Datasheet Resistive touch screen controller LSI series 4-wire Resistive Touch Screen Controller BU21026MUV General Description Key Specifications BU21026MUV is a low power 4-wire resistive touch Power supply voltage 1.65V to 3.60V screen controller. BU21026MUV measures coordinates Temperature range -30 to 85 and touch pressures with a 12bit A/D converter. Standby current 0.8uA (Max.) BU21026MUV has a digital filter for noise reduction. Operating current 120uA (Typ.) Coordinate resolution 12Bits Features W(Typ) x D(Typ) x H(Max) 4-wire resistive touch screen controller Package Single 1.65V to 3.60V supply. VQFN020V4040 4.00mm x 4.00mm x 1.00mm Low standby current ( 0.8uA max) 12bit SAR A/D converter 2-wire serial interface Command base interface Digital filter Touch pressure measurement Auto power down control Built-in clock oscillation circuit . Applications Equipment with a built in user interface of 4-wire resistive touch screen Portable device such as smart phone, tablet, PDA. Digital still camera, digital video camera, portable TV. PC / PC peripheral equipment such as laptop PC, touch screen monitor, printer. VDD Typical Application Circuit(s) 3 1.0 F 0.1F 2 2.2k 2.2k GND Master ( 2-wire serial interface ) Auxilary Input AUX SDA SDA 10 XP SCL SCL 0.1 F 10 YP INT GPIO 0.1 F BU21026 10 XN AD1 0.1 F Touch YN AD0 Screen 10 1 0.1 F 5 GND GND GND 4 1. 4-wire resistive touch screen 2. Pull-up resistor for 2-wire serial interface 3. Bypass capacitors 4. Diodes for ESD protection 5. Low pass filter for noise reduction Product structure : Silicon monolithic integrated circuit This product has no designed protection against radioactive rays . www.rohm.com TSZ02201-0L5L0FF00890-1-2 2016 ROHM Co., Ltd. All rights reserved. 1/19 TSZ22111 14 001 4.Aug.2016 Rev.001 GND VDDBU21026MUV Contents General Description ........................................................................................................................................................................ 1 Features.......................................................................................................................................................................................... 1 Applications .................................................................................................................................................................................... 1 Key Specifications ........................................................................................................................................................................... 1 Package .......................................................................................................................................................................................... 1 Typical Application Circuit(s) ........................................................................................................................................................... 1 Contents ......................................................................................................................................................................................... 2 Pin Configuration(s) ........................................................................................................................................................................ 3 Pin Description(s) ........................................................................................................................................................................... 3 Equivalent circuit ............................................................................................................................................................................. 3 Block Diagram(s) ............................................................................................................................................................................ 4 Description of Block(s) .................................................................................................................................................................... 4 Power on Reset ........................................................................................................................................................................... 4 A/D Converter ............................................................................................................................................................................. 4 Touch Screen I/F ......................................................................................................................................................................... 4 Touch Detection .......................................................................................................................................................................... 5 Digital Filter ................................................................................................................................................................................. 5 Absolute Maximum Ratings ............................................................................................................................................................ 6 (Note 1) Thermal Resistance ............................................................................................................................................................... 6 Recommended Operating Conditions ............................................................................................................................................. 6 Electrical Characteristics................................................................................................................................................................. 6 Power on Reset Timing Chart ......................................................................................................................................................... 7 2-wire Serial Interface Timing Chart ................................................................................................................................................ 7 2-wire Serial Interface ..................................................................................................................................................................... 8 Start Condition ............................................................................................................................................................................. 8 Stop Condition ............................................................................................................................................................................. 8 Data Transfer .............................................................................................................................................................................. 8 Acknowledge Bit (sending) .......................................................................................................................................................... 8 Acknowledge Bit (receiving) ........................................................................................................................................................ 8 Address Byte ............................................................................................................................................................................... 8 Command Byte ........................................................................................................................................................................... 9 Write Protocol ............................................................................................................................................................................ 11 Read Protocol ........................................................................................................................................................................... 12 Operation ...................................................................................................................................................................................... 13 Position Detection of Touch Screen........................................................................................................................................... 13 Touch Pressure Measurement .................................................................................................................................................. 13 A/D Conversion Time ................................................................................................................................................................ 14 A/D Sampling Time with 2-wire Serial Interface ........................................................................................................................ 14 Operational Notes ......................................................................................................................................................................... 15 Ordering Information ..................................................................................................................................................................... 17 Marking Diagrams ......................................................................................................................................................................... 17 Physical Dimension, Tape and Reel Information ........................................................................................................................... 18 Revision History ............................................................................................................................................................................ 19 www.rohm.com TSZ02201-0L5L0FF00890-1-2 2016 ROHM Co., Ltd. All rights reserved. 2/19 TSZ22111 15 001 4.Aug.2016 Rev.001