19-3038; Rev 3; 5/12

+5V, Fail-Safe, 40Mbps, Profibus RS-485/

RS-422 Transceivers
General Description Features

MAX3465–MAX3469
The MAX3465–MAX3469 are high-speed differential ♦ Recommended for Profibus Applications
bus transceivers for RS-485 and RS-422 communica-
tions. They are designed to meet TIA/EIA-422-B, ♦ Up to 40Mbps Data Rate
TIA/EIA-485-A, V.11, and X.27 standards. The trans- ♦ 15ns Transmitter Propagation Delay
ceiver complies with the Profibus specification provid- ♦ 20ns Receiver Propagation Delay
ing +2.1V minimum output level with a 54Ω load,
40Mbps data rate, and output skew less than 2ns. Each ♦ 2ns Transmitter and Receiver Skew
part contains one three-state differential line driver and ♦ High Differential Driver Output Level (2.1V on 54Ω)
one differential input line receiver. The devices operate
from a +5V supply and feature true fail-safe circuitry, ♦ Hot-Swap Versions
which guarantees a logic-high receiver output when the ♦ 1µA Shutdown Supply Current
receiver inputs are open or shorted. This enables all
receiver outputs on a terminated bus to output logic ♦ Low Supply Current Requirements (2.5mA, typ)
highs when all transmitters are disabled. ♦ Allow Up to 128 Transceivers on the Bus
All devices feature a 1/4-standard-unit load receiver ♦ True Fail-Safe Receiver while Maintaining EIA/TIA-
input impedance that allows 128 transceivers on the 485 Compatibility
bus. Driver and receiver propagation delays are guar-
anteed under 20ns for multidrop, clock distribution ♦ Designed for Multipoint Transmissions on Long
applications. Drivers are short-circuit current limited or Noisy Bus Lines
and are protected against excessive power dissipation ♦ Full-Duplex and Half-Duplex Versions Available
by thermal-shutdown circuitry. The driver and receiver
feature active-high and active-low enables, respective- ♦ Phase Controls to Correct for Twisted-Pair
ly, that can be connected together externally to serve Reversal for 14-Pin Versions
as a direction control. ♦ Current-Limiting and Thermal Shutdown for
Driver Overload Protection
Ordering Information
Applications PART TEMP RANGE PIN-PACKAGE
High-Speed RS-485 Communications MAX3465CSD 0°C to +70°C 14 SO
High-Speed RS-422 Communications MAX3465CPD 0°C to +70°C 14 Plastic DIP
Level Translators MAX3465ESD -40°C to +85°C 14 SO

Industrial-Control Local Area Networks MAX3465EPD -40°C to +85°C 14 Plastic DIP

Profibus Applications Ordering Information continued at end of data sheet.

Devices are also available in a lead(Pb)-free/RoHS-compliant
package. Specify lead-free by adding “+” to the part number
when ordering.

Pin Configurations appear at end of data sheet.

Selector Guide
RECEIVER/ LOW- RECEIVER/
PART HALF/FULL INDEPENDENT
DRIVER POWER HOT SWAP DRIVER PHASE PIN COUNT
NUMBER DUPLEX SHDN PIN
ENABLE SHUTDOWN SELECT
MAX3465 Full Yes Yes Yes Yes Yes 14
MAX3466 Full Yes Yes No Yes Yes 14
MAX3467 Full No No No No No 8
MAX3468 Half Yes Yes Yes No No 8
MAX3469 Half Yes Yes No No No 8

For pricing, delivery, and ordering information, please contact Maxim Direct 1
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
MAX3465–MAX3469

