Rohm BU21023MUV Resistive type touch screen controller ic Datasheet

Touch Screen Controller ICs
Resistive Type
Touch Screen Controller ICs
BU21023GUL, BU21023MUV, BU21024FV-M
No.11105EAT01
●Description
Unlike most resistive touch screen controllers, the BU21023/ BU21024 4-wire resistive touch screen controllers enable
dual-touch detection and gesture recognition. These intelligent controllers expose a set of registers to a host processor and
are software configurable. The controllers can detect single point coordinates, dual coordinates, pinch, spread, rotate left
and rotate right gestures, enabling pan and zoom operations in applications that previously had to rely exclusively on
capacitive touch technology. Resistive touch does not require custom panel development which reduces development cost
and results in faster time to market across a family of products.
●Features
1) Enables single touch, dual touch & gesture recognition using standard 4-wire resistive touch panels
2) Adjustable touch detection threshold allows fine tuning of pressure sensitivity for an application
3) Enables measurement of single point touch pressure
2
4) SPI and I C like interface for interfacing to host processor
5) Programmable interrupt polarity
6) 10-bit ADC provides sufficient resolution for finger or stylus inputs
7) Firmware for internal CPU may be downloaded from Host processor or from an EEPROM
8) Includes filtering options to eliminate false coordinates
9) Built in support for intelligent calibration
10) Easy to swap X & Y coordinates or adapt to different touch panel connections
11) Single 3V power supply
12) Available in a range of small package sizes and temperature ranges
13) Ideally suited for large volume automotive, consumer and industrial applications
●Application
・Products with a LCD that can benefit from pan and zoom operations.
・Smart phones, Digital Cameras, Video Cameras, GPS Receivers, Printers,
Copiers, automotive navigation panels, touch kiosks
・Tablet PCs , Notebook computers, LCD displays (with USB interface)
●Line up matrix
Parameter
BU21023GUL
BU21023MUV
BU21024FV-M
4-wire resistive
touch screen
4-wire resistive
touch screen
4-wire resistive
touch screens
Maximum detection point
2
2
2
Integrated Filter process
Yes
Yes
Yes
Gesture Detection
Yes
Yes
Yes
Supplied Voltage Range(V)
2.7 － 3.6
2.7 － 3.6
2.7 － 3.6
Temperature Range(℃)
-20 － 85
-20 － 85
-40 － 85
Host I/F
4-wire SPI
2-wire serial
4-wire SPI
2-wire serial
4-wire SPI
2-wire serial
PKG
VCSP50L2
VQFN028V5050
SSOP-B28
Screen
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© 2011 ROHM Co., Ltd. All rights reserved.
1/17
2011.08 - Rev.A
Technical Note
BU21023GUL,BU21023MUV,BU21024FV-M
●Absolute Maximum Ratings
Parameter
Symbol
Ratings
Unit
Power supply voltage
VDD
-0.3 ～ 4.5
V
Input voltage
VIN
VSS-0.3 ～ VDD+0.3
V
BU21023GUL
Power dissipation
BU21023MUV
Pd
BU21024FV-M
Storage temperature range
*1
mW
704 *2
mW
850 *3
mW
-50 ～ 125
℃
830
Tstg
Condition
*1 Derate by 7.04 mW /℃ centigrade when ambient temperature exceeds 25℃. Measured using Epoxy-Glass PCB measuring 50x58x1.75 mm
*2 Derate by 8.30mW /℃ centigrade when ambient temperature exceeds 25℃. Measured using Epoxy-Glass PCB measuring 50x58x1.75mm
*3 Derate by 8.50mW /℃ centigrade when ambient temperature exceeds 25℃. Measured using Epoxy-Glass PCB measuring 50x58x1.75mm
●Recommended Operating Conditions
Parameter
Power supply voltage
Digital core power supply
Operating
temperature range
BU21023GUL
BU21023MUV
Symbol
Ratings
Unit
Min.
Typ.
Max.
VDD
2.70
3.00
3.60
V
DVDD
1.62
1.80
1.98
V
-20
25
85
℃
-40
25
85
℃
Condition
DVDD_EXT=H
Topr
BU21024FV-M
Note: The BU21023/BU21024 controllers can be operated with a single 3V VDD supply.
It is also possible to supply 1.8V DVDD from an external source if the DVDD_EXT pin is connected to logic high.
●Electrical Characteristics (Ta=25℃, VDD=3.00V)
Parameter
Symbol
Limits
Min.
Typ.
Max.
Unit
Condition
Low-level input voltage
VIL
VSS-0.5
-
0.2×VDD
V
High-level input voltage
VIH
0.8×VDD
-
VDD+0.5
V
Low-level output voltage
VOL
-
-
VSS+0.4
V
High-level output voltage
VOH
VDD-0.4
-
-
V
Standby current
Ist
-
-
1
µA
RSTB=L
Sleep current1
Icc1
-
60
100
µA
DVDD_EXT=L
Sleep current2
Icc2
-
10
20
µA
DVDD_EXT=H
Operating current
Idd
-
4
6
mA
No load
Freq
18
20
22
MHz
Oscillation frequency
Resolution
Ad
1024×1024
Bit
Differential non-linearity error
DNL
-3.0
-
+3.0
LSB
Integral non-linearity error
INL
-3.0
-
+3.0
LSB
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© 2011 ROHM Co., Ltd. All rights reserved.
