DS36C280M [NSC]
Slew Rate Controlled CMOS EIA-RS-485 Transceiver; 压摆率控制的CMOS EIA -RS - 485收发器
| 型号： | DS36C280M |
| 厂家： | 
National Semiconductor |
| 描述： | Slew Rate Controlled CMOS EIA-RS-485 Transceiver |
| 文件： | 总10页 (文件大小：172K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
July 1998
DS36C280
Slew Rate Controlled CMOS EIA-RS-485 Transceiver
General Description
Features
n 100% RS-485 compliant
The DS36C280 is a low power differential bus/line trans-
ceiver designed to meet the requirements of RS-485 Stan-
dard for multipoint data transmission. In addition, it is com-
patible with TIA/EIA-422-B.
— Guaranteed RS-485 device interoperation
n Low power CMOS design: ICC 500 µA max
n Adjustable slew rate control
— Minimizes EMI affects
n Built-in power up/down glitch-free circuitry
— Permits live transceiver insertion/displacement
The slew rate control feature allows the user to set the driver
rise and fall times by using an external resistor. Controlled
edge rates can reduce switching EMI.
n DIP and SOIC packages available
The CMOS design offers significant power savings over its
bipolar and ALS counterparts without sacrificing ruggedness
against ESD damage. The device is ideal for use in battery
powered or power conscious applications. ICC is specified at
500 µA maximum.
n Industrial temperature range: −40˚C to +85˚C
n On-board thermal shutdown circuitry
— Prevents damage to the device in the event of
excessive power dissipation
The driver and receiver outputs feature TRI-STATE® capabil-
ity. The driver outputs operate over the entire common mode
range of −7V to +12V. Bus contention or fault situations are
handled by a thermal shutdown circuit, which forces the
driver outputs into the high impedance state.
n Wide common mode range: −7V to +12V
n Receiver open input fail-safe (Note 1)
1
n
n
⁄
⁄
4
unit load (DS36C280): ≥128 nodes
unit load (DS36C280T): ≥64 nodes
1
2
n ESD (human body model): ≥2 kV
The receiver incorporates a fail safe circuit which guarantees
a high output state when the inputs are left open (Note 1) .
Connection and Logic Diagram
Truth Table
DRIVER SECTION
DE/RE*
DI
H
L
DO/RI
DO*/RI*
H
H
L
H
L
L
H
Z
X
Z
RECEIVER SECTION
DE/RE*
RI-RI*
RO
H
L
L
≥+0.2V
≤−0.2V
X
L
H
Z
L
OPEN (Note 1)
H
DS012052-1
Note 1: Non-terminated, Open Inputs only
Order Number DS36C280TM, DS36C280TN
DS36C280M and DS36C280N
See NS Package Number M08A or N08E
TRI-STATE® is a registered trademark of National Semiconductor Corporation.
© 1999 National Semiconductor Corporation
DS012052
www.national.com
Absolute Maximum Ratings (Note 2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Storage Temperature Range
Lead Temperature
−65˚C to +150˚C
+260˚C
(Soldering 4 sec.)
