Electronic Components Datasheet Search |
|
MAX3097 Datasheet(PDF) 10 Page - Maxim Integrated Products |
|
MAX3097 Datasheet(HTML) 10 Page - Maxim Integrated Products |
10 / 16 page ___________Applications Information 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. Two signals, A (A and A) and B (B and B) provide incremental pulses as the shaft turns, while the index signal, Z (Z and Z) occurs only once per revolution to allow synchronization of the shaft to a known position. Digital signal processing (DSP) tech- niques are used to count the pulses and provide feed- back of both shaft position and shaft velocity for a stable positioning system. Shaft encoders typically transmit RS-485 signals over twisted-pair cables since the signal often has to travel across a noisy electrical environment (Figure 7). Detecting Faults Signal integrity from the shaft encoder to the DSP is essential for reliable system operation. Degraded sig- nals could cause problems ranging from simple mis- counts to loss of position. In an industrial environment, many problems can occur within the three twisted pairs. The MAX3097E/MAX3098E can detect various types of common faults, including a low-input-level sig- nal, open-circuit wires, short-circuit wires, and an input signal outside the common-mode input voltage range of the receiver. Detecting Short Circuits In Figure 8, if wires A and A are shorted together, then A and A will be at the same potential, so the difference in the voltage between the two will be approximately 0. This causes fault A to trigger since the difference between A - A is less than the differential fault threshold. Detecting Open-Circuit Conditions Detecting an open-circuit condition is similar to detect- ing a short-circuit condition and relies on the terminat- ing resistor being across A and A. For example, if the wire drops out of the A terminal, A pulls A through the terminating resistor to look like the same signal. In this condition, VID is approximately 0 and a fault occurs. ±15kV ESD-Protected, 32Mbps, 3V/5V, Triple RS-422/RS-485 Receivers with Fault Detection 10 ______________________________________________________________________________________ CHARGE-CURRENT LIMIT RESISTOR DISCHARGE RESISTANCE STORAGE CAPACITOR Cs 150pF RC 50M Ω to 100MΩ RD 330 Ω HIGH- VOLTAGE DC SOURCE DEVICE UNDER TEST tr = 0.7ns to 1ns 30ns 60ns t 100% 90% 10% I A A B B Z Z Figure 7. Typical Shaft Encoder Output Figure 6a. IEC 1000-4-2 ESD Test Model Figure 6b. IEC 1000-4-2 ESD Generator Current Waveform |
Similar Part No. - MAX3097 |
|
Similar Description - MAX3097 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |