- 您现在的位置：买卖IC网 > PDF目录296197 > HWD485 (Electronic Theatre Controls, Inc.) Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers PDF资料下载
参数资料
| 型号： | HWD485 |
| 厂商： | Electronic Theatre Controls, Inc. |
| 元件分类： | RS-485 |
| 英文描述： | Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers |
| 中文描述： | 低功耗，限摆率限制RS-485/RS-422收发器 |
| 文件页数： | 3/20页 |
| 文件大小： | 502K |
| 代理商： | HWD485 |
Low-Power Shutdown Mode
(HWD481/HWD483/HWD487)
A low-power shutdown mode is initiated by bringing
both RE high and DE low. The devices will not shut
down unless both the driver and receiver are disabled.
In shutdown, the devices typically draw only 0.1A of
supply current.
RE and DE may be driven simultaneously; the parts are
guaranteed not to enter shutdown if RE is high and DE
is low for less than 50ns. If the inputs are in this state
for at least 600ns, the parts are guaranteed to enter
shutdown.
For the HWD481, HWD483, and HWD487, the tZH and
tZL enable times assume the part was not in the low-
power shutdown state (the HWD485/HWD488–HWD491
and HWD1487 can not be shut down). The tZH(SHDN)
and tZL(SHDN) enable times assume the parts were shut
down (see Electrical Characteristics).
It takes the drivers and receivers longer to become
enabled from the low-power shutdown state
(tZH(SHDN), tZL(SHDN)) than from the operating mode
(tZH, tZL). (The parts are in operating mode if the
–
R
—
E
–
,
DE inputs equal a logical 0,1 or 1,1 or 0, 0.)
Driver Output Protection
Excessive output current and power dissipation caused
by faults or by bus contention are prevented by two
mechanisms. A foldback current limit on the output
stage provides immediate protection against short cir-
cuits over the whole common-mode voltage range (see
Typical Operating Characteristics). In addition, a ther-
mal shutdown circuit forces the driver outputs into a
high-impedance state if the die temperature rises
excessively.
Propagation Delay
Many digital encoding schemes depend on the differ-
ence between the driver and receiver propagation
delay times. Typical propagation delays are shown in
Figures 15–18 using Figure 14’s test circuit.
The difference in receiver delay times, | tPLH - tPHL |, is
typically under 13ns for the HWD481, HWD485,
HWD490, HWD491, and HWD1487 and is typically less
than 100ns for the HWD483 and HWD487–HWD489.
The driver skew times are typically 5ns (10ns max) for
the HWD481, HWD485, HWD490, HWD491, and
HWD1487, and are typically 100ns (800ns max) for the
HWD483 and HWD487–HWD489.
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
10dB/div
0Hz
5MHz
500kHz/div
10dB/div
0Hz
5MHz
500kHz/div
Figure 12. Driver Output Waveform and FFT Plot of HWD481/
HWD485/HWD490/HWD491/HWD1487 Transmitting a 150kHz
Signal
Figure 13. Driver Output Waveform and FFT Plot of HWD483/
HWD487–HWD489 Transmitting a 150kHz Signal
11
相关PDF资料 |
PDF描述 |
|---|---|
| HWD485CPA | Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers |
| HWD485CSA | Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers |
| HWD485EPA | Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers |
| HWD485ESA | Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers |
| HWD485MJA | Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers |
相关代理商/技术参数 |
参数描述 |
|---|---|
| HWD485C/D | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers |
| HWD485CPA | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers |
| HWD485CSA | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers |
| HWD485CUA | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers |
| HWD485EPA | 制造商:未知厂家 制造商全称:未知厂家 功能描述:Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers |
发布紧急采购，3分钟左右您将得到回复。