Featured Products Easy to mount • Supports long wiring distances Capacitive Switch Controllers BU21072MUV/BU21078MUV/BU21077MUV/BU21079F Compatible with large appliances Cop Scan Supports long wiring distances y Durable • Stain-resistant − Can be used on thick and/or curved surfaces, increasing design flexibility Menu ＋ Class-Leading Noise Immunity (IEC61000-4-6 Compliant) ● High noise immunity ● No EMI countermeasures results in fewer parts required ROHM utilizes a proprietary high-sensitivity detection AFE for high noise immunity. As a result, ROHM’s capacitive switches were able to clear the difficult IEC61000-4-6 standard for noise testing. Simple Operation Small Mounting Area Low Power Consumption Reduced Standby Power Conventional ROHM ±3V ±10V ±10V GND noise immunity Overlay Thickness (mm) Compressor Noise Support for wiring distances over 1m ensure compatibility with large appliances Overlay Thickness (Acrylic Board) Conventional ROHM 10mm 15mm High noise immunity makes it possible to separate the IC from the electrodes across much greater distances than conventional products, providing greater design flexibility. Electrode Wiring Length Conventional 30 to 50cm Parasitic capacitance: 7.1pF 6 7 5cm 5cm High Sensitivity 10mm 1m Sensor Electrodes 15mm ROHM 1m+ ROHM survey ROHM survey 3 5 Electrode Size (mm 2) GND Unmatched wiring distance compatibility Operating Area 4 Noise countermeasure required Normally, in order to minimize the effects of noise from the AC line, compressor, or other source, noise suppression components are required. However, the BU2107x series features high noise immunity, eliminating the need for noise countermeasures, simplifying design while reducing costs significantly. Inoperable Area 3 Compressor Power Supply AC Plug High-speed sampling and analog circuitry 12 0 AC Noise ROHM survey Electrode Size vs. Overlay Thickness 6 Noise countermeasure required Touch Panel Compatible even with 15mm acrylic overlays 9 Ex: AC Noise Immunity Best-In-Class Sensitivity 15 Specialized internal circuitry reduces the number of parts required for EMI countermeasures. IC Capacitive Touch Controller IC Block Diagram VDD (Sensor) AVDD LDO28 VREF : 10ch BU21078 : 12ch BU21077,79 : 8ch LDO15 Supports direct connection to Li-ion batteries BU21072 DVDD POR OSC LOGIC Touch AEF_CNT A/D PROM No EMI countermeasure required TEST Electrode (PCB) AFE WRAM SDA SCL C/V Converter WDTR MPU HOST I/F SIN0-9 Sensor AFE LED0-5 DTG LEDDRV PWM_CNT INT VSS (LED) BU21072 : 6ch BU21078 : 8ch BU21077,79 : --- Application Examples Capacitive Touch Switches Capacitive Touchscreens High-speed sensing technology utilized for high noise immunity touch switch operation Our touchscreen controllers utilize an original mutual-type, single-layer multi-touch AFE* for high noise immunity *AFE (Analog Front End) Menu User Interface Control Technology (Cultivated through years of user interface development) Successive Approximation A/D Converter PC Interface Noise-cancelling technology through high S/N ratio High-accuracy high noise-cancelling technology based on over a decade of development experience High-sensitivity detection circuitry Resistive Touchscreens We offer a broad lineup compatible with resistive touchscreens of all types, including single, dual, automotive-grade, and systems not equipped with an MCU. Capacitive Switch Controller Lineup Part No. Supply Voltage (V) No. of Channels LED Drive CH LED PWM Control Matrix Control Interface Package BU21072MUV 3.0 to 3.6 10 6 ○ 4×4 I 2C VQFN024V4040 BU21078MUV 3.0 to 3.6 12 8 ○ 6×6 I 2C VQFN028V5050 BU21077MUV 3.0 to 5.5 8 - - 8ch (flexible combination) I 2C VQFN020V4040 BU21079F 3.0 to 5.5 8 - - 4×4 I 2C SOP16 The content specified in this document is correct as of October 1st, 2013. [O_024] Catalog No.56O6715E 10.2013 ROHM © PDF