2/17
2011.08 - Rev.A
Technical Note
BU21023GUL,BU21023MUV,BU21024FV-M
●HOST-I/F mode (4-wire SPI)
(SCK=SCL_SCK, SI=SDA_SI, CSB=SEL_CSB, SO=SO)
Condition : VDD = 3.0V Ta=25℃
Parameter
Symbol
Limits
Min.
Typ.
Max.
Unit
CSB setup time
t1
30
-
-
ns
SCK "H" level period
t2
30
-
-
ns
SCK "L" level period
t3
30
-
-
ns
SI setup time
t4
20
-
-
ns
SI holding time
t5
20
-
-
ns
CSB holding time
t6
20
-
-
ns
CSB "H" level time
t7
50
-
-
ns
Data output delay time
t8
-
-
15
ns
SCK frequency
t9
-
-
15
MHz
Condition
Note: SPI interface is selected by tying IFSEL pin to logic low. IFSEL= logic high selects the 2-wire interface
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© 2011 ROHM Co., Ltd. All rights reserved.
3/17
2011.08 - Rev.A
Technical Note
BU21023GUL,BU21023MUV,BU21024FV-M
●HOST-I/F mode (2-wire serial)
(SCL=SCL_SCK, SDA=SDA_SI)
2
The 2-wire serial mode presents an I C like interface for all practical purposes, but it is not a complete implementation
2
2
conforming to the I C specification. The BU21023MUV/ BU21023GUL / BU21024FV-M devices can co-exist with other I C
devices on the same bus. The slave address for 2-wire serial communication is 5Ch or 5Dh. This is determined by the
SEL_CSB pin.
SEL_CSB = “L”
SEL_CSB = “H”
: Slave address = 5Ch
: Slave address = 5Dh
tSU;STO
tHD;STA
SDA
tSU;DAT
tHD;DAT
SCL
SCL
Address
Data
ACK
Parameter
Symbol
ACK
Data
ACK
Limits
Unit
Min.
Typ.
Max.
fSCL
0
-
400
kHz
tHD:STA
0.6
-
-
µs
SCL “L”
tLOW
1.3
-
-
µs
SCL “H”
tHIGH
0.6
-
-
µs
Data hold time
tHD:DAT
0.1
-
-
µs
Data setup time
tSU:DAT
0.1
-
-
µs
STOP condition setup time
tSU:STO
0.6
-
-
µs
SCL clock frequency
START condition hold time
Condition
・Write protocol
S
SLAVE ADDRESS
W
A
7bit = 5Ch or 5Dh
・Read protocol
S
SLAVE ADDRESS
7bit = 5Ch or 5Dh
REGISTER
ADDRESS
8bit
REGISTER
ADDRESS
8bit
from master to slave
from slave to master
W
A
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© 2011 ROHM Co., Ltd. All rights reserved.
A
WRITE DATA
A
P
S SLAVE ADDRESS R
A
8bit
A
S
P
R
W
A
N
4/17
READ DATA
N
7bit = 5Ch or 5Dh
8bit
= START condition
= STOP condition
= data direction READ (SDA HIGH)
= data direction WRITE (SDA LOW)
= acknowledge (SDA LOW)
= not acknowledge (SDA HIGH)
2011.08 - Rev.A
P
Technical Note
BU21023GUL,BU21023MUV,BU21024FV-M
●EEPROM I/F
BU21023/BU21024 controllers include an EEPROM interface for firmware download.
Device address of EEPROM is set via register 0x51(EEPROM_ADDR).
Timing chart
tSU;STO
tHD;STA
SDA
tSU;DAT
tHD;DAT
SCL
Address
Parameter
Read
/Write
Data
ACK
Limits
Symbol
Unit
Min.
Typ.
Max.
fSCL
270
310
350
kHz
tHD:STA
0.7
-
0.9
µs
SCL ”L” width
tLOW
1.4
-
1.8
µs
SCL ”H” width
tHIGH
1.4
-
1.8
µs
Data hold time
tHD:DAT
0.7
-
0.9
µs
Data setup time
tSU:DAT
0.7
-
0.9
µs
STOP setup time
tSU:STO
0.7
-
0.9
µs
SCL clock frequency
START hold time
ACK
Data
ACK
Condition
Protocol
*IC does not support the write command.
*IC supports the following read command.
Start
S
SLAVE
ADDRESS
WA
1st WORD
ADDRESS
A
2nd WORD
ADDRESS
A
DATA(0)
A
DATA(n-3)
A
DATA(n-2)
A
DATA(n-1)
A
DATA(n)
N
P
Stop
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© 2011 ROHM Co., Ltd. All rights reserved.
5/17
2011.08 - Rev.A
Technical Note
BU21023GUL,BU21023MUV,BU21024FV-M
●Background Information
A resistive touch panel is made up of a multilayer sandwich of resistive films and protective coatings all sitting on top of an
LCD display. Resistive touch panels work by direct contact of a stylus or a finger flexing a pair of resistive films, hence any
blunt pointing instrument or a gloved finger may be used.