Supply Voltage (VCC) to GND ..................................-0.3V to +6V SO (derate 8.33mW/°C above +70°C) .........................667mW
Control Input Voltage (RE, DE, DI, SHDN, TXP, RXP) DIP (derate 10mW/°C above +70°C) ...........................800mW
to GND....................................................-0.3V to (VCC + 0.3V) Operating Temperature Range
Driver Output Voltage (Y, Z) to GND .........................-8V to +13V MAX346_C__ ......................................................0°C to +70°C
Receiver Input Voltage (A, B) to GND.......................-8V to +13V MAX346_E__....................................................-40°C to +85°C
Differential Driver Output Voltage (Y - Z) ...............................±8V Junction Temperature ......................................................+150°C
Differential Receiver Input (A - B) ..........................................±8V Storage Temperature Range .............................-65°C to +150°C
Receiver Output Voltage (RO) to GND.......-0.3V to (VCC + 0.3V) Lead Temperature (soldering, 10s) .................................+300°C
Output Driver Current (Y, Z) ...........................................±250mA Soldering Temperature (reflow)
Continuous Power Dissipation (TA = +70°C) Lead(Pb)-Free..............................................................+260°C
SO (derate 5.88mW/°C above +70°C) .........................471mW Containing Lead(Pb)....................................................+240°C
DIP (derate 9.09mW/°C above +70°C) ........................727mW
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
(VCC = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Power-Supply Range VCC 4.75 5.25 V
DRIVER
Differential Driver Output
VOD Figure 5, R = ∞ VCC V
(No Load)
Differential Driver Output VOD Figure 5, R = 27Ω 2.1 V
Change in Magnitude of
ΔVOD Figure 5, R = 50Ω or 27Ω (Note 2) 0.2 V
Differential Output Voltage
Driver Common-Mode Output
VOC Figure 5, R = 50Ω or 27Ω 3 V
Voltage
Change in Magnitude of
ΔVOC Figure 5, R = 50Ω or 27Ω (Note 2) 0.2 V
Common-Mode Voltage
Input High Voltage VIH DE, DI, RE, SHDN 2.0 V
Input Low Voltage VIL DE, DI, RE, SHDN 0.8 V
Input Hysteresis VHYS DE, DI, RE, SHDN 50 mV
Output Leakage (Y and Z) Full DE = GND, VCC = VIN = +12V +125
IO µA
Duplex GND or +5.25V VIN = -7V -100
Input Current IIN DI, RE, DE, SHDN ±1 µA
Pulldown Current RXP = TXP = VCC 5 15 30 µA
Driver Short-Circuit Output 0 ≤ VOUT ≤ +12V, output low +250
IOSD mA
Current (Note 3) -7V ≤ VOUT ≤ VCC, output high -250
Driver Short-Circuit Foldback (VCC - 1V) ≤ VOUT ≤ +12V, output low +25
IOSFD mA
Output Current (Note 3) -7V ≤ VOUT ≤ +1V, output high -25
Thermal Shutdown Threshold 140 °C
RECEIVER
Differential Input Capacitance CA, B Between A and B 8 pF
Input Current (A and B) Full DE = GND, VIN = +12V +250
IA, B µA
Duplex VCC = GND or +5.25V VIN = -7V -200

2
 +5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
ELECTRICAL CHARACTERISTICS (continued)

MAX3465–MAX3469
(VCC = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Receiver Differential Threshold
VTH -7V ≤ VCM ≤ +12V -200 -125 -50 mV
Voltage
Receiver Input Hysteresis ΔVTH VCM = 0 20 mV
Receiver Output High Voltage VOH IO = -4mA, VA - VB = VTH VCC - 1.5 V
Receiver Output Low Voltage VOL IO = 4mA, VB - VA = VTH 0.4 V
Three-State Output Current at
IOZR 0 ≤ VO ≤ VCC ±1 µA
Receiver
Receiver Input Resistance RIN -7V ≤ VCM ≤ +12V 48 kΩ
Receiver Output Short-Circuit
IOSR 0 ≤ VRO ≤ VCC ±7 ±95 mA
Current
A, B, Y, and Z pins
ESD Protection ±6 kV
(MAX3467/MAX3468/MAX3469)
SUPPLY CURRENT
Normal Operation
IQ No load, DI = VCC or DI = GND 2.5 4 mA
(Static Condition)
Supply Current in SHDN ISHDN DE = GND and RE = VCC, or SHDN = VCC 1 10 µA
SWITCHING CHARACTERISTICS
tPLH Figures 6 and 7, RDIFF = 54Ω,
Driver Propagation Delay 15 ns
tPHL CL = 50pF
Driver Differential Output Rise or tR Figures 6 and 7, RDIFF = 54Ω,
10 ns
Fall Time tF CL = 50pF
Figures 6 and 7, RDIFF = 54Ω,
Driver Output Skew |tPLH - tPHL| tSKEW 2 ns
CL = 50pF, TXP = GND or open
Driver Output Transition Skew Guaranteed by design 1 ns
Maximum Data Rate 30 40 Mbps
Figures 8 and 9, S2 closed, RL = 500Ω,
Driver Enable to Output High tZH 30 ns
CL = 50pF
Figures 8 and 9, S1 closed, RL = 500Ω,
Driver Enable to Output Low tZL 30 ns
CL = 50pF
Figures 8 and 9, S1 closed, RL = 500Ω,
Driver Disable Time from Low tLZ 30 ns
CL = 50pF
Figures 8 and 9, S2 closed, RL = 500Ω,
Driver Disable to Output High tHZ 30 ns
CL = 50pF
RL = 500Ω, CL = 50pF, S1 closed (Figures
Driver Enable Skew Time |tZL - tZH| 5 ns
8 and 9), output low
RL = 500Ω, CL = 50pF, S2 closed (Figures
Driver Disable Skew Time |tZL - tZH| 5 ns
8 and 9), output high
tPLH
Receiver Propagation Delay Figure 10, CL = 15pF (Note 4) 20 ns
tPHL

