MAX3469ESA+ [MAXIM]
Line Transceiver, 1 Func, 1 Driver, 1 Rcvr, BICMOS, PDSO8, 0.150 INCH, MS-012AA, SOIC-8;
| 型号： | MAX3469ESA+ |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Line Transceiver, 1 Func, 1 Driver, 1 Rcvr, BICMOS, PDSO8, 0.150 INCH, MS-012AA, SOIC-8 |
| 文件： | 总14页 (文件大小：309K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-3038; Rev 0; 10/03
+5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
General Description
Features
ꢀ Recommended for Profibus Applications
The MAX3465–MAX3469 are high-speed differential
bus transceivers for RS-485 and RS-422 communica-
tions. They are designed to meet TIA/EIA-422-B,
TIA/EIA-485-A, V.11, and X.27 standards. The trans-
ceiver complies with the Profibus specification provid-
ing +2.1V minimum output level with a 54Ω load,
40Mbps data rate, and output skew less than 2ns. Each
part contains one three-state differential line driver and
one differential input line receiver. The devices operate
from a +5V supply and feature true fail-safe circuitry,
which guarantees a logic-high receiver output when the
receiver inputs are open or shorted. This enables all
receiver outputs on a terminated bus to output logic
highs when all transmitters are disabled.
ꢀ Up to 40Mbps Data Rate
ꢀ 15ns Transmitter Propagation Delay
ꢀ 20ns Receiver Propagation Delay
ꢀ 2ns Transmitter and Receiver Skew
ꢀ High Differential Driver Output Level (2.1V on 54Ω)
ꢀ Hot-Swap Versions
ꢀ 1µA Shutdown Supply Current
ꢀ Low Supply Current Requirements (2.5mA, typ)
ꢀ Allow Up to 128 Transceivers on the Bus
All devices feature a 1/4-standard-unit load receiver
input impedance that allows 128 transceivers on the
bus. Driver and receiver propagation delays are guar-
anteed under 20ns for multidrop, clock distribution
applications. Drivers are short-circuit current limited
and are protected against excessive power dissipation
by thermal-shutdown circuitry. The driver and receiver
feature active-high and active-low enables, respective-
ly, that can be connected together externally to serve
as a direction control.
ꢀ True Fail-Safe Receiver while Maintaining EIA/TIA-
485 Compatibility
ꢀ Designed for Multipoint Transmissions on Long
or Noisy Bus Lines
ꢀ Full-Duplex and Half-Duplex Versions Available
ꢀ Phase Controls to Correct for Twisted-Pair
Reversal for 14-Pin Versions
ꢀ Current-Limiting and Thermal Shutdown for
Driver Overload Protection
Ordering Information
Applications
High-Speed RS-485 Communications
High-Speed RS-422 Communications
Level Translators
PART
TEMP RANGE
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
14 SO
MAX3465CSD
MAX3465CPD
MAX3465ESD
MAX3465EPD
14 Plastic DIP
14 SO
Industrial-Control Local Area Networks
Profibus Applications
14 Plastic DIP
Ordering Information continued at end of data sheet.
Pin Configurations appear at end of data sheet.
Selector Guide
RECEIVER/
DRIVER
ENABLE
LOW-
POWER
SHUTDOWN
RECEIVER/
DRIVER PHASE
SELECT
PART
NUMBER
HALF/FULL
DUPLEX
INDEPENDENT
SHDN PIN
HOT SWAP
PIN COUNT
MAX3465
MAX3466
MAX3467
MAX3468
MAX3469
Full
Full
Full
Half
Half
Yes
Yes
No
Yes
Yes
No
Yes
No
Yes
Yes
No
Yes
Yes
No
14
14
8
No
Yes
Yes
Yes
Yes
Yes
No
No
No
8
No
No
8
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
+5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (V ) to GND ..................................-0.3V to +6V
CC
Continuous Power Dissipation (ꢁ = +70°C)
A
8-Pin SO (derate 5.88ꢂW/°C above +70°C)................471ꢂW
8-Pin DIP (derate 9.09ꢂW/°C above +70°C)...............727ꢂW
14-Pin SO (derate 8.33ꢂW/°C above +70°C)..............667ꢂW
14-Pin DIP (derate 10ꢂW/°C above +70°C)................800ꢂW
Operating ꢁeꢂperature Range
MAX346_C__ ......................................................0°C to +70°C
MAX346_E__....................................................-40°C to +85°C
Junction ꢁeꢂperature......................................................+150°C
Storage ꢁeꢂperature Range.............................-65°C to +150°C
Lead ꢁeꢂperature (soldering% 10s) .................................+300°C
Control Input Voltage (RE% DE% DI% SHDN% ꢁXP% RXP)
to GND....................................................-0.3V to (V
Driver Output Voltage (Y% Z) to GND.........................-8V to +13V
Receiver Input Voltage (A% B) to GND.......................-8V to +13V
Differential Driver Output Voltage (Y - Z)............................... 8V
Differential Receiver Input (A - B).......................................... 8V
+ 0.3V)
CC
Receiver Output Voltage (RO) to GND.......-0.3V to (V
Output Driver Current (Y% Z) ........................................... 250ꢂA
+ 0.3V)
CC
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.
