ROHM BU21008MUV Technical data

Capacitive Sensor Control IC Series

Capacitive Sensor Switch Control IC

BU21008MUV

●Description

BU21008MUV are the capacitive sensor controller with 16 channels respectively. Half of sensor ports are available to use to LED driver with PWM function. PWM function can control light ambient. Also gesture function can recognize the short touch, long touch and finger motion.

●Features

1) Gesture function

2) LED driver with PWM available

3) 2 wire serial interface

4) Power supply = 2.5V to 3.3V, I/O power supply = 1.7V to 3.3V

5) Integrated 10bit AD converter, clock and reset

6) Package VQFN032V5050

●Applications

It is possible to use it widely as a switch such as a Mobile phone, Portable equipment, and Audiovisual apparatuses.

●Absolute Maximum Ratings (Ta=25℃)

PARAMETER SYMBOL

APPLIED VOLTAGE

INPUT VOLTAGE

STORAGE TEMPERATURE RANGE Tstg -55 125 ℃

POWER DISSIPATION Pd 304 mW

Ambient temperature reduces a permission loss by 3.1mW per case more than 25 degrees Celsius, 1 degree Celsius.

●Recommended Operating conditions

PARAMETER SYMBOL

APPLIED VOLTAGE

OPERATINGTEMPERATURE RANGE Topr -40 25 85 ℃

AVD D - 0 . 3 4. 5

DVDD -0.3 4.5

AIN -0.3 AVDD+0.3

V

VDIN -0.3 DVDD+0.3

AVDD 2.5 3.0 3.3 V

DVDD 1.7 3.0 3.3 V

MIN MAX

MIN TYP MAX

RATING

No.09048EBT04

UNIT

V

UNIT

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2009.04 - Rev.B

BU21008MUV

●Electrical characteristics(Especially, Topr=25℃ and AVDD=DVDD=0 as long as it doesn't specify it.)

PARAMETER SYMBOL

H INPUT VOLTAGE VIHIO

L INPUT VOLTAGE VILIO

Output "H" voltage VOHIO

VOLLED

Output "L" voltage

VOLTXD

VOLINT

Input leakage current IIZ

MIN TYP MAX

DVDDx0.8 - DVDD+0.3 V

DVSS-0.3

DVDD-0.7

AVSS

DVSS

-1

RATING

-

UNIT Condition

DVDDx0.2 V

DVDD V

0.5

DVDDx0.3

0.5

IOH=-2[mA]. Overshoot is excluded.

I

OL=8[mA]. Undershoot is excluded. LED output.

I

OL=3[mA]. Undershoot is

excluded. SDA/TXD

V

application.

OL=2[mA]. Undershoot is excluded. INT

I application.

1 μA

Technical Note

DVDD > 2[V]

DVDD ≦ 2[V]

Off leakage current IOZ

Standby current IST

Current of operation IDD

-1

-

- - 2 μA

- 300 - μA

1 μA

Shutdown (SDN＝”L”)

●A/D Converter

PARAMETER SYMBOL

MIN TYP MAX

RATING

UNIT Condition

Resolution - 10 - bit

Analog Input voltage VAIN AVSS - AVDD V change clock frequency fadck 0.2 - 2.0 MHz change time ftim - 77 - μsec fadck = 1[MHz] Zero scale voltage - - AVSS+0.07 V full scale voltage AVDD-0.07 - - V differential Non line accurate DNL - - ±3 LSB Integrate Non line accurate INL - - ±3 LSB

●CR Oscillator characteristic

PARAMETER SYMBOL

Frequency Oscillation

f

cr

MIN TYP MAX

0.4 0.8 2.0 MHz

RATING

UNIT Condition

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2009.04 - Rev.B

BU21008MUV

●Block Diagram, Pin configuration

AVDD DVDD

Technical Note

SDA/TXD

CLK_EXT

SCL

RXD

SDN

CS

TSTD

INT

SREF

SIN[15:0]

CS

SCL

SDA/TXD

RXD

SDN

CLK_EXT

Sensor I/F、 CV translate circuit

Reset

generation

Power on Reset

Conversion

sequence control

Clock

generation

CR oscill ation

AVSS

ADC

Data correction and

making to format

Data register

host I/F

DVSS

Power

management

INT

MODE[1:0]