Touch panel resolution
The resolution of a touch panel is typically measured in dots per inch (dpi) and is a function of the physical size of the touch
panel and the ADC used in the conversion circuitry. For example, a 3”x5” panel used with the BU21023/BU21024 devices
can provide a theoretical resolution of 1024 /5 = 204 dpi. In the case of resistive touch panels, the direct contact nature of its
operation and finger thickness often impose an upper limit on the effective system resolution that may be achieved,
regardless of the resolution of the ADC itself.
●Functional Description
The BU21023/BU21024 devices connect to a standard 4-wire resistive touch screen on one side and to a host processor on
the other side. The BU21024 includes four additional sense terminals allowing it to be used with either 4-wire or 8-wire
resistive touch screens. The BU21023/BU21024 include the analog and digital circuitry to process and provide dual touch
coordinate data and pinch, spread, rotate-right and rotate-left gesture information to the host CPU.
The BU21023/BU21024 devices include an internal CPU and provide a high degree of programmability by exposing a set of
2
registers that can be accessed by a host CPU through SPI or I C like serial interfaces. The IFSEL pin determines whether
2
SPI or I C like interface is selected, The BU21023/BU21024 devices include an INT pin whose polarity can be programmed
via registers. When an interrupt occurs, for example, due to touch detection, the host processor is required to read an
interrupt status register to determine the cause of the interrupt and take appropriate action.
The program memory of the internal CPU may be initialized via the host interface or via an external EEPROM. This is
selected by a register setting.
The BU21023/BU21024 devices support two sensing modes; continuous and interval sensing modes, that are register
selectable. In the continuous sensing mode, the embedded CPU reads Z, X & Y coordinates continuously when a touch is
detected. The interval sensing mode allows a delay to be inserted between each cycle. The continuous sensing mode is
used more often though the interval sensing mode minimizes power consumption. The continuous sensing mode typically
completes a sampling cycle consisting of Z, X & Y measurements in approximately 2.3 mS.
The BU21023/BU21024 devices enable optimization of touch detection threshold for a given panel. They also include
several sophisticated calibration algorithms.
This document includes a description of the registers followed by flow charts that describe specific steps that a host
processor must follow. Often, a flow chart requires other flow charts to explain the steps in finer detail.
The document also includes information on touch screen parameters that one should to look for while selecting resistive
touch panels for multi-touch.
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© 2011 ROHM Co., Ltd. All rights reserved.
6/17
2011.08 - Rev.A
Technical Note
BU21023GUL,BU21023MUV,BU21024FV-M
●Block Diagram / Description of each block
【BU21023GUL / BU21023MUV】
Work
Memory
XP
XN
YP
ADC
(10bit)
Panel
I/F
CPU
(8bit)
YN
EEPROM
I/F
ECL
EDA
Program
Memory
Filter
SEL_CSB
CLK_EXT
Clock
Generator
OSC
Register
SCL_SCK
Host
I/F
SDA_SI
SO
INT
Regulator
T4
T3
T2
T1
RSTB
VSS
VDD
DVDD_EXT
AVDD
DVDD
PVDD
IFSEL
Screen I/F
4-wire resistive touch screen interface
ADC
10bit A/D converter
OSC
Internal 20MHz oscillator block with optional external clock input
Regulator
Internal regulator provides 1.8V DVDD supply. DVDD can also be supplied from an
external source if DVDD_EXT pin is tied high.
Clock Generator
System clock and timing generation (10MHz CPU clock)
CPU Core
For dual touch processing, programmability and host interface
Work memory
Data memory for CPU
Program Memory
EEPROM I/F
Host I/F
Program memory for CPU. Code can be downloaded by host processor or from an
external EEPROM
To connect to external EEPROM if downloading program memory from EEPROM. Use
of external EEPROM is optional.
4-wire SPI or 2-wire I2C like interface provides access to registers
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© 2011 ROHM Co., Ltd. All rights reserved.
7/17
2011.08 - Rev.A
Technical Note
BU21023GUL,BU21023MUV,BU21024FV-M
【BU21024FV-M】
Work
memory
XP
XN
EEPROM
I/F
ECL
EDA
YP
YN
XPM
ADC
(10bit)
Panel
I/F
CPU
(8bit)
XNM
Program
memory
Filter
YPM
YNM
SEL_CSB
Clock
generator
Osc
CLK_EXT
register
SCL_SCK
Host
I/F
SDA_SI
SO
INT
Regulator
T4
T3
T2
T1
RSTB
VSS
VDD
DVDD
DVDD_EXT
AVDD
PVDD
IFSEL
Screen I/F
4-wire or 8-wire resistive touch screen interface
ADC
10bit A/D converter
OSC
Internal 20MHz oscillator block with optional external clock input
Regulator
Internal regulator provides 1.8V DVDD supply. DVDD can also be supplied from an
external source if DVDD_EXT pin is tied high.
Clock Generator
System clock and timing generation (10MHz CPU clock)
CPU Core
For dual touch processing, programmability and host interface
Work memory
Data memory for CPU
Program Memory
EEPROM I/F
Host I/F
Program memory for CPU. Code can be downloaded by host processor or from an
external EEPROM
To connect to external EEPROM if downloading program memory from EEPROM. Use
of external EEPROM is optional.
4-wire SPI or 2-wire I2C like interface provides access to registers
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© 2011 ROHM Co., Ltd. All rights reserved.
8/17
2011.08 - Rev.A
Technical Note
BU21023GUL,BU21023MUV,BU21024FV-M
●Pin Description
【BU21023GUL】
No.