ELECTRICAL CHARACTERISTICS
(V
= +5V 5ꢀ% ꢁ = ꢁ
to ꢁ
% unless otherwise noted. ꢁypical values are at V
= +5V and ꢁ = +25°C.) (Note 1)
CC A
CC
A
MIN
MAX
PARAMETER
Power-Supply Range
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V
4.75
5.25
V
CC
DRIVER
Differential Driver Output
(No Load)
V
V
Figure 5% R = ∞
Figure 5% R = 27Ω
V
V
V
V
OD
CC
Differential Driver Output
2.1
OD
Change in Magnitude of
Differential Output Voltage
∆V
Figure 5% R = 50Ω or 27Ω (Note 2)
Figure 5% R = 50Ω or 27Ω
0.2
3
OD
Driver Coꢂꢂon-Mode Output
Voltage
V
V
V
OC
Change in Magnitude of
Coꢂꢂon-Mode Voltage
∆V
Figure 5% R = 50Ω or 27Ω (Note 2)
0.2
OC
Input High Voltage
Input Low Voltage
Input Hysteresis
V
DE% DI% RE% SHDN
DE% DI% RE% SHDN
DE% DI% RE% SHDN
2.0
V
V
IH
V
0.8
IL
V
50
15
ꢂV
HYS
V
V
= +12V
= -7V
+125
IN
IN
Output Leakage (Y and Z) Full
Duplex
DE = GND% V
=
CC
I
µA
O
GND or +5.25V
DI% RE% DE% SHDN
RXP = ꢁXP = V
-100
5
Input Current
I
1
30
µA
µA
IN
Pulldown Current
CC
0 ≤ V
≤ +12V% output low
+250
OUꢁ
Driver Short-Circuit Output
Current (Note 3)
I
ꢂA
OSD
-7V ≤ V
≤ V % output high
-250
+25
OUꢁ
CC
(V
CC
- 1V) ≤ V
≤ +12V% output low
OUꢁ
Driver Short-Circuit Foldback
Output Current (Note 3)
I
ꢂA
OSFD
-7V ≤ V
≤ +1V% output high
+25
OUꢁ
ꢁherꢂal-Shutdown ꢁhreshold
RECEIVER
140
8
°C
Differential Input Capacitance
C
Between A and B
DE = GND%
pF
µA
A% B
V
V
= +12V
= -7V
+250
IN
IN
Input Current (A and B) Full
Duplex
I
A% B
V
= GND or +5.25V
CC
-200
2
_______________________________________________________________________________________
+5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
ELECTRICAL CHARACTERISTICS (continued)
(V
= +5V 5ꢀ% ꢁ = ꢁ
to ꢁ
% unless otherwise noted. ꢁypical values are at V
= +5V and ꢁ = +25°C.) (Note 1)
CC A
CC
A
MIN
MAX
PARAMETER
SYMBOL
CONDITIONS
≤ +12V
CM
MIN
TYP
-125
20
MAX
UNITS
Receiver Differential ꢁhreshold
Voltage
V
-7V ≤ V
-200
-50
ꢂV
ꢁH
Receiver Input Hysteresis
∆V
V
= 0
CM
ꢂV
V
ꢁH
Receiver Output High Voltage
Receiver Output Low Voltage
V
I
I
= -4ꢂA% V - V = V
V
- 1.5
CC
OH
O
O
A
B
ꢁH
V
= 4ꢂA% V - V = V
0.4
1
V
OL
B
A
ꢁH
ꢁhree-State Output Current at
Receiver
I
0 ≤ V ≤ V
µA
kΩ
ꢂA
OZR
O
CC
Receiver Input Resistance
R
-7V ≤ V
≤ +12V
CM
48
IN
Receiver Output Short-Circuit
Current
I
0 ≤ V
≤ V
CC
7
95
OSR
RO
A% B% Y% and Z pins
(MAX3467/MAX3468/MAX3469)
ESD Protection
6
kV
SUPPLY CURRENT
Norꢂal Operation
(Static Condition)
I
No load% DI = V
or DI = GND
2.5
1
4
ꢂA
µA
Q
CC
Supply Current in SHDN
I
t
DE = GND and RE = V % or SHDN = V
CC
10
SHDN
CC
SWITCHING CHARACTERISTICS
t
t
PLH
PHL
Figures 6 and 7% R
C = 50pF
L
= 54Ω%
= 54Ω%
= 54Ω%
DIFF
DIFF
DIFF
Driver Propagation Delay
15
10
ns
ns
ns
t
R
Driver Differential Output Rise or
Fall ꢁiꢂe
Figures 6 and 7% R
C = 50pF
L
t
F
Figures 6 and 7% R
C = 50pF% ꢁXP = GND or floating
L
Driver Output Skew |t
- t
|
2
1
PLH PHL
SKEW
Driver Output ꢁransition Skew
Maxiꢂuꢂ Data Rate
Guaranteed by design
ns
30
40
Mbps
Figures 8 and 9% S2 closed% R = 500Ω%
C = 50pF
L
L
Driver Enable to Output High
Driver Enable to Output Low
Driver Disable ꢁiꢂe froꢂ Low
Driver Disable ꢁiꢂe froꢂ High
Driver Enable Skew ꢁiꢂe
t
t
30
30
30
30
5
ns
ns
ns
ns
ns
ns
ns
ZH
Figures 8 and 9% S1 closed% R = 500Ω%
L
t
ZL
LZ
HZ
C = 50pF
L
Figures 8 and 9% S1 closed% R = 500Ω%
L
C = 50pF
L
Figures 8 and 9% S2 closed% R = 500Ω%
L
t
C = 50pF
L
R = 500Ω% C = 50pF% S1 closed (Figures
L
L
|t
t
|
ZL - ZH
8 and 9)% output low
R = 500Ω% C = 50pF% S2 closed (Figures
L
L
Driver Disable Skew ꢁiꢂe
Receiver Propagation Delay
|t
t
|
5
ZL - ZH
8 and 9)% output high
t
t
PLH
PHL
Figure 10% C = 15pF (Note 4)
20
L
_______________________________________________________________________________________
3
+5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
ELECTRICAL CHARACTERISTICS (continued)
(V
= +5V 5ꢀ% ꢁ = ꢁ
to ꢁ
% unless otherwise noted. ꢁypical values are at V
= +5V and ꢁ = +25°C.) (Note 1)
CC A
CC
A
MIN
MAX
PARAMETER
Receiver Output Skew
SYMBOL
|t
CONDITIONS
MIN
TYP
MAX
UNITS
-
Figure 10% C = 15pF% RXP = GND or
L
floating (Note 4)
PLH
2
ns
t
|
PHL
Figures 8 and 11% R = 1kΩ% C = 15pF%
S1 closed (Note 4)
L
L
Receiver Enable to Output Low
Receiver Enable to Output High
t
30
30
30
ns
ns
ns
ZL
Figures 8 and 11% R = 1kΩ% C = 15pF%
L
L
t
ZH
S2 closed (Note 4)
Figures 8 and 11% R = 1kΩ% C = 15pF%
L
L
Receiver Disable ꢁiꢂe froꢂ Low
t
LZ
S1 closed (Note 4)
Figures 8 and 11% R = 1kΩ% C = 15pF%
S2 closed (Note 4)
(Note 5)
L
L
Receiver Disable ꢁiꢂe froꢂ High
ꢁiꢂe to Shutdown
t
30
800
4
ns
ns
µs
HZ
t
50
SHDN
Driver Enable froꢂ Shutdown to
Output High
Figures 8 and 9% R = 500Ω% C = 50pF%
L L
S2 closed (Note 5)
t
ZH (SHDN)
Driver Enable froꢂ Shutdown to
Output Low
Figures 8 and 9% R = 500Ω% C = 50pF%
S1 closed (Note 5)
L
L
t
4
4
4
µs
µs
µs
ZL (SHDN)
Receiver Enable froꢂ Shutdown to
Output High
Figures 8 and 11% R = 1kΩ% C = 15pF%
L
L
t
ZH (SHDN)
S2 closed (Notes 4% 5)
Receiver Enable froꢂ Shutdown to
Output Low
Figures 8 and 11% R = 1kΩ% C = 15pF%
L
L
t
ZL (SHDN)
S1 closed (Notes 4% 5)
Note 1: All currents into the device are positive; all currents out of the device are negative. All voltages are referenced to device
ground% unless otherwise noted.
