19-1727; Rev 0; 7/00
±15kV ESD-Protected, 32Mbps, 3V/5V,
Triple RS-422/RS-485 Receivers with Fault Detection
General Description
The MAX3097E/MAX3098E feature three high-speed RS-
485/RS-422 receivers with fault-detection circuitry and
fault-status outputs. The receivers’ inputs have fault
thresholds that detect when the part is not in a valid state.
The MAX3097E/MAX3098E indicate when a receiver
input is in an open-circuit condition, short-circuit condi-
tion, or outside the common-mode range. They also
generate a fault indication when the differential input
voltage goes below a preset threshold. See
Ordering
Information
or the
Electrical Characteristics
for thresh-
old values.
The fault circuitry includes a capacitor-programmable
delay to ensure that there are no erroneous fault condi-
tions even at slow edge rates. Each receiver is capable
of accepting data at rates up to 32Mbps.
Features
o
Detects the Following RS-485 Faults:
Open-Circuit Condition
Short-Circuit Condition
Low Differential Voltage Signal
Common-Mode Range Violation
o
ESD Protection
±15kV—Human Body Model
±15kV—IEC 1000-4-2, Air-Gap Discharge
Method
±8kV—IEC 1000-4-2, Contact Discharge Method
o
Single +3V to +5.5V Operation
o
-10V to +13.2V Extended Common-Mode Range
o
Capacitor-Programmable Delay of Fault Indication
Allows Error-Free Operation at Slow Data Rates
o
Independent and Universal Fault Outputs
o
32Mbps Data Rate
o
16-Pin QSOP is 40% Smaller than Industry-
Standard 26LS31/32 Solutions
MAX3097E/MAX3098E
________________________Applications
RS-485/RS-422 Receivers for Motor-Shaft
Encoders
High-Speed, Triple RS-485/RS-422 Receiver with
Extended Electrostatic Discharge (ESD)
Triple RS-485/RS-422 Receiver with Input Fault
Indication
Telecommunications
Embedded Systems
Ordering Information
PART
MAX3097ECEE
MAX3097ECSE
TEMP. RANGE
0°C to +70°C
0°C to +70°C
PIN-
PACKAGE
16 QSOP
16 SO
Typical Application Circuit
ENCODED SIGNALS
A, A, B, B, Z, Z
Ordering Information continued at end of data sheet.
Pin Configuration
TOP VIEW
MAX3097E
MAX3098E
A 1
ALARM
OUTPUTS
DSP
8
A 2
MOTOR
CONTROLLER
B 3
B 4
Z 5
MAX547
12-BIT D/A
Z 6
GND 7
DELAY 8
16 V
CC
15 ALARMA
14 OUTA
RECEIVER
OUTPUTS
MOTOR
MAX3097E
MAX3098E
13 ALARMB
12 OUTB
11 ALARMZ
10 OUTZ
9
ALARMD
MOTOR DRIVER
QSOP/SO/DIP
________________________________________________________________
Maxim Integrated Products
1
For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
±15kV ESD-Protected, 32Mbps, 3V/5V,
Triple RS-422/RS-485 Receivers with Fault Detection
MAX3097E/MAX3098E
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (V
CC
).............................................................+7V
Receiver Input Voltage (A,
A,
B,
B,
Z,
Z)
.............................±25V
Output Voltage (OUT_, ALARM_)...............-0.3V to (V
CC
+ 0.3V)
DELAY ........................................................-0.3V to (V
CC
+ 0.3V)
Continuous Power Dissipation (T
A
= +70°C)
16-Pin QSOP (derate 8.3mW/°C above +70°C)............667mW
16-Pin SO (derate 8.7mW/°C above +70°C).................696mW
16-Pin Plastic DIP (derate 10.53mW/°C
above +70°C).............................................................762mW
Operating Temperature Ranges
MAX3097EC_E...................................................0°C to +70°C
MAX3098E_C_E .................................................0°C to +70°C
MAX3097E_E_E ..............................................-40°C to +85°C
MAX3098E_E_E ..............................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature ......................................................+150°C
Lead Temperature (soldering, 10s) .................................+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.
ELECTRICAL CHARACTERISTICS
(V
CC
= +3V to +5.5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= +5V and T
A
= +25°C.)
