MAX3248EEAI-T Maxim Integrated, MAX3248EEAI-T Datasheet - Page 13

• Manufacturer Part Number: MAX3248EEAI-T
• Description: RS-232 Interface IC
• Manufacturer: Maxim Integrated
• Series: MAX3238E, MAX3248Er

OUTPUTS
+3.0V to +5.5V, 10nA, 250kbps RS-232 Transceivers
INPUTS
LOGIC
LOGIC
0.1µF
0.1µF
*C3 MAY BE RETURNED TO EITHER V
28
25
24
23
22
19
17
14
13
16
21
20
18
1
3
C1+
C1-
C2+
C2-
T1IN
T2IN
T3IN
T4IN
T5IN
FORCEOFF
FORCEON
R1OUTB
R1OUT
R2OUT
R3OUT
with ±15kV ESD-Protected I/O and Logic Pins
Typical Operating Circuit
______________________________________________________________________________________
1µF
AutoShutdown Plus
R1
R2
R3
MAX3238E
MAX3248E
+3.3V
V
GND
CC
CC
26
2
OR GND.
T1
T2
T3
T4
T5
INVALID
T1OUT
T2OUT
T3OUT
T4OUT
T5OUT
5kΩ
5kΩ
5kΩ
R1IN
R2IN
R3IN
V+
V-
27
4
5
6
7
10
12
15
8
9
11
RS-232
OUTPUTS
RS-232
INPUTS
0.1µF*
0.1µF
and Figure 10 shows the same test at 250kbps. For
Figure 9, all transmitters were driven simultaneously at
120kbps into RS-232 loads in parallel with 1000pF. For
Figure 10, a single transmitter was driven at 250kbps,
and all transmitters were loaded with an RS-232 receiv-
er in parallel with 1000pF.
The MAX3238E/MAX3248Es’ ±15kV ESD protection on
both the RS-232 I/Os as well as the logic I/Os makes
them ideal candidates for data cable applications. A
data cable is both an electrical connection and a level
translator, allowing ultra-miniaturization of cell phones
and other small portable devices.
Previous data cable approaches suffered from com-
plexity due to the required protection circuits on both
the logic side of the cable as well as on the RS-232
connections. The example shown in Figure 10 shows
the ease of using the MAX3238E/MAX3248E in data
cable applications.
The MAX3238E/MAX3248Es’ five-transmitter and three-
receiver configuration is optimized for a data communi-
cation equipment (DCE) application, allowing full hard-
ware handshaking. The 9-pin RS-232 connector is
configured for direct attachment to a PC’s serial port.
R1OUTB is also connected to the subminiature con-
nector. This allows the remote system to shut down
until the PC asserts the ready to send (RTS) signal.
R1OUTB stays active when the MAX3238E/MAX3248E
is shut down (FORCEOFF = GND).
TRANSISTOR COUNT: 2110
___________________Chip Information
Data Cable Applications
13