Note 2: ∆V
and ∆V
are the changes in V and V % respectively% when the DI input changes state.
OD OC
OD
OC
Note 3: ꢁhe short-circuit output current applies to peak current just prior to foldback-current liꢂiting; the short-circuit foldback output
current applies during current liꢂiting to allow a recovery froꢂ bus contention.
Note 4: Capacitive load includes test probe and fixture capacitance.
Note 5: Shutdown is enabled by bringing RE high and DE low or by bringing SHDN high. If the enable inputs are in this state for less
than 50ns% the device is guaranteed not to enter shutdown. If the enable inputs are in this state for at least 800ns% the device
is guaranteed to have entered shutdown.
Typical Operating Characteristics
(V
= +5V% ꢁ = +25°C% unless otherwise noted.)
CC
A
NO-LOAD SUPPLY CURRENT
vs. TEMPERATURE
OUTPUT CURRENT
vs. RECEIVER OUTPUT HIGH VOLTAGE
OUTPUT CURRENT
vs. RECEIVER OUTPUT LOW VOLTAGE
35
30
25
20
15
10
5
2.50
60
50
40
30
20
10
0
2.45
2.40
2.35
2.30
2.25
2.20
2.15
2.10
DE = V
CC
DE = GND
0
0
1
2
3
4
5
-40
-20
0
20
40
60
80
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
OUTPUT LOW VOLTAGE (V)
OUTPUT HIGH VOLTAGE (V)
TEMPERATURE (°C)
4
_______________________________________________________________________________________
+5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
Typical Operating Characteristics (continued)
(V
= +5V% ꢁ = +25°C% unless otherwise noted.)
CC
A
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
RECEIVER OUTPUT LOW VOLTAGE
vs. TEMPERATURE
RECEIVER OUTPUT HIGH VOLTAGE
vs. TEMPERATURE
300
200
175
150
125
100
75
4.90
4.85
4.80
4.75
4.70
4.65
4.60
I
= -4mA
I = 4mA
O
O
250
200
150
100
50
0
50
-40
-15
10
35
60
85
-40
-15
10
35
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
RECEIVER PROPAGATION DELAY
vs. TEMPERATURE
DRIVER PROPAGATION DELAY
vs. TEMPERATURE
DRIVER DIFFERENTIAL OUTPUT VOLTAGE
vs. TEMPERATURE
20
18
16
14
12
10
12
10
8
3.5
3.0
2.5
2.0
R
= 54Ω
R
= 54Ω
DIFF
DIFF
6
4
-40
-15
10
35
60
85
-40
-15
10
35
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
OUTPUT CURRENT
vs. DRIVER OUTPUT HIGH VOLTAGE
DRIVER OUTPUT CURRENT
vs. DIFFERENTIAL OUTPUT VOLTAGE
OUTPUT CURRENT
vs. DRIVER OUTPUT LOW VOLTAGE
100
10
1
200
160
120
80
-160
-120
-80
-40
0
40
0.1
0
0
1
2
3
4
5
0
3
6
9
12
-7
-5
-3
-1
1
3
5
DIFFERENTIAL OUTPUT VOLTAGE (V)
OUTPUT LOW VOLTAGE (V)
OUTPUT HIGH VOLTAGE (V)
_______________________________________________________________________________________
5
+5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
Typical Operating Characteristics (continued)
(V
= +5V% ꢁ = +25°C% unless otherwise noted.)
CC
A
DRIVER AND RECEIVER
PROPAGATION DELAYS
ENABLE RESPONSE TIME
EYE DIAGRAM
MAX3465 toc14
MAX3465 toc13
MAX3465 toc15
DI
5V/div
5V/div
DE
Y, Z
1V/div
Y, Z
Y, Z
1V/div
2V/div
RO
5V/div
R
DIFF
= 54Ω
R
= 54Ω
DIFF
R
= 54Ω
DATA RATE = 20Mbps
10ns/div
DATA RATE = 20Mbps
10ns/div
DIFF
20ns/div
Pin Description
PIN
FULL DUPLEX
NAME
FUNCTION
HALF
DUPLEX
MAX3465/
MAX3466
MAX3468/
MAX3469
MAX3467
SHDN
RO
Shutdown. Drive SHDN high to enter low-power shutdown ꢂode.
