Microchip Technology E115

Overview

E115 from Quantum Research Group Ltd. is an evaluation board for the QT115H QTouch™ capacitive touch sensor IC, featuring four independent touch keys with integrated backlighting LEDs and daisy-chain sync capability. It operates from a 9V alkaline battery or 8–12V external DC, uses socketed QT115H ICs and Cs capacitors for sensitivity tuning, and implements time-sequenced sensing to prevent cross-key interference.

For engineers reviewing the E115 datasheet, E115 pinout, E115 application, or E115 equivalent, this board supports rapid prototyping of capacitive touch interfaces with recalibration timeout (10 s), drift compensation, active-high outputs, and multi-board daisy-chaining via dedicated Chain-In/Chain-Out pads.

Technical Context

The E115 implements four QT115H ICs in time-sequenced operation, each driving one copper-pad key and its associated high-intensity LED. Sense electrodes are connected to ground between bursts to suppress crosstalk, and sync pulses propagate from U1 (master) to U4 (slave) to coordinate burst timing.

Each QT115H uses an external Cs capacitor (X7R ceramic or film) to set sensitivity; higher Cs values increase field penetration through plastic panels. The board includes onboard 78L05 regulation, low-voltage detection (~7.5 V), and jumper J3 for slave-mode configuration in multi-board chains.

Key Specifications

Availability

E115 is available at Aetrix Electronics and suitable for capacitive touch interface development, embedded human-machine interface (HMI) prototyping, and multi-key sensor system validation requiring stable component supply and repeatable evaluation hardware.

Supply support for E115 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

Quantum Research Group Ltd. is a UK-based semiconductor company specializing in capacitive touch sensing technology and QTouch™ IC design for robust, low-power human interface applications.

The E115 belongs to QRG's evaluation board product line, designed specifically to accelerate development and validation of QT115H-based touch interfaces in industrial controls, consumer appliances, and interactive panels.

FAQ

What is the primary function of the E115 evaluation board?

The E115 evaluation board is a dedicated platform for rapid testing and development of QT115H QTouch™ capacitive touch sensor ICs. It integrates four independently configurable touch keys with LED feedback, daisy-chain sync capability, and socketed components for sensitivity tuning - enabling immediate hands-on validation of touch performance without custom PCB design. The E115 provides direct access to all QT115H outputs and power interfaces for seamless integration into larger systems.

How does the E115 prevent false triggering between adjacent keys?

The E115 prevents false triggering by using time-sequenced sensing across its four QT115H ICs: only one key is actively sensed at any moment, while the others have their sense electrodes grounded. This eliminates capacitive coupling between keys. Additionally, the physical layout places diagonally opposite keys (e.g., Key 1 and Key 4) to minimize mutual capacitance. The E115's design ensures touch detection remains localized - touching near the edge of one key will not activate an adjacent key.

Can multiple E115 boards be connected together, and how is synchronization handled?

Yes, two or more E115 boards can be daisy-chained using the Chain-In and Chain-Out pads. In this configuration, the first board's U4 QT115H drives the second board's U1 via jumper J3 (set to slave mode). Sync pulses propagate sequentially, preserving time-division sensing integrity across the chain. The E115's documentation confirms this topology supports extended multi-board touch arrays while maintaining stable, non-interfering operation - critical for large-panel HMI development using the E115.

What power options does the E115 support, and what happens when battery voltage drops?

The E115 supports both a 9V alkaline battery and external 8–12V DC input via the Vbb pad on the output connector. An onboard 78L05 regulator supplies stable 5V to the QT115H ICs. A low-power LED illuminates when battery voltage falls below ~7.5V, signaling degraded performance - false or erratic key detection may occur below this threshold. The E115 requires battery removal when using external power to avoid hazardous overcharging and electrolyte leakage.

How is sensitivity adjusted on the E115, and what capacitor types are recommended?

Sensitivity on the E115 is adjusted per key by replacing the socketed Cs capacitors (C5–C8) near each QT115H IC. Higher Cs values increase sensing field penetration through plastic overlays. The E115 user guide explicitly specifies X7R ceramic or, preferably, plastic film capacitors - avoiding NP0/C0G for this application due to insufficient capacitance range. Each Cs capacitor is independently selectable, allowing fine-tuned response across the four keys of the E115.