Pin name
1.
2.
3.
4.
5.
6.
7.
8.
I/O
Function
Fig.
D1
YN
I/O
Panel interface
E
C1
XN
I/O
Panel interface
E
C2
YP
I/O
Panel interface
E
B1
XP
I/O
Panel interface
E
A1
T4
I/O
Test pin
E
A2
PVDD
O
Regulator output (for supply panel voltage)
-
B3
AVDD
O
-
A3
DVDD
I/O
B4
DVDD_EXT
I
Regulator output (for supply analog block)
Regulator output (for supply digital block) or supply digital voltage
(DVDD_EXT="H")
Digital voltage enable (H=Hi-z , L=DVDD Enable)
A4
VDD
-
Supply voltage
-
A5
VSS
-
Ground
-
C3
RSTB
I
H/W reset
E
E
B5
CLK_EXT
I
Supply external clock for debug
A
C4
T1
I
Test pin
A
C5
T2
I
Test pin
A
D4
T3
I
Test pin
A
D5
IFSEL
I
Intereface select pin (L=SPI, H=2wire serial)
A
D3
SO
O
SPI
E5
INT
O
Interrupt output
D2
SEL_CSB
I
SPI
Chip select
2wire
Slave address select
C
E4
SDA_SI
I/O
SPI
Serial data input
2wire
Serial data in-out
C
E3
SCL_SCK
I
SPI
Serial clock input
2wire
Serial clock input
C
E2
EDA
I/O
EEPROM SDA
C
E1
ECL
O
EEPROM SCL
C
Serila data output
2wire
-
F
C
Please use 1.0uF capacitors between AVDD and DVDD to GND, and leave PVDD terminal open.
If DVDD_EXT=”H “, the DVDD pin can be connected to an external 1.8V power source.
Please pull up the ECL, EDA, and INT pins using 10k ohm resistors as shown in the application diagram at the end of this document.
ECL and EDA pins may be directly connected to GND if an external EEPROM is not being used. Please connect a 0.1uF capacitor between T4 and GND.
T1, T2 & T3 pins should be connected to GND.
When using the 2 wire serial interface, please pull up the SCL_SCK, SDA_SI pins via 10k ohms and leave SO unconnected.
Please note that the values of resistors and capacitors mentioned here are only recommended values.
RSTB should be held low until supply voltage VDD has ramped up and has reached a stable level.
The polarity of INT pin is programmable via register 0x30
Connect CLK_EXT to GND for normal use
T4
PVDD
DVDD
VDD
VSS
A
ECL
EDA
SCL_SCK
SDA_SI
INT
YN
SEL_CSB
SO
T3
IFSEL
XN
YP
RSTB
T1
T2
AVDD
DVDD_EXT
CLK_EXT
E
XP
AVDD
DVDD_EXT
CLK_EXT
B
D
XN
YP
RSTB
T1
T2
C
C
YN
SEL_CSB
SO
T3
IFSEL
XP
D
B
ECL
EDA
SCL_SCK
SDA_SI
INT
E
T4
PVDD
DVDD
VDD
VSS
1
2
3
4
5
A
1
2
3
4
5
TOP VIEW (BALL SIDE DOWN)
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© 2011 ROHM Co., Ltd. All rights reserved.
BOTTOM VIEW (BALL SIDE UP)
9/17
2011.08 - Rev.A
Technical Note
BU21023GUL,BU21023MUV,BU21024FV-M
【BU21023MUV】
No.
Pin name
fig
-
-
-
2
NC
-
-
-
3
NC
-
4
YN
I/O
5
XN
6
YP
7
XP
I/O
8
T4
9
PVDD
10
-
-
Panel interface
E
I/O
Panel interface
E
I/O
Panel interface
E
Panel interface
E
I/O
Test pin
E
O
Regulator output (for supply panel voltage)
-
AVDD
O
-
11
DVDD
I/O
12
DVDD_EXT
I
Regulator output (for supply analog block)
Regulator output (for supply digital block) or supply digital voltage
(DVDD_EXT="H")
Digital voltage enable (H=Hi-Z , L=DVDD enable)
E
13
VDD
-
Supply voltage
-
14
VSS
-
Ground
-
15
RSTB
I
H/W reset
E
16
CLK_EXT
I
Supply external clock for debug
A
17
T1
I
Test pin
A
18
T2
I
Test pin
A
19
T3
I
Test pin
A
20
IFSEL
I
Intereface select pin (L=SPI, H=2wire serial)
21
SO
O
22
INT
O
23
SEL_CSB
I
SPI
Chip select
2wire
Slave address select
C
24
SDA_SI
I/O
SPI
Serial data input
2wire
Serial data in-out
C
25
SCL_SCK
I
SPI
Serial clock input
2wire
Serial clock input
26
EDA
I/O
EEPROM SDA
27
ECL
O
EEPROM SCL
28
NC
-
SPI
Serila data output
-
A
2wire
-
F
Interrupt output
C
C
C
C
-
-
XN
XP
7
YN
4
YP
NC
3
6
NC
2
5
NC
T1
17
1
T2
18
RSTB
T3
19
15
IFSEL
20
16 CLK_EXT
SO
Please use 1.0uF capacitors between AVDD and DVDD to GND, and leave PVDD terminal open.