PARAMETER
Supply Voltage Range
Supply Current
Receiver Differential Threshold
Voltage (Note 1)
Receiver Input Hysteresis
Output High Voltage
Output Low Voltage
Receiver Input Resistance
Input Current
(A ,
A
, B ,
B
(Z ,
Z
)
Output Short-Circuit Current
FAULT DETECTION
MAX3097E Fault-Detection
Receiver Differential Threshold
Voltage (Note 3)
MAX3098EA Fault-Detection
Receiver Differential Threshold
Voltage (Note 3)
F
DIFH
V
CM
= 0
F
DIFL
F
DIFH
V
CM
= 0
F
DIFL
Low limit
-0.20
-0.12
Low limit
High limit
-475
0.12
-275
0.20
V
High limit
275
475
mV
SYMBOL
V
CC
I
CC
V
TH
∆V
TH
V
OH
V
OL
R
IN
No load
-10V
≤
V
CM
≤
13.2V
-10V
≤
V
CM
≤
13.2V
V
CC
= 4.75V, I
O
= -4mA, V
ID
= 200mV
V
CC
= 3.0V, I
O
= -1mA, V
ID
= 200mV
V
CC
= 4.75V, I
O
= +4mA, V
ID
= -200mV
V
CC
= 3.0V, I
O
= +1mA, V
ID
= -200mV
-10V
≤
V
CM
≤
13.2V
V
IN
= 13.2V
(Note 2)
V
IN
= -10V
(Note 2)
90
0.07
-0.05
V
CC
- 1.5
V
CC
- 1.0
0.4
0.4
160
0.14
mA
-0.11
±105
mA
-200
40
CONDITIONS
MIN
3
TYP
3.1
MAX
5.5
4.0
+200
UNITS
V
mA
mV
mV
V
V
kΩ
I
IN
V
CC
= 0 or 5.5V
0
≤
V
RO
≤
V
CC
I
OSR
2
_______________________________________________________________________________________
±15kV ESD-Protected, 32Mbps, 3V/5V,
Triple RS-422/RS-485 Receivers with Fault Detection
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +3V to +5.5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= +5V and T
A
= +25°C.)
MAX3097E/MAX3098E
PARAMETER
MAX3098EB Fault-Detection
Receiver Differential Threshold
Voltage (Note 3)
Fault-Detection Common-Mode
Voltage Range (Note 4)
DELAY Current Source
DELAY Threshold
ESD PROTECTION
SYMBOL
F
DIFH
V
CM
= 0
F
DIFL
F
CMH
F
CML
High limit
Low limit
CONDITIONS
High limit
Low limit
MIN
70
-250
13.2
TYP
MAX
250
UNITS
mV
-70
V
µA
V
-10
9
1.55
3.1
10
1.73
3.29
±15
±15
±8
11
1.90
3.5
V
CC
= 5V, V
DELAY
= 0
V
CC
= 3V
V
CC
= 5V
Human Body Model
ESD Protection
(A,
A,
B,
B,
Z,
Z)
IEC1000-4-2 (Air-Gap Discharge)
IEC1000-4-2 (Contact Discharge)
kV
SWITCHING CHARACTERISTICS
(V
CC
= +3V to +5.5V, V
ID
= ±3.0V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
CC
= +5V and T
A
= +25°C.)
PARAMETER
Propagation Delay from Input to
Output
Receiver Skew |t
PLH
- t
PHL
|
Channel-to-Channel
Propagation Delay Skew
Maximum Data Rate
FAULT DETECTION
Differential Fault Propagation
Delay to Output (Note 5)
Minimum Differential Slew Rate
to Avoid False Alarm Output
Common-Mode Fault
Propagation Delay to Output
(Note 5)
t
CMFLH
C
L
= 15pF, Figures 1, 4
t
CMFHL
1.5
t
DFLH
C
LF
= 15pF, Figures 1, 3
t
DFHL
MAX3097E (Note 6)
MAX3098E (Note 7)
1.0
V/µs
0.33
15
µs
1.2
15
µs
f
MAX
SYMBOL
t
PLH
, t
PHL
t
SKEW
C
L
= 15pF,
Figures 1, 2
CONDITIONS
V
CC
= 4.5V to 5.5V
V
CC
= 3.0V to 3.6V
MIN
TYP
MAX
75
85
±10
±10
32
UNITS
ns
ns
ns
Mbps
C
L
= 15pF, Figures 1, 2
C
L
= 15pF, Figures 1, 2
C
L
= 15pF, Figure 1
Note 1:
Note 2:
Note 3:
Note 4:
V
CM
is the common-mode input voltage. V
ID
is the differential input voltage.
V
IN
is the input voltage at pins A, A, B, B, Z, Z.
A differential terminating resistor is required for proper function of open-circuit fault detection (see
Applications Information).
See
Applications Information
for a discussion of the receiver common-mode voltage range and the operating conditions for
fault indication.
