MAXIM MAX3097E, MAX3098E User Manual

General Description

The MAX3097E/MAX3098E feature three high-speed RS­485/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 condi­tion, 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 thresh­old values.

The fault circuitry includes a capacitor-programmable
delay to ensure that there are no erroneous fault condi­tions even at slow edge rates. Each receiver is capable
of accepting data at rates up to 32Mbps.

________________________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

Features

♦ Detects the Following RS-485 Faults:

Open-Circuit Condition
Short-Circuit Condition
Low Differential Voltage Signal
Common-Mode Range Violation

♦ ESD Protection

±15kV—Human Body Model
±15kV—IEC 1000-4-2, Air-Gap Discharge
Method
±8kV—IEC 1000-4-2, Contact Discharge Method

♦ Single +3V to +5.5V Operation

♦ -10V to +13.2V Extended Common-Mode Range

♦ Capacitor-Programmable Delay of Fault Indication

Allows Error-Free Operation at Slow Data Rates

♦ Independent and Universal Fault Outputs

♦ 32Mbps Data Rate

♦ 16-Pin QSOP is 40% Smaller than Industry-

Standard 26LS31/32 Solutions

MAX3097E/MAX3098E

±15kV ESD-Protected, 32Mbps, 3V/5V,

Triple RS-422/RS-485 Receivers with Fault Detection

________________________________________________________________ Maxim Integrated Products 1

Pin Configuration

ENCODED SIGNALS

A, A, B, B, Z, Z

MOTOR DRIVER

MOTOR

MOTOR
CONTROLLER

ALARM
OUTPUTS

RECEIVER
OUTPUTS

DSP

8

MAX3097E
MAX3098E

MAX547

12-BIT D/A

Typical Application Circuit

19-1727; Rev 0; 7/00

For free samples and the latest literature, visit www.maxim-ic.com or phone [phone].
For small orders, phone [phone].

Ordering Information

Ordering Information continued at end of data sheet.

PART TEMP. RANGE

MAX3097ECEE 0°C to +70°C 16 QSOP

MAX3097ECSE 0°C to +70°C 16 SO

PIN­PACKAGE

TOP VIEW

1

AV

A

2

B

GND

DELAY

3

4

B

Z

5

Z

6

7

8

QSOP/SO/DIP

MAX3097E
MAX3098E

16

15

14

13

12

11

10

9

CC

ALARMA

OUTA

ALARMB

OUTB

ALARMZ

OUTZ

ALARMD

MAX3097E/MAX3098E

±15kV ESD-Protected, 32Mbps, 3V/5V,
Triple RS-422/RS-485 Receivers with Fault Detection

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC= +3V to +5.5V, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at VCC= +5V and TA = +25°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.

Supply Voltage (VCC).............................................................+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

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Supply Voltage Range V

Supply Current I

Receiver Differential Threshold
Voltage (Note 1)

Receiver Input Hysteresis ∆V

Output High Voltage V

Output Low Voltage V

Receiver Input Resistance R

Input Current
(A , A , B , B (Z , Z )

Output Short-Circuit Current I

FAULT DETECTION

MAX3097E Fault-Detection
Receiver Differential Threshold
Voltage (Note 3)

MAX3098EA Fault-Detection
Receiver Differential Threshold
Voltage (Note 3)

CC

No load 3.1 4.0 mA

-10V ≤ VCM ≤ 13.2V -200 +200 mV

-10V ≤ VCM ≤ 13.2V 40 mV

TH

VCC = 4.75V, IO = -4mA, VID = 200mV V

VCC = 3.0V, IO = -1mA, VID = 200mV VCC - 1.0

VCC = 4.75V, IO = +4mA, VID = -200mV 0.4

VCC = 3.0V, IO = +1mA, VID = -200mV 0.4

-10V ≤ V

IN

≤ 13.2V 90 160 kΩ

CM

VCC = 0 or 5.5V

RO

≤ V

CC

0 ≤ V

V

F

CC

TH

OH

OL

I

IN

OSR

DIFH

VCM = 0

F

DIFL

F

DIFH

VCM = 0

F

DIFL

3 5.5 V

- 1.5

CC

V

= 13.2V

IN

(Note 2)

= -10V

V

IN

(Note 2)

0.07 0.14

-0.05 -0.11

±105 mA

High limit 275 475

Low limit -475 -275

High limit 0.12 0.20

Low limit -0.20 -0.12

V

V

mA

mV

V

MAX3097E/MAX3098E

±15kV ESD-Protected, 32Mbps, 3V/5V,

Triple RS-422/RS-485 Receivers with Fault Detection

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VCC= +3V to +5.5V, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at VCC= +5V and TA = +25°C.)

SWITCHING CHARACTERISTICS

(VCC= +3V to +5.5V, VID= ±3.0V, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at VCC= +5V and TA = +25°C.)

Note 1: VCMis the common-mode input voltage. VIDis the differential input voltage.
Note 2: V

IN

is the input voltage at pins A, A, B, B, Z, Z.

Note 3: A differential terminating resistor is required for proper function of open-circuit fault detection (see Applications Information).
Note 4: 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

) ≥ SRD.

Note 7: Equivalent pulse test: 0.62V / (t

DFLH

- t

DFHL

) ≥ SRD.

