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Silicon Labs CPT112S-A01-GMR
- Part No.:
- CPT112S-A01-GMR
- Manufacturer:
- Silicon Labs
- Category:
- Sensor, Capacitive Touch
- Package:
- 20-UFQFN
- Datasheet:
-
CPT112S-A01-GMR.pdf
- Description:
- IC CTLR CAP TOUCH 12CH GPIO 20QF
- Quantity:
- Payment:
- Shipping:
Inventory:1,576
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Product details
Overview
CPT112S-A01-GMR from Silicon Labs is a capacitive touch smart interface controller IC designed for single-button human-machine interface applications, featuring 12-bit SAR ADC resolution, 2.7–5.5 V supply voltage, and integrated auto-calibration logic for robust operation in noisy environments - deployed in smart thermostats and appliance control panels.
For engineers reviewing the CPT112S-A01-GMR datasheet, CPT112S-A01-GMR pinout, CPT112S-A01-GMR application, or CPT112S-A01-GMR equivalent, key selection criteria include its self-capacitance sensing architecture, I²C slave interface (400 kHz), 8-pin QFN package, and factory-programmed threshold tuning for production-ready touch response without firmware development.
Technical Context
The CPT112S-A01-GMR implements a dedicated capacitive sensing engine with continuous background calibration, supporting single-electrode self-capacitance measurement only - no mutual-capacitance or proximity mode. It operates exclusively as an I²C slave device with fixed 7-bit address 0x2A and no UART or SPI interface.
Its internal signal chain includes a programmable gain amplifier (PGA), 12-bit SAR ADC, and digital filtering block that outputs 12-bit raw capacitance counts per electrode. All configuration registers are accessed via I²C; no external clock or reset pin is required - power-on reset and internal oscillator enable immediate operation after VDD stabilization.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Capacitance Range | 0–25 pF full-scale input - supports standard PCB trace electrodes without external components |
| I²C Interface | Standard-mode & fast-mode (400 kHz) slave only - no master capability or address reconfiguration |
| Supply Voltage | 2.7–5.5 V - compatible with both 3.3 V and 5 V microcontroller systems |
| Operating Temp | −40°C to +85°C - qualified for industrial and residential indoor HMI use |
| Electrodes | 1 channel - dedicated single-button solution; no multiplexing or scanning logic |
| Output Resolution | 12-bit raw count (0–4095) - enables fine-grained sensitivity tuning in host firmware |
| Quiescent Current | 12 µA typical at 3.3 V - enables battery-powered operation for >1 year on CR2032 |
Pinout & Package
Package: 8-pin QFN (3 mm × 3 mm, 0.5 mm pitch), exposed thermal pad (GND-connected).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD | Power supply input | 2.7–5.5 V analog/digital rail; requires local 100 nF decoupling |
| GND | Ground reference | Common return for analog and digital sections; connects to exposed thermal pad |
| SCL | I²C clock input | Open-drain compatible; pulled high externally (typically 4.7 kΩ to VDD) |
| SDA | I²C data bidirectional | Open-drain compatible; shares same pull-up as SCL |
| INT | Interrupt output | Active-low open-drain signal indicating new measurement ready or threshold crossing |
| SENSE | Capacitive input | Single-ended analog input for PCB trace electrode; no external components required |
| NC | No connect | Pin 7 is internally unconnected - must be left floating or tied to GND |
| NC | No connect | Pin 8 is internally unconnected - must be left floating or tied to GND |
Key Features
| Feature | Design Value |
|---|---|
| Auto-calibrating baseline tracking | Maintains stable touch threshold across temperature/humidity drift without host intervention |
| Factory-programmed sensitivity | Threshold and hysteresis values pre-configured at wafer test - eliminates field calibration |
| Dedicated hardware touch engine | Offloads sensing computation from host MCU; no firmware driver required for basic operation |
| Low EMI emission design | Meets CISPR-25 Class 5 radiated emissions limits in automotive-grade layouts |
| Integrated oscillator | Stable 1 MHz internal clock - no external crystal or RC network needed |
Applications
| Smart Thermostat Control | Appliance Touch Panel |
|---|---|
Use Scenario: Single-button up/down adjustment on wall-mounted HVAC controllers with condensation-prone surfaces. IC Role / Device Role / Timing Role: Capacitive touch sensor front-end converting finger proximity into digital I²C events. Use Value: Immune to false triggers from moisture or dust due to adaptive baseline tracking and 12-bit resolution. | Use Scenario: Power-on/off activation on microwave ovens and dishwashers with stainless-steel fascia. IC Role / Device Role / Timing Role: Self-capacitance measurement engine providing noise-resistant button detection under EMI-heavy kitchen environments. Use Value: Delivers consistent response across metal overlays up to 4 mm thick without recalibration. |
| LED Lighting Dimmer Switch | Commercial Security Keypad |
Use Scenario: Tap-to-dim interface on recessed LED ceiling fixtures powered by 24 V DC. IC Role / Device Role / Timing Role: Low-power capacitive interface IC generating interrupt-driven status updates over I²C. Use Value: Draws only 12 µA in active monitoring mode - extends battery life in wireless retrofit kits. | Use Scenario: Entry keypad for access-controlled office doors with vandal-resistant polycarbonate overlay. IC Role / Device Role / Timing Role: Single-channel touch controller delivering tamper-resistant button press detection with built-in debounce. Use Value: Factory-tuned thresholds prevent accidental activation during cleaning or environmental vibration. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar capacitive touch interface applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Microchip AT42QT1011-MAHR | Single-button QTouch IC with identical 8-pin SOIC/QFN; uses different I²C address (0x4A) and lacks factory-programmed thresholds | Requires host-side calibration routine; less suitable for zero-firmware deployments | Select when existing firmware already supports AT42QT1011 register map and layout allows SOIC footprint |
| STMicroelectronics STMTS012QTR | 1-channel touch controller in 6-pin TSOP; supports only 3.3 V supply and offers no factory tuning - all parameters set via external resistor | Higher sensitivity variability across units; unsuitable for high-volume consumer assembly without binning | Select for cost-sensitive designs where 3.3 V only operation and manual tuning are acceptable |
Compared with AT42QT1011-MAHR and STMTS012QTR, the CPT112S-A01-GMR delivers plug-and-play reliability through factory-programmed thresholds and wider supply range, reducing qualification time and eliminating post-solder calibration steps in mass production.
Availability
CPT112S-A01-GMR is available at Aetrix Electronics and suitable for smart thermostat control, appliance touch panels, LED lighting dimmers, and commercial security keypads requiring stable component supply across multi-year production cycles.
Supply support for CPT112S-A01-GMR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Silicon Labs is a fabless semiconductor company specializing in secure, intelligent wireless and wired connectivity solutions for IoT, industrial, and consumer markets.
The CPT112S-A01-GMR belongs to Silicon Labs' Smart Interface Controller IC family, engineered specifically for ultra-low-power, production-ready capacitive touch interfaces in cost-sensitive HMI applications.
FAQ
What is the I²C address of the CPT112S-A01-GMR?
The CPT112S-A01-GMR uses a fixed 7-bit I²C slave address of 0x2A. This address is hard-coded in silicon and cannot be modified via pins or registers. Host systems must configure their I²C master to target 0x2A for communication. The CPT112S-A01-GMR does not support address selection resistors or alternate addressing modes.
Does the CPT112S-A01-GMR require external passive components for basic operation?
No, the CPT112S-A01-GMR requires no external passive components for fundamental capacitive sensing. Only VDD decoupling (100 nF ceramic) and I²C pull-ups (4.7 kΩ) are needed. The CPT112S-A01-GMR integrates its oscillator, PGA, ADC, and calibration logic - eliminating external RC networks, crystals, or trimming potentiometers.
Can the CPT112S-A01-GMR drive an LED or relay directly?
No, the CPT112S-A01-GMR has no GPIO or driver outputs capable of sourcing/sinking load current. Its INT pin is an open-drain interrupt signal only (max 20 µA sink). Any actuation - such as LED illumination or relay control - must be handled by an external MCU or driver circuit triggered by the CPT112S-A01-GMR's I²C status or INT assertion.
Is the CPT112S-A01-GMR qualified for automotive applications?
The CPT112S-A01-GMR is rated for −40°C to +85°C and meets CISPR-25 Class 5 emissions, but it is not AEC-Q200 qualified. It is intended for industrial and residential indoor use. For automotive cabin applications, designers should verify mechanical mounting, humidity sealing, and system-level EMC compliance separately - the CPT112S-A01-GMR itself carries no automotive qualification.
How is sensitivity calibrated on the CPT112S-A01-GMR?
Sensitivity is factory-programmed during wafer test and stored in one-time-programmable (OTP) memory. No runtime calibration is needed - the CPT112S-A01-GMR performs autonomous baseline tracking and threshold comparison using this pre-set configuration. Host firmware reads only final touch/no-touch status or raw 12-bit counts via I²C; no register writes affect core sensing behavior.
CPT112S-A01-GMR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Silicon Labs
- Package/Case:
- 20-UFQFN
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Not For New Designs
- Programmable:
- Not Verified
- Type:
- Buttons, Slider
- Proximity Detection:
- Yes
- Number of Inputs:
- Up to 12
- LED Driver Channels:
- -
- Interface:
- I2C
- Resolution:
- -
- Voltage - Supply:
- 1.8V ~ 3.6V
- Current - Supply:
- 3.1mA
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-QFN (3x3)
CPT112S-A01-GMR FAQ
1.How can I place an order for CPT112S-A01-GMR through Aetrix?
Please submit a Request for Quotation (RFQ) for CPT112S-A01-GMR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for CPT112S-A01-GMR reliable?
The price and inventory of CPT112S-A01-GMR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for CPT112S-A01-GMR is usually 5 days.
3.What payment methods are accepted for CPT112S-A01-GMR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for CPT112S-A01-GMR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for CPT112S-A01-GMR?
CPT112S-A01-GMR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your CPT112S-A01-GMR order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for CPT112S-A01-GMR?
For technical support, including CPT112S-A01-GMR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your CPT112S-A01-GMR requirements.
6.How does Aetrix verify that CPT112S-A01-GMR is sourced from the original manufacturer or authorized distributors?
All CPT112S-A01-GMR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that CPT112S-A01-GMR meets industry standards.
7.What is the process for return or replacement of CPT112S-A01-GMR?
All CPT112S-A01-GMR units undergo pre-shipment inspection (PSI). If there is an issue with CPT112S-A01-GMR, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The CPT112S-A01-GMR part is unused and in its original packaging.
Return procedure for CPT112S-A01-GMR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
CPT112S-A01-GMR Tags
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IQS228B00000000TSR
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MTCH101T-I/OT
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IQS323001CSR
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