pcf8593 NXP Semiconductors, pcf8593 Datasheet - Page 23

• Manufacturer Part Number: pcf8593
• Description: Low Power Clock/calendar
• Manufacturer: NXP Semiconductors

Philips Semiconductors
14 APPLICATION INFORMATION
14.1
14.1.1
By evaluating the average capacitance necessary for the
application layout a fixed capacitor can be used. The
frequency is best measured via the 1 Hz signal which can
be programmed to occur at the interrupt output (pin 7). The
frequency tolerance depends on the quartz crystal
tolerance, the capacitor tolerance and the
device-to-device tolerance (on average 5
Average deviations of 5 minutes per year can be
achieved.
14.1.2
Using the alarm function (via the I
than 1 Hz can be generated at the interrupt output for fast
setting of a trimmer.
1997 Mar 25
handbook, full pagewidth
Low power clock/calendar
(1) Example Philips DLC 196 Double-Layer Capacitor family.
Quartz frequency adjustment
M
M
ETHOD
ETHOD
1: F
2: OSCI T
IXED
OSCI
(1)
1 F
RIMMER
CAPACITOR
OSCO
OSCI
2
C-bus) a signal faster
CLOCK CALENDAR
PCF8593
RESET
10
Fig.23 Application diagram.
V SS
6
).
SCL
SDA
SDA
(I C-bus)
23
2
Procedure:
Routine:
14.1.3
Direct measurement of oscillator output (accounting for
test probe capacitance).
SCL
Power-on
Apply RESET
Initialization (alarm functions).
Set clock to time T and set alarm to time T + T
At time T + T (interrupt) repeat routine.
SDA
SCL
V DD
R
M
RESET
ETHOD
TRANSMITTER/
RECEIVER
R
MASTER
3:
R: pull-up resistor
R =
DIRECT OUTPUT
C BUS
V DD
t
r
MBD825
Product specification
PCF8593