CXTC8964LF is a single-key touch sensor switch chip based on CMOS process, built-in LDO voltage regulator circuit, working voltage range of 2.4V ~ 5.5V, suitable for a variety of power supply environment. The chip can be used on the surface of non-conductive media such as glass, ceramics, and plastics to achieve contactless touch, which greatly expands the product design and use scenarios.
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[ CXTC8964LF ]"
CXTC8964LF: High-performance single-key touch sensor switch chip, intelligent replacement of mechanical keys
In modern electronic product design, touch sensing technology is gradually replacing traditional mechanical buttons and becoming the mainstream way of user interaction. As a switch chip designed for single-button touch and proximity sensing, CXTC8964LF is widely used in home appliances, lighting, toys, smart devices and other fields for its low power consumption, high sensitivity and strong anti-interference ability. This article will analyze the functional characteristics, working modes, application circuits and design points of the CXTC8964LF in depth to help engineers better understand and use the chip and improve product experience and reliability.
1. Product Overview and Application Scenarios
CXTC8964LF is a single-key touch sensor switch chip based on CMOS process, built-in LDO voltage regulator circuit, working voltage range of 2.4V ~ 5.5V, suitable for a variety of power supply environment. The chip can be used on the surface of non-conductive media such as glass, ceramics, and plastics to achieve contactless touch, which greatly expands the product design and use scenarios.
Typical applications include:
· Household appliances: such as smart sockets, fans, kitchen appliances, etc;
· Light control: desk lamp, wall lamp, decorative lamp touch switch;
· Toys and electronic gifts: interactive toys, music boxes, creative gifts;
· Industrial control: instrument panel, security equipment, medical equipment.
2. core features and technical advantages
2.1. Ultra-low power design
The CXTC8964LF has a quiescent current of only 1.5 μA(3.0V no load) in low-power mode and 4 μA in fast mode, which greatly extends the life of battery-powered equipment.
2.2. Fast response and high stability
The chip supports two detection modes of low power consumption and fast speed, and the shortest response time is only 45ms. The built-in de-jitter circuit and noise suppression mechanism can effectively prevent false triggering and improve system reliability.
2.3. Automatic sensitivity calibration
The CXTC8964LF has an environmental adaptive function, which can automatically adjust the detection threshold according to changes in external media, temperature, etc. to ensure that it maintains a stable touch response in different use environments.
2.4. Multiple output modes can be configured.
Through the configuration of HLD and OLH pins, synchronous mode and hold mode output can be realized, and high active level or low active level output can be supported to adapt to different system logic requirements.
2.5. Long press protection and reset mechanism
The chip has a built-in 16-second long-press protection function to avoid system lock-up caused by objects covering the touch area for a long time, and resume normal detection after automatic reset.
Detailed explanation of 3. working mode
3.1. Synchronous mode (HLD = 0)
In this mode, the output signal is synchronized with the touch action: the output is valid when touched, and the output returns to the initial state when released. Suitable for applications that require immediate feedback, such as tact switches, temporary triggers, etc.
3.2. Hold mode (HLD = 1)
The output remains in a state after a touch until it is touched again. Suitable for switch applications, such as light switches, power switches, etc., to achieve "press once on, press again off" logic.
3.3. Output polarity selection (OLH pin)
· OLH = 0: Output high active
· OLH = 1: Output low active
Users can flexibly choose according to the requirements of the post-stage circuit, simplifying the system design.
4. sensitivity adjustment and PCB layout recommendations
4.1. Medium thickness
It is suggested that the thickness of the cover plate should be between 0.5mm and 1.2mm, too thick may lead to a decrease in sensitivity.
4.2. External adjustment capacitor
0 ~ 75pF capacitor can be connected between TCH pin and GND, and the greater the capacitance, the lower the sensitivity. 10pF is recommended for initial commissioning.
4.3. Touch PAD Design
· The minimum area is recommended to be 3 × 5mm, and the maximum area should not exceed 8 × 8mm;
· If using FPC soft board, PAD mirror layer and bottom layer should avoid copper;
· The traces should be short and away from high frequency and RF signals to avoid parallelism or crossover.
4.4. Power supply and filtering
It is recommended to connect 0.1μF and 2.2μF capacitors in parallel between VDD and GND to ensure stable power supply. Input pins can be connected in series with 100Ω resistors for enhanced ESD protection.
5. Typical Application Circuit
The following diagram shows a typical application circuit for CXTC8964LF, which is suitable for most touch switch scenarios:
VDD → C1(0.1μF) C2(2.2μF) → GND
TCH → R2(1K) → KEY（触摸PAD）
TCH → C3(10pF) → GND
HLD → GND/VDD（模式选择）
OLH → GND/VDD（输出极性选择）
OUT → R1(1K) → V-out（至MCU或负载）
The circuit structure is simple, less peripheral components, easy to fast proofing and mass production.
6. electrical parameters and reliability
CXTC8964LF under 3.0V supply:
· Operating current: low power mode 1.5 μA, fast mode 4μA
· Output drive capability: 8mA sink current
· Working temperature:-20 ℃ ~ 85 ℃
· Storage temperature:-40 ℃ ~ 125 ℃
Chip built-in LDO, support 2.4V ~ 5.5V wide voltage input, adapt to a variety of power environment.
7. Package and Pin Description
The CXTC8964LF adopts SOT23-6L package, small size, convenient welding, pin definition is as follows:
· OUT-CMOS output
· GND-power supply ground
· TCH-touch signal input
· OLH-Output High/Low Active Selection
· VDD-power supply positive
· HLD-HOLD/SYNC MODE SELECTION
8. epilogue
As a single-key touch sensor chip with high integration, low power consumption and strong anti-interference, CXTC8964LF provides a reliable and flexible solution for replacing traditional mechanical switches. Its intelligent functions such as automatic calibration, multi-mode output and long-press protection significantly improve the user experience and system stability of the end product. Whether it is home appliances, lighting or consumer electronics, CXTC8964LF can help developers achieve more concise, more beautiful, more durable touch interaction design.
For more technical information, sample support or design guidance, please visit our official websitejtm-ic.comWe will provide you with comprehensive product solutions and technical services.
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