Datasheet

MAX3387E
3V, ±15kV ESD-Protected, AutoShutdown Plus
RS-232 Transceiver for PDAs and Cell Phones
6 _______________________________________________________________________________________
C1+ Positive Terminal of the Voltage-Doubler Charge-Pump Capacitor
Pin Description
V+ +5.5V Supply Generated by the Charge Pump
C1- Negative Terminal of the Voltage-Doubler Charge-Pump Capacitor
C2+ Positive Terminal of the Inverting Charge-Pump Capacitor
C2- Negative Terminal of the Inverting Charge-Pump Capacitor
V- -5.5V Generated by the Charge Pump
T1IN
TTL/CMOS Transmitter Inputs
R3OUT
TTL/CMOS Receiver Outputs. Swing between 0V and V
L
.
R2OUT
R1OUT
V
L
Logic-Level Supply. All CMOS inputs and outputs are referenced to this supply.
R3IN
R2IN
R1IN
RS-232 Receiver Inputs
T3OUT
T2OUT
T1OUT
RS-232 Transmitter Outputs
GND Ground
V
CC
+3.0V to +5.5V Supply Voltage
NAME FUNCTION
FORCEOFF
Force-Off Input. Drive FORCEOFF low to shut down transmitters and on-board power sup-
ply. This overrides all automatic circuitry and FORCEON (Table 1).
1
2
3
4
5
6
7
12
13
14
15
16
17
18
19
20
21
22
23
PIN
24
FORCEON
Force-On Input. Drive FORCEON high to override automatic circuitry keeping transmitters
on (FORCEOFF must be high) (Table 1).
11
INVALID
Output of the Valid Signal Detector. INVALID is high if a valid RS-232 signal is present on
the receiver inputs.
9
T3IN TTL/CMOS Transmitter Inputs10
8 T2IN