Recommended Operating
Conditions
Supply Voltage (VCC
Input Voltage (DE/RE*, & DI)
Common Mode (VCM
)
+12V
−0.5V to (VCC +0.5V)
)
Min
+4.75
−7
Typ
Max
+5.25
+12
Units
±
±
Driver Output/Receiver Input
Input Voltage (DO/RI, DO*/RI*)
Receiver Output Voltage
15V
14V
Supply Voltage (VCC
)
+5.0
V
V
Bus Voltage
−0.5V to (VCC +0.5V)
Operating Free Air Temperature (TA)
@
Maximum Package Power Dissipation +25˚C
DS36C280T
DS36C280
−40
0
+25
+25
+85
+70
˚C
˚C
M Package 1190 mV, derate
N Package 794 mV, derate
9.5 mW/˚C above +25˚C
6.0 mW/˚C above +25˚C
Electrical Characteristics (Notes 3, 4)
Over Supply Voltage and Operating Temperature ranges, unless otherwise specified
Symbol
Parameter
Conditions
Reference
Min
Typ
Max Units
DIFFERENTIAL DRIVER CHARACTERISTICS
VOD1
VOD0
VOD0*
VOD2
Differential Output Voltage
Output Voltage
IO = 0 mA (No Load)
IO = 0 mA
1.5
0
5.0
5.0
5.0
V
V
V
V
V
V
(422)
(485)
Output Voltage
(Output to GND)
RL = 50Ω
0
Differential Output Voltage
(Termination Load)
(422)
(485)
(Note 5)
Figure 1
2.0
1.5
−0.2
2.8
2.3
0.1
RL = 27Ω
5.0
∆VOD2
VOD3
VOC
Balance of VOD2
RL = 27Ω or 50Ω
+0.2
|VOD2 − VOD2*
|
(422, 485)
Figure 2
Differential Output Voltage
(Full Load)
R1 = 54Ω, R2 = 375Ω
VTEST = −7V to +12V
RL = 27Ω
1.5
2.0
5.0
V
Driver Common Mode
Output Voltage
(485)
(422)
(Note 5)
Figure 1
0
0
3.0
3.0
V
V
V
RL = 50Ω
∆VOC
Balance of VOC
RL = 27Ω or
RL = 50Ω
−0.2
+0.2
|VOC − VOC*
|
(422, 485)
(485) Figure 4
(485)
IOSD
Driver Output Short-Circuit
Current
VO = +12V
200
+250
−250
mA
mA
VO = −7V
−190
RECEIVER CHARACTERISTICS
VTH
Differential Input High
Threshold Voltage
VO = VOH, IO = −0.4 mA
−7V ≤ VCM ≤ +12V
VO = VOL, IO = 0.4 mA
−7V ≤ VCM ≤ +12V
VCM = 0V
+0.035
+0.2
V
V
(Note 6)
(422, 485)
VTL
Differential Input Low
Threshold Voltage
−0.2 −0.035
VHST
RIN
RIN
IIN
Hysteresis
70
mV
kΩ
kΩ
mA
mA
mA
mA
mA
mA
mA
mA
mV
V
Input Resistance
Input Resistance
−7V ≤ VCM ≤ +12V
−7V ≤ VCM ≤ +12V
DS36C280T
DS36C280
VIN = +12V
VIN = −7V
24
48
0
68
68
Line Input Current
(Note 8)
Other Input = 0V
DE = VIL, RE* = VIL
VCC = 4.75 to 5.25
or 0V
DS36C280
0.19
−0.1
0.19
−0.1
0.19
−0.1
0.19
−0.1
0.25
−0.2
0.5
0
DS36C280T VIN = +12V
0
VIN = −7V
VIN = +12V
VIN = −7V
0
−0.4
0.25
−0.2
0.5
IING
Line Input Current
Glitch (Note 8)
Other Input = 0V
DE = VIL, RE* = VIL
VCC = +3.0V
DS36C280
0
0
DS36C280T VIN = +12V
VIN = −7V
0
or 0V TA = 25˚C
RS = 500Ω
0
−0.4
±
IB
Input Balance Test
(422) (Note 10)
RO
Figure 11
400
VOH
VOL
High Level Output Voltage
Low Level Output Voltage
IOH = −4 mA, VID = +0.2V
IOL = +4 mA, VID = −0.2V
3.5
4.6
0.3
0.5
V
www.national.com
2
Electrical Characteristics (Notes 3, 4) (Continued)
Over Supply Voltage and Operating Temperature ranges, unless otherwise specified
Symbol
