参数资料
| 型号： | ISL32483EIBZ-T7A |
| 厂商： | Intersil |
| 文件页数： | 3/17页 |
| 文件大小： | 0K |
| 描述： | IC TXRX RS485 FAULT PROT 14SOIC |
| 产品培训模块： | Solutions for Industrial Control Applications |
| 标准包装： | 250 |
| 类型： | 收发器 |
| 驱动器/接收器数： | 1/1 |
| 规程： | RS422，RS485 |
| 电源电压： | 4.5 V ~ 5.5 V |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 14-SOIC（0.154"，3.90mm 宽） |
| 供应商设备封装： | 14-SOIC |
| 包装： | 带卷 (TR) |
ISL32483E, ISL32485E
11
FN7785.1
March 27, 2012
Intersil’s unique cable invert function is superior to that found on
competing devices, because the Rx full fail-safe function is
maintained, even when the Rx polarity is reversed. Competitor
devices implement the Rx invert function simply by inverting the
Rx output. This means that with the Rx inputs floating or shorted
together, the Rx appropriately delivers a logic 1 in normal
polarity, but outputs a logic low when the IC is operated in the
inverted mode. Intersil’s innovative Rx design guarantees that,
with the Rx inputs floating or shorted together (VID=0V), the Rx
output remains high, regardless of the state of the invert pins.
The full duplex ISL32483E includes two invert pins that allow for
separate control of the Rx and Tx polarities. If only the Rx cable is
miswired, then only the RINV pin need be driven to a logic 1. If
the Tx cable is miswired, then DINV must be connected to a logic
high. The half-duplex version has only one logic pin (INV) that,
when high, switches the polarity of both the Tx and the Rx blocks.
High VOD Improves Noise Immunity and
Flexibility
The ISL3248xE driver design delivers larger differential output
voltages (VOD) than the RS-485 standard requires or than most
RS-485 transmitters can deliver. The typical ±2.5V VOD provides
more noise immunity than networks built using many other
transceivers.
Another advantage of the large VOD is the ability to drive more
than two bus terminations, which allows for utilizing the
ISL3248xE in “star” and other multi-terminated, nonstandard
network topologies.
and includes load lines for four (30) and six (20) 120
terminations. The figure shows that the driver typically delivers
±1.3V into six terminations, and the “Electrical Specifications” on
temperature range. The RS-485 standard requires a minimum
1.5V VOD into two terminations, but the ISL3248xE delivers
RS-485 voltage levels with 2x to 3x the number of terminations.
Hot Plug Function
When a piece of equipment powers up, there is a period of time
in which the processor or ASIC driving the RS-485 control lines
(DE, RE) is unable to ensure that the RS-485 Tx and Rx outputs
are kept disabled. If the equipment is connected to a bus, a
driver activating prematurely during power-up may crash the bus.
To avoid this scenario, the ISL3248xE devices incorporate a “Hot
Plug” function. Circuitry monitoring VCC ensures that, during
power-up and power-down, the Tx and Rx outputs remain disabled,
regardless of the state of DE and RE, if VCC is less than ≈3.5V. This
gives the processor or ASIC a chance to stabilize and drive the
RS-485 control lines to the proper states. Figure 9 illustrates the
power-up and power-down performance of the ISL3248xE
compared to an RS-485 IC without the Hot Plug feature.
ESD Protection
All pins on the ISL3248xE devices include Class 3 (>8kV)
Human Body Model (HBM) ESD protection structures that are
good enough to survive ESD events commonly seen during
manufacturing. Even so, the RS-485 pins (driver outputs and
receiver inputs) incorporate more advanced structures that
allow them to survive ESD events in excess of ±16.5kV HBM
(±15kV for full-duplex version). The RS-485 pins are particularly
vulnerable to ESD strikes, 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. The new ESD
structures protect the device whether or not it is powered up,
and without interfering with the exceptional ±25V CMR. This
built-in ESD protection minimizes the need for board-level
protection structures (e.g., transient suppression diodes) and
the associated, undesirable capacitive load they present.
Data Rate, Cables, and Terminations
RS-485/RS-422 are intended for network lengths up to 4000 feet,
but the maximum system data rate decreases as the transmission
length increases. These 1Mbps versions can operate at full data
rates with lengths up to 800 feet (244m). Jitter is the limiting
parameter at this data rate, so employing encoded data streams
(e.g., Manchester coded or Return-to-Zero) may allow increased
transmission distances.
Twisted pair is the cable of choice for RS-485/RS-422 networks.
Twisted pair cables tend to pick up noise and other
electromagnetically induced voltages as common mode signals,
which are effectively rejected by the differential receivers in these
ICs.
FIGURE 9. HOT PLUG PERFORMANCE (ISL3248XE) vs ISL83088E
WITHOUT HOT PLUG CIRCUITRY
TIME (40s/DIV)
VCC
RECEIVE
R
OUTPUT
(V)
DRIV
E
R
Y
OUTPUT
(V
)
2.5
5.0
2.5
5.0
VC
C
(
V
)
RL = 1k
RO
0
2.5
5.0
0
A/Y
RL = 1k
3.5V
RE = GND
DE, DI = VCC
2.8V
ISL3248XE
ISL83088E
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相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL32485E | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Fault Protected, Extended CMR, RS-485/RS-422 Transceivers |
| ISL32485EIBZ | 功能描述:IC TXRX RS485 FAULT PROT 8SOIC RoHS:是 类别:集成电路 (IC) >> 接口 - 驱动器，接收器，收发器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:50 系列:- 类型:收发器 驱动器/接收器数:1/1 规程:RS422，RS485 电源电压:4.75 V ~ 5.25 V 安装类型:通孔 封装/外壳:8-DIP（0.300"，7.62mm） 供应商设备封装:8-PDIP 包装:管件 产品目录页面:1402 (CN2011-ZH PDF) |
| ISL32485EIBZ-T | 功能描述:IC TXRX RS485 FAULT PROT 8SOIC RoHS:是 类别:集成电路 (IC) >> 接口 - 驱动器，接收器，收发器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- 类型:发射器 驱动器/接收器数:4/0 规程:RS422，RS485 电源电压:4.75 V ~ 5.25 V 安装类型:表面贴装 封装/外壳:16-SOIC（0.154"，3.90mm 宽） 供应商设备封装:16-SOIC 包装:带卷 (TR) |
| ISL32485EIBZ-T7A | 功能描述:RS-422/RS-485 接口 IC 8LD OVP -40+85 5V PO LARITY REV 1/2 DUP RoHS:否 制造商:Maxim Integrated 数据速率:1136 Kbps 工作电源电压:3 V to 5.5 V 电源电流:5.9 mA 工作温度范围:- 40 C to + 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-28 封装:Tube |
| ISL32490E | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:±60V Fault Protected, 5V, RS-485/RS-422 Transceivers with ±25V CMR |
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