EM6420V4LF40D+

Overview

The EM6420V4LF40D+ is an ultra low power capacitive touch sensor interface IC manufactured by EM Microelectronic. It supports scanning up to 16 capacitive sensors sequentially, with parameters configurable via host microcontroller or configuration inputs. The device offers user-selectable communication interfaces including 4-wire SPI, I2C, 4-bit parallel, and 8-bit direct output. It operates within a supply voltage range of 1.2 V to 2.0 V or 2.2 V to 3.6 V. Power consumption is specified at 8.0 µA @ 3.0 V in Low Power Mode and 2.0 µA @ 3.0 V in Ultra Low Power Mode for 16 sensors scanned at 8 Hz. Nominal sensor capacitance ranges from 3 to 31 pF, with scan frequencies adjustable from 1 Hz to 128 Hz.

Feature Summary

• Supports up to 16 analogue sensor inputs per device, scalable via parallel connection
• Provides multiple user-selectable communication interfaces: 4-wire SPI, I2C, 4-bit parallel, and 8-bit direct output
• Features configurable active edge IRQ output signals and an active high enable input
• Operates without requiring software development or tuning for basic functionality

Applications

• Mobile phones and cordless phones
• PDAs and keyboards
• White and brown goods appliances
• Toys
• Lighting sliders for dimming control

Procurement Notes

Verify the specific ordering suffix LF40D+ against the manufacturer's current datasheet to confirm package type and compliance status. Ensure the selected supply voltage range matches the required application constraints, as decoupling capacitor requirements vary between the low (1.2-2.0 V) and high (2.2-3.6 V) voltage configurations. Confirm availability of necessary external components such as decoupling capacitors and booster capacitors for the chosen operating mode.

Selection Notes

Select the EM6420 when an ultra-low power solution for capacitive touch sensing is required. Choose the appropriate supply voltage range based on system battery or mains power constraints. Consider the number of sensors needed; if more than 16 are required, plan for multiple devices in parallel. Evaluate the communication interface options (SPI, I2C, parallel, or direct output) to match the host microcontroller capabilities. Ensure the nominal sensor capacitance falls within the 3 to 31 pF range for optimal performance.

Part Context

The EM6420 is part of EM Microelectronic's portfolio of ultra-low power ASICs designed for touch screen interfaces. It integrates a CoolRISC core, RAM, ROM, and various timers to manage sensor scanning and communication. The device is available in naked die form or SMT packages like MLF32-36-40. It is designed for applications where tamper-proofing, clean designs, and hygiene are critical, offering a software-free touch function alternative to traditional buttons.

Replacement Considerations

Publicly confirmed substitute part numbers for the EM6420V4LF40D+ are not available in the provided documentation. Users should consult EM Microelectronic directly for potential alternatives or updated component recommendations.