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參數(shù)資料
| 型號： | ICL3243CV-T |
| 元件分類： | 收發(fā)器 |
| 英文描述： | Transceiver |
| 中文描述： | 收發(fā)器 |
| 文件頁數(shù)： | 12/28頁 |
| 文件大?。?/td> | 705K |
| 代理商： | ICL3243CV-T |
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12
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 automatic powerdown functionality.
Devices with the automatic powerdown feature include an
INVALID output signal, which switches low to indicate that
invalid levels have persisted on all of the receiver inputs for
more than 30
μ
s (see Figure 7). INVALID switches high 1
μ
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. When automatic
powerdown is utilized, INVALID = 0 indicates that the
ICL32XX is in powerdown mode.
The time to recover from automatic powerdown mode is
typically 100
μ
s.
Receiver ENABLE Control (ICL3221/22/23/41 Only)
Several devices also feature an EN input to control the
receiver outputs. Driving EN high disables all the inverting
(standard) receiver outputs placing them in a high
impedance state. This is useful to eliminate supply current,
due to a receiver output forward biasing the protection diode,
when driving the input of a powered down (V
CC
= GND)
peripheral (see Figure 2). The enable input has no effect on
transmitter nor monitor (R
OUTB
) outputs.
Capacitor Selection
The charge pumps require 0.1
μ
F capacitors for 3.3V
operation. For other supply voltages refer to Table 3 for
capacitor values. Do not use values smaller than those listed
in Table 3. Increasing the capacitor values (by a factor of 2)
reduces ripple on the transmitter outputs and slightly
reduces power consumption. C
2
, C
3
, and C
4
can be
increased without increasing C
1
’s value, however, do not
increase C
1
without also increasing C
2
, C
3
, and C
4
to
maintain the proper ratios (C
1
to the other capacitors).
When using minimum required capacitor values, make sure
that capacitor values do not degrade excessively with
temperature. If in doubt, use capacitors with a larger nominal
value. The capacitor’s equivalent series resistance (ESR)
usually rises at low temperatures and it influences the
amount of ripple on V+ and V-.
Power Supply Decoupling
In most circumstances a 0.1
μ
F bypass capacitor is
adequate. In applications that are particularly sensitive to
power supply noise, decouple V
CC
to ground with a
capacitor of the same value as the charge-pump capacitor C
1
.
Connect the bypass capacitor as close as possible to the IC.
Transmitter Outputs when Exiting
Powerdown
Figure 8 shows the response of two transmitter outputs
when exiting powerdown mode. As they activate, the two
transmitter outputs properly go to opposite RS-232 levels,
with no glitching, ringing, nor undesirable transients. Each
transmitter is loaded with 3k
in parallel with 2500pF. Note
that the transmitters enable only when the magnitude of the
supplies exceed approximately 3V.
FIGURE 6. DEFINITION OF VALID RS-232 RECEIVER LEVELS
0.3V
-0.3V
-2.7V
2.7V
INVALID LEVEL - POWERDOWN OCCURS AFTER 30
μ
s
VALID RS-232 LEVEL - ICL32XX IS ACTIVE
VALID RS-232 LEVEL - ICL32XX IS ACTIVE
INDETERMINATE - POWERDOWN MAY OR
MAY NOT OCCUR
INDETERMINATE - POWERDOWN MAY OR
MAY NOT OCCUR
RECEIVER
INPUTS
TRANSMITTER
OUTPUTS
INVALID
OUTPUT
V+
V
CC
0
V-
V
CC
0
t
INVL
t
INVH
INVALID
REGION
}
FIGURE 7. AUTOMATIC POWERDOWN AND INVALID
TIMING DIAGRAMS
AUTOPWDN
PWR UP
TABLE 3. REQUIRED CAPACITOR VALUES
V
CC
(V)
C
1
(
μ
F)
C
2
, C
3
, C
4
(
μ
F)
3.0 to 3.6
0.1
0.1
4.5 to 5.5
0.047
0.33
3.0 to 5.5
0.1
0.47
ICL3221, ICL3222, ICL3223, ICL3232, ICL3241, ICL3243
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相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| ICL3243CVZ | 功能描述:RS-232接口集成電路 RS232 3V 3D/5R AUTODWN 28TSSOP COM RoHS:否 制造商:Exar 數(shù)據(jù)速率:52 Mbps 工作電源電壓:5 V 電源電流:300 mA 工作溫度范圍:- 40 C to + 85 C 安裝風格:SMD/SMT 封裝 / 箱體:LQFP-100 封裝: |
| ICL3243CVZ-T | 功能描述:RS-232接口集成電路 RS232 3V 3D/5R AUTODWN 28TSSOP COM RoHS:否 制造商:Exar 數(shù)據(jù)速率:52 Mbps 工作電源電壓:5 V 電源電流:300 mA 工作溫度范圍:- 40 C to + 85 C 安裝風格:SMD/SMT 封裝 / 箱體:LQFP-100 封裝: |
| ICL3243E | 制造商:INTERSIL 制造商全稱:Intersil Corporation 功能描述:【15kV ESD Protected, +3V to +5.5V, 1Microamp, 250kbps, RS-232 Transmitters/Receivers |
| ICL3243ECA | 功能描述:RS-232接口集成電路 3-5.5V TXRX ESD RoHS:否 制造商:Exar 數(shù)據(jù)速率:52 Mbps 工作電源電壓:5 V 電源電流:300 mA 工作溫度范圍:- 40 C to + 85 C 安裝風格:SMD/SMT 封裝 / 箱體:LQFP-100 封裝: |
| ICL3243ECAH-T | 制造商:Rochester Electronics LLC 功能描述:- Tape and Reel |
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