DVSS

DVDD

AVDD

SREF

SIN[0]

SIN[1]/LED[0]

SIN[2]

SIN[3]/LED[1]

MODE[1]

MODE[0]

AVSS

TSTA

SIN[15]/LED[7]

SIN[4]

SIN[13]/LED[6]

SIN[12]

SIN[11]/LED[5]

SIN[10]

SIN[9]/LED[4]

SIN[8]

SIN[7]/LED[3]

SIN[6]

SIN[13]/LED[6]

SIN[4]

SIN[5]/LED[2]

・Sensor I/F CV translate circuit

This module selects between sensor inputs. The selection sequences between all 16 channels.

・AD Conversion

The voltage into which CV is converted is converted into a digital value. Conversion is 10 bit and full scale corresponds to AVDD.

・Conversion sequence control

Performs timing generation for the analogue circuitry and a sequencer circuit for selection of the sensor channel for conversion.

・Data correction and making to format

This module provides the digital intelligence of the sensor. The block includes, amongst other things, scaling, adding offsets and input filtering for de-bouncing. Registers are formatted to simplify usage by the software application. The block implements auto-calibration to manage drift in temperature, process variation, voltage variation and aging effects.

・Data register

This stores the results for the software application. Please refer to the register map for details.

・HOST I/F

2 wire serial interface.

・Power management

The power management block provides smart power control. When the sensors are not in use, the Controller automatically transitions into a low-power mode. When a sensor is touched, then the device automatically wakes up and enters its normal operation. The chip drives an INT pin for alerting the controller device in this case.

・Reset generation

The circuit is initialized by a either a soft reset command or by the external SDN pin.

・Clock generation

The device has an internal oscillator. Provision is also made if the application would like to make use of an external clock input.

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BU21008MUV

●Pin Description

Pin No.

10 SIN13/LED6 AIn/Out

11 SIN14 AIn

12 SIN15/LED7 AIn/Out

13 TSTA AIn

14 AVSS Ground

Name I/O Function Note

1 SIN4 AIn

2 SIN5/LED2 AIn/Out

3 SIN6 AIn

4 SIN7/LED3 AIn/Out

5 SIN8 AIn

6 SIN9/LED4 AIn/Out

7 SIN10 AIn

8 SIN11/LED5 AIn/Out

9 SIN12 AIn

sensor input4

sensor input 5 /PW Drive LEDcontrol output 2

sensor input6

sensor input 7 /PWM Drive LED control output 3

sensor input8

sensor input 9 /LED control output 4

sensor input10

sensor input 11 /LED control output 5

sensor input12

sensor input 13 /LED control output 6

sensor input14

sensor input 15 /LED control output 7

Test input for analog block

Analog ground -

- AVDD "Hi-Z" ④

sensor input , LED drive select

- AVDD "Hi-Z" ④

sensor input , LED drive select

- AVDD "Hi-Z" ④

sensor input , LED drive select

- AVDD "Hi-Z" ④

sensor input , LED drive select

- AVDD "Hi-Z" ④

sensor input , LED drive select

- AVDD "Hi-Z" ④

sensor input , LED drive select NC on the substrate is recommended.

Technical Note

Supply

Reference

AVDD "Hi-Z" ④

- - -

Reset

Level

I/O

Pad

15 MODE[0] In

16 MODE[1] In

17 TSTD In

18 CLK_EXT In

19 INT Out

20 SDA/TXD In/Out

21 SCL In

22 RXD In

23 CS In

24 SDN In

25 DVSS Ground

26 DVDD Power

27 AVDD Power

28 SREF AIn

Mode selection, input0

Mode selection, input1

Digital part test input Usually must be tide to "L"

External system clock input Usually tide to"L"

Output of interrupt

Communication data sending and receiving(2wires serial)

Communication synchronous clock input system clock input (2wires serial) Slave address selection (2wires serial mode)

Shutdown input

Digital part ground

Digital part Power supply

Analog part Power supply

Standard capacitor input

00 = 2wires serial, internal clock

"L" : Active mode "H" : Idle mode ※2

- DVDD

- DVDD - ②

"L" : Internal clock "H" : external clock "L" : 5Ah "H" : 5Bh "L" : Halt condition "H" : state of operation

- - - -

- - - ④

- AVDD "Hi-Z" ④

DVDD - ①

DVDD "L" ③

"Hi-Z"

-

DVDD - ②

DVDD - -

⑤ ②

29 SIN0 AIn

30 SIN1/LED0 AIn/Out

31 SIN2 AIn

32 SIN3/LED1 AIn/Out

*1 Initial State When internal organs power-on reset is effective Halt condition SDN=”L”

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sensor input 0

sensor input 1 /PWM Drive LEDcontrol output 0

sensor input 2

sensor input 3 /PWM Drive LEDcontrol output 1

4/16

- AVDD "Hi-Z" ④

sensor input , LED drive select

AVDD "Hi-Z" ④

sensor input , LED drive select

AVDD "Hi-Z" ④

2009.04 - Rev.B

BU21008MUV

●I/O Circuit

①CMOS INPUT ②CMOS Schmitt INPUT ③CMOS OUTPUT

Technical Note

CIN

④CMOS 3stute OUTPUT with

ANALOG-SW

PAD

⑤CMOS Schmitt INOUT

ASW

AIN

PADI

OE

CIN

OEN

PADCIN

PADI

I

PAD

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BU21008MUV

Technical Note

●HOST I/F ・2 wire serial, BUS (Pin configuration, MODE［1:0］＝00b)

Slave mode only Slave Address = 5Ah,5Bh selection possible. Normal (Normal mode. 100kHz Transfer rate) Fs mode (Fast mode. 400kHz Transfer rate) also. Not adapting sequential read / write.

【Data format】

t

HD;STA

t

SU;STO

SDA

t

SU;DAT

t

HD;DAT

SCL

Address

Read

ACK

Data Data

ACK

Parameter

Standard mode High Speed mode

MIN MAX MIN MAX fSCL : SCL Clock Freq 0 100 0 400 kHz tHD;STA : START condition hold time 4.0 - 0.6 - μsec tLOW : SCL “L” 4.7 - 1.3 - μsec tHIGH : SCL “H” 4.0 - 0.6 - μsec tHD;DAT : Data hold time 0.1 3.45 0.1 0.9 μsec tSU;DAT : Data setup time 0.25 - 0.1 - μsec tSU;STO : START condition hold time 4.0 - 0.6 - μsec tBUF : Free time of bus between STOP condition and START condition

4.7 - 1.3 - μsec

【PROTOCOL】

Unit

・Write Protocol

S SLAVE ADDRESS W

7bit = 5Ah or 5Bh 8bit 8bit

・Read Protocol

S SLAVE ADDRESS W

7bit = 5Ah or 5Bh 8bit 7bit = 5Ah or 5Bh 8bit

from Master to Slave S = START condition

from Slave to Master P = STOP condition

R = data direction READ (SDA HIGH)

W = data direction WRITE (SDA LOW)

A = acknowledge (SDA LOW)

N = not acknowledge (SDA HIGH)

A

REGISTER

ADDRESS

REGISTER

ADDRESS

A WRITE DATA AP

A S SLAVE ADDRESS R A READ DATA N P

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BU21008MUV

●Register map

Address Register name R/W Length Explanation

1*h SENS_DATA R 1byte / channel Sensor output data. One for each channel.

32h, 33h BTN R 2byte Button On/Off.

35h BTN_STATE R 1byte Button state data.

4*h OFFSET R 1byte / channel Offset correction data. One for each channel.

60h, 61h GES_VEL R 2byte Gesture duration.

62h GES_DIR R 1byte Gesture direction.

E0h FEAD_CTL W 1byte PWM control setting.

E1h FEAD_CLK W 1byte PWM clock setting.

E2h GES_CLR W 1byte Gesture clear control.

E3h GES_CTL W 1byte Gesture control.

E4h GES_CLK W 1byte Gesture clock setting.

E5h GES_TIMEOUT W 1byte Gesture time-out data setting.

Technical Note

E6h GES_TEST W 1byte Gesture test function.

EEh CALIB W 1byte Soft calibration execution.

EFh DONE W 1byte Setting done command.

F0h, F1h SENS_CH W 2byte Sensor channel enables.