3
 +5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
ELECTRICAL CHARACTERISTICS (continued)
MAX3465–MAX3469

(VCC = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
|tPLH - Figure 10, CL = 15pF, RXP = GND or open
Receiver Output Skew 2 ns
tPHL| (Note 4)
Figures 8 and 11, RL = 1kΩ, CL = 15pF,
Receiver Enable to Output Low tZL 30 ns
S1 closed (Note 4)
Figures 8 and 11, RL = 1kΩ, CL = 15pF,
Receiver Enable to Output High tZH 30 ns
S2 closed (Note 4)
Figures 8 and 11, RL = 1kΩ, CL = 15pF,
Receiver Disable Time from Low tLZ 30 ns
S1 closed (Note 4)
Figures 8 and 11, RL = 1kΩ, CL = 15pF,
Receiver Disable Time from High tHZ 30 ns
S2 closed (Note 4)
Time to Shutdown tSHDN (Note 5) 50 800 ns
Driver Enable from Shutdown to Figures 8 and 9, RL = 500Ω, CL = 50pF,
tZH (SHDN) 4 µs
Output High S2 closed (Note 5)
Driver Enable from Shutdown to Figures 8 and 9, RL = 500Ω, CL = 50pF,
tZL (SHDN) 4 µs
Output Low S1 closed (Note 5)
Receiver Enable from Shutdown to Figures 8 and 11, RL = 1kΩ, CL = 15pF,
tZH (SHDN) 4 µs
Output High S2 closed (Notes 4, 5)
Receiver Enable from Shutdown to Figures 8 and 11, RL = 1kΩ, CL = 15pF,
tZL (SHDN) 4 µs
Output Low 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: ΔVOD and ΔVOC are the changes in VOD and VOC, respectively, when the DI input changes state.
Note 3: The short-circuit output current applies to peak current just prior to foldback-current limiting; the short-circuit foldback output
current applies during current limiting to allow a recovery from 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
(VCC = +5V, TA = +25°C, unless otherwise noted.)

NO-LOAD SUPPLY CURRENT OUTPUT CURRENT OUTPUT CURRENT

vs. TEMPERATURE vs. RECEIVER OUTPUT LOW VOLTAGE vs. RECEIVER OUTPUT HIGH VOLTAGE
2.50 60 35
MAX3465 toc03
MAX3465 toc02
MAX3465 toc01

2.45 30
NO-LOAD SUPPLY CURRENT (mA)

50
2.40 DE = VCC
OUTPUT CURRENT (mA)
OUTPUT CURRENT (mA)

25
40
2.35
20
2.30 30
DE = GND 15
2.25
20
10
2.20
10 5
2.15

2.10 0 0
-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 0 1 2 3 4 5
TEMPERATURE (°C) OUTPUT LOW VOLTAGE (V) OUTPUT HIGH VOLTAGE (V)

4
 +5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
Typical Operating Characteristics (continued)

MAX3465–MAX3469
(VCC = +5V, TA = +25°C, unless otherwise noted.)

