UTC UT84520

CMOS IC

QW-R502-004,A

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