F2h LED_CH W 1byte LED channel enables.

F3h, F4h IDLE_CH W 2byte Idle mode release control.

F5h LED_LINK W 1byte LED linkage to sensor input.

F6h TIMES W 1byte

F7h TH_ON2 W 1byte

F8h, F9h TH_ON2_CH W 2byte Per channel selection of whether to use TH_ON or TH_ON2.

FAh CMD W 1byte Simultaneous press and idle mode entry.

FBh GAIN_FILTER W 1byte Gain setting, filter function.

FCh TH_ON W 1byte

FDh TH_OFF W 1byte

FEh DLED W 1byte Register to allow simple writing to LEDs.

Defines the sampling interval and number of samples required to recognize a button press. A second threshold value in the detection of a button going from OFF state to ON state.

A threshold value in the detection of a button going from OFF state to ON state. A threshold value in the detection of a button going from ON state to OFF state.

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BU21008MUV

【1*h : Sensor Output Data】

Name: SENS_DATA Address: 1* h (one byte per sensor channel) Description: The sensor output that converts to 10bit. Scaling, offsets and filtering (when enabled) are applied.

The most significant 8 bits are presented to the software with this register.

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0

1*h SD_*[7] SD_*[6] SD_*[5] SD_*[4] SD_*[3] SD_*[2] SD_*[1] SD_*[0]

R/W R R R R R R R R

Initial val. 1 0 0 0 0 0 0 0

【32h / 33h : Button On/Off】

Name: BTN Address: 32h, 33h Description: This is the state of the sensor when considered as an ON/OFF button. Here 1 : On. 0 :Off.

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 32h CH7 CH6 CH5 CH4 CH3 CH2 CH1 CH0 33h CH15 CH14 CH13 CH12 CH11 CH10 CH9 CH8

R/W R R R R R R R R

Initial val. 0 0 0 0 0 0 0 0

【35h : Button State Data】

Name: BTN_STATE Address: 35h Description: This provides information about the press.

CH[3:0] : Effective channel ：

This indicates which button is dominant.

SIMUL : Button effective ：

This indicates that the effective channel corresponds to a valid button press according to the thresholds. 1 : On. 0 : Off.

CONTINU : A push and hold is effective ：

Indicates that the button was pressed and held for more than push/hold judgment time. 1 : On. 0 : Off.

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 35h CONTINU - - SIMUL CH[3] CH[2] CH[1] CH[0]

R/W R - - R R R R R

Initial val. 0 - - 0 0 0 0 0

【4* h : Offset Correction Data】

Name: OFFSET Address: 4* h (one byte per sensor channel) Description: This is the offset required to correct the sense data to half scale during the calibration procedure.

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0

4*h OFS_*[7] OFS_*[6] OFS_*[5] OFS_*[4] OFS_*[3] OFS_*[2] OFS_*[1] OFS_*[0]

R/W R R R R R R R R

Initial val. 1 0 0 0 0 0 0 0

【60h / 61h : Gesture Duration】

Name: GES_VEL Address: 60h, 61h Description: Indicates the duration of the gesture in number of internal clocks. The count is a clock set with 0xE4(GES_CLK). It is possible to count up to 0～4095 clocks. Gesture duration＝(gesture sampling interval) * VEL [sec]

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 60h VEL[7] VEL[6] VEL[5] VEL[4] VEL[3] VEL[2] VEL[1] VEL[0] 61h - - - - VEL[11] VEL[10] VEL[9] VEL[8]

R/W R R R R R R R R

Initial val. 0 0 0 0 0 0 0 0

Technical Note

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Technical Note

【62h : Gesture Direction Judgment】

Name: GES_DIR Address: 62h Description: Gesture direction judgment

DIR_A : gesture direction A

0xE3(GES_CTL) reference

DIR_B : gesture direction B

0xE3(GES_CTL) reference

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 62h - - - - - - DIR_B DIR_A

R/W - - - - - - R R

Initial val. - - - - - - 0 0

【E0h : PWM Control Setting】

Name: FEAD_CTRL Address: E0h Description: The following LEDs can be output as PWM-LED0, LED1, LED2, and LED3.

EN : enable

When the LED port is used as PWM, 1 is written. LED0 = EN[0], LED 1= EN[1], LED2 = EN[2], LED3 = EN[3].

