MAX3241E MAXIM [Maxim Integrated Products], MAX3241E Datasheet - Page 7

• Manufacturer Part Number: MAX3241E
• Manufacturer: MAXIM [Maxim Integrated Products]

±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,
The MAX3222E/MAX3232E/MAX3237E/MAX3241E’s
internal power supply consists of a regulated dual
charge pump that provides output voltages of +5.5V
(doubling charge pump) and -5.5V (inverting charge
pump), over the 3.0V to 5.5V V
pump operates in discontinuous mode; if the output
voltages are less than 5.5V, the charge pump is
enabled, and if the output voltages exceed 5.5V, the
charge pump is disabled. Each charge pump requires
a flying capacitor (C1, C2) and a reservoir capacitor
(C3, C4) to generate the V+ and V- supplies (Figure 1).
The transmitters are inverting level translators that con-
vert TTL/CMOS-logic levels to ±5.0V EIA/TIA-232-com-
pliant levels.
The MAX3222E/MAX3232E/MAX3237E/MAX3241E
transmitters guarantee a 250kbps data rate with worst-
case loads of 3kΩ in parallel with 1000pF, providing
compatibility with PC-to-PC communication software
(such as LapLink™). Transmitters can be paralleled to
drive multiple receivers or mice.
The MAX3222E/MAX3237E/MAX3241E’s transmitters are
disabled and the outputs are forced into a high-imped-
LapLink is a trademark of Traveling Software.
_________________________________________________Pin Description (continued)
*These pins have an active positive feedback resistor internal to the MAX3237E, allowing unused inputs to be left unconnected.
_______________Detailed Description
SO/DIP
17
18
—
—
—
MAX3222E
Dual Charge-Pump Voltage Converter
TSSOP/
SSOP
11, 14
19
20
—
—
_______________________________________________________________________________________
SO/DIP
Up to 1Mbps, True RS-232 Transceivers
16
—
—
—
—
MAX3232E
RS-232 Transmitters
CC
PIN
1, 10, 11,
TSSOP/
SSOP
range. The charge
19
—
20
—
—
MAX3237E
14*
15*
26
16
—
MAX3241E
20, 21
ance state when the device is in shutdown mode (SHDN =
GND). The MAX3222E/MAX3232E/MAX3237E/MAX3241E
permit the outputs to be driven up to ±12V in shutdown.
The MAX3222E/MAX3232E/MAX3241E transmitter
inputs do not have pull-up resistors. Connect unused
inputs to GND or VCC. The MAX3237E transmitter
inputs have a 400kΩ active positive feedback resistor,
allowing unused inputs to be left unconnected.
For higher-speed serial communications, the MAX3237E
features MegaBaud operation. In MegaBaud operating
mode (MBAUD = V
guarantee a 1Mbps data rate with worst-case loads of
3kΩ in parallel with 250pF for 3.0V < V
±10% operation, the MAX3237E transmitters guarantee a
1Mbps data rate into worst-case loads of 3kΩ in parallel
with 1000pF.
The receivers convert RS-232 signals to CMOS-logic
output levels. The MAX3222E/MAX3237E/MAX3241E
receivers have inverting three-state outputs. Drive EN
high to place the receiver(s) into a high-impedance
state. Receivers can be either active or inactive in shut-
down (Table 1).
26
22
—
—
R_OUTB
MBAUD
NAME
SHDN
N.C.
V
CC
MAX3237E MegaBaud Operation
+3.0V to +5.5V Supply Voltage
Shutdown Control. Active low.
No Connection
MegaBaud Control Input. Connect to
GND for normal operation; connect to
V
Noninverting Complementary
Receiver Outputs. Always active.
CC
CC
), the MAX3237E transmitters
for 1Mbps transmission rates.
FUNCTION
RS-232 Receivers
CC
< 4.5V. For 5V
7