ur7hcpxz-p440 Semtech Corporation, ur7hcpxz-p440 Datasheet - Page 3

• Manufacturer Part Number: ur7hcpxz-p440
• Description: Advanced Click-to-select No-drifttm Ps/2 Force Stick Controller
• Manufacturer: Semtech Corporation

The UR7HCPXZ-P440 consists
functionally of five major sections
(see Functional Diagram, previous
page). These are the PixiPoint
Interface, the 16-Bit Timer, the
Oscillator Circuit, the PS/2
Communication Port and the 8042
Emulation Port. All sections
communicate with each other and
operate concurrently.
The PixiPoint
(but very firm) “beam” with four
Strain Gages – one on each of the
sides. If the force is applied
precisely in the X direction, then it
will produce a change of resistance
of only the two X gages. Force in
the Y direction will cause changes
only in the Y gages. One of the
pair of the gages will increase,
while the other will concurrently
decrease the resistance.
If the user presses on the sensor
from the top (Z Axis), all of the
strain gages will decrease the
resistance.
When the test current is passed
through the gages, these resistance
changes are converted into the
voltage changes. These signals are
very small, typically under 1 mV Full
Scale.
The Signal Conditioning Circuit
(patent pending) balances and
amplifies the incoming signals for
digitizing by a built-in A/D
converter.
Copyright Semtech 2000-2001
DOC7-PXZ-P440-DS-111
FUNCTIONAL DESCRIPTION
SIGNAL CONDITIONING CIRCUIT
TM
Z sensor is a flexible
TM
Z
Semtech’s proprietary circuit can correct a significant imbalance between
the gages in each X and Y pair (+/- 25%), allowing relaxed manufacturing
tolerances for the sensors, interconnecting cabling, and temperature-shift
induced errors (no performance degradation over the full operating
temperature range and for large temperature gradients between the
paired gages).
Mnemonic
VDD
VSS
VSS2
OSCIN
_OSCOUT
_RESET
MDAT
MCLK
XCLK
XCLK1
XDAT
_LB
_MB
_RB
DRV_XY0
DRV_XY1
Z_SIG0
Z_SIG1
DRVZ
SELX
SELZ
INH
VREF
AD
DA
OFST
SPWR0
SPWR1
SPWR2
SPWR3
SPWR4
PWROFF
Note: An underscore before a pin mnemonic denotes an active low signal.
Pin Types Legend: AI=Analog Input; I=Input; O=Output; I/O=Input or Output;
I/O (nd)=Input or Output with N-chanel Open Drain driver
PIN DEFINITIONS
3
SIGNAL CONDITIONING CIRCUIT (CON’T)
Pin #
11
10
21
20
17
18
16
23
24
25
12
13
14
15
22
31
32
26
27
28
29
30
19
8
7
9
6
4
2
3
5
1
Type
P
P
P
I
O
I
I/O (nd)
I/O (nd)
I
I/O (nd)
I/O (nd)
I/O (nd)
I/O (nd)
I/O (nd)
I/O
I/O
I/O
I/O
I/O
O
O
O
AI
AI
I/O
I/O
I/O
I/O
I/O
I/O
I/O
I/O
Name and Function
Power Supply: +5V
Ground
Ground
Oscillator Input: external clock input or one
side of the Ceramic Resonator with built-in Load
Capacitors
Oscillator Output: open for external clock
input or other side of the Ceramic Resonator with
built-in Load Capacitors
Reset: apply 0V to provide orderly start-up
Mouse Data: connects to host’s data line
Mouse Clock: connects to host’s clock line
External Mouse Clock: PS/2 clock signal from
external mouse
External Mouse Clock 1: connect to XCLK
External Mouse Data: PS/2 data signal from
external mouse
Left Button: active low, strobed sampling
Middle Button: active low, strobed sampling
Right Button: active low, strobed sampling
Sensor’s Excitation Driver
Sensor’s Excitation Driver: connect to DRV_XY0
Sensor’s Excitation Driver
Sensor’s Excitation Driver: connect to Z_SIG0
Sensor’s Excitation Driver
Select X: control line for analog multiplexer
Select Z: control line for analog multiplexer
Multiplexer Inhibit Signal: active high
Reference Voltage for built-in A/D
Analog to Digital Converter Input
Digital to Analog Converter Output
Offset: resets the offset circuit during inactivity
Switched Power Driver
Switched Power Driver: connect to SPWR0
Switched Power Driver: connect to SPWR0
Switched Power Driver: connect to SPWR0
Switched Power Driver: connect to SPWR0
Reserved: power management control
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