max485.pdf

(133 KB) Pobierz
19-0410; Rev 3; 7/96
±15kV ESD-Protected, Slew-Rate-Limited,
Low-Power, RS-485/RS-422 Transceivers
_______________General Description
The MAX481E, MAX483E, MAX485E, MAX487E–MAX491E,
and MAX1487E are low-power transceivers for RS-485 and
RS-422 communications in harsh environments. Each driver
output and receiver input is protected against ±15kV electro-
static discharge (ESD) shocks, without latchup. These parts
contain one driver and one receiver. The MAX483E,
MAX487E, MAX488E, and MAX489E feature reduced slew-
rate drivers that minimize EMI and reduce reflections caused
by improperly terminated cables, thus allowing error-free
data transmission up to 250kbps. The driver slew rates of the
MAX481E, MAX485E, MAX490E, MAX491E, and MAX1487E
are not limited, allowing them to transmit up to 2.5Mbps.
These transceivers draw as little as 120µA supply current
when unloaded or when fully loaded with disabled drivers
(see Selection Table). Additionally, the MAX481E,
MAX483E, and MAX487E have a low-current shutdown
mode in which they consume only 0.5µA. All parts operate
from a single +5V supply.
Drivers are short-circuit current limited, and are protected
against excessive power dissipation by thermal shutdown
circuitry that places their outputs into a high-impedance
state. The receiver input has a fail-safe feature that guaran-
tees a logic-high output if the input is open circuit.
The MAX487E and MAX1487E feature quarter-unit-load
receiver input impedance, allowing up to 128 transceivers
on the bus. The MAX488E–MAX491E are designed for full-
duplex communications, while the MAX481E, MAX483E,
MAX485E, MAX487E, and MAX1487E are designed for half-
duplex applications. For applications that are not ESD sen-
sitive see the pin- and function-compatible MAX481,
MAX483, MAX485, MAX487–MAX491, and MAX1487.
________________________Applications
Low-Power RS-485 Transceivers
Low-Power RS-422 Transceivers
Level Translators
Transceivers for EMI-Sensitive Applications
Industrial-Control Local Area Networks
____________________________Features
©
ESD Protection: ±15kV—Human Body Model
©
Slew-Rate Limited for Error-Free Data
Transmission (MAX483E/487E/488E/489E)
©
Low Quiescent Current:
120µA (MAX483E/487E/488E/489E)
230µA (MAX1487E)
300µA (MAX481E/485E/490E/491E)
©
-7V to +12V Common-Mode Input Voltage Range
©
Three-State Outputs
©
30ns Propagation Delays, 5ns Skew
(MAX481E/485E/490E/491E/1487E)
©
Full-Duplex and Half-Duplex Versions Available
©
Allows up to 128 Transceivers on the Bus
(MAX487E/MAX1487E)
©
Current Limiting and Thermal Shutdown for
Driver Overload Protection
______________Ordering Information
PART
TEMP. RANGE
PIN-PACKAGE
MAX481 ECPA
0°C to +70°C
8 Plastic DIP
MAX481ECSA
0°C to +70°C
8 SO
MAX481EEPA
-40°C to +85°C
8 Plastic DIP
MAX481EESA
-40°C to +85°C
8 SO
Ordering Information continued on last page.
______________________________________________________________Selection Table
RECEIVER/
DRIVER
ENABLE
QUIESCENT
CURRENT
( m A)
NUMBER OF
TRANSMITTERS
ON BUS
PART
NUMBER
HALF/FULL
DUPLEX
DATA RATE
(Mbps)
SLEW-RATE
LIMITED
LOW-POWER
SHUTDOWN
PIN
COUNT
MAX481E
MAX483E
MAX485E
MAX487E
MAX488E
MAX489E
MAX490E
MAX491E
MAX1487E
Half
Half
Half
Half
Full
Full
Full
Full
Half
2.5
0.25
2.5
0.25
0.25
0.25
2.5
2.5
2.5
No
Yes
No
Yes
Yes
Yes
No
No
No
Yes
Yes
No
Yes
No
No
No
No
No
Yes
Yes
Yes
Yes
No
Yes
No
Yes
Yes
300
120
300
120
120
120
300
300
230
32
32
32
128
32
32
32
32
128
8
8
8
8
8
14
8
14
8
________________________________________________________________ Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
791617031.167.png 791617031.177.png 791617031.188.png 791617031.199.png 791617031.001.png 791617031.012.png 791617031.022.png 791617031.033.png 791617031.044.png 791617031.055.png 791617031.065.png 791617031.076.png 791617031.087.png 791617031.098.png 791617031.109.png 791617031.120.png 791617031.130.png 791617031.131.png 791617031.132.png 791617031.133.png 791617031.134.png 791617031.135.png 791617031.136.png 791617031.137.png 791617031.138.png 791617031.139.png 791617031.140.png 791617031.141.png 791617031.142.png 791617031.143.png 791617031.144.png
 
