Tittron — Industrial USB & Serial Connectivity

TTL-RS232-4P-MOD1

TTL ↔ RS232 Converter Module  |  DB9 Female (RS232)  +  4Pin TTL Header (VCC,GND,TX,RX)
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Overview

TTL-RS232-4P-MOD1 TTL-RS232 level translator
TTL-RS232-4P-MOD1
TTL-RS232 Level Translator

The TTL-RS232-4P-MOD1 TTL-RS232 converter is a professional serial level-shifting unit. It provides separate level translation paths: TTL signals are translated to standard RS232 levels, and RS232 signals are translated to TTL logic levels. It features a DB9 RS232 female connector and a 4-pin TTL header (VCC, GND, TX, RX), with no onboard USB interface. Designed to interconnect legacy RS232 serial hardware and TTL serial devices, it delivers stable serial communication between mismatched serial interfaces.

This module covers many practical use cases: radio modification, GPS module debugging, automotive electronic testing, firmware flashing for DVD players and set-top boxes, hard drive repair and others. It supports debugging and program downloading for mainstream MCUs including STC, STM32, NXP, Renesas and NEC. Compact and simple to wire, it is widely adopted for equipment maintenance, field industrial debugging and embedded system development.

Warning: The DB9 port carries RS232 level (±10V), and the 4Pin header is TTL level. Do NOT connect RS232 signal directly to MCU IO pins, otherwise the port will be burned. This module has no electrical isolation.

Features

  • Separate level translation paths: TTL → RS232 and RS232 → TTL, no USB port
  • 4-pin TTL header: VCC, GND, TX, RX
  • Supply voltage: 3.3V ~ 5.5V, powered from the TTL side
  • Compatible with STC, STM32, NXP, Renesas, NEC MCU programming and debugging
  • Connects legacy RS232 serial devices: industrial equipment, GPS, set-top boxes, automotive serial ports
  • Pre-assembled module, compact size, convenient for embedded debugging

Typical Applications

  • Radio: Refitting and signal debugging
  • GPS: Module debugging and automotive serial testing
  • Firmware: Set-top box / DVD firmware flashing
  • MCU: STC, STM32, NXP, Renesas, NEC programming & debugging
  • Maintenance & Development: Hard drive repair and embedded system development
Tittron  |  www.tittron.com  |  [email protected]
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Tittron — Industrial USB & Serial Connectivity

TTL-RS232-4P-MOD1

TTL ↔ RS232 Converter Module  |  DB9 Female (RS232)  +  4Pin TTL Header (VCC,GND,TX,RX)
EN

Specifications

Basic Parameters

ModelTTL-RS232-4P-MOD1
Conversion TypeSeparate level translation paths: TTL → RS232 and RS232 → TTL
TTL PinsVCC, GND, TX, RX
InterfaceDB9 Female (RS232) + 4-Pin Header (TTL), No USB
Supply Voltage3.3V ~ 5.5V (Powered from TTL side)
Recommended Baud Rate≤ 115200 bps
IsolationNon-isolated
Form FactorAssembled Module (With Connectors)

Important Notes

  • Power Supply Limit: Only 3.3V~5.5V input allowed. Do NOT apply 12V / 24V high voltage. VCC and GND must not be reversed; reverse polarity will destroy the chip. Supply voltage shall match the logic level of your TTL device.
  • Cross TX/RX & Common GND: Connect module TX to device RX, module RX to device TX. GND of both sides must be linked. Missing common GND causes garbled data, communication failure or hardware damage.
  • Serial Parameter Matching: Baud rate, data bits, stop bits and parity must be identical on both communication sides. Rates higher than 115200 bps are prone to packet loss and corruption.
  • Avoid Hot Plug: Plug / unplug TTL pins while power off. Hot-plugging introduces surge and ESD that may damage the chip and peripheral serial ports.
  • Level Identification: DB9 carries RS232 (±10V), 4Pin header is TTL level. Never feed RS232 signal directly into MCU IO pins.
  • Programming Timing: Follow boot & reset sequence for STC, STM32 and other MCUs. Confirm the target device uses RS232 serial before using this converter.
  • ESD Protection: Take anti-static measures in dry environments. Discharge static electricity before touching the PCB. Static electricity can damage communication ICs.
  • No Isolation: This module is non-isolated. If large ground potential difference exists between two devices, communication will be unstable or hardware may burn. Add an isolated module in such cases.
Tittron  |  www.tittron.com  |  Tel: +86-755-85288085  |  [email protected]
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