MAX202E Просмотр технического описания (PDF) - Maxim Integrated
Номер в каталоге
Компоненты Описание
производитель
MAX202E Datasheet PDF : 25 Pages
| |||
MAX202E–MAX213E,
MAX232E/MAX241E
±15kV ESD-Protected,
5V RS-232 Transceivers
+5V
0.1μF*
0.1μF*
0.1μF*
0V (+5V)
0V (+5V)
0.1μF*
C1+
VCC
V+
C1- MAX2_ _E
C2+ VCC
0.1μF*
V-
C2- 400kΩ
T_
T_IN
T_OUT
R_
R_OUT
R_IN
EN (EN)
5kΩ
SHDN (SHDN)
3kΩ 2500pF
+5V
0.1μF*
0.1μF*
0.1μF*
0.1μF*
C1+
VCC
V+
C1- MAX2_ _E
C2+ VCC
0.1μF*
V-
C2-
400kΩ
T_
T_IN
T_OUT
0V (+5V)
R_OUT
EN (EN)
R_
R_IN
5kΩ
0V (+5V) SHDN (SHDN)
7kΩ
50pF
MINIMUM SLEW-RATE TEST CIRCUIT
( ) ARE FOR MAX213E
* 1μF FOR MAX232E/MAX241E
MAXIMUM SLEW-RATE TEST CIRCUIT
TRANSMITTER INPUT PULL-UP RESISTORS, ENABLE, AND SHUTDOWN ARE NOT PROVIDED ON THE MAX202E, MAX203E, AND MAX232E.
ENABLE AND SHUTDOWN ARE NOT PROVIDED ON THE MAX207E AND MAX208E.
Figure 3. Transition Slew-Rate Circuit
Detailed Description
The MAX202E–MAX213E, MAX232E/MAX241E consist of
three sections: charge-pump voltage converters, dri-
vers (transmitters), and receivers. These E versions
provide extra protection against ESD. They survive
±15kV discharges to the RS-232 inputs and outputs,
tested using the Human Body Model. When tested
according to IEC1000-4-2, they survive ±8kV contact-
discharges and ±15kV air-gap discharges. The rugged
E versions are intended for use in harsh environments
or applications where the RS-232 connection is fre-
quently changed (such as notebook computers). The
standard (non-“E”) MAX202, MAX203, MAX205–
MAX208, MAX211, MAX213, MAX232, and MAX241 are
recommended for applications where cost is critical.
+5V to ±10V Dual Charge-Pump
Voltage Converter
The +5V to ±10V conversion is performed by dual
charge-pump voltage converters (Figure 4). The first
charge-pump converter uses capacitor C1 to double
the +5V into +10V, storing the +10V on the output filter
capacitor, C3. The second uses C2 to invert the +10V
into -10V, storing the -10V on the V- output filter capaci-
tor, C4.
In shutdown mode, V+ is internally connected to VCC by
a 1kΩ pull-down resistor, and V- is internally connected
to ground by a 1kΩ pull up resistor.
RS-232 Drivers
With VCC = 5V, the typical driver output voltage swing
is ±8V when loaded with a nominal 5kΩ RS-232 receiv-
er. The output swing is guaranteed to meet EIA/TIA-
232E and V.28 specifications that call for ±5V minimum
output levels under worst-case conditions. These
include a 3kΩ load, minimum VCC, and maximum oper-
ating temperature. The open-circuit output voltage
swings from (V+ - 0.6V) to V-.
Input thresholds are CMOS/TTL compatible. The
unused drivers’ inputs on the MAX205E–MAX208E,
MAX211E, MAX213E, and MAX241E can be left uncon-
nected because 400kΩ pull up resistors to VCC are
included on-chip. Since all drivers invert, the pull up
resistors force the unused drivers’ outputs low. The
MAX202E, MAX203E, and MAX232E do not have pull
up resistors on the transmitter inputs.
www.maximintegrated.com
Maxim Integrated | 9
Share Link: 