If DVDD_EXT=”H “, the DVDD pin can be connected to an external 1.8V power source.
Please pull up the ECL, EDA, and INT pins using 10k ohm resistors as shown in the application diagram at the end of this document.
ECL and EDA pins may be directly connected to GND if an external EEPROM is not being used. Please connect a 0.1uF capacitor between
T4 and GND. T1, T2 & T3 pins should be connected to GND.
When using the 2 wire serial interface, please pull up the SCL_SCK, SDA_SI pins via 10k ohms and leave SO unconnected.
Please note that the values of resistors and capacitors mentioned here are only recommended values.
RSTB should be held low until supply voltage VDD has ramped up and has reached a stable level.
The polarity of INT pin is programmable via register 0x30
Connect CLK_EXT to GND for normal use
INT
22
14
VSS
NC
28
8
T4
SEL_CSB
23
13
VDD
ECL
27
9
PVDD
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© 2011 ROHM Co., Ltd. All rights reserved.
15
NC
TOP VIEW (LEAD SIDE DOWN)
RSTB
VSS
17
14
16
22
T1
INT
CLK_EXT
VDD
T4
18
13
8
T2
23
28
19
SEL_CSB
NC
20
DVDD_EXT
T3
12
IFSEL
24
21
SDA_SI
PVDD
SO
AVDD
9
7
10
27
6
26
ECL
XP
EDA
YP
DVDD
5
AVDD
11
4
10
25
XN
26
SCL_SCK
YN
EDA
DVDD
3
DVDD_EXT
11
2
12
25
NC
24
NC
SDA_SI
SCL_SCK
1
4.
5.
6.
7.
8.
Function
NC
21
1.
2.
3.
I/O
1
BOTTOM VIEW (LEAD SIDE UP)
10/17
2011.08 - Rev.A
Technical Note
BU21023GUL,BU21023MUV,BU21024FV-M
【BU21024FV-M】
No.
Pin name
fig
I/O
EEPROM SDA
C
2
ECL
O
EEPROM SCL
C
3
YNM
I/O
Panel interface (Test input)
E
4
XNM
I/O
Panel interface (Test input)
E
5
YPM
I/O
Panel interface (Test input)
E
6
XPM
I/O
Panel interface (Test input)
E
7
YN
I/O
Panel interface
E
8
XN
I/O
Panel interface
E
9
YP
I/O
Panel interface
E
10
XP
I/O
Panel interface
E
11
T4
I/O
Test pin
E
12
PVDD
O
Regulator output (for supply panel voltage)
-
13
AVDD
O
-
14
DVDD
I/O
15
DVDD_EXT
I
Regulator output (for supply analog block)
Regulator output (for supply digital block) or supply digital voltage
(DVDD_EXT="H")
Digital voltage enable (H=Hi-Z , L=DVDD enable)
16
VDD
-
Supply voltage
-
17
VSS
-
Ground
-
18
RSTB
I
H/W reset
E
19
CLK_EXT
I
Supply external clock for debug
A
20
T1
I
Test pin
A
21
T2
I
Test pin
A
22
T3
I
Test pin
A
23
IFSEL
I
Intereface select pin (L=SPI, H=2wire serial)
A
SPI
Serila data output
2wire
-
E
24
SO
O
25
INT
O
26
SEL_CSB
I
SPI
Chip select
2wire
Slave address select
C
27
SDA_SI
I/O
SPI
Serial data input
2wire
Serial data in-out
C
SCL_SCK
I
SPI
Serial clock input
2wire
Serial clock input
C
Interrupt output
F
C
DVDD_EXT
TOP VIEW
15
14
DVDD
VDD
16
13
AVDD
VSS
17
12
PVDD
RSTB
18
11
T4
CLK_EXT
19
10
XP
T1
20
9
YP
T2
21
8
XN
T3
22
7
YN
XPM
IFSEL
6
YPM
23
5
XNM
SO
25
4
YNM
INT
26
3
24
27
2
ECL
SEL_CSB
28
1
EDA
SDA_SI
Please use 1.0uF capacitors between AVDD and DVDD to GND, and leave PVDD terminal open.
If DVDD_EXT=”H “, the DVDD pin can be connected to an external 1.8V power source.
Please pull up the ECL, EDA, and INT pins using 10k ohm resistors as shown in the application diagram at the end of this document.
ECL and EDA pins may be directly connected to GND if an external EEPROM is not being used. Please connect a 0.1uF capacitor between
T4 and GND. T1, T2 & T3 pins should be connected to GND.
When using the 2 wire serial interface, please pull up the SCL_SCK, SDA_SI pins via 10k ohms and leave SO unconnected.
Please note that the values of resistors and capacitors mentioned here are only recommended values.
RSTB should be held low until supply voltage VDD has ramped up and has reached a stable level.
The polarity of INT pin is programmable via register 0x30
Connect CLK_EXT to GND for normal use
Please leave the XPM, XNM, YPM, YNM terminals open if using a 4-wire touch screen. These pins should be connected to the reference leads of an
8-wire touch screen if one is being used.
SCL_SCK
4.
5.
6.
7.
8.
9.
Function
EDA
28
1.
2.
3.
I/O
1
TOP VIEW
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© 2011 ROHM Co., Ltd. All rights reserved.
