NSC DS89C387TMEA

DS89C387
Twelve Channel CMOS Differential Line Driver
General Description
The driver’s input (DI) is compatible with both TTL and
CMOS signal levels.
The DS89C387 is a high speed twelve channel CMOS differential driver that meets the requirements of TIA/EIA-422-B.
The DS89C387 features a low ICC specification of 1.5 mA
maximum, which makes it ideal for battery powered and
power conscious applications. The device replaces three
DS34C87s and offers a PC board space savings up to 30%.
The twelve channel driver is available in a SSOP package.
The device is ideal for wide parallel bus applications.
Each TRI-STATE ® enable (EN) allows the driver outputs to
be active or in a HI-impedance off state. Each enable is common to only two drivers for flexibility and control. The drivers
may be disabled to turn off load current and to save power
when data is not being transmitted.
n Low power ICC: 1.5 mA maximum
n Meets TIA/EIA-422-B (RS-422)
n Guaranteed AC parameters:
— Maximum driver skew −3 ns
— Maximum transition time −10 ns
n Available in SSOP packaging:
— Requires 30% less PCB space than 3 DS34C87TMs
Connection Diagram
Functional Diagram
Features
48L SSOP
DS89C387
DS012086-2
1/6 of package
Truth Table
Enable
Input
EN
DI
DO
Outputs
DO*
L
X
Z
Z
H
H
H
L
H
L
L
H
DS012086-1
Order Number DS89C387TMEA
See NS Package Number MS48A
TRI-STATE ® is a registered trademark of National Semiconductor Corporation.
© 1998 National Semiconductor Corporation
DS012086
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DS89C387 Twelve Channel CMOS Differential Line Driver
May 1995
Absolute Maximum Ratings (Notes 1, 2)
Lead Temperature (TL)
(Soldering 4 sec.)
260˚C
This device does not meet 2000V ESD rating. (Note 11)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Operating Conditions
Supply Voltage (VCC)
−0.5 to 7.0V
−1.5 to VCC +1.5V
DC Voltage (VIN)
−0.5 to 7V
DC Output Voltage (VOUT)
± 20 mA
Clamp Diode Current (IIK, IOK)
± 150 mA
DC Output Current, per pin (IOUT)
± 500 mA
DC VCC or GND Current (ICC)
−65˚C to +150˚C
Storage Temperature Range (TSTG)
Maximum Power Dissipation (PD) @ 25˚C (Note 3)
SSOP Package
1359 mW
Supply Voltage (VCC)
DC Input or Output Voltage (VIN, VOUT)
Operating Temperature Range (TA)
DS89C387T
Input Rise or Fall Times (tr, tf)
Min
4.50
0
Max
5.50
VCC
Units
V
V
−40
+85
500
˚C
ns
DC Electrical Characteristics (Notes 2, 4)
VCC = 5V ± 10% (unless otherwise specified)
Symbol
VIH
Parameter
Conditions
High Level Input
Min
Max
Units
2.0
Typ
VCC
V
GND
0.8
V
Voltage
VIL
Low Level Input
Voltage
VOH
VOL
High Level Output
VIN = VIH or VIL,
Voltage
IOUT = −20 mA
VIN = VIH or VIL,
Low Level Output
Voltage
VT
Differential Output
Voltage
|VT|–|VT|
Difference In
Differential Output
VOS
Common Mode
Output Voltage
|VOS–VOS|
Difference In
Common Mode Output
IIN
Input Current
ICC
Quiescent Supply
Current
IOZ
TRI-STATE Output
Leakage Current
ISC
Output Short
Circuit Current
IOFF
2.5
3.4
0.3
IOUT = 48 mA
RL = 100Ω
2.0
2.0
(Note 5)
RL = 100Ω
(Note 5)
VIN = VCC, GND, VIH, or VIL
IOUT = 0 µA,
600
VIN = VCC or GND
VIN = 2.4V or 0.5V (Note 6)
VOUT = VCC or GND
−115
Control = VIL
VIN = VCC or GND
Power Off Output
(Notes 5, 7)
VCC = 0V
Leakage Current
(Note 5)
−30
VOUT = 6V
VOUT = −0.25V
0.5
3.1
(Note 5)
RL = 100Ω
(Note 5)
RL = 100Ω
V
V
V
0.4
V
3.0
V
0.4
V
± 1.0
µA
1500
µA
0.8
2.0
mA
± 0.5
± 5.0
µA
−150
mA
100
µA
−100
µA
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 device
should be operated at these limits. The table of “Electrical Characteristics” provide conditions for actual device operation.
Note 2: Unless otherwise specified, all voltages are referenced to ground. All currents into device pins are positive; all currents out of device pins are negative.
Note 3: Ratings apply to ambient temperature at 25˚C. Above this temperature derate SSOP (MEA) Package 10.9 mW/˚C.
Note 4: Unless otherwise specified, min/max limits apply across the −40˚C to 85˚C temperature range. All typicals are given for VCC = 5V and TA = 25˚C.
Note 5: See TIA/EIA-422-B for exact test conditions.
Note 6: Measured per input. All other inputs at VCC or GND.
Note 7: This is the current sourced when a high output is shorted to ground. Only one output at a time should be shorted.
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2
Switching Characteristics (Note 4)
VCC = 5V ± 10%, tr, tf ≤ 6 ns (Figures 1, 2, 3, 4)
Symbol
tPLH, tPHL
Parameter
Propagation Delay
Min
Typ
Max
Units
S1 Open
Conditions
2
6
11
ns
0
Input to Output
Skew
(Note 8)
S1 Open
0.5
3
ns
tTLH, tTHL
Differential Output Rise
S1 Open
6
10
ns
ns
And Fall Times
tPZH
Output Enable Time
S1 Closed
12
25
tPZL
Output Enable Time
S1 Closed
13
26
ns
tPHZ
Output Disable Time (Note 9)
S1 Closed
4
8
ns
tPLZ
Output Disable Time (Note 9)
S1 Closed
6
12
CPD
Power Dissipation
ns
100
pF
6
pF
Capacitance (Note 10)
CIN
Input Capacitance
Note 8: Skew is defined as the difference in propagation delays between complementary outputs at the crossing point.
Note 9: Output disable time is the delay from the control input being switched to the output transistors turning off. The actual disable times are less than indicated
due to the delay added by the RC time constant of the load.
Note 10: CPD determines the no load dynamic power consumption, PD = CPD V2CC f + ICC VCC, and the no load dynamic current consumption, IS = CPD VCC f +
ICC.
Note 11: ESD Rating: HBM (1.5 kΩ, 100 pF)
Inputs ≥ 1500V
Outputs ≥ 1000V
EIAJ (0Ω, 200 pF)
All Pins ≥ 350V
Logic Diagram
DS012086-3
3
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Parameter Measurement Information
DS012086-4
C1 = C2 = C3 = 40 pF (including Probe and Jig Capacitance), R1 = R2 = 50Ω, R3 = 500Ω
FIGURE 1. AC Test Circuit
DS012086-5
FIGURE 2. Propagation Delays
DS012086-6
FIGURE 3. Enable and Disable Times
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4
Parameter Measurement Information
(Continued)
DS012086-7
Input pulse; f = 1 MHz, 50%, tr ≤ 6 ns, tf ≤ 6 ns
FIGURE 4. Differential Rise and Fall Times
Typical Application
DS012086-8
* RT is optional although highly recommended to reduce reflection.
FIGURE 5. Two-Wire Balanced System, RS-422
not always consistant. Therefore, skew calculated in this
datasheet, may not be calculated the same as skew defined
in another. This is important to remember whenever making
a skew comparison.
Skew may be calculated for the DS89C387, from many different propagation delay measurements. They may be classified into three categories, single-ended, differential, and
complementry. Single-ended skew is calculated from tPHL
and tPLH measurements (see Figures 6, 7). Differential skew
is calculated from tPHLD and tPLHD measurements (see Figures 8, 9). Complementry skew is calculated from tPHL and
tPLH measurements (see Figures 10, 11).
Application Information
SKEW
Skew may be thought of in a lot of different ways, the next
few paragraphs should clarify what is represented by “Skew”
in the datasheet and how it is determined. Skew, as used in
this databook, is the absolute value of a mathematical difference between two propagation delays. This is commonly accepted throughout the semiconductor industry. However,
there is no standardized method of measuring propagation
delay, from which skew is calculated, of differential line drivers. Elucidating, the voltage level, at which propagation delays are measured, on both input and output waveforms are
(Circuit 2)
(Circuit 1)
DS012086-9
DS012086-10
FIGURE 6. Circuits for Measuring Single-Ended Propagation Delays (See Figure 7)
5
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Application Information
(Continued)
Waveforms for Circuit 1
Waveforms for Circuit 2
DS012086-12
DS012086-11
FIGURE 7. Propagation Delay Waveforms for Circuit 1 and Circuit 2 (See Figure 6)
In Figure 2, VX, where X is a number, is the waveform voltage level at which the propagation delay measurement either starts or stops. Furthermore, V1 and V2 are normally
identical. The same is true for V3 and V4. However, as mentioned before, these levels are not standardized and may
vary, even with similar devices from other companies. Also
note, NC (no connection) in Figure 1 means the pin is not
used in propagation delay measurement for the corresponding circuit.
The single-ended skew provides information about the pulse
width distortion of the output waveform. The lower the skew,
the less the output waveform will be distorted. For best case,
skew would be zero, and the output duty cycle would be
50%, assuming the input has a 50% duty cycle.
However, if V3 and V4 are specified voltages, then V3 and
V4 are less likely to be equal to the crossing point voltage.
Thus, the differential propagation delays will not be measured to zero volts on the differential waveform.
The differential skew also provides information about the
pulse width distortion of the differential output waveform relative to the input waveform. The higher the skew, the greater
the distortion of the differential output waveform. Assuming
the input has a 50% duty cycle, the differential output will
have a 50% duty cycle if skew equals zero and less than a
50% duty cycle if skew is greater than zero.
(Circuit 4)
(Circuit 3)
DS012086-15
FIGURE 10. Circuit for Measuring Complementary
Skew (See Figure 11)
DS012086-13
FIGURE 8. Circuit for Measuring Differential
Propagation Delays (See Figure 9)
Waveforms for Circuit 4
Waveforms for Circuit 3
DS012086-16
FIGURE 11. Waveforms for Circuit 4 (See Figure 10)
DS012086-14
Complementary skew is calculated from single-ended propagation delay measurements on complementary output signals, DO and DO*. Note, when V3 and V4 are absolute values, they are identical on DO and DO*; but vary whenever
they are relative values.
FIGURE 9. Propagation Delay Waveforms
for Circuit 3 (See Figure 8)
For differential propagation delays, V1 should equal V2. Furthermore, the crossing point of DO and DO* corresponds to
zero volts on the differential waveform (see bottom waveform in Figure 9). This is true whether V3 equals V4 or not.
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The complementary skew reveals information about the contour of the rising and falling edge of the differential output
6
Application Information
low propagation delay. The minimum channel to channel
skew is 0 ns since it is possible for all 12 drivers to have
identical propagation delays. Note, this is best and worst
case calculations used whenever Skew (channel) is not independently characterized and specified in the datasheet.
The device to device skew may be calculated in the same
way and the results are the same. Therefore, the device to
device skew is 9 ns and 0 ns maximum and minimum respectively.
(Continued)
signal of the driver. This is important information because the
receiver will interpret the differential output signal. If the differential transitions do not continuously ascend or decend
through the receivers threshold region, errors may occur. Errors may also occur if the transitions are too slow.
In addition, complementary skew provides information about
the common mode modulation of the driver. The common
mode voltage is represented by (DO–DO*)/2. This information may be used as a means for determining EMI affects.
Only “Skew” is specified in this datasheet for the DS89C387.
It refers to the complementary skew of the driver. Complementary skew is measured at both V3 and V4 (see
Figure 11).
More information can be calculated from the propagation delays. The channel to channel and device to device skew may
be calculated in addition to the types of skew mentioned previously. These parameters provide timing performance information beneficial when designing. The channel to channel
skew is calculated from the variation in propagation delay
from receiver to receiver within one package. The device to
device skew is calculated from the variation in propagation
delay from one DS89C387 to another DS89C387.
For the DS89C387, the maximum channel to channel skew
is 9 ns (tp max–tp min) where tp is the low to high or high to
TABLE 1. DS89C387 Skew Table
Parameter
Min
Typ
Max
Units
Skew (comp.)
0
0.5
3
ns
Skew (channel)
0
9
ns
Skew (device)
0
9
ns
Note Skew (comp.) in Table 1 is the same as “Skew” in the
datasheet. Also Skew (channel) and Skew (device) are calculations, but are guaranteed by the propagation delay tests.
Both Skew (channel) and Skew (device) would normally be
tighter whenever specified from characterization data.
The information in this section of the datasheet is to help
clarity how skew is defined in this datasheet. This should
help when designing the DS89C387 into most applications.
DS89C387 Equivalent Input/Output Circuits
DS012086-18
FIGURE 13. Driver Input or
Driver Enable Equivalent Circuit
DS012086-17
FIGURE 12. Driver Output Equivalent Circuit
7
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Pin Descriptions
TABLE 2. Device Pin Names and Descriptions
Pin #
Pin
Name
7, 8, 15, 16, 22, 23,
DI
TTL/CMOS Compatible Driver Input
DO
Non-Inverting Driver Output Pin
DO*
Inverting Driver Output Pin
Pin Description
31, 32, 39, 40, 46, 47
2, 6, 9, 13, 17, 21,
26, 30, 33, 37, 41, 45
3, 5, 10, 12, 18, 20,
27, 29, 34, 36, 44, 44
4, 11, 19, 28, 35, 43
EN
38
VCC
Positive Power Supply Pin +5 ± 10%
14, 24
GND
Device Ground Pin
1, 25, 48
NC
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Active High Dual Driver Enabling Pin
Unused Pin (NOT CONNECTED)
8
9
DS89C387 Twelve Channel CMOS Differential Line Driver
Physical Dimensions
inches (millimeters) unless otherwise noted
48-Lead (0.300" Wide) Molded Shrink Small Outline Package, JEDEC
Order Number DS89C387TMEA
NS Package Number MS48A
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