em3027 EM Microelectronic, em3027 Datasheet - Page 25

• Manufacturer Part Number: em3027
• Description: Real-time Clock With I2c Or Spi Interface, Crystal Temperature Compensation, Battery Switchover And Trickle Charger
• Manufacturer: EM Microelectronic

If the power supply of the EM3027 (V
oscillator has a very low power consumption, the clock generation is sensitive to fast supply changes and clock pulses
could be lost.
If in the application, positive or negative V
EM3027 must be used, according to the following figure :
Figure 9 : Typical Schematic
The RC filter is composed of a capacitor (C) and resistor (R) implemented per example by a 2kΩ resistor and a 47 µF
capacitor. The capacitor can be increased if needed.
Copyright © 2008, EM Microelectronic-Marin SA
07/08 – rev B
( rechargeable
11 Using EM3027 with disturbed Supply Voltage on V
or Not )
Battery
protection resistor
Lithium battery
(optional)
Crystal
+
1K Ω
Super Cap.
C
Tantalum
Or
C D
XO
XI
V
BACK
V
CC
Supply
CC
EM3027
) is disturbed, the circuit must be protected against V
CC
V
V
SS
CC
fast slopes may occur, an RC low pass filter in the V
V
SS
CLKOUT
Interface
Serial
= 0V
INT
R
25
nIRQ
CC
V
V
CC
SS
(Application)
µ C
Application
Clock for
V
CC_EXT
CC
CC
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supply connection of the
fast transients. As the