Receiver Output. When RE is low and (A - B) ≥ -50ꢂV% RO is high; if (A - B) ≤
-200ꢂV% RO is low.
1
2
—
—
Receiver Output Enable. Drive RE low to enable RO; RO is high iꢂpedance
when RE is high. Drive RE high and DE low to enter low-power shutdown ꢂode.
2
1
RE
Driver Output Enable. Drive DE high to enable driver output. ꢁhe driver
outputs are high iꢂpedance when DE is low. Drive RE high and DE low to
enter low-power shutdown ꢂode.
3
—
2
DE
Driver Input. With DE high% a low on DI forces the noninverting output low and
the inverting output high. Siꢂilarly% a high on DI forces the noninverting output
high and the inverting output low.
4
5
—
3
3
4
5
DI
GND
ꢁXP
Ground
ꢁransꢂitter Phase. Connect ꢁXP to GND% or leave unconnected for norꢂal
transꢂitter phase/polarity. Connect ꢁXP to V to invert the transꢂitter
CC
6% 7
4
phase/polarity. ꢁXP has an internal 15µA pulldown.
Noninverting Driver Output
8
9
10
11
—
5
6
—
—
—
—
Y
Z
B
A
Inverting Driver Output
Inverting Receiver Input
Noninverting Receiver Input
7
Receiver Phase. Connect RXP to GND% or leave unconnected for norꢂal
12
8
—
RXP
receiver phase/polarity. Connect RXP to V to invert the receiver
CC
phase/polarity. RXP has an internal 15µA pulldown.
Positive Supply: +4.75V ≤ V
capacitor.
≤ +5.25V. Bypass V
to GND with a 0.1µF
CC
CC
13
—
—
V
CC
14
—
—
1
—
—
8
7
6
B
A
Inverting Receiver Input and Inverting Driver Output
Noninverting Receiver Input and Noninverting Driver Output
6
_______________________________________________________________________________________
+5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
Function Tables
MAX3465/MAX3466
MAX3467
TRANSMITTING
INPUTS
DE
TRANSMITTING
OUTPUTS
OUTPUTS
INPUT
RE
X
DI
1
SHDN
Z
Y
DI
1
Z
0
1
Y
1
0
1
1
0
0
X
0
0
0
X
1
0
1
1
0
X
0
0
0
X
X
X
High-Z
High-Z
1
Shutdown
Shutdown
RECEIVING
X
INPUTS
A - B
OUTPUT
RO
1
RECEIVING
INPUTS
≥ -0.05V
OUTPUT
≤ -0.2V
0
RE
0
DE
X
A - B
SHDN
RO
Open/Shorted
1
≥ -0.05V
0
0
0
0
X
1
1
0
0
X
≤ -0.2V
0
X
Open/Shorted
1
MAX3468/MAX3469
1
1
X
X
X
High-Z
Shutdown
Shutdown
TRANSMITTING
1
0
INPUTS
OUTPUTS
X
X
RE
X
DE
1
DI
1
B
A
1
0
0
1
X
1
0
0
0
X
X
High-Z
High-Z
1
0
Shutdown
RECEIVING
INPUTS
OUTPUT
RE
0
DE
X
A - B
≥ -0.05V
≤ -0.2V
Open/Shorted
X
RO
1
0
X
0
1
0
X
1
1
High-Z
Shutdown
1
0
X
_______________________________________________________________________________________
7
+5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
Pin Configurations and Typical Operating Circuit
V
CC
V
RE
DE
CC
TOP VIEW
MAX3465
MAX3466
0.1µF
4
14
SHDN
1
2
3
4
5
6
7
14
V
CC
9
Y
RO
RE
R
13 RXP
5
R
t
RO
DI
D
R
DI
10
12
11
10
9
A
Z
DE
B
12
11
A
B
DI
Z
D
2
8
R
t
RO
TXP
RXP
D
R
GND
GND
Y
8
TXP
13
3
GND
6, 7
DIP/SO
RE
DE
GND
Figure 1. MAX3465/MAX3466 Pin Configuration and Typical Full-Duplex Operating Circuit
0.1µF
V
CC
TOP VIEW
MAX3467
V
CC 1
5
6
Y
Z
3
2
R
t
RO
DI
D
R
DI
V
1
2
3
4
8
7
6
5
A
B
Z
CC
R
RO
DI
8
7
A
B
D
R
t
Y
GND
RO
D
R
DIP/SO
4
GND
GND
Figure 2. MAX3467 Pin Configuration and Typical Full-Duplex Operating Circuit
TOP VIEW
DE
R
0.1µF
MAX3468
MAX3469
V
RO
RE
DE
DI
1
2
3
4
R
8
7
6
5
RO
RE
DE
DI
1
2
3
4
R
8
7
DI
V
B
A
CC
CC
B
A
B
A
R
R
t
t
6
5
D
D
D
RO
GND
GND
DIP/SO
RE
NOTE: PIN LABELS Y AND Z ON TIMING, TEST, AND WAVEFORM DIAGRAMS REFER TO PINS A AND B WHEN DE IS HIGH.
