PCA9620H/Q900/1,51 NXP Semiconductors, PCA9620H/Q900/1,51 Datasheet - Page 35

• Manufacturer Part Number: PCA9620H/Q900/1,51
• Description: LCD Drivers 480 SEGMENT LCD SEGMENT DRIVER
• Manufacturer: NXP Semiconductors

Specifications of PCA9620H/Q900/1,51

• Number Of Segments: 60
• Maximum Clock Frequency: 14500 Hz
• Operating Supply Voltage: 2.5 V to 5.5 V
• Maximum Power Dissipation: 400 mW
• Maximum Operating Temperature: + 105 C
• Package / Case: LQFP-80
• Maximum Supply Current: 200 uA
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 935291899518

NXP Semiconductors
PCA9620
Product data sheet
7.4.7 Temperature readout
In case it is desired to change the charge pump frequency, it is recommended to make a
graph like
basically imply to find out what would be the maximum V
be the maximum load currents required. Then it can be decided which is the best setting
of bit CPF.
Tuning the charge pump frequency might be a difficult task to do and requires good
knowledge of the application in which the IC is being used; therefore, NXP recommends
to keep the CPF bit set logic 0 to have the maximum charge pump frequency, thus having
the maximum driving strength.
The PCA9620 has a built-in temperature sensor which provides a 8 bit digital value,
TD[7:0], of the ambient temperature. This value can be read through the I
Figure 49 on page
Equation
The measurement needs about 5 ms to complete and is repeated periodically as soon as
bit TME is set logic 1 (see
to the system clock and hence varies with changes in the chosen frame frequency, see
Table
Table 28.
Due to the nature of a temperature sensor, oscillations on the V
this, a filter has been implemented in PCA9620. The system is shown in
Like any other filtering, the digital temperature filter (see
delay in the measurement of temperature. This behavior is illustrated in
T (°C)
Selected frame frequency
60 Hz
200 Hz
300 Hz
Fig 27. Temperature measurement block with digital temperature filter
28.
=
11:
0.9375
Figure 26
Temperature measurement update rate
MEASUREMENT
TEMPERATURE
BLOCK
All information provided in this document is subject to legal disclaimers.
×
TD 7:0
52). The actual temperature is determined from TD[7:0] using
and understand what the application requirements are. This would
[
Rev. 1 — 9 December 2010
] 40
Table 9 on page
–
unfiltered
TD[7:0]
enabled or disabled
TEMPERATURE
by bit TFE
DIGITAL
FILTER
Universal LCD driver for low multiplex rates
7). The time between measurements is linked
Temperature measurement update rate
3.3 s
1 s
0.67 s
TD[7:0]
filtered
LCD
Figure
requirements and what would
To the readout register
via I
the V
block
LCD
27) introduces a certain
2
LCD
C-bus and to
may occur. To avoid
PCA9620
compensation
© NXP B.V. 2010. All rights reserved.
Figure
2
013aaa260
Figure
C interface (see
28.
27.
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