11/17
2011.08 - Rev.A
Technical Note
BU21023GUL,BU21023MUV,BU21024FV-M
PAD
PAD
Fig. B
Fig. A
PAD
PAD
Fig. D
Fig. C
PAD
CIN
Fig. E
PAD
Fig. F
●Fig. BU21023GUL / BU21023MUV / BU21024FV-M I/O equivalent circuit
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© 2011 ROHM Co., Ltd. All rights reserved.
12/17
2011.08 - Rev.A
Technical Note
BU21023GUL,BU21023MUV,BU21024FV-M
●Application Circuit
【BU21023GUL/BU21023MUV】
BU21023GUL/MUV support 2 host interfaces (4-wire SPI and 2-wire serial bus).
The figures below are shown application circuit when each interface is used.
(Although BU21023GUL is CSP package, it is shown in similar figure for comparing.)
*Please connect the terminal of ECL/EDA with VSS, when firmware is download form HOST.
*Please insert TVS diode each sensor line from the perspective that enhances resistance to ESD.
*In 4-wire SPI using case, pull up INT terminal to VDD or host IO voltage (max4.5V).
If no using, connect to GND.
VDD
EEPROM
VDD
Host
10kohm
10kohm
INT
SEL_CSB
SCL_SCK
SDA_SI
EDA
ECL
10kohm
SO
(10kohm)
IFSEL
panel
T3
YN
T2
BU21023
XN
T1
0.1uF
VDD
VSS
VDD
DVDD
1.0uF
DVDD_EXT
TVS diode
AVDD
RSTB
PVDD
EXT_CLK
XP
T4
YP
1.0uF
Example 1 : BU21023GUL/MUV application circuit(4-wireSPI)
In 2-wire serial interface using case,
please pull up INT, SCL_SCK, SDA_SI terminal to VDD or host IO voltage(max4.5V).
VDD
EEPROM
VDD
Host
10kohm
10kohm
10kohm
INT
SEL_CSB
SCL_SCK
SDA_SI
EDA
ECL
10kohm
10kohm
SO
IFSEL
panel
T3
YN
T2
BU21023
XN
T1
0.1uF
1.0uF
VSS
VDD
DVDD
TVS diode
DVDD_EXT
RSTB
AVDD
XP
PVDD
EXT_CLK
T4
YP
VDD
1.0uF
Example 2 : BU21023GUL/MUV application circuit(2-wire Serial bus)
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© 2011 ROHM Co., Ltd. All rights reserved.
13/17
2011.08 - Rev.A
Technical Note
BU21023GUL,BU21023MUV,BU21024FV-M
【BU21024FV-M】
BU21024FV-M support 2 host interfaces (4-wire SPI and 2-wire serial bus).
The figures below are shown Application Circuit when each interface is used.
(Although BU21023GUL is CSP package, it is shown in similar figure for comparing.)
*Please connect the terminal of ECL/EDA with VSS, when Firmware is download form HOST.
*Please insert TVS diode each sensor line from the perspective that enhances resistance to ESD.
*In 4-wire SPI using case, pull up INT terminal to VDD or host IO voltage(max4.5V).
If no using, connect to GND.
VDD
VDD
10kohm
VDD
10kohm
10kohm
1
EDA
SCL_SCK
28
2
ECL
SDA_SI
27
3
YNM
SEL_CSB
26
4
XNM
INT
25
5
YPM
SO
24
6
XPM
IFSEL
23
7
YN
T3
22
8
XN
T2
21
9
YP
T1
20
10
XP
CLK_EXT
19
11
T4
EEPROM
Host
(10kohm)
BU21024FV-M
panel
RSTB 18
0.1uF
TVS diode
12
PVDD
VSS
17
13
AVDD
VDD
16
14
DVDD
DVDD_EXT
15
VDD
1.0uF
1.0uF
Example 3 : BU21024FV-M Application Circuit(4-wireSPI)
VDD
10kohm
VDD
VDD
10kohm
10kohm
1
EDA
SCL_SCK
28
2
ECL
SDA_SI
27
3
YNM
SEL_CSB
26
4
XNM
INT
25
5
YPM
SO
24
6
XPM
IFSEL
23
7
YN
T3
22
8
XN
T2
21
9
YP
T1
20
10
XP
CLK_EXT
19
11
T4
EEPROM
BU21024FV-M
Host
VDD
panel
RSTB 18
0.1uF
TVS diode
12
PVDD
VSS
17
13
AVDD
VDD
16
14
DVDD
DVDD_EXT
15
VDD
1.0uF
1.0uF
Example 4 : BU21024FV-M Application Circuit(2-wire Serial bus)
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© 2011 ROHM Co., Ltd. All rights reserved.
14/17
2011.08 - Rev.A
Technical Note
BU21023GUL,BU21023MUV,BU21024FV-M
BU21024FV-M has the other pins for debug except for 4-wire resistive touch screen interface (XP, YP, XN, YN).
When debug, there are 4 monitor pins corresponding to four past terminals.
(In 4-wire, supply and detect voltage of screen on 4 pins. When debug, if this function is enable,
it is possible to supply voltage on past 4pins and detect voltage on 4 pins with **M separately. )
To remove the noise of Screen itself, the filter is composed of discrete circuit.
