PCF8523 NXP [NXP Semiconductors], PCF8523 Datasheet - Page 18

• Manufacturer Part Number: PCF8523
• Description: Real-Time Clock (RTC) and calendar
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
PCF8523
Product data sheet
An unreliable battery will not ensure data integrity during periods of backup battery
operation.
When V
Figure
1. The battery low flag BLF is set logic 1.
2. An interrupt is generated if the control bit BLIE (register Control_3) is enabled. The
3. The flag BLF (register Control_3) remains logic 1 until the battery is replaced. BLF
Fig 11. Battery low detection behavior with bit BLIE set logic 1 (enabled)
V
DD
V
interrupt remains active until the battery is replaced (BLF set logic 0) or when bit BLIE
is disabled (BLIE set logic 0).
cannot be cleared using the interface. It is cleared automatically by the battery low
detection circuit when the battery is replaced.
(= 2.5 V)
th(bat)low
= V
INT1
V
11):
BLF
BBS
BAT
BAT
drops below the threshold value V
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 30 March 2011
internal power supply (= V
th(bat)low
V
BAT
Real-Time Clock (RTC) and calendar
, the following sequence occurs (see
BBS
)
PCF8523
© NXP B.V. 2011. All rights reserved.
013aaa323
18 of 66