参数资料
型号: MAX3221EETE+T
厂商: Maxim Integrated Products
文件页数: 18/19页
文件大小: 0K
描述: IC TXRX RS232 250KBPS SD 16-TQFN
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 2,500
类型: 收发器
驱动器/接收器数: 1/1
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-WQFN 裸露焊盘
供应商设备封装: 16-TQFN-EP(5x5)
包装: 带卷 (TR)
±15kV ESD-Protected, 1A, 3.0V to 5.5V, 250kbps,
RS-232 Transceivers with AutoShutdown
RS-232 Receivers
The MAX3221E/MAX3223E/MAX3243E’s receivers con-
vert RS-232 signals to CMOS-logic output levels. All
receivers have inverting three-state outputs and can be
active or inactive. In shutdown (FORCEOFF = low) or in
AutoShutdown, the MAX3221E/MAX3223E’s receivers
are active (Table 1). Drive EN high to place the receiv-
er(s) in a high-impedance state. The MAX3243E’s
receivers are high-impedance when the part is in shut-
down (FORCEOFF = low).
The MAX3243E features an extra, always-active com-
plementary output (R2OUTB). R2OUTB monitors
receiver activity while the other receivers are high-
impedance. This allows Ring Indicator to be monitored
without forward biasing other devices connected to the
receiver outputs. This is ideal for systems where VCC
drops to 0 in shutdown to accommodate peripherals
such as UARTs (Figure 2).
The MAX3221E/MAX3223E/MAX3243E feature an
INVALID output that is enabled low when no valid RS-232
signal levels have been detected on all receiver inputs.
INVALID is functional in any mode (Figures 3 and 5).
AutoShutdown
The MAX3221E/MAX3223E/MAX3243E achieve a 1A
supply current with Maxim’s new AutoShutdown fea-
ture, which operates when FORCEON is low and
FORCEOFF is high. When these devices sense no valid
signal levels on all receiver inputs for 30s, the on-
board charge pump and drivers are shut off, reducing
supply current to 1A. This occurs if the RS-232 cable
is disconnected or the connected peripheral transmit-
ters are turned off. The device turns on again when a
valid level is applied to any RS-232 receiver input. As a
result, the system saves power without changes to the
existing BIOS or operating system.
Table 2 and Figure 3c summarize the MAX3221E/
MAX3223E/MAX3243E operating modes. FORCEON
and FORCEOFF override AutoShutdown. When neither
control is asserted, the IC selects between these states
automatically, based on receiver input levels. Figures
3a, 3b, and 5a depict valid and invalid RS-232 receiver
levels. Figure 5 shows the input levels and timing dia-
gram for AutoShutdown operation.
MAX3243E
T1OUT
R2OUTB
Tx
5k
UART
VCC
T1IN
THREE-STATED
LOGIC
TRANSITION
DETECTOR
R2IN
PROTECTION
DIODE
R2OUT
FORCEOFF = GND
VCC
TO
P
Rx
PREVIOUS
RS-232
Tx
UART
SHDN = GND
VCC
GND
Rx
5k
a) OLDER RS-232: POWERED-DOWN UART DRAWS CURRENT FROM ACTIVE
RECEIVER OUTPUT IN SHUTDOWN.
b) NEW MAX3243E: IN SHUTDOWN, R2OUTB IS USED TO MONITOR EXTERNAL
DEVICES AND R2OUT IS THREE STATED, ELIMINATING A CURRENT PATH
THROUGH THE UART'S PROTECTION DIODE.
GND
PROTECTION
DIODE
I
Figure 2. The MAX3243E detects RS-232 activity when the
UART and interface are shut down.
8
Maxim Integrated
MAX3221E/MAX3223E/MAX3243E
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MAX3221EEUE 功能描述:RS-232接口集成电路 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:
MAX3221EEUE+ 功能描述:RS-232接口集成电路 1uA 3-5.5V Tcvr w/AutoShutdown 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:
MAX3221EEUE+T 功能描述:RS-232接口集成电路 1uA 3-5.5V Tcvr w/AutoShutdown 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:
MAX3221EEUE-T 功能描述:RS-232接口集成电路 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:
MAX3221EIDB 功能描述:RS-232接口集成电路 RS-232 Line Driver/Receiver 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: