GPIO ICs
Keyencoder IC
BU1852GUW
No.11098EAT04
●Description
Keyencoder IC BU1852GUW can monitor up to 8x12 matrix (96 keys), which means to be adaptable to Qwerty keyboard.
We adopt the architecture that the information of the only key which status is changed, like push or release, is encoded into
the 8 bits data. This can greatly reduce the CPU load which tends to become heavier as the number of keys increase.
(Previously, all key's status is stored in the registers.) When the number of keys is small, the extra ports can be used as
GPIO. Furthermore, auto sleep function contributes to low power consumption, when no keys are pressed. It is also
equipped with the various functions such as ghost key rejection, N-key Rollover, Built-in power on reset and oscillator.
●Features
1) Monitor up to 96 matrix keys.
2) Under 3µA Stand-by Current
3) Built-in Power on Reset.
4) Ghost key rejection.
5) Keyscan / GPIO selectable
6) 3 volt tolerant Input
●Absolute maximum ratings (Ta=25℃)
Parameter
Symbol
Ratings
-0.3 ~ +2.5
Unit
V
Conditions
VDD≦VDDIO
VDD
VDDIO
VI1
Supply Voltage
-0.3 ~ +4.5
V
1
-0.3 ~ VDD +0.3※
V
XRST, XI, TW, PORENB
ADR
1
Input voltage
VI2
-0.3 ~ VDDIO +0.3※
-0.3 ~ +4.5
V
XINT, SCL, SDA,
COL[11:0], ROW[7:0]
VIT
V
Storage temperature range
Package power
Tstg
PD
-55 ~ +125
℃
mW
2
272※
※
This IC is not designed to be X-ray proof.
※1 It is prohibited to exceed the absolute maximum ratings even including +0.3 V.
※2 Package dissipation will be reduced each 2.72mW/℃ when the ambient temperature increases beyond 25℃.
●Operating conditions
Ratings
Parameter
Symbol
Unit
Conditions
Min.
1.65
Typ.
1.80
Max.
1.95
Supply voltage range
(VDD)
VDD
VDDIO
VI1
V
V
Supply voltage range
(VDDIO)
1.65
-0.2
-0.2
-0.2
-30
1.80
3.60
VDD+0.2
VDDIO+0.2
3.60
-
-
V
XRST, XI, TW, PORENB
ADR
Input voltage range
VI2
V
XINT, SCL, SDA,
COL[11:0], ROW[7:0]
VIT
-
V
Operating temperature range
Topr
25
+85
℃
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2011.01 - Rev.A
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