Figure 3. MAX3468/MAX3469 Pin Configuration and Typical Full-Duplex Operating Circuit
8
_______________________________________________________________________________________
+5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
defined logic level. Leakage currents up to 10µA froꢂ the
Detailed Description
high-iꢂpedance output could cause DE to drift to an
ꢁhe MAX3465–MAX3469 high-speed transceivers for
incorrect logic state. Additionally% parasitic circuit board
RS-485/RS-422 coꢂꢂunication contain one driver and
one receiver. ꢁhese devices feature true fail-safe cir-
cuitry% which guarantees a logic-high receiver output
when the receiver inputs are open or shorted% or when
they are connected to a terꢂinated transꢂission line
with all drivers disabled (see the True Fail-Safe sec-
tion). ꢁhe MAX3465–MAX3469’s driver slew rates allow
transꢂit speeds up to 40Mbps.
capacitance could cause coupling of V
or GND to DE.
CC
ꢁhese factors could iꢂproperly enable the driver.
When V rises% an internal pulldown circuit holds DE
CC
low for around 15µs. After the initial power-up
sequence% the pulldown circuit becoꢂes transparent%
resetting the hot-swap-tolerable input.
Hot-Swap Input Circuitry
ꢁhe MAX3465/MAX3468 enable inputs feature hot-swap
capability. At the input there are two NMOS devices% M1
ꢁhe MAX3468 and MAX3469 are half-duplex trans-
ceivers% while the MAX3465% MAX3466% and MAX3467
are full-duplex transceivers. All of these parts operate
froꢂ a single +5V supply. Drivers are output short-cir-
cuit current liꢂited. ꢁherꢂal-shutdown circuitry protects
drivers against excessive power dissipation. When acti-
vated% the therꢂal-shutdown circuitry places the driver
outputs into a high-iꢂpedance state. ꢁhe MAX3465
and MAX3468 devices have a hot-swap input structure
that prevents disturbances on the differential signal
lines when a circuit board is plugged into a hot back-
plane (see the Hot-Swap Capability section). All
devices have output levels that are coꢂpatible with
Profibus standards.
and M2 (Figure 4). When V
raꢂps froꢂ 0% an internal
CC
15µs tiꢂer turns on M2 and sets the SR latch% which
also turns on M1. ꢁransistors M2% a 2ꢂA current sink%
and M1% a 100µA current sink% pull DE to GND through a
5.6kΩ resistor. M2 is designed to pull DE to the disabled
state against an external parasitic capacitance up to
100pF that can drive DE high. After 15µs% the tiꢂer
deactivates M2 while M1 reꢂains on% holding DE low
against three-state leakages that can drive DE high. M1
reꢂains on until an external source overcoꢂes the
required input current. At this tiꢂe% the SR latch resets
and M1 turns off. When M1 turns off% DE reverts to a
standard% high-iꢂpedance CMOS input. Whenever V
drops below 1V% the hot-swap input is reset.
CC
True Fail-Safe
ꢁhe MAX3465–MAX3469 guarantee a logic-high receiv-
er output when the receiver inputs are shorted or open%
or when they are connected to a terꢂinated transꢂis-
sion line with all drivers disabled. ꢁhis is done by set-
ting the receiver threshold between -50ꢂV and
-200ꢂV. If the differential receiver input voltage (A - B)
is greater than or equal to -50ꢂV% RO is logic high. If
A - B is less than or equal to -200ꢂV% RO is logic low. In
the case of a terꢂinated bus with all transꢂitters dis-
abled% the receiver’s differential input voltage is pulled
to 0V by the terꢂination. With the receiver thresholds of
the MAX3465–MAX3469% this results in a logic high with
a 50ꢂV ꢂiniꢂuꢂ noise ꢂargin. Unlike previous true
fail-safe devices% the -50ꢂV to -200ꢂV threshold coꢂ-
plies with the 200ꢂV EIA/ꢁIA-485 standard.
For RE there is a coꢂpleꢂentary circuit eꢂploying two
PMOS devices pulling to V
.
