Real time clock module
Epson Toyocom
Small size, low profile model package
SERIAL-INTERFACE REAL TIME CLOCK MODULE
RX - 4574 LC
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Built in frequency adjusted 32.768 kHz crystal unit.
Interface Type
:
:
:
:
3-wire serial interface
1.6 V to 5.5 V
1.3 V to 5.5 V
Operating voltage range
Wide Timekeeper voltage range
Low backup current
0.35
µA / 3 V (Typ.)
Actual size
32.768 kHz frequency output function
:
C-MOS output With Control Pin
The various functions include full calendar, alarm, timer.
Block diagram
Overview
32.768 kHz
CONTROL LINE
• 32.768 kHz frequency output function
• FOUT pin output (C-MOS output), CL=30 pF
• Output frequency is selectable from 1/30 Hz to 32.768 kHz
(32 Values)
OSC
DIVIDER
CLOCK and
CALENDAR
• Timer function
FOUT
FCON
• Timer function which can be set up between
1/4096 second and 255 minutes.
OUTPUT
TIMER
ALARM
CONTROLLER
REGISTER
• It is recorded automatically to TF-bit at the time of event
occurrence, and it’s possible to output with /TIRQ pin output
(open-drain output).
/ TIRQ
/ AIRQ
INTERRUPTS
CONTROLLER
• Selectable one time mode or repeat mode.
REGISTER
• Alarm function
• Alarm function can be set to any combination of day of
week, hour, or minute.
DATA
CLK
CONTROL
REGISTER
BUS
•It is recorded automatically to AF-bit at the time of event
occurrence, and it’s possible to output with /AIRQ pin output
(open-drain output).
INTERFACE
CIRCUIT
CE 1
CE 0
SHIFT REGISTER
Functions are compatible with RTC-4574 SA / JE / NB.
Pin Function
Terminal connection /External dimensions
(Unit:mm)
Signal Name Input / Output
Function
−
RX 4574 LC
The chip enabled input pin 0. (Built-in pull-down resistance)
When both CE0 and CE1 pins are at the “H” level , access to this
Real time clock module becomes possible.
CE0
CE1
Input
Input
DD
12. V
1. N.C.
The chip enabled input pin 1.
When the CE1 pin is at the HIGH level, the FOUT pin is in the output state.
2. N.C.
11. CE1
10. CLK
9. DATA
8. CE0
CLK
Input
Bi-directional
Output
The shift clock input pin for serial data transfer.
3. /TIRQ
4. /AIRQ
5. FCON
6. FOUT
DATA
The data input / output pin for serial data transfer.
This pin outputs the reference clock signal at 32.768 kHz ( C-MOS output ).
High impedance at the time of output off.
2.4
2.8
FOUT
FCON
/ AIRQ
/ TIRQ
Input
The input pin for the FOUT output control.
The open drain output pin for alarm and time update interrupts.
The open drain output pin for timer interrupt.
Connected to a positive power supply.
Output
Output
7. GND
V
DD
−
VSOJ 12pin
GND
Connected to a ground.
Specifications (characteristics)
Refer to application manual for details.
!
Recommended Operating Conditions
!
Current consumption characteristics
Ta = −40 °C to +85 °C
Item
Symbol
Condition
Min.
Typ.
Max.
Unit
Item
Symbol
Condition
Min. Typ. Max. Unit
DD
Power voltage
Clock voltage
Operating
V
V
1.6
1.3
3.0
3.0
5.5
5.5
V
V
CLK
DD
V
= 5 V
0.45 0.9
µA
OPR
°
T
-40
+25
+85
C
CE0, CE1 = GND
temperature
BK
I
FOUT ;output OFF
( Hi - z )
DD
V
!
Frequency characteristics
= 3 V
0.35 0.7
Item
Symbol
Condition
Rating
Unit
Current
Consumption
DD
V
a
°
C
T
V
= +25
Frequency
tolerance
−6
10
CE0 = GND
∆
±
*
×
f / f
5
23
= 5 V
8.0 20.0
µA
DD
= 3.0 V
DD
CE1 = V
a
°
T
= +25
C
32k
I
1 Max.
3 Max.
s
FOUT ;
32.768 kHz output ON
CL = 30 pF
DD
DD
V
Oscillation
Start-up time
V
= 1.6 V
STA
t
a
°
°
C
= 3 V
5.0 12.0
T
= -40 C to +85
s
DD
V
= 1.6 V
*Equivalent to 1 minute of monthly deviation
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