It is possible to ease the decrease of screen voltage's dynamic range, which is caused by wiring resistance on the PCB.
Note: These debug terminals are only for debug. So, please don’t use them in normal application using.
VDD
VDD
10kohm
VDD
10kohm
10kohm
1
EDA
SCL_SCK
28
2
ECL
SDA_SI
27
3
YNM
SEL_CSB
26
4
XNM
INT
25
5
YPM
SO
24
6
XPM
IFSEL
23
7
YN
T3
22
8
XN
T2
21
9
YP
T1
20
10
XP
CLK_EXT
19
EEPROM
Host
1nF
10 ohm
1nF
10 ohm
(10kohm)
1nF
10 ohm
1nF
BU21024FV-M
panel
11
RSTB 18
T4
0.1uF
TVS diode
12
PVDD
VSS
17
13
AVDD
VDD
16
14
DVDD
DVDD_EXT
15
VDD
1.0uF
1.0uF
Example 5 : BU21024FV-M Application Circuit(4-wireSPI with RC filter)
VDD
VDD
10kohm
VDD
10kohm
10kohm
1
EDA
SCL_SCK
28
2
ECL
SDA_SI
27
3
YNM
SEL_CSB
26
4
XNM
INT
25
5
YPM
SO
24
6
XPM
IFSEL
23
7
YN
T3
22
8
XN
T2
21
9
YP
T1
20
10
XP
CLK_EXT
19
11
T4
EEPROM
Host
10 ohm
1nF
10 ohm
1nF
10 ohm
VDD
1nF
10 ohm
1nF
BU21024FV-M
panel
RSTB 18
0.1uF
TVS diode
12
PVDD
VSS
17
13
AVDD
VDD
16
14
DVDD
DVDD_EXT
15
VDD
1.0uF
1.0uF
Example 6 : BU21024FV-M Application Circuit(2-wire Serial bus with RC filter)
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© 2011 ROHM Co., Ltd. All rights reserved.
15/17
2011.08 - Rev.A
Technical Note
BU21023GUL,BU21023MUV,BU21024FV-M
●Notes for use
(1) Absolute Maximum Ratings
An excess in the absolute maximum ratings, such as supply voltage, temperature range of operating conditions, etc.,
can break down devices thus making impossible to identify breaking mode such as a short circuit or an open circuit. If
any special mode exceeding the absolute maximum ratings is assumed, consideration should be given to take physical
safety measures including the use of fuses, etc.
(2) Operating conditions
These conditions represent a range within which characteristics can be provided approximately as expected. The
electrical characteristics are guaranteed under the conditions of each parameter.
(3) Reverse connection of power supply connector
The reverse connection of power supply connector can break down ICs. Take protective measures against
the breakdown due to the reverse connection, such as mounting an external diode between the power supply
and the IC's power supply terminal.
(4) Power supply line
Design PCB pattern to provide low impedance for the wiring between the power supply and the GND lines. In this regard,
for the digital block power supply and the analog block power supply, even though these power supplies has the same
level of potential, separate the power supply pattern for the digital block from that for the analog block, thus suppressing
the diffraction of digital noises to the analog block power supply resulting from impedance common to the wiring
patterns. For the GND line, give consideration to design the patterns in a similar manner. Furthermore, for all power
supply terminals to ICs, mount a capacitor between the power supply and the GND terminal. At the same time, in order
to use an electrolytic capacitor, thoroughly check to be sure the characteristics of the capacitor to be used present no
problem including the occurrence of capacity dropout at a low temperature, thus determining the constant.
(5) GND voltage
Make setting of the potential of the GND terminal so that it will be maintained at the minimum in any operating state.
Furthermore, check to be sure no terminals are at a potential lower than the GND voltage including an actual electric
transient.
(6) Short circuit between terminals and erroneous mounting
In order to mount ICs on a set PCB, pay thorough attention to the direction and offset of the ICs. Erroneous mounting
can break down the ICs. Furthermore, if a short circuit occurs due to foreign matters entering between terminals or
between the terminal and the power supply or the GND terminal, the ICs can break down.
(7) Operation in strong electromagnetic field
Be noted that using ICs in the strong electromagnetic field can malfunction them.
(8) Inspection with set PCB
On the inspection with the set PCB, if a capacitor is connected to a low-impedance IC terminal, the IC can suffer stress.
Therefore, be sure to discharge from the set PCB by each process. Furthermore, in order to mount or dismount the set
PCB to/from the jig for the inspection process, be sure to turn OFF the power supply and then mount the set PCB to the
jig. After the completion of the inspection, be sure to turn OFF the power supply and then dismount it from the jig. In
addition, for protection against static electricity, establish a ground for the assembly process and pay thorough attention
to the transportation and the storage of the set PCB.
(9) Input terminals
In terms of the construction of IC, parasitic elements are inevitably formed in relation to potential. The operation of the
parasitic element can cause interference with circuit operation, thus resulting in a malfunction and then breakdown of
the input terminal. Therefore, pay thorough attention not to handle the input terminals, such as to apply to the input
terminals a voltage lower than the GND respectively, so that any parasitic element will operate. Furthermore, do not
apply a voltage to the input terminals when no power supply voltage is applied to the IC. In addition, even if the power
supply voltage is applied, apply to the input terminals a voltage lower than the power supply voltage or within the
guaranteed value of electrical characteristics.
