The MAX3232 TTL to RS-232 Interface Module uses built-in charge pumps to convert between TTL logic level serial and standard RS-232 ±V serial.
- MAX3232 based TTL to RS-232 Interface Module
- Cable assembly, 4-pin F/F, 8″ long
KEY FEATURES OF MAX3232 TTL TO RS-232 INTERFACE MODULE:
- Use MAX3232 Interface chip
- Built-in charge pumps generate the required ± voltages for RS-232
- Standard DB-9 Female connector for RS232 connection
- 3.0 to 5.5V operation
These modules allow microcontrollers to interface their logic level TTL serial to the RS-232 standard that requires ± voltage signaling per the TIA/EIA-232-F spec. This also allows the RS-232 to be used over longer distances than when using TTL serial.
The module is based on the MAX3232 chip and can operate at 3.3 or 5V. It has two built-in charge pumps to provide the necessary ± voltages required to meet the RS-232 standard. Maximum bit rate is 120Kbit/s.
The maximum input receiver voltage range is ± 25V which will handle pretty much any RS232 that you are likely to connect to.
The main RS-232 connection is via a standard DB-9 Female connector, but a RS-232 2nd channel is also brought out to a header for connection flexibility.
- Pin 2 = T1OUT
- Pin 3 = R1IN
- Pin 5 = Ground
The module has a two 4-pin headers on the assembly. The 4-pin row near the edge of the board provides the main interface to use.
1 x 4 Header (Board edge side)
- GND = Ground – Connect to uC ground
- Tx = R1OUT on MAX3232 chip – Connect to uC RX line
- Rx = D1IN on MAX3232 chip – Connect to uC TX line.
- Vcc = 3.3 or 5V
The other part of the header brings out the 2nd channel of the MAX3232 which might be useful in some applications.
1 x 4 Header (DB-9 side)
- T2O = D2OUT on MAX3232 chip
- R2I = R2IN on MAX3232 chip
- R2O = D2OUT on MAX3232 chip
- T2I = D2IN on MAX3232 chip
There is a red LED on the module that indicates transmit activity and a green LED that indicates receive activity.
The module has two holes for mounting.
OUR EVALUATION RESULTS:
At 3.3V Vcc, the RS-232 output swing was measured at ± 6V with no load and the TTL I/O is 5V tolerant, so it can be operated at 3.3V even when using with a 5V microprocessor. With a Vcc of 5V, the output swing was measured at ± 9V.
These modules work well and are simple to use and basically transparent in their operation. Just make sure that you have the TX/RX hooked up correctly along with power and ground.
BEFORE THEY ARE SHIPPED, THESE MODULES ARE:
- Sample inspected and tested per incoming shipment
|Vcc||Range||3.0 to 5.5V|
|RS232 Output Swing||Vcc = 3.3V||± 6V (measured)|
|Vcc = 5V||± 9V (measured)|
|Imax||Output short circuit current||±35mA|
|Dimensions||L x W (PCB)||39 x 32mm (1.5 x 1.25″)|