±15kV ESD-Protected, Slew-Rate-Limited,
Low-Power, RS-485/RS-422 Transceivers
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (V CC ) .............................................................12V
Control Input Voltage (R — – , DE)...................-0.5V to (V CC + 0.5V)
Driver Input Voltage (DI).............................-0.5V to (V CC + 0.5V)
Driver Output Voltage (Y, Z; A, B) ..........................-8V to +12.5V
Receiver Input Voltage (A, B).................................-8V to +12.5V
Receiver Output Voltage (RO)....................-0.5V to (V CC + 0.5V)
Continuous Power Dissipation (T A = +70°C)
8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) ....727mW
14-Pin Plastic DIP (derate 10.00mW/°C above +70°C) ..800mW
8-Pin SO (derate 5.88mW/°C above +70°C).................471mW
14-Pin SO (derate 8.33mW/°C above +70°C)...............667mW
Operating Temperature Ranges
MAX4_ _C_ _/MAX1487EC_ A .............................0°C to +70°C
MAX4_ _E_ _/MAX1487EE_ A...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10sec) .............................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
DC ELECTRICAL CHARACTERISTICS
(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Differential Driver Output (no load)
V OD1
5
V
R = 50 ½
(RS-422)
2
Differential Driver Output
(with load)
V OD2
V
R = 27 ½
(RS-485), Figure 8
1.5
5
Change in Magnitude of Driver
Differential Output Voltage for
Complementary Output States
Æ V OD
R = 27 ½
or 50 ½ , Figure 8
0.2
V
Driver Common-Mode Output
Voltage
V OC
R = 27 ½
or 50 ½ , Figure 8
3
V
Change in Magnitude of Driver
Common-Mode Output Voltage
for Complementary Output States
Æ
V OD
R = 27
½
or 50
½
, Figure 8
0.2
V
DE, DI, R — –
Input High Voltage
V IH
2.0
V
DE, DI, R — –
DE, DI, R — –
Input Low Voltage
V IL
0.8
V
Input Current
I IN1
±2
µA
DE = 0V;
V CC = 0V or 5.25V,
all devices except
MAX487E/MAX1487E
V IN = 12V
1.0
mA
Input Current
(A, B)
V IN = -7V
V IN = 12V
V IN = -7V
-0.8
I IN2
0.25
MAX487E/MAX1487E,
DE = 0V, V CC = 0V or 5.25V
mA
-0.2
Receiver Differential Threshold
Voltage
V TH
-7V ²
V CM ²
12V
-0.2
0.2
V
Receiver Input Hysteresis
Æ V TH
V CM = 0V
I O = -4mA, V ID = 200mV
I O = 4mA, V ID = -200mV
70
mV
Receiver Output High Voltage
V OH
3.5
V
Receiver Output Low Voltage
V OL
0.4
V
Three-State (high impedance)
Output Current at Receiver
I OZR
0.4V ²
V O ²
2.4V
±1
µA
-7V ² V CM ² 12V, all devices except
MAX487E/MAX1487E
12
k ½
Receiver Input Resistance
R IN
-7V
²
V CM ²
12V, MAX487E/MAX1487E
48
k
½
2
_______________________________________________________________________________________
791617031.145.png 791617031.146.png 791617031.147.png 791617031.148.png 791617031.149.png 791617031.150.png 791617031.151.png 791617031.152.png 791617031.153.png 791617031.154.png 791617031.155.png 791617031.156.png 791617031.157.png 791617031.158.png 791617031.159.png 791617031.160.png 791617031.161.png 791617031.162.png 791617031.163.png 791617031.164.png 791617031.165.png 791617031.166.png 791617031.168.png 791617031.169.png 791617031.170.png 791617031.171.png 791617031.172.png 791617031.173.png 791617031.174.png 791617031.175.png 791617031.176.png
 
