MAX232 RS232-TTL DB-9 Serial Port Converter Module

MAX232 RS232-to-TTL DB-9 Serial Port Converter Module

The MAX232 RS232-to-TTL Converter Module is a compact, reliable interface board that converts standard RS232 serial signals to TTL logic levels and vice versa. It is ideal for connecting microcontrollers such as Arduino, PIC, AVR, ARM, and STM32 to RS232 devices including PCs, CNC machines, PLCs, industrial equipment, and legacy serial peripherals. The module is powered from a single 5V supply and uses the MAX232 chipset with built-in charge-pump capacitors for stable voltage level conversion.

Key Features

• Converts RS232 (±7V to ±12V) to TTL (0 to 5V) logic levels
• Based on the reliable MAX232 integrated circuit
• Integrated DB-9 female serial connector for direct connection to PCs and RS232 devices
• Supports full-duplex communication (separate TX and RX)
• Onboard electrolytic and charge-pump capacitors for stable operation from a single 5V supply
• Compact design with clearly labeled TTL pins for quick wiring
• High noise immunity and stable data transmission over typical RS232 distances

Specifications

• Chipset: MAX232
• Interface Type: RS232 to TTL
• TTL Voltage Level: 5V
• RS232 Voltage Range: ±7V to ±12V
• Power Supply: 5V DC
• Communication Mode: Full duplex
• Connector: DB-9 female (RS232 side)
• Baud Rate Support: Up to 120 kbps (typical)
• Operating Temperature: -40°C to +85°C

Pin Description (TTL Side)

• VCC: +5V power input
• GND: Ground
• TXD: TTL transmit output (to RX of microcontroller)
• RXD: TTL receive input (to TX of microcontroller)

Applications

• Microcontroller serial communication and debugging
• Arduino and embedded system projects requiring RS232 devices
• Interfacing industrial RS232 equipment, CNC and PLC systems
• Programming or diagnosing legacy serial peripherals
• Connecting PCs or laptops with DB-9 serial ports to modern TTL devices

Compatibility and Usage Tips

• Ensure the TTL side of the module is powered with a stable 5V supply before connecting RS232 devices.
• Connect TXD on the module to the RX pin on your microcontroller and RXD to the microcontroller TX pin for correct data flow.
• Do not connect RS232 signals directly to microcontroller pins without a level shifter like this MAX232 module.
• Keep cable lengths reasonable for your baud rate and environment to maintain signal integrity.
• For higher baud rates or long-distance runs, verify signal quality and consider shielding or differential solutions if needed.

Ordering Notes

Images are for illustration purposes only. Check the product photos and pin labels before wiring. Contact support if you need help confirming compatibility with your hardware.