Note 5:
Applies to the individual channel immediate-fault outputs (ALARM_) and the general delayed-fault output (ALARMD) when
there is no external capacitor at DELAY.
Note 6:
Equivalent pulse test: 1.3V / (t
DFLH
- t
DFHL
)
≥
SR
D
.
Note 7:
Equivalent pulse test: 0.62V / (t
DFLH
- t
DFHL
)
≥
SR
D
.
_______________________________________________________________________________________
3
±15kV ESD-Protected, 32Mbps, 3V/5V,
Triple RS-422/RS-485 Receivers with Fault Detection
MAX3097E/MAX3098E
Typical Operating Characteristics
(Typical values are at V
CC
= +5V and T
A
= +25°C.)
ALARMD OUTPUT DELAY
vs. CAPACITANCE
MAX3097E/8Etoc01
RECEIVER PROPAGATION DELAY
vs. TEMPERATURE
MAX3097E/8E toc02
SUPPLY CURRENT vs.
TEMPERATURE
NO LOAD
4
SUPPLY CURRENT (mA)
V
CC
= 5.0V
3
V
CC
= 3.3V
2
MAX3097E/8E toc03
10,000
70
RECEIVER PROPAGATION DELAY (ns)
5
ALARMD OUTPUT DELAY (µs)
1000
60
V
CC
= 3.3V
50
100
V
CC
= 5V
10
V
CC
= 3V
V
CC
= 5.0V
40
1
1
1
10
100
CAPACITANCE (pF)
1000
10,000
30
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
0
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
RECEIVER OUTPUT LOW VOLTAGE
vs. OUTPUT CURRENT
4.5
OUTPUT LOW VOLTAGE (V)
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
-45 -40 -35 -30 -25 -20 -15 -10 -5
OUTPUT CURRENT (mA)
0
0
0
V
CC
= 3.3V
V
CC
= 5.0V
MAX3097E/8E toc04
RECEIVER OUTPUT HIGH VOLTAGE
vs. OUTPUT CURRENT
MAX3097E/8E toc05
DELAYED ALARM OUTPUT
MAX3097E/8E toc06
5.0
6
5
OUTPUT HIGH VOLTAGE (V)
4
3
2
1
V
CC
= 3.3V
V
CC
= 5.0V
CH 1
GND
CH 2
GND
CH 3
GND
5
10
15
20
25
30
OUTPUT CURRENT (mA)
20µs/div
CH1: V
A
, 5V/div
CH2: V
ALARMA
, 5V/div
CH3: V
ALARMD
, 5V/div
V
A
= GND, C
DELAY
= 270pF
4
_______________________________________________________________________________________
±15kV ESD-Protected, 32Mbps, 3V/5V,
Triple RS-422/RS-485 Receivers with Fault Detection
MAX3097E/MAX3098E
Typical Operating Characteristics (continued)
(Typical values are at V
CC
= +5V and T
A
= +25°C.)
COMMON-MODE VOLTAGE FAULT
(HIGH SIDE)
MAX3097E/8E toc07a
COMMON-MODE VOLTAGE FAULT
(LOW SIDE)
MAX3097E/8E toc07b
MAX3097E
LOW DIFFERENTIAL INPUT FAULT
MAX3097E/8E toc08
CH 1
GND
CH 1
GND
CH 1
GND
CH 2
CH 3
2ms/div
CH1: V
A
+ AC(60Hz), 10V/div
CH2: V
OUTA
, 5V/div
CH3: V
ALARMA
, 5V/div
V
CC
= 3V
GND
GND
CH 2
CH 3
2ms/div
CH1: V
A
+ AC(60Hz), 10V/div
CH2: V
OUTA
, 5V/div
CH3: V
ALARMA
, 5V/div
V
CC
= 3V
GND
GND
CH 2
100µs/div
CH1: V
A
, 200mV/div
CH2: V
ALARMA
, 5V/div
V
A
= GND
GND
SLEW-RATE FAULT
MAX3097E/8E toc09
FAULT-DETECTION RECEIVER DIFFERENTIAL
THRESHOLD VOLTAGE SHIFT vs.
COMMON-MODE VOLTAGE
12
THRESHOLD SHIFT (mV)
GND
8
4
0
-4
-8
MAX3097E
MAX3097E/8E toc10
CH 1
MAX3098E
CH 2
GND
CH1: V
A
, 5V/div
CH2: V
ALARMA
, 5V/div
SLEW RATE = 0.05V/µs
V
A
= GND
-10
-5
0
5
10
COMMON-MODE VOLTAGE (V)
_______________________________________________________________________________________
5
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