Parameter
Conditions
Reference
Min
Typ
Max Units
RECEIVER CHARACTERISTICS
IOSR
IOZR
Short Circuit Current
VO = GND
RO
7
35
85
mA
µA
±
1
TRI-STATE Leakage
Current
VO = 0.4V to 2.4V
DEVICE CHARACTERISTICS
VIH
VIL
IIH
High Level Input Voltage
Low Level Input Voltage
High Level Input Current
Low Level Input Current
2.0
VCC
0.8
2
V
V
GND
DE/RE*,
DI
VIH = VCC
µA
µA
µA
mA
µA
µA
IIL
VCC = 5.0V
−2
VIL = 0V
VCC = +3.0V
−2
SR = 0V
SR
−1
ICCR
ICCD
Power Supply Current
(No Load)
Driver OFF, Receiver ON
Driver ON, Receiver OFF
200
200
500
500
VCC
Switching Characteristics (Notes 4, 9, 11)
Over Supply Voltage and Operating Temperature ranges, unless otherwise specified
Symbol
Parameter
Conditions
Reference
Min
10
10
0
Typ
Max
Units
ns
DRIVER CHARACTERISTICS
tPHLD
tPLHD
tSKD
Differential Propagation
Delay High to Low
RL = 54Ω, CL = 100 pF
Figures 5, 6
399
400
1
1000
1000
10
Differential Propagation
Delay Low to High
ns
Differential Skew
ns
|tPHLD − tPLHD
Rise Time
Fall Time
|
tr
SR = Open
SR = 100 kΩ
SR = Short
CL = 15 pF
CL = 100 pF
2870
3070
1590
1640
337
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
tf
tr
Rise Time
Fall Time
tf
tr
Rise Time
Fall Time
100
100
1000
1000
2000
800
tf
348
tPHZ
tPLZ
tPZH
tPZL
Disable Time High to Z
Disable Time Low to Z
Enable Time Z to High
Enable Time Z to Low
Figures 7, 8
Figures 9, 10
Figures 7, 8
Figures 9, 10
1100
500
300
500
300
500
RECEIVER CHARACTERISTICS
tPHL
Propagation Delay
High to Low
CL = 15 pF
30
30
0
210
190
400
400
ns
ns
tPLH
Propagation Delay
Low to High
Figures 12, 13
tSK
Skew, |tPHL − tPLH
|
20
50
55
40
45
50
ns
ns
ns
ns
ns
tPLZ
tPHZ
tPZL
tPZH
Output Disable Time
CL = 15 pF
150
150
150
150
Figures 14, 15, 16
Output Enable Time
Note 2: “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 table of “Electrical Characteristics” specifies conditions of device operation.
Note 3: Current into device pins is defined as positive. Current out of device pins is defined as negative. All voltages are referenced to ground except V
OD1
and V .
OD2
Note 4: All typicals are given for: V
CC
= +5.0V, T = + 25˚C.
A
Note 5: Delta |V
| and Delta |V | are changes in magnitude of V
and V , respectively, that occur when input changes state.
OC
OD2 OC OD2
3
www.national.com
Switching Characteristics (Notes 4, 9, 11) (Continued)
Note 6: Threshold parameter limits specified as an algebraic value rather than by magnitude.
Note 7: Hysteresis defined as V
HST
= V − V .
TH TL
Note 8:
Note 9:
I
includes the receiver input current and driver TRI-STATE leakage current.
includes probe and jig capacitance.
IN
C
L
Note 10: For complete details of test, see RS-485.
Note 11: SR = GND for all Switching Characteristics unless otherwise specified.