MODE : mode

The mode of PWM is selected from four kinds.

mode MODE Fade in Fade out

1 0 0 None Fig 1 2 0 1 Fig 2 Fig 1 3 1 0 None Fig 3 4 1 1 Fig 4 Fig 3

16 14 12 10

8 6

Brightness

4 2 0

0246810121416

time

16 14

12 10

8 6

Brightness

4 2 0

0246810121416

time

Fig 1. Fig 2.

Brightness

16 14

12 10

8 6

4 2 0

0 2 4 6 8 10 12 14 16

16 14

12 10

8 6

Brightness

4

2 0

0 2 4 6 8 10 12 14 16

timetime

Fig 3. Fig 4.

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0

E0h - - MODE[1] MODE[0] EN[3] EN[2] EN[1] EN[0] R/W - - W W W W W W

Initial val. - - 0 0 1 1 1 1

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【E1h : PWM Clock Setting】

Name: FEAD_CLK Address: E1h Description: This register defines the divide ratio of the clock used for PWM. This also relates to the fade-in and fade-out time according to the following relationship.

Fead in/out =1 / ( ( Internal oscillation frequency) / ( 2 * 16 * 16 * 16 * ( F_DIV+1 ) * 16) ) [sec] For example with an internal clock of 1.1MHz possible range is 0.119～1.906 [sec]

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0

E1h - - - - F_DIV[3] F_DIV[2] F_DIV[1] F_DIV[0] R/W - - - - W W W W

Initial val. - - - - 0 1 1 1

【E2h : Gesture Clear】

Name: GES_CLR Address: E2h Description: This register when written to clears GES_VEL and GES_DIR. It is cleared by one, and it returns to 0 by the automatic operation.

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0

E2h CLR - - - - - - R/W W - - - - - - -

Initial val. 0 - - - - - - -

【E3h : Gesture Function Setting】

Name: GES_CTL Address: E3h Description: This register controls what key-press sequence is recognized as a gesture. Only 4 channels may be used-SIN0, SIN2, SIN4, and SIN6.

EN : enable

These are the enable bits. One is provided for each of the 4 sense inputs used for gesture. EN[0] is for SN0, EN[1] is for SN2, EN[2] is for SN4 and EN[3] is for SN6. 1 is to enable and 0 is for disable.

MODE : mode

0 : Requires all sensors to be present in the sequence before the gesture is recognized.(All detection mode) 1 : Allows one or more of the keys to be missed in the sequence.(Verbose mode)

The condition and the direction of detection that can be detected in each mode are as follows.

mode MODE Direction(GES_DIR) Detected

All detection 0

Verbose 1

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0

E3h - - - MODE EN[3] EN[2] EN[1] EN[0] R/W - - - W W W W W

Initial val. - - - 1 1 1 1 1

DIR_A 1)SIN0→SIN2→SIN4→SIN6 DIR_B 1)SIN6→SIN4→SIN2→SIN0

1)SIN0→SIN2→SIN4

2)SIN0→SIN2→ SIN6

DIR_A

DIR_B

3) SIN2→SIN4→SIN6

4)SIN0→ SIN4

5) SIN2→ SIN6

1)SIN6→SIN4→SIN2

2)SIN6→SIN4→ SIN0

3) SIN4→SIN2→SIN0

4)SIN6→ SIN2

5) SIN4→ SIN0

Technical Note

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BU21008MUV

【E4h : Gesture Clock Setting】

Name: GES_CLK Address: E4h Description: This register allows setting of the time base for the gesture detection. It sets a divide ratio of the clock used. The maximum judgment time and the sampling interval of the gesture can be set by changing this clock.