SHUTDOWN SUPPLY CURRENT RECEIVER OUTPUT LOW VOLTAGE RECEIVER OUTPUT HIGH VOLTAGE
vs. TEMPERATURE vs. TEMPERATURE vs. TEMPERATURE
300 MAX3465 toc04 200 4.90

MAX3465 toc05

MAX3465 toc06
IO = -4mA IO = 4mA

RECEIVER OUTPUT HIGH VOLTAGE (mV)

RECEIVER OUTPUT LOW VOLTAGE (mV)
SHUTDOWN SUPPLY CURRENT (nA)

250 175 4.85

200 150 4.80

150 125 4.75

100 100 4.70

50 75 4.65

0 50 4.60
-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 DRIVER PROPAGATION DELAY DRIVER DIFFERENTIAL OUTPUT VOLTAGE
vs. TEMPERATURE vs. TEMPERATURE vs. TEMPERATURE
20 12 3.5
MAX3465 toc07

MAX3465 toc08

MAX3465 toc09
RDIFF = 54Ω RDIFF = 54Ω

18
PROPAGATION DELAY (ns)

PROPAGATION DELAY (ns)

10
OUTPUT VOLTAGE (V)

3.0
16
8
14
2.5
6
12

10 4 2.0
-40 -15 10 35 60 85 -40 -15 10 35 60 85 -40 -15 10 35 60 85
TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C)

DRIVER OUTPUT CURRENT OUTPUT CURRENT vs. DRIVER OUTPUT OUTPUT CURRENT
vs. DIFFERENTIAL OUTPUT VOLTAGE LOW VOLTAGE (TA = +25°C) vs. DRIVER OUTPUT HIGH VOLTAGE
100 200 -160
MAX3465 toc10

MAX3465 toc12
MAX3465 toc11

160
-120
OUTPUT CURRENT (mA)

OUTPUT CURRENT (mA)

OUTPUT CURRENT (mA)

10
120
-80
80
1
-40
40

0.1 0 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)
MAX3465–MAX3469

(VCC = +5V, TA = +25°C, unless otherwise noted.)

DRIVER AND RECEIVER
PROPAGATION DELAYS ENABLE RESPONSE TIME EYE DIAGRAM
MAX3465 toc13 MAX3465 toc14 MAX3465 toc15

DI 5V/div
5V/div DE

Y, Z Y, Z
2V/div Y, Z 1V/div
1V/div

RO
5V/div

RDIFF = 54Ω DATA RATE = 20Mbps RDIFF = 54Ω RDIFF = 54Ω DATA RATE = 20Mbps

10ns/div 20ns/div 10ns/div

Pin Description
PIN
HALF
FULL DUPLEX
DUPLEX NAME FUNCTION
MAX3465/ MAX3468/
MAX3467
MAX3466 MAX3469
1 — — SHDN Shutdown. Drive SHDN high to enter low-power shutdown mode.
Receiver Output. When RE is low and (A - B) ≥ -50mV, RO is high; if (A - B) ≤
2 2 1 RO
-200mV, RO is low.
Receiver Output Enable. Drive RE low to enable RO; RO is high impedance
3 — 2 RE
when RE is high. Drive RE high and DE low to enter low-power shutdown mode.

Driver Output Enable. Drive DE high to enable driver output. The driver
outputs are high impedance when DE is low. Drive RE high and DE low to
4 — 3 DE
enter low-power shutdown mode. Do not leave RE unconnected when using
the MAX3466 or MAX3469.
Driver Input. With DE high, a low on DI forces the noninverting output low and
5 3 4 DI the inverting output high. Similarly, a high on DI forces the noninverting output
high and the inverting output low.
6, 7 4 5 GND Ground
Transmitter Phase. Connect TXP to GND, or leave unconnected for normal
8 — — TXP transmitter phase/polarity. Connect TXP to VCC to invert the transmitter
phase/polarity. TXP has an internal 15µA pulldown.
9 5 — Y Noninverting Driver Output
10 6 — Z Inverting Driver Output
11 7 — B Inverting Receiver Input
12 8 — A Noninverting Receiver Input
Receiver Phase. Connect RXP to GND, or leave unconnected for normal
13 — — RXP receiver phase/polarity. Connect RXP to VCC to invert the receiver
phase/polarity. RXP has an internal 15µA pulldown.
14 1 8 VCC Positive Supply: +4.75V ≤ VCC ≤ +5.25V. Bypass VCC to GND with a 0.1µF capacitor.
— — 7 B Inverting Receiver Input and Inverting Driver Output
— — 6 A Noninverting Receiver Input and Noninverting Driver Output
6
 +5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
Function Tables

