TM1650 LED Driver IC Features, Working Principle, Applications, Usage and More
12 December 2023
Ⅱ. Symbol, footprint and pin configuration of TM1650
Ⅲ. Features of TM1650 LED driver
Ⅳ. Technical parameters of TM1650 LED driver
Ⅴ. How does the TM1650 LED driver work?
Ⅵ. Applications and typical application circuit of TM1650 LED driver
Ⅶ. What are the advantages of TM1650 LED driver?
Ⅷ. How to use the TM1650 chip?
Ⅸ. What are the differences between TM1650, TM1651 and TM1652?
The TM1650 serves as a digital tube driver chip featuring numerous pins, enabling the manipulation of the digital display on a digital tube. It can be directly connected to a microcontroller or other external controllers and sends data and commands through a simple communication protocol. It integrates internal circuits such as MCU input or output control digital interface, keypad scanning, LED driver, data latch, and glow adjustment. In addition, the TM1650 also features low power consumption and multiple brightness adjustments, making it widely used in digital display applications.
The TM1650 communicates using a 2-wire serial transmission protocol (note that this data transmission protocol is not the standard I2C protocol). The chip only needs to communicate with the MCU through two pins to complete the drive of the digital tube, thus effectively saving the MCU pin resources and simplifying the complexity of the digital tube display circuit.
Replacements and equivalents:
• CD4511
• HT16K33
• MAX7219
• PCA9685
The pictures above are the symbol, footprint and pin configuration of TM1650. Among them, TM1650 has 16 pins, whose names and descriptions are as follows.
Pin 1 (DIG1): LED segment driver output 1/keypad scan output 1
Pin 2 (SCL): Data input
Pin 3 (SDA): Clock input
Pin 4 (GND): Logic ground
Pin 5 (DIG2 ): LED segment drive output 2/Keypad scan output 2
Pin 6 (DIG3): LED segment drive output 3/Keypad scan output 3
Pin 7 (DIG4): LED segment driver output 4/keypad scan output 4
Pin 8 (A/KI1): LED segment driver output A/Keypad scan input KI1
Pin 9 (B/KI2): LED segment driver output B/keypad scan input KI2
Pin 10 (VDD): Logic power supply
Pin 11 (C/KI3): LED segment drive output C/key scan input KI3
Pin 12 (D/KI4 ): LED segment drive output D/key scan input KI4
Pin 13 (E/KI5): LED segment drive output E/key scan input KI5
Pin 14 (F/KI6 ): LED segment drive output F/key scan input KI6
Pin 15 (G/KI7): LED segment drive output G/key scan input KI7
Pin 16 (DP/KP): LED segment output DP/keypad flag output KP
• TM1650 has strong anti-interference ability.
• It has built-in data latch circuit and power-on reset circuit.
• It supports various package forms such as DIP16 and SOP16.
• TM1650 is mainly used in LED drive control dedicated circuits.
• It has a keyboard scanning interface that can detect and read keyboard input, and then control the LED display accordingly.
• Operating voltage: 3V ~ 5V
• Package forms: DIP16/SOP16
• Keyboard scanning: 7×4bit, supports 4 key combinations
• Matrix button drive mode: 7x4 matrix button, does not support combination keys
• Digital tube drive mode: 8-segment x 4-bit common cathode digital tube
• Communication interface: Class IIC, uses the same timing sequence as IIC, but does not fully comply with the IIC protocol and does not have a slave address
*IIC protocol
I2C (Inter-Integrated Circuit BUS) integrated circuit bus: This bus is designed by NXP (formerly PHILIPS) company and is mainly used for communication between the master controller and slave devices. It is employed in scenarios involving minimal data volume, featuring a limited transmission range and supporting only a single host at a time.
Hardware IIC: This circuit is a hardware implementation, utilizing the hardware I2C that corresponds to the chip's I2C peripherals and functions in tandem with the corresponding I2C driver circuit. The dedicated I2C pins employed by this hardware circuit exclusively facilitate its communication with I2C peripherals, typically involving direct calls to internal registers for configuration.
Software IIC: Software IIC communication refers to the IIC simulated by the two IO ports of the microcontroller. It uses software to control pin status to simulate 2C communication waveforms, and uses software to simulate the working mode of registers.
The TM1650 chip uses serial communication to transmit data with external devices through clock signals and data signals. The chip supports driving 4-bit, 6-bit and 8-bit common anode digital tubes, and provides a variety of brightness settings and display modes.
In TM1650, data transmission is divided into two stages, namely writing address and writing data. First we send the command to write the address and then the data to be displayed. Each write address corresponds to the position of a 7-segment LED digital tube. By sending the write addresses and data one by one, independent control of multiple digital tubes can be achieved.
1. Applications of TM1650
• Set top box
• Keyboard control
• LED lighting system
• Household appliances
• Smart home
• Thermometer and clock
2. Typical application circuit of TM1650
The following is the wiring circuit diagram of TM1650 driving common cathode digital screen.
Note:
• When laying out chip power and ground lines, we should try to widen the line width.
• The filter capacitor of the chip should be placed close to the pins of TM1650 during layout to enhance the filtering effect.
• Since the on-state voltage drop of the blue digital tube is about 3.0V, the TM1650 power supply should be selected 5.0V.
The advantages of TM1650 over other digital display components mainly lie in its low power consumption and brightness adjustment function. Since the brightness of digital tubes usually has a greater impact on battery life, the TM1650 can achieve multiple brightness adjustments through the internal PWM controller, thereby extending battery life. In addition, the serial communication method of TM1650 is very convenient, which can reduce the use of microcontroller pins and further reduce system costs.
1. Power connection
Connect the VCC and GND pins, typically designated for power supply, to provide power to the chip. Please ensure that the voltage meets the specifications of the chip to avoid damage to the chip.
2. I2C interface connection
The TM1650 communicates through the I2C interface. We connect the SCL (clock line) and SDA (data line) pins to the microcontroller or other host device and make sure to observe the I2C bus level requirements when connecting.
3. Setting the I2C address (optional)
The TM1650 chip allows its address to be set via configuration pins or via I2C commands. This is useful in situations where more than one TM1650 device needs to be used. If there is only one TM1650 device, we can use the default address.
4. Controlling the LED display
We can send specific I2C commands to the TM1650 to control the brightness of the LEDs, the content of the display, and so on. Please refer to the datasheet of TM1650 for the specific command format and function.
5. Driving 7-segment digital tube or matrix LEDs
TM1650 chip usually supports 4x8 matrix or 7-segment digital tube display. By setting appropriate register values, we can control the LED status and display contents.
6. Setting brightness
The TM1650 allows setting the brightness level of the LEDs. By adjusting the relevant register values, the brightness of the LEDs can be changed to suit different environments and requirements.
7. Handling key input (optional)
Some TM1650 chip models support keystroke input detection. If your application needs to handle key inputs, please consult the relevant datasheet and connect the corresponding pins.
8. Software control
Compose code in the relevant programming language (such as C, C++, Python, etc.) and engage with the TM1650 through I2C communication to implement the logic for controlling the LED display.
TM1650: TM1650 is a driver chip suitable for controlling 4-bit digital LED display, which can control 4-bit common negative or common positive digital LED digital tube display. The TM1650 facilitates the ease of digital display communication with microcontrollers or other devices through the I2C bus.
TM1651: TM1651 is also a digital LED display driver chip, similar to TM1650, but it has a higher level of integration. TM1651 not only controls the 8-bit common anode LED digital tube display, but also integrates the key scanning function. It can not only be used to display numbers, but also detect external key input, which makes it more suitable for some application scenarios that require displaying numbers and detecting key input at the same time.
TM1652: TM1652 is a digital LED display driver chip, similar to TM1651. It can also control the 8-bit common anode LED digital tube display, and also has a key scanning function. Compared with TM1651, TM1652 has improved performance and is more suitable for occasions that require higher display quality.
Frequently Asked Questions
1. What is the purpose of the TM1650?
The TM1650 is designed to simplify the process of controlling multiple LEDs in a display, especially in applications where there is a need for displaying numerical or alphanumeric characters.
2. What is TM1650 in English?
LED TM1650 is a kind of keyboard scan interface (light emitting diode display) dedicated drive control circuit. Internal integrated MCU Digital input and output control interface, data latches, LED driver, keyboard scanning, brightness adjustment circuit.
3. What are some typical applications of the TM1650?
The TM1650 is often used in applications where numeric or alphanumeric displays are required, such as digital clocks, temperature displays, and other projects where numerical information needs to be shown.
4. What type of displays can be controlled by the TM1650?
The TM1650 is commonly used to drive seven-segment LED displays, but it can also be used for other types of displays, such as dot matrix displays.
