BU1851GUW-E2 [ROHM]
Microprocessor Circuit, CMOS, PBGA35, VBGA-35;
| 型号： | BU1851GUW-E2 |
| 厂家： | 
ROHM |
| 描述： | Microprocessor Circuit, CMOS, PBGA35, VBGA-35 外围集成电路 |
| 文件： | 总15页 (文件大小：538K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
GPIO ICs Series
Key Encoder IC
BU1851GUW
No.09098EAT03
●Description
Key Encoder IC can monitor up to 8x8 matrix (64 keys), which means to be adaptable to Qwerty keyboard. We apt the
architecture that the information of the only key which status is changed, like push or release, is encodehe 8 bits
data. This can greatly reduce the CPU load which tends to become heavier as the number of keys cre
(Previously, all key's status is stored in the registers.)
Furthermore, auto sleep function contribute to low power consumption, when no keys are pressed. It is lso equipped with
the various functions such as ghost key rejection, N-key Rollover, Built-in power on reset anscillator.
●Features
1) Monitor up to 64-matrix keys
2) Under 5A Stand-by Current
3) Built-in Power On Reset
4) Ghost key rejection
●Absolute maximum ratings
(Ta=25℃)
Item
Supply Voltage*1
Input voltage
Symbol
Value
-0.3 ~ +4.5
-0.3 ~ VDD
-12
Unit
V
comment
VDD
VI
V
Storage temperature range
Package power
Tstg
PD
℃
mW
This IC is not designed to be X-ray pf.
*1 It is prohibited to exceed the absolaximum ratings evencluding +0.3 V.
*2 Package dissipation will buced each 2.72mW/ oC wn tambient temperature increases beyond 25 oC.
●Operating Condit
Limit
Typ
Item
Syml
Unit
Condition
Min
2.20
-0.2
Max
3.60
Suptage range（VDD）
DD
VIN
3.30
-
V
V
put voltage range
VDD+0.2
Operating temperature range
Topr
-30
25
+85
℃
External clock
Fclk
Rxi
0.8
1.0
1.2
MHz
CLKSEL=VDD
External resistor
118.8
120
121.2
kΩ
To Xi pin, when CLKSEL=VSS
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© 2009 ROHM Co., Ltd. All rights reserved.
2009.09 - Rev.A
1/12
Technical Note
BU1851GUW
● Package Specification
U1851
Lot No.
Fig.1 Package Specification（VBGA035W040）
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2009.09 - Rev.A
2/12
© 2009 ROHM Co., Ltd. All rights reserved.
Technical Note
BU1851GUW
● Pin Assignment
1
2
3
4
5
6
TESTM0
XRST
XO
XI
ROW0
TESTM3
A
B
C
D
E
F
CLKSEL
VDD
VDD
VSS
VDD
PORENB
VSS
ROW2
ROW4
ROW6
CO
L1
ROW1
ROW3
KINT
KSDA
VDD
VSS
ROW
KSCL
COL6
COL7
COL4
COL5
COL2
7
TESTM1
COL3
TESTM2
Fig.2 Pin Dam（Top View）
● Block Diagram
XI
CLK
VDD
Oscillato
TESTM[3:0]
Column
Drive
COL[7:0]
8bit
8bit
KINT
KSCL
KSDA
3wire
Control
Key
Encoder
Key Scan
3wire
Timeout
Row
8bit
8bit
Monitor
ROW[7:0]
Reset
Gen
XRST
Power
On
Reset
PORENB
VSS
Fig.3 Functional Block Diagram
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2009.09 - Rev.A
3/12
© 2009 ROHM Co., Ltd. All rights reserved.
Technical Note
BU1851GUW
● Pin-out Functional Descriptions
Cell
Type
PIN name
I/O
Function
Init
VDD
VSS
-
-
I
Power supply (Core, I/O)
GND
-
-
I
-
-
XRST
Reset（Low Active）
A
H: External clock is used
L: Internal CR oscillator is used
External clock input when “CLKSEL” is H.
120k is attached up to VDD when “CLKSEL”
is L.