Parameter Measurement Information
DS012052-2
FIGURE 1. Driver VOD2 and VOC
DS012052-5
FIGURE 5. Driver Differential
Propagation Delay Test Circuit
DS012052-18
FIGURE 2. Driver VOD3
DS012052-3
FIGURE 3. Driver VOH and VOL
DS012052-6
FIGURE 6. Driver Differential Propagation Delays
and Differential Rise and Fall Times
DS012052-4
Vtest = −7V to +12V
FIGURE 4. Driver IOSD
DS012052-7
FIGURE 7. TRI-STATE Test Circuit (tPZH , tPHZ
)
www.national.com
4
Parameter Measurement
Information (Continued)
DS012052-10
FIGURE 10. TRI-STATE Waveforms (tPZL, tPLZ
)
DS012052-8
FIGURE 8. TRI-STATE Waveforms (tPZH, tPHZ
)
DS012052-11
FIGURE 11. Receiver VOH and VOL
DS012052-9
FIGURE 9. TRI-STATE Test Circuit (tPZL, tPLZ
)
DS012052-12
FIGURE 12. Receiver Differential
Propagation Delay Test Circuit
DS012052-13
FIGURE 13. Receiver Differential Propagation Delay Waveforms
DS012052-14
FIGURE 14. Receiver TRI-STATE Test Circuit
5
www.national.com
Parameter Measurement Information (Continued)
DS012052-15
FIGURE 15. Receiver Enable and Disable Waveforms (tPLZ, tPZL
)
DS012052-16
FIGURE 16. Receiver Enable and Disable Waveforms (tPHZ, tPZH
)
Typical Application Information
DS012052-17
FIGURE 17. Typical Pin Connection
TABLE 1. Device Pin Descriptions
Pin
#
Name
Description
1
RO
Receiver Output: When DE/RE* (Receiver Enable) is LOW, the receiver is enabled (ON), if DO/RI ≥
DO*/RI* by 200 mV, RO will be HIGH. If DO/RI ≤ DO*/RI* by 200 mV, RO will be LOW. Additionally RO
will be HIGH for OPEN (Non-terminated) inputs.
2
3
SR
Slew Rate Control: A resistor connected to Ground controls the Driver Output rising and falling edge
rates.
DE/RE*
Combined Driver and Receiver Output Enable: When signal is LOW the receiver output is enabled and
the driver outputs are in TRI-STATE (OFF). When signaI is HlGH, the receiver output is in TRI-STATE
(OFF) and the driver outputs are enabled.
4
DI
Driver Input: When DE/RE* is HlGH, the driver is enabled, if DI is LOW, then DO/RI will be LOW and
DO*/RI* will be HIGH. If DI is HIGH, then DO/RI is HIGH and DO*/RI* is LOW.
www.national.com
6
Typical Application Information (Continued)
TABLE 1. Device Pin Descriptions (Continued)
Pin
#
Name
Description
5
GND
Ground Connection
6
DO/RI
DO*/RI*
VCC
Driver Output/Receiver Input, 485 Bus Pin.
Driver Output/Receiver Input, 485 Bus Pin.
7
8
Positive Power Supply Connection: Recommended operating range for VCC is +4.75V to +5.25V.
DS36C280 has a slew rate control for EMI conscious appli-
cations. Refer to the sleep mode and slew rate control por-
tion of the application information section in the correspond-
ing datasheet for more information on these features.
Unit Load
A unit load for a RS-485 receiver is defined by the input cur-
rent versus the input voltage curve. The gray shaded region
is the defined operating range from −7V to +12V. The top
border extending from −3V at 0 mA to +12V at +1 mA is de-
fined as one unit load. Likewise, the bottom border extending
from +5V at 0 mA to −7V at −0.8 mA is also defined as one
unit load (see Figure 18 ). A RS-485 driver is capable of driv-
ing up to 32 unit loads. This allows upto 32 nodes on a single
bus. Although sufficient for many applications, it is sometime
desirable to have even more nodes. For example an aircraft
that has 32 rows with 4 seats per row could benefit from hav-
ing 128 nodes on one bus. This would allow signals to be
transferred to and from each individual seat to 1 main sta-
tion. Usually there is one or two less seats in the last row of
the aircraft near the restrooms and food storage area. This
frees the node for the main station.
DS012052-19
FIGURE 18. Input Current vs Input Voltage
Operating Range
The DS36C278, the DS36C279, and the DS36C280 all have
⁄2 unit load and ⁄ unit load (UL) options available. These
1
1
4
devices will allow upto 64 nodes or 128 nodes guaranteed
over temperature depending upon which option is selected.
Slew Rate Control
1
The
the
⁄
2
UL option is available in industrial temperature and
UL is available in commercial temperature.
UL device the top and bottom borders shown in
The DS36C280 features an adjustable slew rate control.