Gesture sampling interval = 1 / ( ( Internal oscillation frequency) / ( 2 * 16 * 16 ) * 1 [sec] … G_DIV = 0 1 / ( ( Internal oscillation frequency) / ( 2 * 16 * 16 ) * 2 [sec] … G_DIV = 1 1 / ( ( Internal oscillation frequency) / ( 2 * 16 * 16 ) * 4 [sec] … G_DIV = 2 1 / ( ( Internal oscillation frequency) / ( 2 * 16 * 16 ) * 8 [sec] … G_DIV = 3

Gesture maximum judgment time＝(Gesture sampling interval) * TO * 16 [sec]

For example with an internal clock of 1.1MHz

G_DIV Gesture sampling interval[msec] Gesture maximum judgment time[sec]

0 0.46 1.90 1 0.93 3.81 2 1.86 7.62 3 3.72 15.2

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0

E4h - - - - - - G_DIV[1] G_DIV[0] R/W - - - - - - W W

Initial val. - - - - - - 1 0

【E5h : Gesture Timeout Data Setting】

Name: GES_TIMEOUT Address: E5h Description: The maximum judgment time of the gesture is set. A key sequence which exceeds this time is not recognized.

Gesture Maximum Judgment Time＝(Gesture sampling interval) * TO * 16 [sec]

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0

E5h TO[7] TO[6] TO[5] TO[4] TO[3] TO[2] TO[1] TO[0] R/W W W W W W W W W

Initial val. 1 1 1 1 1 1 1 1

【E6h : Gesture Test Setting】

Name: GES_TIMEOUT Address: E6h Description: When this test bit is enabled (1) then the lower 4 bits of 0xFE(DLED) are used for the gesture recognition instead of the sensor inputs.

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 E6h - - - - - - - TEST R/W - - - - - - - W

Initial val. - - - - - - - 0

【EEh : Soft Calibration】

Name: CALIB Address: EEh Description: This forces a chip re-calibration when a 1 is written and returns to 0 afterward automatically. Please note that one should always re-calibrate after changing the gain adjustment value.

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 EEh - - - - - - - CALIB R/W - - - - - - - W

Initial val. - - - - - - - 0

Technical Note

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【EFh : Setting Done, Detect Start】

Name: DONE Address: EFh Description: This register should be written to following register updates.

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 EFh - - - - - - - DONE R/W - - - - - - - W

Initial val. - - - - - - - 0

【F0h / F1h : Sensor Channel Setting】

Name: SENS_CH Address: F0h / F1h Description: Individual enabling and disabling of sensor channels. 1：Effective 0：Not in use

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 F0h SIN7 SIN6 SIN5 SIN4 SIN3 SIN2 SIN1 SIN0 F1h SIN15 SIN14 SIN13 SIN12 SIN11 SIN10 SIN9 SIN8

R/W W W W W W W W W

Initial val. 0 0 0 0 0 0 0 0

【F2h : LED Channel Setting】

Name: LED_CH Address: F2h Description: Enables and disables the channels to be used as LED outputs. Valid for the 8 LED outputs.1：Effective 0：Not in use

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0

F2h LED7 LED6 LED5 LED4 LED3 LED2 LED1 LED0

R/W W W W W W W W W

Initial val. 0 0 0 0 0 0 0 0

【F3h / F4h : Idle Exit Condition】

Name: IDLE_CH Address: F3h / F4h Description: Defines which channels cause the device to wake up-i.e. go from idle mode to normal operation on a key press. Selection is made on a per channel basis. 1：Effective 0：Not used

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 F3h SIN7 SIN6 SIN5 SIN4 SIN3 SIN2 SIN1 SIN0 F4h SIN15 SIN14 SIN13 SIN12 SIN11 SIN10 SIN9 SIN8

R/W W W W W W W W W

Initial val. 1 1 1 1 1 1 1 1

【F5h : LED to Sensor Linkage】

Name: LED_LINK Address: F5h Description: Allows the LED outputs to be automatically linked to the input channels without need for any software control. 1 : It synchronizes with the button. 0 : It synchronizes with data (The register name: DLED) from host.

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 F5h LED7 LED6 LED5 LED4 LED3 LED2 LED1 LED0

R/W W W W W W W W W

Initial val. 1 1 1 1 1 1 1 1

Technical Note

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2009.04 - Rev.B

BU21008MUV

Technical Note

【F6h : Sampling Interval and Number of Samples Used for Button Press】

Name: TIMES Address: F6h Description: Defines the sampling interval and number of samples required to recognise as a button press.

CONT_T[3:0] : Push and hold judgment time ：

Governs how long it is before the chip decides it is push and hold. Given by the following equation: Push-Hold Time = system clockx2

19

xCONT_T (Example: system clock 1[MHz] time : About 520[msec]).