CLKSEL
XI
I
I
I
I
B
G
XO
O
O
Test pin*1
L
C
C
KINT
Key Interrupt
H
KSCL
KSDA
ROW0
I
I/O
I
Clock for serial interface
I
I
A
D
Serial data inout for serial interface
ROW1
ROW2
ROW3
ROW4
ROW5
ROW6
ROW7
COL0
I
I
I
Row input from key tri
(Pull-u
I
E
ll-up
I
I
I
I
O
O
O
O
O
O
O
I
COL1
COL2
COL3
Columut to key matrix
L
C
COL4
CO
COL6
COL7
PORENB
TESTM0
TESTM1
TESTM2
TESTM3
Power on reset enable (Low Active)
Test Pin*2
I
I
B
F
I
I
I
I
*1 Note: This pin must be open in normal operation.
*2 Note: All these pins must be tied down to GND in normal operation.
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© 2009 ROHM Co., Ltd. All rights reserved.
2009.09 - Rev.A
4/12
Technical Note
BU1851GUW
C
D
A
E
B
F
G
Fig.4 Equivalent IO circuit agra
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2009.09 - Rev.A
5/12
© 2009 ROHM Co., Ltd. All rights reserved.
Technical Note
BU1851GUW
● Functional Description
1. Power mode
The device enters the state of Power Down when XRST=”Low”. When XRST=High after powered, the device enters the standby
state.
Power On Reset
A Power On Reset logic is implemented in this device. Therefore, it will operate correctly even if the XRST port is not used.
In this case, the XRST port must be connected to high (VDD), and the PORENB port must be connected to low (VSS). If
you don’t want to use Power On reset, you must connect PORENB port to high (VDD).
Power Down State
The device enters Power Down state by XRST=”Low”. An internal circuit is initialized, and key encoding a3wirinterface
are invalid. Power On Reset becomes inactive during this state.
Stand-by State
The device enters the stand-by state by setting XRST to "High". In this state, the device is waiting for keys pressed.
When a key is pressed, the state will change to operation. Power On Reset is active in this se if PORENB = low.
Operating State
The device enters the operating state by pressing keys. The device will scan the key rix and encode the key code,
and then the 3wire interface tries to start communication by driving KINT ow”ee sec.2 for the details. After
communicating with host device, when no keys are pressed, the device rets to the stand-by state. Power On
Reset is active in this state if PORENB=low.
2. 3wire Interface
KINT
KSCL
invalid
Bit7
Bit6
Bit0
KSDA
Start bit
sent by host device
sent by
Fig.5 Proto
Figure 5 shows the protocof BU1851. BU1851 potocol basically consists of 3 wire configuration (KINT, KSCL, and
KSDA) as shown above. e that this 3wire inteccompletely different from I2C and other standard bus interface.
Procedure
1. When BU185etects key events, Kinterrupt is generated to host with driving Low.
2. After the host dcts KINT intupt, e ost is supposed to send start bit.
3. After BU1851 detects start bit, 8bit data (key code) transmission on KSDA will start synchronized with the rising
edge SCL clock signal, ch ent from the host.
4. 8 bit data re followed by “0” th bit is always “0”), and then BU1851 drives High on KINT line.
time
.6 shows the 3wire timeout sequence. It is suppose to happen when Host doesn’t response anything in a certain time.
1. bu1851 generates KINT interrupt.
2. But Host doesn’t response within 500ms.
3. BU1851 stops KINT, and tries to communicate again by generating KINT.
4. BU1851 will go into the stand-by state when the communication fails five times.
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© 2009 ROHM Co., Ltd. All rights reserved.
2009.09 - Rev.A
6/12
Technical Note
BU1851GUW
Power
Mode
Operating state
Stand-by state
KINT
start again
5 times fail -->
state will change to stand-by
communication doesn't establish.
(Host doesn't response within 500ms)
Fig.6 3wire timeout
See also “3wire interface AC characteristics”.
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© 2009 ROHM Co., Ltd. All rights reserved.
2009.09 - Rev.A
7/12
Technical Note
BU1851GUW
3. Key code Assignment
Table 1 shows the key code assignment. These key codes are sent through KSDA line corresponding to the pushed or released
keys as indicated in section 2.
Table.1 Key code
ROW0
0x01
0x81
0x02
0x82
0x03
0x83
0x04
0x84
0x05
0x85
0x06
0x86
0x07
0x87
x08
0x88
ROW1
0x11
0x91
0x12
0x92
0x13
0x93
0x14
0x94
0x15
0x95
0x16
0x96
x17
0x97
0x18
0x9
ROW2
0x21
0xA1
0x22
0xA2
0x23
0xA3
0x24
0xA4
0x25
0xA5
x26
0xA6
0x27
0xA
0x28
0xA8
ROW3
0x31
0xB1
0x32
0xB2
0x33
0xB3
0x34
0xB4
35
xB5
0x36
0x37
0xB7
0x38
0xB8
ROW4
0x41
0xC1
0x42
0xC2
0x43
0xC3
x44
0xC4
0x45
0x5
0x46
0xC6
0x47
0xC7
0x48
0xC8
ROW5
0x51
0xD1
0x52
0xD2
53
xD3
0x54
0xD4
5
0xD5
0x56
0xD6
0x57
0xD7
0x58
0xD8
ROW6
0x61
0E1
0x62
xE2
0x63
0xE3
0x6
0xE4
0x65
0xE5
0x66
0xE6
0x67
0xE7
0x68
0xE8
ROW7
71
0xF1
0x72
0xF2
0x73
0xF3
0x74
0xF4
0x75
0xF5
0x76
0xF6
0x77
0xF7
0x78
0xF8
M
B
COL0
COL1
COL2
COL3
COL4
COL5
COL6
COL7
M
B
M
B
M
B
M
B
M
B
M
B
M
M: Make e code when the key is presse
B: Break code when the key is released)
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2009.09 - Rev.A
8/12
© 2009 ROHM Co., Ltd. All rights reserved.
Technical Note
BU1851GUW
4. Ghost Key Rejection
Ghost key is an inevitable phenomenon as long as key-switch matrices are used. When three switches located at the corners of
a certain matrix rectangle are pressed simultaneously, the switch that is located at the last corner of the rectangle (the ghost
key) also appears to be pressed, even though the last key is not pressed. This occurs because the ghost key switch is
electrically shorted by the combination of the other three switches (Fig.7). Because the key appears to be pressed electrically, it
is impossible to distinguish which key is the ghost key and which key is pressed. The BU1851 solves the ghost key problem to
use the simple method. If BU1851 detects any three-key combination that generates a fourth ghost key, and BU1851 does not
report anything, indicating the ghost keys are ignored. This means that many combinations of three keys are also ignored when
pressed at the same time. Applications requiring three-key combinations (such as <Ctrl><Alt><Del>) must ensure that the three
keys are not wired in positions that define the vertices of a rectangle (Fig. 8). There is no limit on the number of keys that can be
pressed simultaneously as long as the keys do not generate ghost key events.
PRESSED KEY
EVENT
GST-KEY
T
KEY-SWITCTRIX
Fig.Gst key phenomen
EXMPLES OF VALID THREE-KEY COMBINATIONS
KEY-SWITCH MATRIX
KEY-SWITCH MATRIX
Fig.8 Valid three key combinations
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2009.09 - Rev.A
9/12
© 2009 ROHM Co., Ltd. All rights reserved.
Technical Note
BU1851GUW
● 3wire Interface AC characteristics
State
BIT 0
START
BIT 7
BIT 6
"0"
tLOW;INT
tSU;STA
tHD;INTE
KINT
tHIGH;CLK
1/fSCLK
tLOW;CLK
KSCL
KSDA
tSU;DAT
tHD;DAT
tHD;STA
Fig.9 3wire interface AC timing
VDD=3.30V，Topr=25℃, CLKSEL=H (Sysclk = External Clock)
Item
Symbol
fSCLK
Min
-
yp
-
Max
Unit
kHz
Condition
KSCL Clock Frequency
START Condition
Setup Time
START Condition
Hold Time
tSU;STA
tHD;STA
0.030
-
-
-
-
-
-
-
500
ms
-
-
-
s
s
s
s
s
s
ms
KSCL Low Time
KSCL High Time
Data Setup Time
Data Hold Time
KINT End Hold
KINT Low Time
tLOW;CLK
tHIGH;CLK
U;DAT
23
23
tHIGH;CLK
–
tHIGH;CLK –
(1/Sysclk)x10
(1/Sysclk)x12
tHD;DAT
tHD;INTE
tLOWNT
(1/Sysclk)x0
(1/Ss)x3
500
(1/Sysclk)x12
(1/Sysclk)x5
1200
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© 2009 ROHM Co., Ltd. All rights reserved.
2009.09 - Rev.A
10/12
Technical Note
BU1851GUW
● Application circuit example
2.8V
0.1uF
COL7
COL6
COL5
COL4
COL3
COL2
COL1
COL0
120kΩ
XRST
XI
XO
MPU
open
INT
KINT
SCL
SDA
KSCL
KSDA
ROW0
ROW1
ROW2
ROW3
ROW4
ROW5
OW6
ROW7
Fig. 10 Application circuit example
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© 2009 ROHM Co., Ltd. All rights reserved.
2009.09 - Rev.A
11/12
Technical Note
BU1851GUW
●Ordering part number
B U
1
8
5
1
G U W
-
E
2
Part No.
Part No.
Package
Packaging and forming specification
E2: Embossed tape and reel
GUW:
VBGA035W040
VBGA035W040
<Tape and Reel information>
4.0 ± ±0.1
1PIN MARK
Tape
Embossed carrier tap(with pac
Quantity
2500pcs
E2
Direction
of feed
The direction ie 1pproduct is at the upr left when you hold
reel on the lehaand you pull out the tapn ht hand
(
)
S
0.08
S
A
P=0.5×5
0.75 ± ±0.1
0.5
φ
35- 0.295± 0.05
F
φ
M
0.05
S AB
B
E
D
C
B
A
Direction of feed
1pin
1
2 3 4 5 6
Reel
(Unit : mm)
Oquantity needs to be multiple of the minimum quantity.
∗
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© 2009 ROHM Co., Ltd. All rights reserved.
2009.09 - Rev.A
12/12
Daattaasshheeeett
Notice
Precaution on using ROHM Products
1. Our Products are designed and manufactured for application in ordinary electronic equipments (such as AV equipment,
OA equipment, telecommunication equipment, home electronic appliances, amusement equipment, etc.). If you
intend to use our Products in devices requiring extremely high reliability (such as medical equipment (Note 1), transport
equipment, traffic equipment, aircraft/spacecraft, nuclear power controllers, fuel controllers, car equipment including car
accessories, safety devices, etc.) and whose malfunction or failure may cause loss of human life, bodily injury or
serious damage to property (“Specific Applications”), please consult with the ROHM sales representative in advance.
Unless otherwise agreed in writing by ROHM in advance, ROHM shall not be in any way responsible oable for any
damages, expenses or losses incurred by you or third parties arising from the use of any ROHM’s Productor Specific
Applications.
(Note1) Medical Equipment Classification of the Specific Applications
JAPAN
USA
EU
CHINA
CLASSⅢ
CLASSⅣ
CLASSⅡb
CLASSⅢ
CLASSⅢ
CLASSⅢ
2. ROHM designs and manufactures its Products subject to strict quality contsystem. However, semiconductor
products can fail or malfunction at a certain rate. Please be sure to implemenyour own responsibilities, adequate
safety measures including but not limited to fail-safe design against the pical ury, damage to any property, which
a failure or malfunction of our Products may cause. The following are exaof safety measures:
[a] Installation of protection circuits or other protective devices to imsystem safety
[b] Installation of redundant circuits to reduce the impact of singr multiple circuit faire
3. Our Products are designed and manufactured for use under stdard conditions d not under any special or
extraordinary environments or conditions, as exemplifielow. Accordingly, OHM shall not be in any way
responsible or liable for any damages, expenses or losses isig from the usof ay ROHM’s Products under any
special or extraordinary environments or conditionsf you intend to uProducts under any special or
extraordinary environments or conditions (as exemfied elow), youindeeverification and confirmation of
product performance, reliability, etc, prior to use, mst necessary:
[a] Use of our Products in any types of liquid, iluding water, oils, chemals, and organic solvents
[b] Use of our Products outdoors or in pcwhere the Producae xposed to direct sunlight or dust
[c] Use of our Products in places whthe Products are exposed to sea wind or corrosive gases, including Cl2,
H2S, NH3, SO2, and NO2
[d] Use of our Products in places whethe Products are oed to static electricity or electromagnetic waves
[e] Use of our Products in proto heat-prodmponents, plastic cords, or other flammable items
[f] Sealing or coating our Prowith resin or ing materials
[g] Use of our Products without cleaning residue o(even if you use no-clean type fluxes, cleaning residue of
flux is recommende; or Washing our Products by using water or water-soluble cleaning agents for cleaning
residue after soldering
[h] Use of the Prcts in places subjecdw condensation
4. The Producnot subject to radiation-proof design.
5. Please verify aconfirm chacteris f the final or mounted products in using the Products.
6. In pular, if a transienarge amount of load applied in a short period of time, such as pulse. is applied,
confirman of performance haracteristics after on-board mounting is strongly recommended. Avoid applying power
ding normal rated powerexceeding the power rating under steady-state loading condition may negatively affect
ct performance and reliability.
