参数资料
| 型号： | ISL83387EIV-T |
| 厂商： | Intersil |
| 文件页数： | 12/13页 |
| 文件大小： | 0K |
| 描述： | IC 3DRVR/3RCVR RS232 3V 24-TSSOP |
| 标准包装： | 2,500 |
| 类型： | 收发器 |
| 驱动器/接收器数： | 3/3 |
| 规程： | RS232 |
| 电源电压： | 3 V ~ 5.5 V |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 24-TSSOP（0.173"，4.40mm 宽） |
| 供应商设备封装： | 24-TSSOP |
| 包装： | 带卷 (TR) |
8
FN6040.1
July 8, 2005
giving the user an easy way to determine when the interface
block should power down. Invalid receiver levels occur
whenever the driving peripheral’s outputs are shut off
(powered down) or when the RS-232 interface cable is
disconnected. In the case of a disconnected interface cable
where all the receiver inputs are floating (but pulled to GND
by the internal receiver pull down resistors), the INVALID
logic detects the invalid levels and drives the output low. The
power management logic then uses this indicator to power
down the interface block. Reconnecting the cable restores
valid levels at the receiver inputs, INVALID switches high,
and the power management logic wakes up the interface
block. INVALID can also be used to indicate the DTR or
RING INDICATOR signal, as long as the other receiver
inputs are floating, or driven to GND (as in the case of a
powered down driver).
INVALID switches high 1
s after detecting a valid RS-232
level on a receiver input. INVALID operates in all modes
(forced or automatic powerdown, or forced on), so it is also
useful for systems employing manual powerdown circuitry.
Enhanced Automatic Powerdown
Even greater power savings is available by using the
enhanced automatic powerdown function. When the
enhanced powerdown logic determines that no transitions
have occurred on any of the transmitter nor receiver inputs
for 30 seconds, the charge pump and transmitters
powerdown, thereby reducing supply current to 1
A. The
ISL83387E automatically powers back up whenever it
detects a transition on one of these inputs. This automatic
powerdown feature provides additional system power
savings without changes to the existing operating system.
Enhanced automatic powerdown operates when the
FORCEON input is low, and the FORCEOFF input is high.
Tying FORCEON high disables automatic powerdown, but
manual powerdown is always available via the overriding
FORCEOFF input. Table 2 summarizes the enhanced
automatic powerdown functionality.
Figure 5 illustrates the enhanced powerdown control logic.
Note that once the ISL83387E enters powerdown (manually
or automatically), the 30 second timer remains timed out
(set), keeping the ISL83387E powered down until
FORCEON transitions high, or until a transition occurs on a
receiver or transmitter input.
As stated previously, the INVALID output switches low
whenever invalid levels have persisted on all of the receiver
inputs for more than 30
s (see Figure 7), but this has no
direct effect on the state of the ISL83387E (see the next
sections for methods of utilizing INVALID to power down the
device).
The time to recover from automatic powerdown mode is
typically 100
s.
Emulating Standard Automatic Powerdown
If enhanced automatic powerdown isn’t desired, the user can
implement the standard automatic powerdown feature
(mimics the function on the ICL3221E/23E/43E) by
connecting the INVALID output to the FORCEON and
FORCEOFF inputs, as shown in Figure 6. After 30
s of
invalid receiver levels, INVALID switches low and drives the
ISL83387E into a forced powerdown condition. INVALID
switches high as soon as a receiver input senses a valid
FIGURE 4. DEFINITION OF VALID RS-232 RECEIVER LEVELS
0.3V
-0.3V
-2.7V
2.7V
INVALID LEVEL - INVALID = 0
VALID RS-232 LEVEL - INVALID = 1
INDETERMINATE
FIGURE 5. ENHANCED AUTOMATIC POWERDOWN LOGIC
30s
TIMER
S
R
FORCEOFF
AUTOPWDN
FORCEON
R_IN
T_IN
EDGE
DETECT
EDGE
DETECT
FIGURE 6. CONNECTIONS FOR AUTOMATIC POWERDOWN
WHEN NO VALID RECEIVER SIGNALS ARE
PRESENT
FORCEOFF
INV
A
LI
D
CPU
I/O
FORCEON
ISL83387E
UART
ISL83387E
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相关代理商/技术参数 |
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|---|---|
| ISL83387EIVZ | 功能描述:RS-232接口集成电路 W/ANNEAL RS232 3V 3D /3R 15KV SHTDWN 24LD RoHS:否 制造商:Exar 数据速率:52 Mbps 工作电源电压:5 V 电源电流:300 mA 工作温度范围:- 40 C to + 85 C 安装风格:SMD/SMT 封装 / 箱体:LQFP-100 封装: |
| ISL83387EIVZ-T | 功能描述:IC 3DRVR/3RCVR RS232 3V 24-TSSOP RoHS:是 类别:集成电路 (IC) >> 接口 - 驱动器，接收器，收发器 系列:- 标准包装:250 系列:- 类型:收发器 驱动器/接收器数:2/2 规程:RS232 电源电压:3 V ~ 5.5 V 安装类型:表面贴装 封装/外壳:16-TSSOP（0.173"，4.40mm 宽） 供应商设备封装:16-TSSOP 包装:带卷 (TR) |
| ISL83483 | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:3.3V, Low Power, High Speed or Slew Rate Limited, RS-485/RS-422 Transceivers |
| ISL83483_04 | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:3.3V, Low Power, High Speed or Slew Rate Limited, RS-485/RS-422 Transceivers |
| ISL83483IB | 功能描述:IC TXRX RS-485/422 8-SOIC RoHS:否 类别:集成电路 (IC) >> 接口 - 驱动器，接收器，收发器 系列:- 标准包装:1,000 系列:- 类型:收发器 驱动器/接收器数:2/2 规程:RS232 电源电压:3 V ~ 5.5 V 安装类型:表面贴装 封装/外壳:16-SOIC（0.295"，7.50mm 宽） 供应商设备封装:16-SOIC 包装:带卷 (TR) |
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