This feature allows more control over EMl levels than tradi-
tion fixed edge rate devices. The slew rate control may be
adjusted with or without any external components. The
DS36C280 offers both low power (ICC 500 µA max) and low
EMI for an RS-485 interface.
1
⁄
4
First, for a 1
⁄
2
Figure 18 are scaled. Both 0 mA reference points at +5V and
−3V stay the same. The other reference points are +12V at
+0.5 mA for the top border and −7V at −0.4 mA for the bot-
1
tom border (see Figure 18 ). Second, for a
⁄4 UL device the
The slew rate control is located at pin two of the device and
only controls the driver output edges. The slew rate control
pin (SR) may be left open or shorted to ground, with or with-
out a resistor. When the SR pin is shorted to ground without
a resistor, the driver output edges will transition typically
350 ns. When the SR pin is left open, the driver output edges
will transition typically 3 µs. When the SR pin is shorted to
ground with a resistor, the driver output edges will transition
between 350 ns and 3 µs depending on the resistor value.
Refer to the slew rate versus resistor value curve in this
datasheet for determining resistor values and expected typi-
cal slew rate value. Please note, when slowing the edge
rates of the device (see Figure 19 ) will decrease the maxi-
mum data rate also.
top and bottom borders shown in Figure 18 are scaled also.
Again, both 0 mA reference points at +5V and −3V stay the
same. The other reference points are +12V at +0.25 mA for
the top border and −7V at −0.2 mA for the bottom border
(see Figure 18 ).
1
1
The advantage of the
⁄ UL and ⁄ UL devices is the in-
2
4
creased number of nodes on one bus. In a single master
multi-slave type of application were the number of slaves ex-
ceeds 32, the DS36C278/279/280 may save in the cost of
extra devices like repeaters, extra media like cable, and/or
extra components like resistors.
The DS36C279 and DS36C280 have addition feature which
offer more advantages. The DS36C279 has an automatic
sleep mode function for power conscious applications. The
7
www.national.com
Slew Rate Control (Continued)
Differential Rise/Fall Time
vs Slew Rate Resistor
DS012052-20
FIGURE 19. Slew Rate Resistor
vs Rise/Fall Time
www.national.com
8
Physical Dimensions inches (millimeters) unless otherwise noted
8-Lead (0.150" Wide) Molded Small Outline Package, JEDEC
Order Number DS36C280TM
NS Package Number M08A
8-Lead (0.300" Wide) Molded Dual-In-Line Package
Order Number DS36C280TN
NS Package Number N08E
9
www.national.com
LIFE SUPPORT POLICY
NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DE-
VICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMI-
CONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are devices or sys-
tems which, (a) are intended for surgical implant into
the body, or (b) support or sustain life, and whose fail-
ure 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 rea-
sonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
National Semiconductor
Corporation
Americas
Tel: 1-800-272-9959
Fax: 1-800-737-7018
Email: support@nsc.com
National Semiconductor
Europe
National Semiconductor
Asia Pacific Customer
Response Group
Tel: 65-2544466
Fax: 65-2504466
National Semiconductor
Japan Ltd.
Tel: 81-3-5639-7560
Fax: 81-3-5639-7507
Fax: +49 (0) 1 80-530 85 86
Email: europe.support@nsc.com
Deutsch Tel: +49 (0) 1 80-530 85 85
English Tel: +49 (0) 1 80-532 78 32
Français Tel: +49 (0) 1 80-532 93 58
Italiano Tel: +49 (0) 1 80-534 16 80
Email: sea.support@nsc.com
www.national.com
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.
相关型号：
DS36C280MX/NOPB
IC LINE TRANSCEIVER, PDSO8, 0.150 INCH, PLASTIC, SOIC-8, Line Driver or Receiver
NSC
DS36C280TMX/NOPB
IC LINE TRANSCEIVER, PDSO8, 0.150 INCH, PLASTIC, SOIC-8, Line Driver or Receiver
NSC
©2020 ICPDF网 联系我们和版权申明