CC
V
CC
15µs
TIMER
TIMER
Hot-Swap Capability
5.6kΩ
DE
Hot-Swap Inputs
When circuit boards are inserted into a “hot” or pow-
ered backplane% disturbances to the enable and differ-
ential receiver inputs can lead to data errors. Upon
initial circuit board insertion% the processor undergoes
its power-up sequence. During this period% the proces-
sor output drivers are high iꢂpedance and are unable
to drive the DE input of the MAX3465/MAX3468 to a
EN
(HOT SWAP)
2mA
100µA
M1
M2
Figure 4. Simplified Structure of the Driver Enable Pin (DE)
_______________________________________________________________________________________
9
+5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
3V
Y
DE
1.5V
1.5V
0V
R
t
t
, t
LZ
ZL(SHDN) ZL
V
Y, Z
OD
V
+ 0.5V
- 0.5V
OL
50%
OUTPUT NORMALLY LOW
OUTPUT NORMALLY HIGH
V
OL
R
V
OC
Z
Y, Z
0V
50%
t
V
OH
t
, t
HZ
ZH(SHDN) ZH
Figure 5. Driver DC Test Load
Figure 9. Driver Enable and Disable Times
3V
DE
Y
DI
R
DIFF
V
C
ID
L
f = 1MHz, t ≤ 3ns, t ≤ 3ns
R
F
Z
V
OH
RO
1.5V
1.5V
OUTPUT
V
OL
A
t
t
PLH
PHL
1V
INPUT
Figure 6. Driver Timing Test Circuit
B
-1V
Figure 10. Receiver Propagation Delays
f = 1MHz, t ≤ 3ns, t ≤ 3ns
R
F
3V
0V
DI
1.5V
1.5V
t
t
PHL
PLH
1/2 V
O
Z
3V
V
O
1.5V
RE
1.5V
Y
0V
1/2 V
O
t
, t
t
LZ
V
DIFF
= V (Y) - V (Z)
ZL(SHDN) ZL
V
0V
V
RO
O
CC
90%
90%
V
+ 0.5V
- 0.5V
OL
V
DIFF
1.5V
OUTPUT NORMALLY LOW
OUTPUT NORMALLY HIGH
10%
10%
-V
O
t
t
F
R
t
= | t - t
PLH PHL
|
SKEW
RO
1.5V
t
V
OH
0V
Figure 7. Driver Propagation Delays
t
, t
HZ
ZH(SHDN) ZH
Figure 11. Receiver Enable and Disable Times
V
CC
S1
S2
R
L
OUTPUT
UNDER TEST
C
L
Figure 8. Enable/Disable Timing Test Load
10 ______________________________________________________________________________________
+5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
Propagation Delay
Many digital encoding scheꢂes depend on the difference
between the driver and receiver propagation delay tiꢂes.
ꢁypical propagation delays are shown in the Typical
Operating Characteristics. ꢁhe difference in receiver delay
B
RECEIVER
OUTPUT
R
ATE
V
ID
A
tiꢂes% |t
- t
|% is a ꢂaxiꢂuꢂ of 2ns. ꢁhe driver skew
PLH PHL
tiꢂe |t
- t
| is also a ꢂaxiꢂuꢂ of 2ns.
PLH PHL
Typical Applications
Figure 12. Receiver Propagation Delay Test Circuit
ꢁhe MAX3465–MAX3469 transceivers are designed for
bidirectional data coꢂꢂunications on ꢂultipoint bus
transꢂission lines. Figures 13 and 14 show typical net-
work applications circuits. ꢁo ꢂiniꢂize reflections% the
line should be terꢂinated at both ends in its character-
istic iꢂpedance% and stub lengths off the ꢂain line
should be kept as short as possible.
Applications Information
128 Transceivers on the Bus
ꢁhe standard RS-485 receiver input iꢂpedance is 12kΩ
(one unit load)% and the standard driver can drive up to
32 unit loads. ꢁhe MAX3465–MAX3469 faꢂily of trans-
ceivers has a 1/4-unit-load receiver input iꢂpedance
(48kΩ)% allowing up to 128 transceivers to be connect-
ed in parallel on one coꢂꢂunication line. Any coꢂbina-
tion of these devices and/or other RS-485 transceivers
with a total of 32 unit loads or less can be connected to
the line.
Profibus Termination
ꢁhe MAX3465–MAX3469 are designed for driving
Profibus terꢂination networks. With a worst-case load-
ing of two terꢂination networks with 220Ω terꢂination
iꢂpedance and 390Ω pullups and pulldowns% the dri-
vers can drive V
> 2.1V output.