SAMP[3:0] : Sampling Interval ：

Given by the following equation: Sampling interval = system clockx2

13

xSAMP (Example: system clock 1[MHz] time : About 8.2[msec]).

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 F6h CONT_T[3] CONT_T[2] CONT_T[1] CONT_T[0] SAMP[3] SAMP[2] SAMP[1] SAMP[0]

R/W W W W W W W W W

Initial val. 0 0 0 0 0 0 0 0

【F7h : Button OFF→ON Threshold】

Name: TH_ON2 Address: F7h Description: A second threshold value for determining a button off→on judgment of sensor. The sensor output value of 8bit (register SENS_DATA) is compared with 128+ ON2 [6:0], and if it is larger, the button is determined active.

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 F7h - ON2[6] ON2[5] ON2[4] ON2[3] ON2[2] ON2[1] ON2[0]

R/W - W W W W W W W

Initial val. - 0 0 1 0 0 0 0

【F8h / F9h : Button OFF→ON Threshold Selection】

Name: TH_ON2_CH Address: F8h / F9h Description: This register is used to relate either threshold TH_ON or TH_ON2 to particular sensor channels for button press activity determination. 1 : TH_ON2 is applied 0 :TH_ON is applied

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 F8h SIN7 SIN6 SIN5 SIN4 SIN3 SIN2 SIN1 SIN0 F9h SIN15 SIN14 SIN13 SIN12 SIN11 SIN10 SIN9 SIN8

R/W W W W W W W W W

Initial val. 0 0 0 0 0 0 0 0

【FAh : Simultaneous Press and Idle Mode Entry】

Name: CMD Address: FAh Description:

SIMUL_SEL : Simultaneous push judgment element choice ：

In the case of simultaneous key press a decision must be made to select the dominant channel. The chip allows for two alternative methods. Either it can be based on whichever key press was first, or the priority can be based on the highest signal level.

1 : A level of a sensor gives priority 0 : Give priority to the channel pushed earliest

INTERMIT_EN : Intermittent and the drive are enable. ：

Whether intermittent is driven at the idol mode is selected.

1：Intermittent is driven. 0：Intermittent is not driven. Initial state：Intermittent is driven.

IDLE_T[3:0] : non-detect time-out setting ：

This sets the time the chip takes to go from normal mode to idle mode in a period key inactivity.

Duration = system clockx2

19

xIDLE_T (Example of system clock 1[MHz]time : About 520[msec])

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0

FAh SIMUL_SEL - - INTERMIT_EN IDLE_T[3] IDLE_T[2] IDLE_T[1] IDLE_T[0]

R/W W - - W W W W W

Initial val. 0 - - 1 0 1 1 1

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【FBh : Gain Setting, Filter Function】

Name: GAIN_FILTER Address: FBh Description: Gain adjustment and setting of noise filter function.

GAIN[2:0] : gain setting ：

It uses it for the gain adjustment in eight stages. Initial adjustment value：x1

GAIN[2:0] 000 001 010 011 100 101 110 111

Adjustment value x 1 x 4.22 x 8.4 x 16.5 x 23 x 46 x 69 x 92

FILTER_EN : Filter enable ：

Enables/disables setting of noise filter function 1 : enabled 0 : disabled Initial state : disabled

DELTA[3:0] : Filter follow count setting ：

The follow count to which the noise filter function is effective is set.

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0

FBh GAIN[2] GAIN [1] GAIN[0] FILTER_EN DELTA[3] DELTA[2] DELTA[1] DELTA[0] R/W W W W W W W W W

Initial val. 0 0 0 0 0 0 1 0

【FCh : Switch OFF -> ON Threshold】

Name: TH_ON Address: FCh Description: This register provides a threshold value for determining if a sensor has transitioned from OFF to ON. This is relative value from reference value (128d). So the absolute value of threshold is 128d+ON[6:0]. It makes a threshold value between TH_ON and TH_OFF. TH_ON must be bigger than TH_OFF (TH_ON >= TH_OFF) Maximum threshold is 256d and minimum value is 128d.