De-rate Power Dissipation (Pd) depending on Ambient temperature (Ta). When used in sealed area, confirm the actual
ambient temperature.
8. Confirm that operation temperature is within the specified range described in the product specification.
9. ROHM shall not be in any way responsible or liable for failure induced under deviant condition from what is defined in
this document.
Precaution for Mounting / Circuit board design
1. When a highly active halogenous (chlorine, bromine, etc.) flux is used, the residue of flux may negatively affect product
performance and reliability.
2. In principle, the reflow soldering method must be used; if flow soldering method is preferred, please consult with the
ROHM representative in advance.
For details, please refer to ROHM Mounting specification
Notice - GE
Rev.002
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Precautions Regarding Application Examples and External Circuits
1. If change is made to the constant of an external circuit, please allow a sufficient margin considering variations of the
characteristics of the Products and external components, including transient characteristics, as well as static
characteristics.
2. You agree that application notes, reference designs, and associated data and information contained in this document
are presented only as guidance for Products use. Therefore, in case you use such information, you are solely
responsible for it and you must exercise your own independent verification and judgment in the use of such information
contained in this document. ROHM shall not be in any way responsible or liable for any damages, expenses or losses
incurred by you or third parties arising from the use of such information.
Precaution for Electrostatic
This Product is electrostatic sensitive product, which may be damaged due to electrostatic discharge. e take proper
caution in your manufacturing process and storage so that voltage exceeding the Products mimung will not be
applied to Products. Please take special care under dry condition (e.g. Grounding of human body uipment / solder iron,
isolation from charged objects, setting of Ionizer, friction prevention and temperature / humidity control
Precaution for Storage / Transportation
1. Product performance and soldered connections may deteriorate if the Products are stn the places where:
[a] the Products are exposed to sea winds or corrosive gases, including Cl2S, NH3, SO2, and NO2
[b] the temperature or humidity exceeds those recommended by ROHM
[c] the Products are exposed to direct sunshine or condensation
[d] the Products are exposed to high Electrostatic
2. Even under ROHM recommended storage condition, solderability oducts out of recommened storage time period
may be degraded. It is strongly recommended to confirm solderlity fore using Produts owhich storage time is
exceeding the recommended storage time period.
3. Store / transport cartons in the correct direction, which is icaed on a carton with symbol. Otherwise bent leads
may occur due to excessive stress applied when droppof a carton.
4. Use Products within the specified time after openia midity barrier bagaking is required before using Products of
which storage time is exceeding the recommended orage time period.
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QR code printed on ROHM Products label is r ROHM’s internal unly.
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When disposing Products please dispoem properly uuthorized industry waste company.
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Since our Products might fnder controlled goods rescribed by the applicable foreign exchange and foreign trade act,
please consult with ROHprsentative in case f ort.
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1. All informationd data including not limited to application example contained in this document is for reference
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parties with respect to the information contained in this document.
her Precaution
1. This document may not be reprinted or reproduced, in whole or in part, without prior written consent of ROHM.
2. The Products may not be disassembled, converted, modified, reproduced or otherwise changed without prior written
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3. In no event shall you use in any way whatsoever the Products and the related technical information contained in the
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weapons.
4. The proper names of companies or products described in this document are trademarks or registered trademarks of
ROHM, its affiliated companies or third parties.
Notice - GE
Rev.002
© 2014 ROHM Co., Ltd. All rights reserved.
Daattaasshheeeett
General Precaution
1. Before you use our Pro ducts, you are requested to care fully read this document and fully understand its contents.
ROHM shall not be in an y way responsible or liable for failure, malfunction or accident arising from the use of a ny
ROHM’s Products against warning, caution or note contained in this document.
2. All information contained in this docume nt is current as of the issuing date and subj ect to change without any prior
notice. Before purchasing or using ROHM’s Products, please confirm the la test information with a ROHM sale s
representative.
3. The information contained in this doc ument is provi ded on an “as is” basis and ROHM does not warrant that all
information contained in this document is accurate an d/or error-free. ROHM shall not be in an y way ponsible or
liable for any damages, expenses or losses incurred by you or third parties resulting from inaccuracy or rors of or
concerning such information.
Notice – WE
Rev.001
© 2014 ROHM Co., Ltd. All rights reserved.
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