Rise Time |
TR |
- |
- |
95 |
200 |
ns |
| Output Fall Time |
TF |
- |
- |
40 |
165 |
ns |
NOTES:
- This is not a test parameter, but for information only.
- It may be necessary to clamp the outputs with Schottky diodes when driving extemely long cables with high capacitance between outputs. These diodes should have a forward voltage of less than 0.4V, and be connected with cathode to the output and anode to ground.
| PACKAGE |
SUFFIX |
| Chip Only |
-C |
| 16 Lead SOIC |
-SOP |
 |