MAX3465–MAX3469
MAX3465/MAX3466 MAX3467
TRANSMITTING TRANSMITTING
INPUTS OUTPUTS INPUT OUTPUTS
RE DE DI SHDN Z Y DI Z Y
X 1 1 0 0 1 1 0 1
X 1 0 0 1 0 0 1 0
0 0 X 0 High-Z High-Z
1 0 X X Shutdown RECEIVING
X X X 1 Shutdown INPUTS OUTPUT
A-B RO
RECEIVING ≥ -0.05V 1
INPUTS OUTPUT ≤ -0.2V 0
RE DE A-B SHDN RO Open/Shorted 1
0 X ≥ -0.05V 0 1
0 X ≤ -0.2V 0 0
0 X Open/Shorted 0 1 MAX3468/MAX3469
1 1 X 0 High-Z
TRANSMITTING
1 0 X X Shutdown
INPUTS OUTPUTS
X X X 1 Shutdown
RE DE DI B A
X 1 1 0 1
X 1 0 1 0
0 0 X High-Z High-Z
1 0 X Shutdown

RECEIVING
INPUTS OUTPUT
RE DE A-B RO
0 X ≥ -0.05V 1
0 X ≤ -0.2V 0
0 X Open/Shorted 1
1 1 X High-Z
1 0 X Shutdown

7
 +5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
Pin Configurations and Typical Operating Circuit
MAX3465–MAX3469

DE VCC VCC RE
TOP VIEW
4 14 0.1μF MAX3465
MAX3466
SHDN 1 14 VCC
9 Y
RO 2 R 13 RXP 5 Rt
DI D R RO
10
RE 3 12 A
Z
DE 4 11 B

DI 5 10 Z 12 A
D 2 Rt
GND 6 9 Y RO R D DI
8 11
TXP B
GND 7 8 TXP 13
RXP
3 6, 7 GND
DIP/SO
RE GND DE

Figure 1. MAX3465/MAX3466 Pin Configuration and Typical Full-Duplex Operating Circuit

0.1μF VCC
TOP VIEW
VCC 1 MAX3467

5 Y
3 Rt
DI D R RO
VCC 1 8 A 6
R Z
RO 2 7 B

DI 3 6 Z 8 A
D
2 Rt
GND 4 5 Y RO R D DI
7
B
DIP/SO
4 GND
GND

Figure 2. MAX3467 Pin Configuration and Typical Full-Duplex Operating Circuit

TOP VIEW
DE
0.1μF MAX3468
MAX3469
RO 1 R 8 VCC RO 1 R 8 VCC R DI
7 B B
RE 2 7 B RE 2 Rt Rt
6
DE 3 6 A DE 3 A A
DI 4 D 5 GND DI 4 D 5 D RO
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 Half-Duplex Operating Circuit

8
 +5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
Detailed Description defined logic level. Leakage currents up to 10µA from the

MAX3465–MAX3469
high-impedance output could cause DE to drift to an
The MAX3465–MAX3469 high-speed transceivers for
incorrect logic state. Additionally, parasitic circuit board
RS-485/RS-422 communication contain one driver and
capacitance could cause coupling of VCC or GND to DE.
one receiver. These devices feature true fail-safe cir-
These factors could improperly enable the driver.
cuitry, which guarantees a logic-high receiver output
when the receiver inputs are open or shorted, or when When VCC rises, an internal pulldown circuit holds DE
they are connected to a terminated transmission line low for around 15µs. After the initial power-up
with all drivers disabled (see the True Fail-Safe sec- sequence, the pulldown circuit becomes transparent,
tion). The MAX3465–MAX3469’s driver slew rates allow resetting the hot-swap-tolerable input.
transmit speeds up to 40Mbps.
Hot-Swap Input Circuitry
The MAX3468 and MAX3469 are half-duplex trans- The MAX3465/MAX3468 enable inputs feature hot-swap
ceivers, while the MAX3465, MAX3466, and MAX3467 capability. At the input there are two NMOS devices, M1
are full-duplex transceivers. All of these parts operate and M2 (Figure 4). When VCC ramps from 0, an internal
from a single +5V supply. Drivers are output short-cir- 15µs timer turns on M2 and sets the SR latch, which
cuit current limited. Thermal-shutdown circuitry protects also turns on M1. Transistors M2, a 2mA current sink,
drivers against excessive power dissipation. When acti- and M1, a 100µA current sink, pull DE to GND through a
vated, the thermal-shutdown circuitry places the driver 5.6kΩ resistor. M2 is designed to pull DE to the disabled
outputs into a high-impedance state. The MAX3465 state against an external parasitic capacitance up to
and MAX3468 devices have a hot-swap input structure 100pF that can drive DE high. After 15µs, the timer
that prevents disturbances on the differential signal deactivates M2 while M1 remains on, holding DE low
lines when a circuit board is plugged into a hot back- against three-state leakages that can drive DE high. M1
plane (see the Hot-Swap Capability section). All remains on until an external source overcomes the
devices have output levels that are compatible with required input current. At this time, the SR latch resets
Profibus standards. and M1 turns off. When M1 turns off, DE reverts to a
standard, high-impedance CMOS input. Whenever VCC
True Fail-Safe drops below 1V, the hot-swap input is reset.
The MAX3465–MAX3469 guarantee a logic-high receiv-
er output when the receiver inputs are shorted or open, For RE there is a complementary circuit employing two
or when they are connected to a terminated transmis- PMOS devices pulling to VCC.
sion line with all drivers disabled. This is done by set-
ting the receiver threshold between -50mV and
-200mV. If the differential receiver input voltage (A - B)
is greater than or equal to -50mV, RO is logic high. If VCC
A - B is less than or equal to -200mV, RO is logic low. In
15μs
the case of a terminated bus with all transmitters dis-
TIMER
abled, the receiver’s differential input voltage is pulled
to 0V by the termination. With the receiver thresholds of TIMER
the MAX3465–MAX3469, this results in a logic high with
a 50mV minimum noise margin. Unlike previous true
fail-safe devices, the -50mV to -200mV threshold com-
plies with the ±200mV EIA/TIA-485 standard.
Hot-Swap Capability
5.6kΩ DE
Hot-Swap Inputs EN (HOT SWAP)
When circuit boards are inserted into a “hot” or pow- 2mA
ered backplane, disturbances to the enable and differ- 100μA

