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Capacitive Sensor Control IC Series
Capacitive Sensor Switch Control IC
BU21051FS
●Description BU21051FS are the capacitive sensor controller with 2ch respectively. The IC has the port interface and easy to replace the point of switch to this controller.
No.09048EBT05
●Features 1) Port output interface www.DataSheet4U.com 2) Few software control 3) 2ch GPIO outputs 4) 5V power supply voltage available 5) Integrated 10bit AD converter, clock and reset 6) Package SSOP-A16
●Applications It is possible to use it widely as a switch such as home electric appliance. ●Absolute Maximum Ratings (Ta=25℃) PARAMETER Applied voltage Input voltage Storage temperature range Power dissipation SYMBOL AVDD DVDD VAIN VDIN Tstg Pd RATING MIN -0.3 -0.3 -0.3 -0.3 -55 500 MAX 7.0 7.0 AVDD + 0.3 DVDD + 0.3 125 UNIT V V ℃ mW
Ambient temperature reduces a permission loss by 5mW per case more than 25 degrees Celsius, 1 degree Celsius
●Recommended Operating conditions PARAMETER Applied voltage Operating temperature range SYMBOL AVDD DVDD Topr RATING MIN 4.5 4.5 -40 TYP 5.0 5.0 25 MAX 5.5 5.5 85 UNIT V V ℃
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1/6
2009.04 - Rev.B
BU21051FS
●Electrical characteristics(Especially, Topr=25℃ and AVDD=DVDD=0 as long as it doesn't specify it.) RATING PARAMETER SYMBOL UNIT MIN TYP MAX DC characteristics Input“H”voltage Input“L”voltage Output“H”voltage Output“L”voltage Input leakage current Output leakage current Standby current VIHIO VILIO VOL IIZ IOZ IST IDD DVDD x 0.9 GND – 0.2 GND -1 -1 500 DVDD + 0.2 DVDD x 0.1 DVDD x 0.2 1 1 2 V V V μA μA μA uA
Technical Note
Condition
IOH = -2[mA]. Overshoot is excluded.
Shutdown (SDN=“L”)
●A/D Converter PARAMETER
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SYMBOL
RATING MIN GND 0.2 AVDD - 0.07 TYP 10 13 MAX AVDD 1.0 GND + 0.07 ±3 ±3
UNIT bit V MHz
Condition
Resolution Analog Input voltage Change clock frequency Change time Zero scale voltage Full scale voltage Differential non line accurate Integrate non line accurate DNL INL VAIN fadck ftim
μsec fadck = 1[MHz] V V LSB LSB
-
●CR Oscillator characteristic PARAMETER Oscillation Frequency SYMBOL fcr RATING MIN 0.9 TYP 1.6 MAX 2.5 UNIT MHz Condition
www.rohm.com © 2009 ROHM Co., Ltd. All rights reserved.
2/6
2009.04 - Rev.B
BU21051FS
●Block Diagram, Pin configuration
GAIN[1] GAIN[0] FILTER SDN PO1 PO2 TST AVDD THOFF
Technical Note
DVDD
SREF
SIN1
N.C.
SIN2
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●Sensor I/F CV Conversion Circuit: 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 The voltage signal derived from CV conversion is further converted to digital value by this block. ・Conversion Sequence Control This block controls the process of CV conversion and generates timing of selecting target sensors. ・Noise Filter The GND level dif.