±15kV ESD-Protected, Slew-Rate-Limited,
Low-Power, RS-485/RS-422 Transceivers
DC ELECTRICAL CHARACTERISTICS (continued)
(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX488E/MAX489E,
DE, DI, R — – = 0V or V CC
120
250
MAX490E/MAX491E,
DE, DI, R — – = 0V or V CC
300
500
DE = V CC
500
900
MAX481E/MAX485E,
R — – = 0V or V CC
No-Load Supply Current
(Note 3)
I CC
µA
DE = 0V
DE = V CC
DE = 0V
300
500
300
500
MAX1487E,
R — – = 0V or V CC
230
400
MAX483E
MAX487E
350
650
DE = V CC
DE = 0V
MAX483E/MAX487E,
R — – = 0V or V CC
250
400
120
250
MAX481E/483E/487E, DE = 0V, R — –
Supply Current in Shutdown
I SHDN
= V CC
0.5
10
µA
Driver Short-Circuit Current,
V O = High
I OSD1
-7V ²
V O ² 12V (Note 4)
35
250
mA
Driver Short-Circuit Current,
V O = Low
I OSD2
-7V ²
V O ² 12V (Note 4)
35
250
mA
Receiver Short-Circuit Current
I OSR
0V ²
V O ²
V CC
7
95
mA
ESD Protection
A, B, Y and Z pins, tested using Human Body Model
±15
kV
SWITCHING CHARACTERISTICS—MAX481E/MAX485E, MAX490E/MAX491E, MAX1487E
(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
t PLH
10
40
60
Figures 10 and 12, R DIFF = 54 ½ ,
C L1 = C L2 = 100pF
Driver Input to Output
ns
t PHL
10
40
60
Driver Output Skew to Output
t SKEW
Figures 10 and 12, R DIFF = 54
½
, C L1 = C L2 = 100pF
5
10
ns
Figures 10 and 12,
R DIFF = 54 ½ ,
C L1 = C L2 = 100pF
MAX481E, MAX485E, MAX1487E
3
20
40
Driver Rise or Fall Time
t R , t F
ns
MAX490EC/E, MAX491EC/E
5
20
25
Driver Enable to Output High
t ZH
Figures 11 and 13, C L = 100pF, S2 closed
45
70
ns
Driver Enable to Output Low
t ZL
Figures 11 and 13, C L = 100pF, S1 closed
45
70
ns
Driver Disable Time from Low
t LZ
Figures 11 and 13, C L = 15pF, S1 closed
45
70
ns
Driver Disable Time from High
t HZ
Figures 11 and 13, C L = 15pF, S2 closed
45
70
ns
Figures 10 and 14,
R DIFF = 54
MAX481E, MAX485E, MAX1487E
20
60
200
Receiver Input to Output
t PLH , t PHL
,
C L1 = C L2 = 100pF
Figures 10 and 14, R DIFF = 54
ns
½
MAX490EC/E, MAX491EC/E
20
60
150
| t PLH - t PHL | Differential
Receiver Skew
,
½
t SKD
5
ns
C L1 = C L2 = 100pF
Figures 9 and 15, C RL = 15pF, S1 closed
Figures 9 and 15, C RL = 15pF, S2 closed
Figures 9 and 15, C RL = 15pF, S1 closed
Figures 9 and 15, C RL = 15pF, S2 closed
Receiver Enable to Output Low
t ZL
20
50
ns
Receiver Enable to Output High
t ZH
20
50
ns
Receiver Disable Time from Low
t LZ
20
50
ns
Receiver Disable Time from High
t HZ
20
50
ns
Maximum Data Rate
f MAX
2.5
Mbps
Time to Shutdown
t SHDN
MAX481E (Note 5)
50
200
600
ns
_______________________________________________________________________________________
3
791617031.178.png 791617031.179.png 791617031.180.png 791617031.181.png 791617031.182.png 791617031.183.png 791617031.184.png 791617031.185.png 791617031.186.png 791617031.187.png 791617031.189.png 791617031.190.png 791617031.191.png 791617031.192.png 791617031.193.png 791617031.194.png 791617031.195.png 791617031.196.png 791617031.197.png 791617031.198.png 791617031.200.png 791617031.201.png 791617031.202.png 791617031.203.png 791617031.204.png 791617031.205.png 791617031.206.png 791617031.207.png 791617031.208.png 791617031.209.png 791617031.002.png 791617031.003.png 791617031.004.png 791617031.005.png 791617031.006.png 791617031.007.png 791617031.008.png 791617031.009.png 791617031.010.png 791617031.011.png 791617031.013.png 791617031.014.png 791617031.015.png 791617031.016.png
 
±15kV ESD-Protected, Slew-Rate-Limited,
Low-Power, RS-485/RS-422 Transceivers
SWITCHING CHARACTERISTICS—MAX481E/MAX485E, MAX490E/MAX491E, MAX1487E
(continued)
(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Driver Enable from Shutdown to
Output High (MAX481E)
t ZH(SHDN)
Figures 11 and 13, C L = 100pF, S2 closed
45
100
ns
Driver Enable from Shutdown to
Output Low (MAX481E)
t ZL(SHDN)
Figures 11 and 13, C L = 100pF, S1 closed
45
100
ns
Receiver Enable from Shutdown
to Output High (MAX481E)
Figures 9 and 15, C L = 15pF, S2 closed,
A - B = 2V
t ZH(SHDN)
225
1000
ns
Receiver Enable from Shutdown
to Output Low (MAX481E)
Figures 9 and 15, C L = 15pF, S1 closed,
B - A = 2V
t ZL(SHDN)
225
1000
ns
SWITCHING CHARACTERISTICS—MAX483E, MAX487E/MAX488E/MAX489E
(V CC = 5V ±5%, T A = T MIN to T MAX , unless otherwise noted.) (Notes 1, 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
t PLH
250
800
2000
Figures 10 and 12, R DIFF = 54 ½ ,
C L1 = C L2 = 100pF
Driver Input to Output
ns
t PHL
250
800
2000
Figures 10 and 12, R DIFF = 54
½
,
Driver Output Skew to Output
t SKEW
20
800
ns
C L1 = C L2 = 100pF
Figures 10 and 12, R DIFF = 54 ½ ,
C L1 = C L2 = 100pF
Driver Rise or Fall Time
t R , t F
250
2000
ns
Driver Enable to Output High
t ZH
Figures 11 and 13, C L = 100pF, S2 closed
250
2000
ns
Driver Enable to Output Low
t ZL
Figures 11 and 13, C L = 100pF, S1 closed
250
2000
ns
Driver Disable Time from Low
t LZ
Figures 11 and 13, C L = 15pF, S1 closed
300
3000
ns
Driver Disable Time from High
t HZ
Figures 11 and 13, C L = 15pF, S2 closed
300
3000
ns
t PLH
250
2000
Figures 10 and 14, R DIFF = 54
½
,
Receiver Input to Output
ns
C L1 = C L2 = 100pF
t PHL
250
2000
I t PLH - t PHL I Differential
Receiver Skew
Figures 10 and 14, R DIFF = 54 ½ ,
C L1 = C L2 = 100pF
t SKD
100
ns
Receiver Enable to Output Low
t ZL
Figures 9 and 15, C RL = 15pF, S1 closed
25
50
ns
Receiver Enable to Output High
t ZH
Figures 9 and 15, C RL = 15pF, S2 closed
25
50
ns
Receiver Disable Time from Low
t LZ
Figures 9 and 15, C RL = 15pF, S1 closed
25
50
ns
Receiver Disable Time from High
t HZ
Figures 9 and 15, C RL = 15pF, S2 closed
25
50
ns
Maximum Data Rate
f MAX
t PLH , t PHL < 50% of data period
250
kbps
Time to Shutdown
t SHDN
MAX483E/MAX487E (Note 5)
50
200
600
ns
Driver Enable from Shutdown to
Output High
MAX483E/MAX487E, Figures 11 and 13,
C L = 100pF, S2 closed
t ZH(SHDN)
2000
ns
Driver Enable from Shutdown to
Output Low
MAX483E/MAX487E, Figures 11 and 13,
C L = 100pF, S1 closed
t ZL(SHDN)
2000
ns
Receiver Enable from Shutdown
to Output High
MAX483E/MAX487E, Figures 9 and 15,
C L = 15pF, S2 closed
t ZH(SHDN)
2500
ns
Receiver Enable from Shutdown
to Output Low
MAX483E/MAX487E, Figures 9 and 15,
C L = 15pF, S1 closed
t ZL(SHDN)
2500
ns
4
_______________________________________________________________________________________
791617031.017.png 791617031.018.png 791617031.019.png 791617031.020.png 791617031.021.png 791617031.023.png 791617031.024.png 791617031.025.png 791617031.026.png 791617031.027.png 791617031.028.png 791617031.029.png 791617031.030.png 791617031.031.png 791617031.032.png 791617031.034.png 791617031.035.png 791617031.036.png 791617031.037.png 791617031.038.png 791617031.039.png 791617031.040.png 791617031.041.png 791617031.042.png 791617031.043.png 791617031.045.png 791617031.046.png 791617031.047.png 791617031.048.png 791617031.049.png 791617031.050.png 791617031.051.png 791617031.052.png 791617031.053.png 791617031.054.png 791617031.056.png 791617031.057.png 791617031.058.png 791617031.059.png 791617031.060.png 791617031.061.png 791617031.062.png
 