ential receiver inputs can lead to data errors. Upon M1 M2

initial circuit board insertion, the processor undergoes
its power-up sequence. During this period, the proces-
sor output drivers are high impedance and are unable
to drive the DE input of the MAX3465/MAX3468 to a Figure 4. Simplified Structure of the Driver Enable Pin (DE)

9
 +5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
MAX3465–MAX3469

3V
Y
DE 1.5V 1.5V
0V
R
tZL(SHDN), tZL tLZ
VOD Y, Z
VOL + 0.5V
50% OUTPUT NORMALLY LOW
R VOL
VOC
OUTPUT NORMALLY HIGH
Z Y, Z
50%
VOH - 0.5V
0V
tZH(SHDN), tZH tHZ
Figure 5. Driver DC Test Load

Figure 9. Driver Enable and Disable Times

3V
DE
Y
DI RDIFF
VID CL f = 1MHz, tR ≤ 3ns, tF ≤ 3ns
Z VOH
RO 1.5V 1.5V
OUTPUT
VOL
tPHL tPLH
1V A
INPUT
Figure 6. Driver Timing Test Circuit -1V B

f = 1MHz, tR ≤ 3ns, tF ≤ 3ns Figure 10. Receiver Propagation Delays

3V
DI 1.5V 1.5V
0V
tPLH tPHL
1/2 VO

Z 3V
VO RE 1.5V 1.5V
Y
0V
1/2 VO
VDIFF = V (Y) - V (Z) tZL(SHDN), tZL tLZ
VO VCC
90% 90% VOL + 0.5V
VDIFF 0V RO 1.5V
10% 10% OUTPUT NORMALLY LOW
-VO
tR tF
OUTPUT NORMALLY HIGH
tSKEW = | tPLH - tPHL |
RO 1.5V
VOH - 0.5V
0V
Figure 7. Driver Propagation Delays tZH(SHDN), tZH tHZ