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0

FCh - ON[6] ON[5] ON[4] ON[3] ON[2] ON[1] ON[0] R/W - W W W W W W W

Initial val. - 0 0 1 0 0 0 0

【FDh : Switch ON -> OFF Threshold Value】

Name: TH_OFF Address: FDh Description: This register provides a threshold value for transitioning from ON to OFF. This is relative value from reference value (128d). So absolute value of threshold is 128d+OFF[6:0]. It makes a threshold value between TH_ON and TH_OFF. TH_OFF must be smaller than TH_ON (TH_OFF =< TH_ON) Maximum value is 256d and minimum value is 128d.

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0

FDh - OFF[6] OFF[5] OFF[4] OFF[3] OFF[2] OFF[1] OFF[0] R/W - W W W W W W W

Initial val. - 0 0 0 0 0 0 1

【FEh : LED Port Data】

Name: DLED Address: FEh Description: When LED is not linked with the sensor, it becomes a simple digital output that controls the LED. 1 : Light. 0 : Turned off.

Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0

FEh D7 D6 D5 D4 D3 D2 D1 D0 R/W W W W W W W W W

Initial val. 0 0 0 0 0 0 0 0

Technical Note

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●Operation mode

This IC has a normal mode, idle mode and a shutdown mode as states of operation.

【Normal mode】

This is the normal operation of the device. Output pin INT="L".

【Idle mode】

This is the mode when the normal mode times out due to inactivity on the keys. In this mode the control interface is still alive.

*Usually time-out is aimed at about 200msec or less. *Transition between normal and idle modes is automatic and without software control.

【Shutdown mode】

In this mode the device is completely stopped-and reset. This is achieved by making the terminal SDN L. All analog circuits and the logic circuits are stopped. The return from the shutdown mode returns by making the terminal SDN H.

*After shut-down all registers have their default values.

●Interface and system clock selection

I/F selection with MODE [1:0] pin. System clock selection by RXD.

【Using 2wires serial bus mode (MODE［1:0］＝00b)】

The 2wires serial bus is used for host I/F. RXD=0 in the system clock: Built-in oscillator is used. RXD=1 in the system clock: The clock input from CLK_EXT is used.

●Initialization procedure

A normal power on sequence is:

(1) Power on (2) Setup the registers (3) Write ‘1’ to 0xEF (done register)

●Power supply turning on procedure

You should always power on DVDD at the same time as AVDD or before AVDD.

Technical Note

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●Ordering part number

B U 2 1 0 0 8 M U V - E 2

Technical Note

Part No Part No Package

VQFN032V5050

Quantity

Direction of feed

1.0MAX

0.08 S

0.4± 0.1

0.75

5.0± 0.1

C0.2

5.0± 0.1

1PIN MARK

3.4± 0.1

81

32

25

9

16

24

17

0.25

0.5

+0.03

0.02

+0.05

-

0.04

0.02

-

3.4± 0.1

S

(0.22)

(Unit : mm)

Packaging and forming specification

MUV : VQFN032V5050

Embossed carrier tapeTape 2500pcs

E2

The direction is the 1pin of product is at the upper left when you hold

()

reel on the left hand and you pull out the tape on the right hand

Reel

1pin

Order quantity needs to be multiple of the minimum quantity.

∗

E2：Embossed tape and reel

Direction of feed

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Notes

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Examples of application circuits, circuit constants and any other information contained herein illustrate the standard usage and operations of the Products. The peripheral conditions must be taken into account when designing circuits for mass production.

Great care was taken in ensuring the accuracy of the information specied in this document. However, should you incur any damage arising from any inaccuracy or misprint of such information, ROHM shall bear no responsibility for such damage.

The technical information specied herein is intended only to show the typical functions of and examples of application circuits for the Products. ROHM does not grant you, explicitly or implicitly, any license to use or exercise intellectual property or other rights held by ROHM and other par ties. ROHM shall bear no responsibility whatsoever for any dispute arising from the use of such technical information.

Notice

The Products specied in this document are intended to be used with general-use electronic equipment or devices (such as audio visual equipment, ofce-automation equipment, communication devices, electronic appliances and amusement devices).

The Products specied in this document are not designed to be radiation tolerant.

While ROHM always makes ef forts to enhance the quality and reliability of its Products, a Product may fail or malfunction for a variety of reasons.

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ROHM BU21008MUV Technical data

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