PCF2129AT/2,518 NXP Semiconductors, PCF2129AT/2,518 Datasheet - Page 17

• 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
PCF2129AT
Product data sheet
8.5.1.4 Battery switch-over architecture
8.5.2 Battery backup supply
The architecture of the battery switch-over circuit is shown in
The internal power supply (available on pin BBS) is equal to V
assured that there are decoupling capacitors on the pins V
The V
on the selected battery switch-over function mode:
Table 15.
Battery switch-over function mode
standard
direct switching
disabled
Fig 6.
BBS
Battery switch-over circuit, simplified block diagram
voltage on the output pin BBS is equal to the internal power supply, depending
Output pin BBS
V
V
th(sw)bat
th(sw)bat
All information provided in this document is subject to legal disclaimers.
V
V
BAT
DD
Rev. 5 — 12 February 2013
comparators
V
V
CC
CC
LOGIC
Conditions
V
V
V
V
V
only V
DD
DD
DD
DD
BAT
logic
> V
< V
> V
< V
must be put to ground
DD
V
Integrated RTC, TCXO and quartz crystal
BAT
BAT
BAT
BAT
DD(int)
V
available,
V
BAT
DD
OR V
AND V
DD
DD
switches
V
V
> V
DD(int)
DD(int)
DD
< V
th(sw)bat
, V
Figure
th(sw)bat
DD
BAT
PCF2129AT
or V
(internal
power supply)
, and BBS.
6.
V
BAT
BBS
001aag061
© NXP B.V. 2013. All rights reserved.
. It has to be
V
V
V
V
V
V
BBS
DD
BAT
DD
BAT
DD
equals
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