(10) Ground wiring pattern
If small-signal GND and large-current GND are provided, It will be recommended to separate the large-current GND
pattern from the small-signal GND pattern and establish a single ground at the reference point of the set PCB so that
resistance to the wiring pattern and voltage fluctuations due to a large current will cause no fluctuations in voltages of
the small-signal GND. Pay attention not to cause fluctuations in the GND wiring pattern of external parts as well.
(11) External capacitor
In order to use a ceramic capacitor as the external capacitor, determine the constant with consideration given to a
degradation in the nominal capacitance due to DC bias and changes in the capacitance due to temperature, etc.
(12) Rush current
The IC with some power supplies has a capable of rush current due to procedure and delay at power-on. Pay attention
to the capacitance of the coupling condensers and the wiring pattern width and routing of the power supply and the GND
lines.
(13) Others
In case of use this LSI, please peruse some other detail documents, we called, Technical note, Functional description,
Application note.
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© 2011 ROHM Co., Ltd. All rights reserved.
16/17
2011.08 - Rev.A
Technical Note
BU21023GUL,BU21023MUV,BU21024FV-M
●Ordering part number
B
U
2
Part No.
1
0
2
Part No.
21023
21024
4
F
V
-
M
Package
GUL : VCSP50L2
MUV: VQFN028V5050
FV : SSOP-B28
E
2
Packaging and forming specification
E2: Embossed tape and reel
UCSP50L1 (BD82103GWL)
<Tape and Reel information>
0.1±0.05
0.55MAX
1.5±0.05
1PIN MARK
1.8±0.05
11-φ0.2±0.05
A
0.05 A B
(φ0.15)INDEX POST
Embossed carrier tape
Quantity
3000pcs
Direction
of feed
S
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
)
0.35±0.05
0.08 S
Tape
B
C
B
1
0.3±0.05
2
3
P=0.4×2
A
4
P=0.4×3
1pin
Reel
(Unit : mm)
Direction of feed
∗ Order quantity needs to be multiple of the minimum quantity.
VQFN028V5050
<Tape and Reel information>
5.0±0.1
5.0±0.1
1.0MAX
Embossed carrier tape
Quantity
2500pcs
Direction
of feed
1PIN MARK
2.7±0.1
C0.2
1
7
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
)
(0.22)
0.02 +0.03
-0.02
S
0.08 S
8
2.7±0.1
28
0.4±0.1
Tape
22
14
21
1.0 0.5
15
+0.05
0.25 -0.04
1pin
Reel
(Unit : mm)
Direction of feed
∗ Order quantity needs to be multiple of the minimum quantity.
SSOP-B28
<Tape and Reel information>
10 ± 0.2
(MAX 10.35 include BURR)
15
0.3Min.
1
Embossed carrier tape
Quantity
2000pcs
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
)
14
0.15 ± 0.1
0.1
1.15 ± 0.1
Tape
Direction
of feed
5.6 ± 0.2
7.6 ± 0.3
28
0.1
0.65
0.22 ± 0.1
1pin
Reel
(Unit : mm)
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© 2011 ROHM Co., Ltd. All rights reserved.
17/17
Direction of feed
∗ Order quantity needs to be multiple of the minimum quantity.
2011.08 - Rev.A
Notice
Notes
No copying or reproduction of this document, in part or in whole, is permitted without the
consent of ROHM Co.,Ltd.
The content specified herein is subject to change for improvement without notice.
The content specified herein is for the purpose of introducing ROHM's products (hereinafter
"Products"). If you wish to use any such Product, please be sure to refer to the specifications,
which can be obtained from ROHM upon request.
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 specified 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 specified 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 parties. ROHM shall bear no responsibility whatsoever for any dispute arising from the
use of such technical information.
The Products specified in this document are intended to be used with general-use electronic
equipment or devices (such as audio visual equipment, office-automation equipment, communication devices, electronic appliances and amusement devices).
The Products specified in this document are not designed to be radiation tolerant.
While ROHM always makes efforts to enhance the quality and reliability of its Products, a
Product may fail or malfunction for a variety of reasons.
Please be sure to implement in your equipment using the Products safety measures to guard
against the possibility of physical injury, fire or any other damage caused in the event of the
failure of any Product, such as derating, redundancy, fire control and fail-safe designs. ROHM
shall bear no responsibility whatsoever for your use of any Product outside of the prescribed
scope or not in accordance with the instruction manual.
The Products are not designed or manufactured to be used with any equipment, device or
system which requires an extremely high level of reliability the failure or malfunction of which
may result in a direct threat to human life or create a risk of human injury (such as a medical
instrument, transportation equipment, aerospace machinery, nuclear-reactor controller, fuelcontroller or other safety device). ROHM shall bear no responsibility in any way for use of any
of the Products for the above special purposes. If a Product is intended to be used for any
such special purpose, please contact a ROHM sales representative before purchasing.
If you intend to export or ship overseas any Product or technology specified herein that may
be controlled under the Foreign Exchange and the Foreign Trade Law, you will be required to
obtain a license or permit under the Law.
Thank you for your accessing to ROHM product informations.
More detail product informations and catalogs are available, please contact us.
ROHM Customer Support System
http://www.rohm.com/contact/
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© 2011 ROHM Co., Ltd. All rights reserved.
R1120A