MAX3380E-MAX3381E MAXIM [Maxim Integrated Products], MAX3380E-MAX3381E Datasheet - Page 12

• Manufacturer Part Number: MAX3380E-MAX3381E
• Manufacturer: MAXIM [Maxim Integrated Products]

+2.35V to +5.5V, 1µA, 2Tx/2Rx RS-232 Transceivers
with ±15kV ESD-Protected I/O and Logic Pins
For Figure 9 and Figure 10, a single transmitter was dri-
ven at 460kbps, and all transmitters were loaded with
an RS-232 receiver in parallel with 1000pF.
The MAX3380E/MAX3381Es’ ±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 11 shows
the ease of using the MAX3380E/MAX3381E in data
cable applications. For best performance, keep the
logic level lines short and use the RS-232 level lines to
span any distance.
12
Figure 8. Loopback Test Circuit
______________________________________________________________________________________
C1
C2
V
V
CC
CC
C5
FORCEOFF
C1+
C1-
C2+
C2-
T_ IN
R_ OUT
FORCEON
MAX3380E
MAX3381E
Data Cable Applications
GND
V
CC
V
L
T_ OUT
5kΩ
R_ IN
V+
V-
C3
C4
1000pF
Figure 10. Loopback Test Results at 460kbps (V
Figure 9. Loopback Test Results at 460kbps (V
R1OUT
T1OUT
2V/div
5V/div
2V/div
T1IN
R1OUT
T1OUT
5V/div
5V/div
5V/div
T1IN
V
C
CC
LOAD
V
C
CC
LOAD
= V
= 1000pF
= V
L
= +2.5V, C1 = 0.1µF, C2 = C3 = C4 = 1µF,
= 1000pF
L
= +4.2V, C1 = 0.1µF, C2 = C3 = C4 = 1µF,
TIME (1µs/div)
1µs/div
CC
CC
2V
0
5V
0
-5V
2V
0
-5V
5V
5V
0
5V
0
0
= +4.2V)
= +2.5V)