BU21051FS-E2 Rohm Semiconductor, BU21051FS-E2 Datasheet - Page 3

• Manufacturer Part Number: BU21051FS-E2
• Description: IC CAP SENSOR SWITCH 8CH 16-SSOP
• Manufacturer: Rohm Semiconductor
• Type: Capacitive Switchr

Specifications of BU21051FS-E2

• Input Type: Logic
• Output Type: Logic
• Interface: Port
• Current - Supply: 500µA
• Mounting Type: Surface Mount
• Package / Case: 16-SSOP
• Supply Voltage: 5 V
• Number Of Channels: 2
• Dimensions: 6.6 mm L x 6.2 mm W x 1.5 mm H
• Output Voltage: 5.5 V
• Power Dissipation: 500 mW
• Temperature Range: - 55 C to + 125 C
• Termination Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: BU21051FS-E2TR

●Block Diagram, Pin configuration
●Sensor I/F CV Conversion Circuit:
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BU21051FS
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This part selects target sensor and converts its capacitance to a voltage signal. Specifically, alleight sensors are selected
one-by-one and their capacity is compared to a common referencecapacity. Each difference value is converted to a certain
voltage signal.
・AD Conversion
・Conversion Sequence Control
・Noise Filter
・Compare threshold
・Calibration
・Reset Generation
・Clock Generation
The voltage signal derived from CV conversion is further converted to digital value by this block.
This block controls the process of CV conversion and generates timing of selecting target sensors.
The GND level difference between appliance and human body will cause noises to the CV conversion
CV converted to sensor data On / Off compared with a threshold, the switch converts the signal.
When the capacitance change do not exceed the threshold for a certain period, this blockstarts-up calibration process.
This is internal reset circuit. Reset is initialized by external SDN signal.
Clock from internal RC oscillation circuit is used as system clock.
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Technical Note
2009.04 - Rev.B