- 您現(xiàn)在的位置：買(mǎi)賣(mài)IC網(wǎng) > PDF目錄383359 > MAX3218* (Maxim Integrated Products, Inc.) 1µ.A.1.8V to 4.25V RS-232 Transceiver with AutoShutdown™. PDF資料下載
參數(shù)資料
| 型號(hào)： | MAX3218* |
| 廠商： | Maxim Integrated Products, Inc. |
| 英文描述： | 1µ.A.1.8V to 4.25V RS-232 Transceiver with AutoShutdown™. |
| 文件頁(yè)數(shù)： | 7/12頁(yè) |
| 文件大?。?/td> | 123K |
RS -232 Drivers
The two drivers are identical, and deliver EIA/TIA-232E
and EIA/TIA-562 output voltage levels when V
CC
is
between 1.8V and 4.25V. One transmitter can drive up
to 3k
in parallel with 2500pF at up to 120kbps.
Connect unused drivers to either GND or V
CC
. When
FORCEOFF is driven low, or when AutoShutdown circuit-
ry senses invalid voltage levels at
all
receiver inputs, the
drivers are disabled and their outputs are forced into a
high-impedance state. Driver inputs do not have internal
pull-up resistors.
RS -232 Rec eivers
The two receivers are identical, and accept both
EIA/TIA-232E and EIA/TIA-562 input signals. The
CMOS receiver outputs are inverting and swing rail-to-
rail. Receivers are disabled only when FORCEON and
FORCEOFF inputs are low. (See Table 2.)
S hutdown
When FORCEOFF is low, power supplies are disabled
and the transmitters are placed in a high-impedance
state. Receiver operation is not affected by taking
FORCEOFF low. Power consumption is dramatically
reduced in shutdown mode. Supply current is minimized
when the receiver inputs are static in any one of three
states: floating (ground), GND, or V
CC
.
AutoS hutdown
A 1μA supply current is achieved with Maxim’s new
AutoShutdown feature, which operates when FORCEON
is low and FORCEOFF is high. When the MAX3218
senses no valid signal level on either receiver input for
typically 30μs, the on-board power supply and drivers
shut down, reducing supply current to 1μA. Internal 5k
resistors pull undriven receiver inputs to ground. This
occurs if the RS-232 cable is disconnected or if the con-
nected peripheral transmitters are turned off. The sys-
tem turns on again when a valid level is applied to either
RS-232 receiver input. As a result, the system saves
power without changes to the existing BIOS or operating
system. When using the AutoShutdown feature, INVALID
is high when the device is on and low when the device is
shut down. The INVALID output indicates the condition
of the receiver inputs.
Table 3 summarizes the MAX3218 operating modes.
FORCEON and FORCEOFF override the automatic cir-
cuitry and force the transceiver into its normal operating
state or into its low-power standby state. When neither
control is asserted, the IC selects between these states
automatically based on receiver input levels. Figure 4
depicts valid and invalid RS-232 receiver levels. The
M
1μA S upply Current, 1.8V to 4.25V-Powered
RS -232 Transc eiver with AutoS hutdown
_______________________________________________________________________________________
7
Table 3. AutoShutdown Logic
L
L
H
L
H
H
L
L
No
No
Yes
No
Normal Operation (Forced On)
Shutdown (AutoShutdown)
Shutdown (Forced Off)
Shutdown (Forced Off)
H
H
Yes
Normal Operation
RS-232 SIGNAL
PRESENT AT
RECEIVER INPUT
INVALID OUTPUT
FORCEOFF INPUT
TRANSCEIVER STATUS
FORCEON INPUT
H
L
X
X
X
POWER
MANAGEMENT
UNIT OR
KEYBOARD
CONTROLLER
CPU
I/O
CHIP
WITH
UART
MAX3218
RS-232
FORCEOFF
FORCEON
INVALID
Figure 2. Interface Under Control of PMU
Table 2. Receiver Status
FORCEON
FORCEOFF
RECEIVER STATUS
Receiver Enabled
Receiver Disabled
X
L
H
L
H
X
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| MAX3224ECPP | 5V High-Speed RS-232 Transceivers with 0.1uF Capacitors |
| MAX3224E | 5V High-Speed RS-232 Transceivers with 0.1uF Capacitors |
| MAX3224ECAP | 5V High-Speed RS-232 Transceivers with 0.1uF Capacitors |
| MAX3224EEPP | Digital Media Processor 376-BGA |
| MAX3225ECAP | 5V High-Speed RS-232 Transceivers with 0.1uF Capacitors |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MAX3218C/D | 功能描述:RS-232接口集成電路 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(fēng)格:SMD/SMT 封裝 / 箱體:LQFP-100 封裝: |
| MAX3218CAP | 功能描述:RS-232接口集成電路 Integrated Circuits (ICs) 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(fēng)格:SMD/SMT 封裝 / 箱體:LQFP-100 封裝: |
| MAX3218CAP+ | 功能描述:RS-232接口集成電路 1uA 1.8-4.25V Tcvr w/AutoShutdown 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(fēng)格:SMD/SMT 封裝 / 箱體:LQFP-100 封裝: |
| MAX3218CAP+ | 制造商:Maxim Integrated Products 功能描述:SEMICONDUCTOR ((NW)) |
| MAX3218CAP+T | 功能描述:RS-232接口集成電路 1uA 1.8-4.25V Tcvr w/AutoShutdown 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(fēng)格:SMD/SMT 封裝 / 箱體:LQFP-100 封裝: |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。