MAX3098EB Fault-Detection
Receiver Differential Threshold
Voltage (Note 3)

Fault-Detection Common-Mode
Voltage Range (Note 4)

DELAY Current Source VCC = 5V, V

DELAY Threshold

ESD PROTECTION

ESD Protection
(A, A, B, B, Z, Z)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

F

F

F

F

DIFH

DIFL

CMH

CML

VCM = 0

High limit 13.2

Low limit -10

= 0 9 10 11 µA

DELAY

VCC = 3V 1.55 1.73 1.90

= 5V 3.1 3.29 3.5

V

CC

Human Body Model ±15

IEC1000-4-2 (Air-Gap Discharge) ±15

IEC1000-4-2 (Contact Discharge)

Propagation Delay from Input to
Output

Receiver Skew |t

Channel-to-Channel
Propagation Delay Skew

Maximum Data Rate f

FAULT DETECTION

Differential Fault Propagation
Delay to Output (Note 5)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

t

PLH

- t

PLH

|t

PHL

, t

SKEW

MAX

t

DFLH

t

DFHL

PHL

CL = 15pF,
Figures 1, 2

CL = 15pF, Figures 1, 2 ±10 ns

= 15pF, Figures 1, 2 ±10 ns

C

L

CL = 15pF, Figure 1 32 Mbps

CLF = 15pF, Figures 1, 3

High limit 70 250

Low limit -250 -70

±8

VCC = 4.5V to 5.5V 75

V

= 3.0V to 3.6V 85

CC

15

1.2

mV

V

V

kV

ns

µs

Minimum Differential Slew Rate
to Avoid False Alarm Output

Common-Mode Fault
Propagation Delay to Output
(Note 5)

t

CMFLH

t

CMFHL

MAX3097E (Note 6) 1.0

MAX3098E (Note 7) 0.33

CL = 15pF, Figures 1, 4

V/µs

15

µs

1.5

DELAYED ALARM OUTPUT

MAX3097E/8E toc06

20µs/div

CH 1

CH 2

CH 3

GND

GND

GND

CH1: VA, 5V/div
CH2: V

ALARMA

, 5V/div

CH3: V

ALARMD

, 5V/div

V

A =

GND, C

DELAY

= 270pF

MAX3097E/MAX3098E

±15kV ESD-Protected, 32Mbps, 3V/5V,
Triple RS-422/RS-485 Receivers with Fault Detection

4 _______________________________________________________________________________________

Typical Operating Characteristics

(Typical values are at VCC= +5V and TA= +25°C.)

1

100

10

1000

10,000

1

10010 1000

10,000

ALARMD OUTPUT DELAY

vs. CAPACITANCE

MAX3097E/8Etoc01

CAPACITANCE (pF)

ALARMD OUTPUT DELAY (µs)

VCC = 5V

VCC = 3V

30

40

50

60

70

-40 0-20

20

40 60

RECEIVER PROPAGATION DELAY

vs. TEMPERATURE

MAX3097E/8E toc02

TEMPERATURE (°C)

RECEIVER PROPAGATION DELAY (ns)

80

VCC = 5.0V

VCC = 3.3V

0

1

3

2

4

5

SUPPLY CURRENT vs.

TEMPERATURE

MAX3097E/8E toc03

SUPPLY CURRENT (mA)

-40 0-20

20

40 60

TEMPERATURE (°C)

80

VCC = 5.0V

VCC = 3.3V

NO LOAD

0

0.5

1.0

1.5

2.0

2.5

3.5

3.0

4.5

4.0

5.0

-45 -35-40 -30 -25 -20 -15 -10 -5 0

RECEIVER OUTPUT LOW VOLTAGE

vs. OUTPUT CURRENT

MAX3097E/8E toc04

OUTPUT CURRENT (mA)

OUTPUT LOW VOLTAGE (V)

VCC = 5.0V

VCC = 3.3V

0

1

2

4

3

5

6

010515203025

RECEIVER OUTPUT HIGH VOLTAGE

vs. OUTPUT CURRENT

MAX3097E/8E toc05

OUTPUT CURRENT (mA)

OUTPUT HIGH VOLTAGE (V)

VCC = 5.0V

VCC = 3.3V

MAX3097E/MAX3098E

±15kV ESD-Protected, 32Mbps, 3V/5V,

Triple RS-422/RS-485 Receivers with Fault Detection

_______________________________________________________________________________________ 5

Typical Operating Characteristics (continued)

(Typical values are at VCC= +5V and TA= +25°C.)

MAX3097E

LOW DIFFERENTIAL INPUT FAULT

MAX3097E/8E toc08

CH 2 GND

GND

CH 1

100µs/div

CH1: V

A

, 200mV/div

CH2: V

ALARMA

, 5V/div

V

A =

GND

SLEW-RATE FAULT

MAX3097E/8E toc09

CH 2 GND

GND

CH 1

CH1: V

A

, 5V/div

CH2: V

ALARMA

, 5V/div
SLEW RATE = 0.05V/µs
V

A =

GND

-8

-4

4

0

8

12

-10 0-5 5 10

FAULT-DETECTION RECEIVER DIFFERENTIAL

THRESHOLD VOLTAGE SHIFT vs.

COMMON-MODE VOLTAGE

MAX3097E/8E toc10

COMMON-MODE VOLTAGE (V)

THRESHOLD SHIFT (mV)

MAX3097E

MAX3098E

COMMON-MODE VOLTAGE FAULT

(HIGH SIDE)

COMMON-MODE VOLTAGE FAULT

(LOW SIDE)

CH 1

CH 2

CH 3

CH1: VA + AC(60Hz), 10V/div
CH2: V

OUTA

CH3: V

ALARMA

3V

V

CC =

, 5V/div

, 5V/div

2ms/div

MAX3097E/8E toc07a

GND

GND

GND

CH 1

CH 2

CH 3

CH1: V
CH2: V
CH3: V
V

CC =

A
OUTA
ALARMA

3V

, 5V/div

, 5V/div

2ms/div

+ AC(60Hz), 10V/div

MAX3097E/8E toc07b

GND

GND

GND