PCF2129AT/2,518 NXP Semiconductors, PCF2129AT/2,518 Datasheet - Page 13

• Manufacturer Part Number: PCF2129AT/2,518
• Description: Real Time Clock
• Manufacturer: NXP Semiconductors
• Series: PCF2129r

Specifications of PCF2129AT/2,518

• Rohs: yes
• Function: Clock, Calendar, Alarm, Watchdog, Timestamp
• Rtc Bus Interface: I2C, SPI
• Date Format: Binary
• Time Format: Binary
• Supply Voltage - Max: 4.2 V
• Supply Voltage - Min: 1.2 V
• Maximum Operating Temperature: + 60 C
• Minimum Operating Temperature: - 15 C
• Mounting Style: SMD/SMT
• Package / Case: SOP-20
• Battery Backup Switching: Yes
• Factory Pack Quantity: 2000

NXP Semiconductors
2.
PCF2129AT
Product data sheet
For further information please refer to the application note
8.4.1 Crystal aging correction
8.4 Register Aging_offset
Table 12.
The PCF2129AT has an offset register Aging_offset to correct the crystal aging effects
The accuracy of the frequency of a quartz crystal depends on its aging. The aging offset
adds an adjustment, positive or negative, in the temperature compensation circuit which
allows correcting the aging effect.
At 25 C, the aging offset bits allow a frequency correction of typically 1 ppm per AO[3:0]
value, from 7 ppm to +8 ppm.
Table 13.
[1]
Bit
7 to 4 -
3 to 0 AO[3:0]
AO[3:0]
Decimal
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Default value.
Symbol
Aging_offset - crystal aging offset register (address 19h) bit description
Frequency correction at 25C, typical
All information provided in this document is subject to legal disclaimers.
Rev. 5 — 12 February 2013
Ref. 3
Value
-
see
Table 13
“AN10857”.
Binary
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
Description
unused
aging offset value
Integrated RTC, TCXO and quartz crystal
[1]
PCF2129AT
ppm
+8
+7
+6
+5
+4
+3
+2
+1
0
1
2
3
4
5
6
7
© NXP B.V. 2013. All rights reserved.
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