Figure 11. Receiver Enable and Disable Times

VCC
S1
RL
OUTPUT
UNDER TEST

CL
S2

Figure 8. Enable/Disable Timing Test Load

10
 +5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
Propagation Delay

MAX3465–MAX3469
Many digital encoding schemes depend on the difference
B between the driver and receiver propagation delay times.
ATE R
RECEIVER Typical propagation delays are shown in the Typical
VID OUTPUT Operating Characteristics. The difference in receiver delay
A times, |tPLH - tPHL|, is a maximum of 2ns. The driver skew
time |tPLH - tPHL| is also a maximum of 2ns.
Typical Applications
Figure 12. Receiver Propagation Delay Test Circuit
The MAX3465–MAX3469 transceivers are designed for
bidirectional data communications on multipoint bus
transmission lines. Figures 13 and 14 show typical net-
work applications circuits. To minimize reflections, the
Applications Information line should be terminated at both ends in its character-
istic impedance, and stub lengths off the main line
128 Transceivers on the Bus
should be kept as short as possible.
The standard RS-485 receiver input impedance is 12kΩ
(one unit load), and the standard driver can drive up to Profibus Termination
32 unit loads. The MAX3465–MAX3469 family of trans- The MAX3465–MAX3469 are designed for driving
ceivers has a 1/4-unit-load receiver input impedance Profibus termination networks. With a worst-case load-
(48kΩ), allowing up to 128 transceivers to be connect- ing of two termination networks with 220Ω termination
ed in parallel on one communication line. Any combina- impedance and 390Ω pullups and pulldowns, the dri-
tion of these devices and/or other RS-485 transceivers vers can drive VA-B > 2.1V output.
with a total of 32 unit loads or less can be connected to
the line. Chip Information
PROCESS: BiCMOS
Low-Power Shutdown Mode
(Except MAX3467)
Low-power shutdown mode is initiated by bringing
SHDN high (MAX3465/MAX3466), or both RE high and Ordering Information (continued)
DE low. In shutdown, the devices typically draw only
1µA of supply current. RE and DE can be driven simul- PART TEMP RANGE PIN-PACKAGE
taneously; the devices are guaranteed not to enter shut- MAX3466CSD 0°C to +70°C 14 SO
down if RE is high and DE is low for less than 50ns. If
MAX3466CPD 0°C to +70°C 14 Plastic DIP
the inputs are in this state for at least 800ns, the devices
are guaranteed to enter shutdown. MAX3466ESD -40°C to +85°C 14 SO
MAX3466EPD -40°C to +85°C 14 Plastic DIP
Driver Output Protection
MAX3467CSA 0°C to +70°C 8 SO
Two mechanisms prevent excessive output current and
power dissipation caused by faults or by bus con- MAX3467CPA 0°C to +70°C 8 Plastic DIP
tention. The first, a foldback current limit on the output MAX3467ESA -40°C to +85°C 8 SO
stage, provides immediate protection against short cir- MAX3467EPA -40°C to +85°C 8 Plastic DIP
cuits over the whole common-mode voltage range (see MAX3468CSA 0°C to +70°C 8 SO
the Typical Operating Characteristics). The second, a
thermal-shutdown circuit, forces the driver outputs into MAX3468CPA 0°C to +70°C 8 Plastic DIP
a high-impedance state if the die temperature exceeds MAX3468ESA -40°C to +85°C 8 SO
+140°C. MAX3468EPA -40°C to +85°C 8 Plastic DIP
MAX3469CSA 0°C to +70°C 8 SO
MAX3469CPA 0°C to +70°C 8 Plastic DIP
MAX3469ESA -40°C to +85°C 8 SO
MAX3469EPA -40°C to +85°C 8 Plastic DIP
Devices are also available in a lead(Pb)-free/RoHS-compliant
package. Specify lead-free by adding “+” to the part number
when ordering.

11
 +5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
MAX3465–MAX3469

120Ω 120Ω

B B
DI DE
D D

DE DI
A B A B A A

RO R R RO

RE RE

MAX3468 R R
MAX3469 D D
(HALF-DUPLEX)

DI DE RO RE DI DE RO RE

Figure 13. Typical Half-Duplex RS-485 Network

A Y
120Ω 120Ω
RO R
B D DI
RE Z
DE
DE
Z B RE
120Ω 120Ω
DI D
R RO
Y A

Y Z B A B Y Z B 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

Package Information
For the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages. Note that a “+”, “#”, or
“-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains
to the package regardless of RoHS status.

PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO.

14 SO S14-1 21-0041 90-0112
14 PDIP P14-3 21-0043 —
8 SO S8-2 21-0041 90-0096
8 PDIP P8-1 21-0043 —

12
 +5V, Fail-Safe, 40Mbps, Profibus RS-485/
RS-422 Transceivers
Revision History

MAX3465–MAX3469
REVISION REVISION PAGES
DESCRIPTION
NUMBER DATE CHANGED
0 10/09 Initial release. —
1 1/04 Updated the description for the DE pin in the Pin Description table. 6
2 8/09 Replaced TOC 11. 5
Added lead-free compliant packaging information, updated Figure 3 caption,
3 5/12 1, 8, 11, 12
updated package table

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. The parametric values (min and max limits) shown in
the Electrical. Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated Products, 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000 ____________________ 13
© 2012 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.