TM1814(TA2105B)

TM1814 is a four-channel constant-current adjustable LED driver IC with built-in synchronization control. It accepts constant-current and PWM configuration data from an MCU to achieve a wide variety of display effects. When the signal input is disconnected, it automatically switches to synchronized fixed multi-color pattern cycling, preventing downstream cascaded ICs from ceasing operation due to chip failure. The IC integrates an embedded MCU firmware, single-wire digital interface, data latch, and LED constant-current driver circuitry. The VDD pin incorporates an internal 5V voltage regulator, minimizing the required external components. Suitable for LED decorative products such as guardrail tubes and point light sources.

Applications

• Guard rail tubes
• LED decorative products such as point light sources

Key features

• Power CMOS process
• OUT output port withstand voltage: 32V
• VDD built-in 5V Zener diode; supports 6~24V with series resistor
• Constant current adjustable in 64 levels (6.5mA–38mA)
• PWM brightness control, 256-level adjustable
• Accurate current output matching: channel-to-channel max error ±3%; chip-to-chip max error ±5%
• Single-wire serial cascade interface oscillation: built-in RC oscillator with clock synchronization based on data line signals; after receiving its own data, automatically regenerates subsequent data and forwards it to the next stage via data output — no signal distortion or attenuation over cascaded distance
• Built-in power-on reset circuit; all registers initialized to zero after power-on reset
• External control mode data transfer rate: 800KHz
• Internal control mode data transfer rate: 500KHz
• Internal control mode chip transmit data: 1918 points
• Package: SOP8