Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsInterface ICsInterface IC - receivers RS422, RS485 0/3 SOIC 16

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.

________________________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

ALARMA

OUTA

ALARMB

OUTB

ALARMZ

OUTZ

ALARMD

TOP VIEW

MAX3097E

MAX3098E

QSOP/SO/DIP

GND

DELAY

Pin Configuration

ENCODED SIGNALS

A, A, B, B, Z, Z

MOTOR DRIVER

MOTOR

CONTROLLER

ALARM

OUTPUTS

RECEIVER

OUTPUTS

DSP

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 1-800-998-8800.

For small orders, phone 1-800-835-8769.

Ordering Information

PART TEMP. RANGE

PIN-

PACKAGE

MAX3097ECEE 0°C to +70°C 16 QSOP

MAX3097ECSE 0°C to +70°C 16 SO

Ordering Information continued at end of data sheet.

Summary of content (16 pages)

PAGE 1
9-1727; Rev 0; 7/00 ±15kV ESD-Protected, 32Mbps, 3V/5V, Triple RS-422/RS-485 Receivers with Fault Detection Features ♦ Detects the Following RS-485 Faults: Open-Circuit Condition Short-Circuit Condition Low Differential Voltage Signal Common-Mode Range Violation 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. ♦ Single +3V to +5.
PAGE 2
MAX3097E/MAX3098E ±15kV ESD-Protected, 32Mbps, 3V/5V, Triple RS-422/RS-485 Receivers with Fault Detection ABSOLUTE MAXIMUM RATINGS Supply Voltage (VCC).............................................................+7V Receiver Input Voltage (A, A, B, B, Z, Z) .............................±25V Output Voltage (OUT_, ALARM_)...............-0.3V to (VCC + 0.3V) DELAY ........................................................-0.3V to (VCC + 0.3V) Continuous Power Dissipation (TA = +70°C) 16-Pin QSOP (derate 8.
PAGE 3
±15kV ESD-Protected, 32Mbps, 3V/5V, Triple RS-422/RS-485 Receivers with Fault Detection (VCC = +3V to +5.5V, TA = TMIN to TMAX , unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) PARAMETER SYMBOL CONDITIONS MAX3098EB Fault-Detection Receiver Differential Threshold Voltage (Note 3) FDIFH Fault-Detection Common-Mode Voltage Range (Note 4) FCMH High limit FCML Low limit MIN TYP MAX High limit 70 250 Low limit -250 -70 VCM = 0 mV FDIFL DELAY Current Source 13.
PAGE 4
Typical Operating Characteristics (Typical values are at VCC = +5V and TA = +25°C.) VCC = 5V VCC = 3V 1 10 100 1000 50 VCC = 5.0V 40 10,000 4 VCC = 5.0V 3 VCC = 3.3V 2 1 0 -40 -20 0 20 40 60 -40 80 -20 0 20 40 60 TEMPERATURE (°C) RECEIVER OUTPUT LOW VOLTAGE vs. OUTPUT CURRENT RECEIVER OUTPUT HIGH VOLTAGE vs. OUTPUT CURRENT DELAYED ALARM OUTPUT 3.5 3.0 VCC = 3.3V 2.0 1.5 1.0 MAX3097E/8E toc05 VCC = 5.0V 5 OUTPUT HIGH VOLTAGE (V) MAX3097E/8E toc04 VCC = 5.
PAGE 5
±15kV ESD-Protected, 32Mbps, 3V/5V, Triple RS-422/RS-485 Receivers with Fault Detection COMMON-MODE VOLTAGE FAULT (HIGH SIDE) GND CH 1 CH 2 GND CH 2 GND CH 3 MAX3097E/8E toc08 MAX3097E/8E toc07b MAX3097E/8E toc07a CH 1 GND CH 1 GND GND CH 2 GND GND 2ms/div CH1: VA + AC(60Hz), 10V/div CH2: VOUTA, 5V/div CH3: VALARMA, 5V/div VCC = 3V 2ms/div CH1: VA + AC(60Hz), 10V/div CH2: VOUTA, 5V/div CH3: VALARMA, 5V/div VCC = 3V FAULT-DETECTION RECEIVER DIFFERENTIAL THRESHOLD VOLTAGE SHIFT vs.
PAGE 6
±15kV ESD-Protected, 32Mbps, 3V/5V, Triple RS-422/RS-485 Receivers with Fault Detection MAX3097E/MAX3098E Pin Description 6 PIN NAME 1 A Noninverting Receiver A Input FUNCTION 2 A Inverting Receiver A Input 3 B Noninverting Receiver B Input 4 B Inverting Receiver B Input 5 Z Noninverting Receiver Z Input 6 Z Inverting Receiver Z Input 7 GND 8 DELAY Ground Programmable Delay Terminal. Connect a capacitor from DELAY to GND to set the ALARMD output delay time.
PAGE 7
±15kV ESD-Protected, 32Mbps, 3V/5V, Triple RS-422/RS-485 Receivers with Fault Detection The MAX3097E/MAX3098E feature high-speed, triple RS-485/RS-422 receivers with fault-detection circuitry and fault-status outputs. The fault outputs are active push-pull, requiring no pull-up resistors. The fault circuitry includes a capacitor-programmable delayed FAULT_ output to ensure that there are no erroneous fault conditions even at slow edge rates (see Delayed Fault Output).
PAGE 8
MAX3097E/MAX3098E ±15kV ESD-Protected, 32Mbps, 3V/5V, Triple RS-422/RS-485 Receivers with Fault Detection Table 1. MAX3097E Alarm Function Table (Each Receiver) INPUTS VID (DIFFERENTIAL INPUT VOLTAGE) OUTPUTS COMMON-MODE VOLTAGE OUT_ ALARM_ ALARMD t ≥ DELAY (NOTE 1) FAULT CONDITION ≥0.475V 1 0 0 Normal Operation <0.475V and ≥0.275V 1 Indeterminate Indeterminate Indeterminate <0.275V and ≥0.
PAGE 9
±15kV ESD-Protected, 32Mbps, 3V/5V, Triple RS-422/RS-485 Receivers with Fault Detection ESD protection can be tested in several ways. The receiver inputs are characterized for protection to the following: • ±15kV using the Human Body Model • ±8kV using the Contact Discharge method specified in IEC 1000-4-2 (formerly IEC 801-2) • 15kV using the Air-Gap Discharge method specified in IEC 1000-4-2 (formerly IEC 801-2) ESD Test Conditions ESD performance depends on a number of conditions.
PAGE 10
___________Applications Information RC 50MΩ to 100MΩ Using the MAX3097E/MAX3098E as Shaft Encoder Receivers The MAX3097E/MAX3098E are triple RS-485 receivers designed for shaft encoder receiver applications. A shaft encoder is an electromechanical transducer that converts mechanical rotary motion into three RS-485 differential signals.
PAGE 11
±15kV ESD-Protected, 32Mbps, 3V/5V, Triple RS-422/RS-485 Receivers with Fault Detection Detecting Low Input Differential Due to cable attenuation on long wire runs, it is possible that V ID < 200mV, and incorrect data will be received. In this condition, a fault will be indicated. Delayed Fault Output The delayed fault output provides a programmable blanking delay to allow transient faults to occur without triggering an alarm.
PAGE 12
MAX3097E/MAX3098E ±15kV ESD-Protected, 32Mbps, 3V/5V, Triple RS-422/RS-485 Receivers with Fault Detection Ordering Information (continued) PART TEMP.
PAGE 13
±15kV ESD-Protected, 32Mbps, 3V/5V, Triple RS-422/RS-485 Receivers with Fault Detection SOICN.
PAGE 14
±15kV ESD-Protected, 32Mbps, 3V/5V, Triple RS-422/RS-485 Receivers with Fault Detection QSOP.
PAGE 15
±15kV ESD-Protected, 32Mbps, 3V/5V, Triple RS-422/RS-485 Receivers with Fault Detection PDIPN.
PAGE 16
MAX3097E/MAX3098E ±15kV ESD-Protected, 32Mbps, 3V/5V, Triple RS-422/RS-485 Receivers with Fault Detection NOTES 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.