Motor de Búsqueda de Datasheet de Componentes Electrónicos |
|
ISL32611E Datasheet(PDF) 7 Page - Intersil Corporation |
|
ISL32611E Datasheet(HTML) 7 Page - Intersil Corporation |
7 / 12 page ISL32610E, ISL32611E, ISL32612E 7 FN7869.0 October 21, 2011 Application Information Features These devices utilize a differential input receiver for maximum noise immunity and common mode rejection. Input sensitivity is ±200mV, as required by the RS-422 and RS-485 standards. These receivers’ symmetrical ±200mV switching thresholds deliver less duty cycle distortion than similar receivers with a full-failsafe design (i.e., skewed low/high input thresholds, (such as -200mV/-20mV) which increase the high bit width). This distortion is especially noticeable when the Rx is driven by slow input transitions (see Figure 2). The symmetrical input thresholds also allow more room for increased input hysteresis, thereby increasing the Rx noise immunity. The 70mV hysteresis of this Rx is twice the amount specified for most full-failsafe devices. Receiver input resistance of 96kΩ surpasses the RS-422 specification of 4kΩ, and is eight times the RS-485 “Unit Load (UL)” requirement of 12kΩ minimum. Thus, these products are known as “one-eighth UL” receivers, and there can be up to 256 of these devices on a network while still complying with the RS-485 loading specification. Receiver inputs function with common mode voltages (CMV) of ±2V with VCC = 1.8V, and with CMVs of -7V to +12V for VCC ≥ 2.7V. All the receivers include a “failsafe-if-open” function that guarantees a high level receiver output if the receiver inputs are unconnected (floating). As mentioned previously, the full-failsafe function is not implemented in order to deliver output duty cycles that better match the input. Receivers support data rates up to 256kbps (VCC = 1.8V) or 500kbps (VCC ≥ 3V), and receiver outputs of the ISL32611E and ISL32612E are three-statable via the active low RE or active high RE input. Data Rate Recommendations When coupled with the ISL32613E or ISL32614E 1.8V transmitter ICs, these receivers are useful for networks up to 4000’ (1220m) long, or for data rates up to 500kbps. For 4000’ distances with VCC = 1.8V, the ISL32613E can be used with any of these receivers at data rates ≤ 50kbps. With VCC =3.3V, any transmitter / receiver combination operates over 4000’ at rates up to 128kbps. Shorter networks allow data rates up to 500kbps, as shown in Figures 9, 10, 11 and 12. Network termination resistors are only recommended for networks operating at VCC ≥ 2.7V, and using termination resistors may allow for higher data rates. Low Power Shutdown Mode (ISL32611E and ISL32612E) These devices use a fraction of the power required by most differential receivers (see Figure 1 on page 1), but they also include a shutdown feature that reduces the already low quiescent ICC even further. The ISL32611E and ISL32612E enter shutdown whenever the receiver is disabled (RE = GND or RE =VCC). ESD Protection All pins on these devices include class 3 (>6kV) Human Body Model (HBM) ESD protection structures, but the bus pins (Rx inputs) incorporate advanced structures allowing them to survive ESD events in excess of ±16.5kV HBM and ±16.5kV IEC61000. The bus pins are particularly vulnerable to ESD damage because they typically connect to an exposed port on the exterior of the finished product. Simply touching the port pins, or connecting a cable, can cause an ESD event that might destroy unprotected ICs. These new ESD structures protect the device whether or not it is powered up, and without degrading the common mode range. This built-in ESD protection eliminates the need for board-level protection structures (e.g., transient suppression diodes), and the associated, undesirable capacitive load they present. IEC61000-4-2 Testing The IEC61000 test method applies to finished equipment, rather than to an individual IC. Therefore, the pins most likely to suffer an ESD event are those that are exposed to the outside world (the bus pins in this case), and the IC is tested in its typical application configuration (power applied) rather than testing each pin-to-pin combination. The smaller value current limiting resistor coupled with the larger charge storage capacitor yields a test that is much more severe than the HBM test. The extra ESD protection built into this device’s bus pins allows the design of equipment meeting level 4 criteria without the need for additional board-level protection on the I/O port. AIR-GAP DISCHARGE TEST METHOD For the air-gap discharge test method, a charged probe tip moves toward the IC pin until the voltage arcs to it. The current waveform delivered to the IC pin depends on approach speed, humidity, temperature, etc., so it is difficult to obtain repeatable results. The A and B pins withstand ±16.5kV air-gap discharges. CONTACT DISCHARGE TEST METHOD During the contact discharge test, the probe contacts the tested pin before the probe tip is energized, thereby eliminating the variables associated with the air-gap discharge. The result is a more repeatable and predictable test, but equipment limits prevent testing devices at voltages higher than ±9kV. The ISL32610E, ISL32611E, ISL32612E survive ±9kV contact discharges on the bus pins. |
Número de pieza similar - ISL32611E |
|
Descripción similar - ISL32611E |
|
|
Enlace URL |
Política de Privacidad |
ALLDATASHEET.ES |
¿ALLDATASHEET es útil para Ud.? [ DONATE ] |
Todo acerca de Alldatasheet | Publicidad | Contáctenos | Política de Privacidad | Intercambio de Enlaces | Lista de Fabricantes 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 |