±15kV ESD-Protected, Slew-Rate-Limited,
Low-Power, RS-485/RS-422 Transceivers
NOTES FOR ELECTRICAL/SWITCHING CHARACTERISTICS
Note 1:
All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to device
ground unless otherwise specified.
Note 2:
All typical specifications are given for V CC = 5V and T A = +25°C.
Note 3:
Supply current specification is valid for loaded transmitters when DE = 0V.
Note 4:
Applies to peak current. See Typical Operating Characteristics.
The MAX481E/MAX483E/MAX487E are put into shutdown by bringing R — – high and DE low. If the inputs are in this state for
less than 50ns, the parts are guaranteed not to enter shutdown. If the inputs are in this state for at least 600ns, the parts are
guaranteed to have entered shutdown. See Low-Power Shutdown Modesection.
Note 5:
__________________________________________Typical Operating Characteristics
(V CC = 5V, T A = +25°C, unless otherwise noted.)
OUTPUT CURRENT vs.
RECEIVER OUTPUT LOW VOLTAGE
OUTPUT CURRENT vs.
RECEIVER OUTPUT HIGH VOLTAGE
RECEIVER OUTPUT HIGH VOLTAGE
vs. TEMPERATURE
50
-25
4.8
45
4.6
I RO = 8mA
40
-20
4.4
35
4.2
30
-15
4.0
25
3.8
20
-10
3.6
15
3.4
10
-5
3.2
5
0
0
3.0
0
0.5
1.0
1.5
2.0
2.5
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
-60
-40
-20
0
20
40
60
80
100
OUTPUT LOW VOLTAGE (V)
OUTPUT HIGH VOLTAGE (V)
TEMPERATURE (°C)
RECEIVER OUTPUT LOW VOLTAGE
vs. TEMPERATURE
DRIVER OUTPUT CURRENT vs.
DIFFERENTIAL OUTPUT VOLTAGE
0.9
90
0.8
80
I RO = 8mA
70
0.7
0.6
60
0.5
50
40
0.4
0.3
30
0.2
20
0.1
10
0
0
-60
-40
-20
0
20
40
60
80
100
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
TEMPERATURE (°C)
DIFFERENTIAL OUTPUT VOLTAGE (V)
_______________________________________________________________________________________
5
791617031.063.png 791617031.064.png 791617031.066.png 791617031.067.png 791617031.068.png 791617031.069.png 791617031.070.png 791617031.071.png 791617031.072.png 791617031.073.png 791617031.074.png 791617031.075.png 791617031.077.png 791617031.078.png 791617031.079.png 791617031.080.png 791617031.081.png 791617031.082.png 791617031.083.png 791617031.084.png 791617031.085.png 791617031.086.png 791617031.088.png 791617031.089.png 791617031.090.png 791617031.091.png 791617031.092.png 791617031.093.png 791617031.094.png 791617031.095.png 791617031.096.png 791617031.097.png 791617031.099.png 791617031.100.png 791617031.101.png 791617031.102.png 791617031.103.png 791617031.104.png 791617031.105.png 791617031.106.png 791617031.107.png 791617031.108.png 791617031.110.png 791617031.111.png 791617031.112.png 791617031.113.png 791617031.114.png 791617031.115.png 791617031.116.png 791617031.117.png 791617031.118.png 791617031.119.png 791617031.121.png 791617031.122.png 791617031.123.png 791617031.124.png 791617031.125.png 791617031.126.png 791617031.127.png 791617031.128.png 791617031.129.png
 

Plik z chomika:

Inne pliki z tego folderu:

Inne foldery tego chomika:

Zgłoś jeśli naruszono regulamin