Real time clock module
REAL TIME CLOCK MODULE (I2C-Bus)
For Automotive
Product Number (Please contact us)
RA8900SA: X1B000282Axxx00
RA8900CE: X1B000271Axxx00
Built-in 32.768 kHz-DTCXO, High Stability
and Power Switching
CE
RA 8900 SA/CE
Built in frequency adjusted 32.768 kHz crystal unit and DTCXO.
Interface Type
Interface voltage range
: I2C-Bus interface (400kHz)
: 2.5 V to 5.5 V
RA8900CE
(3.2 × 2.5 × 1.0 mm)
RA8900SA
(10.1 × 7.4 × 3.3 mm)
Temp. compensated voltage range : 2.0 V to 5.5 V
Clock supply voltage range : 1.6 V to 5.5 V
Selectable clock output (32.768 kHz, 1024 Hz, 1 Hz)
Actual size
The various functions include full calendar, alarm, timer, temp. sensor function. RA8900SA
Applications : Car audio, Car navigation system, Clock
Conforms to AEC-Q200
RA8900CE
*The I2C-BUS is a trademark of NXP Semiconductors.
Block diagram
Overview
High Stability
UA ± 3.4 x 10-6
/
-40 ºC to +85 ºC
( Equivalent to 9 seconds of month deviation )
UB ± 5.0 x 10-6
-40 ºC to +85 ºC
( Equivalent to 13 seconds of month deviation )
± 5.0 x 10-6
-30 ºC to +70 ºC
( 32.768 kHz )
DTCXO
/
UC
/
DIVIDER
CLOCK
and
( Equivalent to 13 seconds of month deviation )
CALENDR
32.768 kHz frequency output function
FOUT pin output (C-MOS output), CL=30 pF
Output selectable: 32.768 kHz, 1024 Hz, 1 Hz
VDD
POWER
CONTROLLER
TI MER REGISTER
VBAT
Available automatic battery backup switch-over function
When VDD deteriorates, internal source is switched to VBAT.
A very small leakage current
INTERRUPTS
CONTROLLER
/ INT
ALARM REGISTER
FOUT
FOE
Timer function
Timer function can be set up between 1/4096 second
and 4095 minutes.
CONTROLLER
CONTROL
REGISTER
FOUT
and
SCL
SDA
BUS
SYSTEM
CONTROLLER
Alarm function
Alarm function can be set to day of week, day, hour, and minute.
INTERFACE
CIRCUIT
Temp. sensor function
The temperature data are output to a register by a temp. sensor
function. (Bank.2_Add17h)
Pin Function
Terminal connection/External dimensions
(Unit:mm)
Signal Name
I / O
Function
RA8900SA
RA8900CE
Use by the manufacture for testing.
( Do not connect externally.)
Serial clock input pin.
The pin outputs the reference clock signal.
( CMOS output )
Battery supply.
This pin has charge capability to backup battery.
Connected to a positive power supply
The input pin for the FOUT output control.
1. FOE
2. VDD
3. VBAT
4. FOUT
5. SCL
10. /INT
1. T1(CE)
2. SCL
3. FOUT
4. N.C.
5. VBAT
6. VDD
14. N.C.
13. SDA
12. T2(VPP)
11. GND
T1(CE)
SCL
input
input
9. GND
8. T2(VPP)
7. SDA
FOUT
Output
2.5 ± 0.2
5.0
VBAT
-
10.
/INT
6. T1(CE)
VDD
FOE
/ INT
GND
-
9. N.C.
8. N.C.
input
7.4 0.2
7. FOE
Output Interrupt output (N-ch. open drain).
-
Connected to a ground
SOP14 pin
Use by the manufacture for testing.
( Do not connect externally.)
Data input and output pin.
T2(VPP)
SDA
-
The metal case inside of the molding compound may be exposed on the top or bottom of this product.
This purely cosmetic and does not have any effect on quality, reliability or electrical specs.
I/O
Specifications (characteristics)
Refer to application manual for details.
Electrical Characteristics
32.768 kHz-DTCXO Frequency temperature characteristics (Example)
Item
Symbol
Conditions
Min.
Typ.
Max.
Unit
Operating voltage
VDD
VTEM
VCLK
TOPR
2.5
2.0
1.6
-40
3.0
3.0
3.0
+25
5.5
5.5
5.5
+85
V
Interface voltage
Temp. compensated voltage
Internal clock
Frequency temperature characteristics
10
Temp. compensated Voltage
Clock supply voltage
Operating temperature
V
V
5
32.768 kHz DTCXO
No condensation
ºC
0
1
UA
UB
Ta= -40 ºC to +85 ºC
Ta=-40 ºC to +85 ºC
Ta= -30 ºC to +70 ºC
±3.4
±5.0
f/f
10-6
-5
Stability
2
UC
-10
fSCL=0Hz, /INT=VDD,
FOE =GND
VDD=VBAT
FOUT: OFF
Temp. Compensation
interval 2.0 s.
-15
Current consumption (1)
Current consumption (2)
IDD1
IDD2
VDD = 5V
VDD = 3V
-
-
0.72
0.70
1.5
1.4
Tuning fork X'tal
-20
A
-25
-30
1)
2)
Equivalent to 13 seconds of month deviation.
-45 -35 -25 -15
-5
5
15
25
35
45
55
65
75
85
Equivalent to 9 seconds of month deviation.
Temperature (ºC)