A-B
Chip Information
ꢁRANSISꢁOR COUNꢁ: 610
PROCESS: BiCMOS
Low-Power Shutdown Mode
(Except MAX3467)
Low-power shutdown ꢂode is initiated by bringing
SHDN high (MAX3465/MAX3466)% or both RE high and
DE low. In shutdown% the devices typically draw only
1µA of supply current. RE and DE can be driven siꢂul-
taneously; the devices are guaranteed not to enter shut-
down if RE is high and DE is low for less than 50ns. If
the inputs are in this state for at least 800ns% the devices
are guaranteed to enter shutdown.
Ordering Information (continued)
PART
TEMP RANGE
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
14 SO
MAX3466CSD
MAX3466CPD
MAX3466ESD
MAX3466EPD
MAX3467CSA
MAX3467CPA
MAX3467ESA
MAX3467EPA
MAX3468CSA
MAX3468CPA
MAX3468ESA
MAX3468EPA
MAX3469CSA
MAX3469CPA
MAX3469ESA
MAX3469EPA
14 Plastic DIP
14 SO
Driver Output Protection
ꢁwo ꢂechanisꢂs prevent excessive output current and
power dissipation caused by faults or by bus con-
tention. ꢁhe first% a foldback current liꢂit on the output
stage% provides iꢂꢂediate protection against short cir-
cuits over the whole coꢂꢂon-ꢂode voltage range (see
the Typical Operating Characteristics). ꢁhe second% a
therꢂal-shutdown circuit% forces the driver outputs into
a high-iꢂpedance state if the die teꢂperature exceeds
+140°C.
14 Plastic DIP
8 SO
8 Plastic DIP
8 SO
8 Plastic DIP
8 SO
8 Plastic DIP
8 SO
8 Plastic DIP
8 SO
8 Plastic DIP
8 SO
8 Plastic DIP
______________________________________________________________________________________ 11
+5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
120Ω
120Ω
B
B
DI
DE
DI
D
D
DE
A
B
A
B
A
A
R
R
RO
RE
RO
RE
R
R
D
D
MAX3468
MAX3469
(HALF-DUPLEX)
DI
DE
RO RE
DI
DE
RO RE
Figure 13. Typical Half-Duplex RS-485 Network
A
Y
120Ω
120Ω
120Ω
R
RO
D
DI
B
RE
DE
Z
B
A
DE
RE
Z
120Ω
DI
D
RO
R
Y
B
Y
Z
B
A
B
Y
Z
A
MAX3465
MAX3466
R
R
D
D
MAX3467
(FULL-DUPLEX)
DI
DE RE RO
DI
DE RE RO
NOTE: RE AND DE ON MAX3465/MAX3466/MAX3467 ONLY.
Figure 14. Typical Full-Duplex RS-485 Network
12 ______________________________________________________________________________________
+5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
Package Information
(ꢁhe package drawing(s) in this data sheet ꢂay not reflect the ꢂost current specifications. For the latest package outline inforꢂation%
go to www.maxim-ic.com/packages.)
INCHES
MILLIMETERS
DIM
A
MIN
MAX
0.069
0.010
0.019
0.010
MIN
1.35
0.10
0.35
0.19
MAX
1.75
0.25
0.49
0.25
0.053
0.004
0.014
0.007
N
A1
B
C
e
0.050 BSC
1.27 BSC
E
0.150
0.228
0.016
0.157
0.244
0.050
3.80
5.80
0.40
4.00
6.20
1.27
E
H
H
L
VARIATIONS:
INCHES
1
MILLIMETERS
DIM
D
MIN
MAX
0.197
0.344
0.394
MIN
4.80
8.55
9.80
MAX
5.00
N
8
MS012
AA
TOP VIEW
0.189
0.337
0.386
D
8.75 14
10.00 16
AB
D
AC
D
C
A
B
0 -8
e
A1
L
FRONT VIEW
SIDE VIEW
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, .150" SOIC
APPROVAL
DOCUMENT CONTROL NO.
REV.
1
21-0041
B
1
______________________________________________________________________________________ 13
+5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
Package Information (continued)
(ꢁhe package drawing(s) in this data sheet ꢂay not reflect the ꢂost current specifications. For the latest package outline inforꢂation%
go to www.maxim-ic.com/packages.)
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
14 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2003 Maxiꢂ Integrated Products
Printed USA
is a registered tradeꢂark of Maxiꢂ Integrated Products.
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