Real time clock module
Epson Toyocom
Small size, low profile model package
SERIAL-INTERFACE REAL TIME CLOCK MODULE
RX - 4574 LC
•Built in frequency adjusted 32.768 kHz crystal unit.
•Interface Type
: 3-wire serial interface
•Operating voltage range
: 1.6 V to 5.5 V
•Wide Timekeeper voltage range : 1.3 V to 5.5 V
•Low backup current
: 0.35 µ A / 3 V (Typ.)
•32.768 kHz frequency output function : C-MOS output With Control Pin
•The various functions include full calendar, alarm, timer.
Actual size
Block diagram
Overview
32.768 kHz
OSC
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)
CLOCK and
DIVIDER
CALENDAR
• Timer function
FOUT
FCON
OUTPUT
CONTROLLER
INTERRUPTS
/ TIRQ
ALARM
REGISTER
CONTROLLER
/ AIRQ
• Timer function which can be set up between
1/4096 second and 255 minutes.
• 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).
• Selectable one time mode or repeat mode.
TIMER
REGISTER
• Alarm function
• Alarm function can be set to any combination of day of
week, hour, or minute.
•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).
CONTROL
REGISTER
BUS
CLK
INTERFACE
CIRCUIT
CE 0
SHIFT REGISTER
∗ Functions are compatible with RTC-4574 SA / JE / NB.
Pin Function
Terminal connection / External dimensions
Signal Name Input / Output
Function
CE0
Input
CE1
Input
CLK
Input
DATA
Bi-directional
1. N.C.
3. / TIRQ
Output
Input
/ AIRQ
Output
Output
The open drain output pin for timer interrupt.
VDD
-
Connected to a positive power supply.
GND
-
4. / AIRQ
The open drain output pin for alarm and time update interrupts.
/ TIRQ
11. CE1
10. CLK
2.4
9. DATA
Connected to a ground.
5. FCON
6. FOUT
Power voltage
Clock voltage
Operating
temperature
Condition
Min.
Typ.
Max.
Unit
VDD
VCLK
-
1.6
1.3
3.0
3.0
5.5
5.5
-
-40
+25
+85
Item
Symbol
Oscillation
Start-up time
Symbol
∆f/f
tSTA
Condition
Ta = +25 °C
VDD = 3.0 V
Ta = +25 °C
VDD = 1.6 V
Ta = -40 °C to +85 °C
VDD = 1.6 V
Rating
Unit
5 ± 23 *
× 10
1 Max.
3 Max.
Current
Consumption
−6
s
I32k
s
*Equivalent to 1 minute of monthly deviation
http://www.epsontoyocom.co.jp
Typ.
Max.
VDD
=5V
0.45
0.9
FOUT ;output OFF
( Hi - z )
VDD
=3V
0.35
0.7
CE0 = GND
CE1 = VDD
°C
! Frequency characteristics
Item
T a = −40 °C to +85 °C
CE0, CE1 = GND
V
V
TOPR
! Current consumption characteristics
IBK
Frequency
tolerance
7. GND
2.8
∗ Refer to application manual for details.
Specifications (characteristics)
Symbol
8. CE0
VSOJ − 12pin
! Recommended Operating Conditions
Item
1.2 Max.
FOUT
12. VDD
2. N.C.
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.
The input pin for the FOUT output control.
FCON
(Unit:mm)
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.
The chip enabled input pin 1.
When the CE1 pin is at the HIGH level, the FOUT pin is in the output state.
The shift clock input pin for serial data transfer.
3.6
CE 1
0.5
DATA
Condition
Min.
VDD
=5V
8.0
20.0
FOUT ;
32.768 kHz output ON
CL = 30 pF
VDD
=3V
5.0
12.0
Unit
µA
µA
