UTC UT84520
CMOS
UTC
UNISONIC TECHNOLOGIES CO., LTD.
1
QW-R502-004,C
PS/2 SCROLLING MOUSE CONTROLLER
DESCRIPTION
The UT84520 Scrolling Mouse Controller is specially
designed to control PS/2 mouse deviceThis single chip can
interface with three key-switches and 4X-Y photo-couples plus
Z-axis directly to 8042 controller
There are four types of Z-axis inputs used to implement
scrolling mouse functionality
FEATURES
*Using 50K+5% resistor for RC oscillation
*Compatible with legacy PS/2 mouse
*Compatible with Microsoft PS/2 scrolling mouse
*Built-in noise immunity circuit
*The sampling rate of motion detector is up to 65KHz
*Built-in three step dynamic input impedance
*Three key-switches and four photo-couples inputs
*Photo couple test mode included
*Low power dissipation
*Two types Z direction input:
1.Photo couples input
2.Mechanical input
DIP-16
SOP-16
UTC UT84520
CMOS
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UNISONIC TECHNOLOGIES CO., LTD.
2
QW-R502-004,C
Pin Assignment
X2
CLK
OPT
Z2
Y1
OSCR
Y2
VDD
OSC.OUT
L
M
VSS
R
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
DATA
Z1
X1
Pin Descriptions
Pin No Symbol I/O Function
1 Vdd P
Power
line
2
OSC.OUT
O
The RC oscillation clock output. Or 3mA sink current output for X, Y photo emitters
3 Z1 I
4 Z2 I
Z-axis input.
Photo mode: three steps dynamic input impedance.
5
CLK
I/O
Connect to 8042 auxiliary port CLK line in PS/2 mode.
6
DATA
I/O
Connect to 8042 auxiliary port DATA line in PS/2 mode.
7 OPT I
Input: 200Kohm pull low to Vss.
When Opt is connected to Vdd, UT84520 will enter test mode. In test mode, L will
be the output of X1, while M will be the output of X1. Toggling R key can change
these output to be Y1, Y2 or Z1, Z2 respectively.
8
Vss
P
Power line Gnd
9 R I
10 M I/O
11 L I/O
Three key switches inputs. 200Kohm pull low.
In Z-axis key mode, M key toggling can change the scrolling speed from low to
high
12 X1 I
13 X2 I
14 Y1 I
15 Y2 I
Three step dynamic input impedance. If OSC.OUT is not connected to LEDs, the
dynamic input impedance will be off.
16
OSCR
I
Connect 50Kohm 5% for oscillation
UTC UT84520
CMOS
UTC
UNISONIC TECHNOLOGIES CO., LTD.
3
QW-R502-004,C
Functional Block Diagram
T hre e T yp e s S e le c to r
C o m p a ra to r
V o lta g e S e ns o r
Z -A x is C o unter
C
o
m
p
ar
ator
Mot
i
on D
e
tect
or
C o unter
M ultip le x e r
D
e
bou
nce
C o m m a nd
S ta tus
S ys te m C lo c k
G e n e ra to r
R C O s c illa tio n
T im ing
C o ntro lle r
D a ta I/O
Z 2
Z 1
O P T
X1
X2
Y1
Y2
L
M
R
O S C .O U T
O S C R
D A T A
C LK
ABSOLUTE MAXIMUM RATINGS
PARAMETER VALUE
UNIT
Supply voltage
-0.3~7.5
V
Power dissipation
500
mW
Temperature under bias
0~70
Storage Temperature
-65~150
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UNISONIC TECHNOLOGIES CO., LTD.
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QW-R502-004,C
DC Electrical Characteristics
(Ta = 25 ~70 )
PARAMETER SYMBOL
MIN TYP MAX
UNIT
X1,X2,Y1,Y2,Z1,Z2 (photo mode)
Low input reference current
Ipl 70 uA
X1,X2,Y1,Y2,Z1,Z2 (photo mode)
High input reference current
Iph 106
uA
X1,X2,Y1,Y2,Z1,Z2 (photo mode)
Input current (input impedance) ( 80uA)
Vpl1
0.8 1.2
V
X1,X2,Y1,Y2,Z1,Z2 (photo mode)
Input current (input impedance) ( 500uA)
Vpl2
1.5 2.1
V
L,M,R,OPT,
Input low voltage
Vail 1.5
V
L,M,R,OPT,
Input high voltage
Vaih 3.5
- V
L,M,R
Input current (Vin = 5V)
Imi 18 56
uA
OPT
Input current
Ixi -18 -56
uA
L,M,R,X1,X2,Y1,Y2,Z1,Z2
Input leakage current (Vin = 0V)
Iil 0 -1.0
uA
OPT
Input leakage current (Vin = 5V)
Iih 0 1.0
UA
OSC.OUT
Sink current
Iosc 3 3.6
MA
PS/2 mouse mode :
(Ta = 25 to 70 )
PARAMETER SYMBOL
MIN TYP MAX
UNIT
Operating
voltage
Vdd 4.5 5 5.5 V
Operating current (no load)
Iop
1
mA
CLK, DATA
Positive-going threshold voltage
Vt+ 3.2 3.8
V
CLK, DATA
Negative-going threshold voltage
Vt- 1.2 1.9
V
DATA, CLK
Input current (Vin = 0V)
Idc 0.56 1.86
mA
DATA, CLK
Low output voltage (Iprl = -2mA)
Vprl 0.4
V
*ll parameters in above table are compared with VSS.
UTC UT84520
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UNISONIC TECHNOLOGIES CO., LTD.
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QW-R502-004,C
AC Electrical Characteristics
(Ta = 25 to 70 )
PARAMETER SYMBOL
MIN TYP MAX
UNIT
Oscillating Frequency
Fosc
37-3%
37
37+3%
KHz
Key Debounce
Tkd
12
ms
Rising Edge Crossed Width
Tr
13.5
s
Falling Edge Crossed Width
Tf
13.5
s
Mouse CLK Active Time
Tmca
40.5
s
Mouse CLK Inactive Time
Tmci
40.5
s
Time that Mouse Sample DATA from
CLK rising Edge
Tmdc 13.5 s
System CLK Active Time
Tsca
40.5
s
System CLK Inactive Time
Tsci
40.5
s
Time from DATA Transition to Falling
Edge of CLK
Tsdc 13.5 s
Time from rising Edge of CLK to DATA trasition
Tscd
27.0
s
Time to mouse Inhibit after the 11
th
CLK to ensure mouse
does not start another Transmission
Tpi 0 50
s
Timing Diagram
(A) Photo-couples pulse width
Tr
Tf
X1(Y1)
X2(Y2)
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