BS801B/02B/04B/06B/08B
A.C. Characteristics
Ta=25°C
Test Conditions
Symbol
Parameter
Min.
Typ.
Max.
Unit
VDD
Conditions
fSCD
fKRT1
tKRT2
tKH
SCD Clock
3V
3V
3V
3V
3V
3V
10.4
75
13.0
100
400
40
15.6
125
500
50
kHz
ms
ms
s
¾
¾
¾
¾
¾
¾
Key Response Time in Normal Mode
Key Response Time in Standby Mode
Maximum Key Hold Time
300
30
tCAL1
tCAL2
Auto-Calibration Period - Normal Mode
Auto-Calibration Period - Standby Mode
1.8
7.5
2.5
3.2
s
10.0
12.5
s
Functional Description
Introduction
Part No.
OKW Open
OKW Low
This range of BS80xB touch key devices offer an easy
and reliable means of implementing touch switch func-
tions in a range of applications. A single external capaci-
tor is the only external component required for most
applications while a single line serial bus offers conve-
nient communication with an external MCU.
BS804B
BS806B
BS808B
One-key
Wake-up
Any-key
Wake-up
The logic status of the OKW pin is read when the device
powers up. The logic level on this pin must not be
changed after power on. Internal circuitry ensures that
the internal pull-high resistor on the OKW pin will not
consume current.
Device Operation Modes
All devices have two modes of operation, the Standby
Mode and the Normal Mode. After the device is powered
up it will automatically enter the Standby Mode to con-
serve power. The BS801B and BS802B devices can
then be woken up by touching any of their Keyn pins.
The BS804B, BS806B and BS808B devices can how-
ever be woken up by either a One-key Wake-up using
Key0, or by Any-key Wake-up. The wake-up method is
determined by the status of the OKW pin which is read
only during power-on. The advantage of choosing the
One-key wake-up option is that it consumes less power
than the Any-key wake-up when in the Standby Mode.
Part No.
Normal Mode On Time
BS801B
BS802B
Approx10 sec
BS804B
BS806B
BS808B
Approx 20 secs
K
e
y
O
n
K
e
y
O
n
1
0
/
2
0
s
K
e
y
S
t
a
t
e
P
O
R
S
t
a
n
d
N
b
o
y
r
m
a
l
S
t
a
n
d
b
y
O
p
e
r
a
t
i
n
g
S
t
a
t
e
K
o
u
t
A
c
t
i
v
e
L
o
w
A
c
t
i
v
e
L
o
w
Operating Mode
Rev. 1.00
5
July 7, 2009
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
