Shock sensor signal processing IC
BU3892FV
1.15
±
0.1 6.4
±
0.3
0.1
4.4
±
0.2
Description
The BU3892FV is an IC developed for shock detection
of hard disk. 2-channel signal processing circuit are
incorporated. For 1st STAGE, signal from shock sensor
is amplified by Op amp. The amplification degree and
the value of filtering are determined by external elements.
For 2nd STAGE, output of 1st STAGE is amplified by x10
inverting amplifier. The signal is inputted to window
comparators and shock detection is started.
Features
1) 5V single supply
2) Built-in 7 operational amplifiers and 4 comparators
3) Low input bias current due to CMOS process
4) Low power consumption mode
Applications
Hard disk
Absolute Maximum Ratings (Ta=25˚C)
Parameter
Supply voltage
Power dissipation
Storage temperature range
Input voltage
Output voltage
Operating temperature range
Symbol
V
DD
Pd
Tstg
V
IN
V
OUT
T
OPR
–55
–0.3
–0.3
0
–0.3
Limits
300
∗
~
~
~
~
~
+7.0
+125
V
DD
+0.3
V
DD
+0.3
+70
Dimension (Unit : mm)
5.0
±
0.2
0.3Min.
0.15
±
0.1
16
9
1
8
0.65
0.1
0.22
±
0.1
SSOP-B16
Unit
V
mW
˚C
V
V
∗
Derating : 3.0mW/˚C for operation above Ta=25˚C
∗
This product is not designed for protection against radioactive rays.
˚C
Parameter
Supply voltage
Recommended Operating Conditions (Ta=25˚C)
Symbol
V
DD
V
IL
V
IH
Min.
4.5
3.5
Typ.
-
-
-
Max.
5.5
1.5
V
DD
+0.3
Unit
V
V
V
Input L voltage range
Input H voltage range
-0.3
Electrical characteristics (
Unless otherwise noted; Ta=25˚C, V
DD
=4.5~5.5V)
Parameter
<FIRST STAGE>
Input bias current
Max. output current
Supply voltage rejection ratio
Gain band width
Max. amplitude voltage gain
<REFERENCE INPUT>
Input current
Output impedance
<SECOND STAGE>
Input current
A2in, B2in
"H" threshold voltage
A2in, B2in
"L" threshold voltage
A2in, B2in
<TOTAL>
Recovery time from Power Down
Current consumption
T
RCVRY
I
DD
–
–
–
–
4
15
1
6.5
100
ms
mA
µA
II
2nd
DVH
2nd
DVL
2nd
–11
+0.04
– 0.06
–16
+0.05
– 0.05
–22
+0.06
– 0.04
µA
V
II
REF
RO
REF
–
–
–
–
10
30
µA
Ω
Reference Input=2V
Reference Input=2V
Input current when (Reference input—0.2V)
voltage is applied.
Reference Input=2V
-Clear Shocked=GND level
Relative value with Reference Input
Time when it can be operated in the specification
range after Power Down become "L".
Power Down "L" input
Power Down "H" input
(Ta=25˚C)
(Ta=75˚C)
Symbol
IIB
1ST
IO
1
ST
SVR
1
ST
GB
1
ST
AV
1
ST
Min.
–
–
0.5
65
–
10
Typ.
1
–
–
–
1.4
–
Max.
20
2000
–
–
–
–
Unit
pA
mA
dB
MHz
V/mV
Conditions
Measurement between Ain+, Ain-, Bin+, Bin-
and GND.
Note) Shocked outputs "H" when Power Down becomes "L".
Application Circuit
Bin+
16
Bin-
15
Bout
-
+
14
VDD
13
B2in
12
-Clear shocked
11
shocked
10
N.C
9
1st STAGE
OP-AMP
10k
-
COMPARATOR
100k
+
-
+
-
+
-
+
-
30k
BU3892FV
2nd STAGE
OP-AMP
COMPARATOR
30k
-
30k
2nd STAGE
OP-AMP
+
COMPARATOR
-
+
100k
COMPARATOR
+
-
+
10k
10k
1st STAGE
OP-AMP
+
-
Aout
3
GND
4
-
5
Reference
Output
6
Reference
Input
+
Ain+
1
Ain-
2
A2in
7
8
Power
Down