參數(shù)資料
型號: MAX3130-MAX3131
廠商: Maxim Integrated Products, Inc.
元件分類: RS-232
英文描述: 5V High-Speed RS-232 Transceivers with 0.1uF Capacitors
中文描述: 5V的高速RS - 232收發(fā)器與0.1uF電容
文件頁數(shù): 12/16頁
文件大小: 220K
代理商: MAX3130-MAX3131
M
3V to 5.5V, IrDA Infrared Transc eiver with
Integrated RS -232 Interfac e
12
______________________________________________________________________________________
3CS
7CS
16CS
T2IN (TXD)
CS = BAUD16 CLOCK CYCLES
* HIGH = INFRARED LIGHT PULSE
( ) ARE FOR MAX3131
INFRARED LED
OUTPUT *
Figure 3b. ENDEC Operation, Transmitting Infrared
LapLink is a trademark of Traveling Software.
1μs and three BAUD16 clock cycles) into a full baud
period (Figure 3a). Signals applied to TXD are inverted
and compressed to three BAUD16 clock cycles by the
ENDEC before being transmitted (Figure 3b). The
ENDEC is disabled by connecting the BAUD16 input to
V
CC
or GND.
Dual Charge-Pump V oltage Converter
The MAX3130/MAX3131’s internal power supply con-
sists of a regulated dual charge pump that provides
output voltages of +5.5V (doubling charge pump) and
-5.5V (inverting charge pump) for supply voltages from
+3.0V to +5.5V. The charge pump operates in a dis-
continuous mode: if the output voltages are less than
5.5V, the charge pumps are enabled; if the output volt-
ages exceed 5.5V, the charge pumps stop switching.
Each charge pump requires a flying capacitor (C1, C2)
and a reservoir capacitor (C3, C4) to generate the V+
and V- supplies (Figures 1 and 2). If
RSSD
(or
IRMODE
for MAX3130) is low, both charge pumps shut down.
RS -232 T ransmitters
The RS-232 transmitters are inverting level translators
that convert CMOS-logic levels to ±5.0V EIA/TIA-232
levels. The MAX3130/MAX3131 transmitters are guar-
anteed for data rates of 120kbps, providing compatibili-
ty with PC-to-PC communication software, such as
LapLink. These RS-232 transmitters typically operate
at data rates of 235kbps. The RS-232 transmitter out-
puts are high impedance when either
IRMODE
or
RSSD
are low.
The MAX3130/MAX3131 RS-232 receivers translate RS-
232 signal levels to CMOS-level logic. The RS-232
receivers also perform a logic inversion from input to
output. The receivers are always active and are not
affected by the RS-232 shutdown input (
RSSD
).
__________ Applic ations Information
S hutdown
The MAX3130/MAX3131 have split analog and digital
supplies (V
CC
and AV
CC
) with separate shutdown
modes. When
IRSD
is pulled low, the IR receiver is dis-
abled and AV
CC
current reduces to <1μA. When
RSSD
or
IRMODE
is pulled low, the RS-232 charge pumps
are disabled and the RS-232 transmitter outputs
become high impedance. In this mode, the V
CC
current
reduces to <10μA.
IR LED S elec tion
The IrDA specification calls for an IR transmitter with a
peak wavelength between 850nm and 900nm. Within a
±15° half-cone angle, the output intensity of the IR LED
must be between 40mW/sr and 500mW/sr. Outside a
±30° half-cone angle, the output intensity of the IR LED
must fall below 40mW/sr. Within these cases, the opti-
cal rise and fall times of the IR LED must be less than
600ns. Based on these system requirements the HP
HSDL-4220, the Temic TSHF5400, or equivalent IR
LEDs are appropriate choices.
Powering the IR LED
Set the current in the IR LED with an external resistor.
Using the IR LED manufacturer’s data sheet, select a
forward current that meets the IrDA specifications dis-
cussed in the IR LED Selection section. Determine the
forward bias voltage of the IR LED (V
IRLED
) and the
voltage drop across the MAX3130/MAX3131 LED driver
(see LEDC Voltage vs. LEDC Current graph in the
Typical Operating Characteristics) and choose the cur-
rent-setting resistor based on the following equation:
R
SET
= (V
CC
- V
IRLED
- V
LEDC
) / I
SET
Using the HP HSDL-4220 IR LED as an example:
V
CC
= 5V, I
SET
= 100mA, V
IRLED
= 1.67V
V
LEDC
= 90mV
R
SET
= (5V - 1.67V - 90mV) / 0.1A = 32.4
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參數(shù)描述
MAX3131CAI 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 安裝風格:SMD/SMT 封裝 / 箱體:LQFP-100 封裝:
MAX3131CAI-T 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 安裝風格:SMD/SMT 封裝 / 箱體:LQFP-100 封裝:
MAX3131EAI 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 安裝風格:SMD/SMT 封裝 / 箱體:LQFP-100 封裝:
MAX3131EAI+ 功能描述:RS-232接口集成電路 3-5.5V IrDA Infrared Tcvr w/RS-232 Int 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:
MAX3131EAI+T 功能描述:RS-232接口集成電路 3-5.5V IrDA Infrared Tcvr w/RS-232 Int 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: