S-35192A
www.ablic.com
3-WIRE REAL-TIME CLOCK
© ABLIC Inc., 2006-2018
Rev.3.2_04
The S-35192A is a CMOS 3-wire real-time clock IC which operates with the very low current consumption in the wide range of
operation voltage. The operation voltage is 1.3 V to 5.5 V so that the S-35192A can be used for various power supplies from
main supply to backup battery. Due to the 0.45 A current consumption and wide range of power supply voltage at time
keeping, the S-35192A makes the battery life longer. In the system which operates with a backup battery, the included free
registers can be used as the function for user's backup memory. Users always can take back the information in the registers
which is stored before power-off the main power supply, after the voltage is restored.
The S-35192A has the function to correct advance / delay of the clock data speed, in the wide range, which is caused by the
crystal oscillation circuit's frequency deviation. Correcting according to the temperature change by combining this function
and a temperature sensor, it is possible to make a high precise clock function which is not affected by the ambient
temperature.
Features
Low current consumption:
0.45 A typ. (VDD = 3.0 V, Ta = 25C)
Constant output of 32.768 kHz clock pulse (Nch open-drain output)
Wide range of operating voltage:
1.3 V to 5.5 V
Built-in clock correction function
Built-in free user register
3-wire (MICROWIRE) CPU interface
Built-in alarm function
Built-in flag generator during detection of low power voltage or at power-on
Auto calendar up to the year 2099, automatic leap year calculation function
Built-in constant voltage circuit
Built-in 32.768 kHz crystal oscillation circuit (built-in Cd, external Cg)
Lead-free (Sn 100%), halogen-free
Applications
Mobile game device
Mobile AV device
Digital still camera
Digital video camera
Electronic power meter
DVD recorder
TV, VCR
Mobile phone, PHS
Package
SNT-8A
1
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
Block Diagram
XIN
XOUT
Oscillatoion
circuit
Divider,
timing generator
Clock correction register
Status register 1
INT
INT register 1
controller 1
32KO
Comparator 1
Real-time data register
Day of
Second Minute Hour
Day Month Year
the week
Status register 2
Comparator 2
Free register
VDD
Low power supply
voltage detector
Power-on
detection circuit
INT register 2
controller 2
Shift register
Constant-voltage
circuit
VSS
Figure 1
2
INT
Serial
interface
SIO
SCK
CS
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
Product Name Structure
1. Product name
S-35192A -
I8T1
U
Environmental code
U:
Lead-free (Sn 100%), halogen-free
Package name (abbreviation) and IC packing specification*1
I8T1: SNT-8A, Tape
Product name
*1.
Refer to the tape drawing.
2. Package
Table 1
Package Name
SNT-8A
Package Drawing Codes
Dimension
Tape
Reel
Land
PH008-A-P-SD
PH008-A-C-SD
PH008-A-R-SD
PH008-A-L-SD
3
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
Pin Configuration
1. SNT-8A
Table 2
Pin No. Symbol
Top view
1
2
3
4
Figure 2
8
7
6
5
S-35192A-I8T1U
I/O
Pin for constant
output of
Output
32.768 kHz
Connection pins
for quartz
crystal
GND pin
1
32KO
2
XOUT
3
XIN
4
VSS
5
CS
Input pin for
chip select
6
SCK
Input pin for
serial clock
7
SIO
I/O pin for
serial data
VDD
Pin for positive
power supply
8
4
Description
List of Pins
Configuration
Nch open-drain output
(no protective diode at VDD)
CMOS input
Input
(built-in pull-down resistor.
no protective diode at VDD)
CMOS input
Input
(no protective diode at VDD)
Nch open-drain output
Bi-directional (no protective diode at VDD)
CMOS input
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
Pin Functions
1. CS (input for chip select) pin
This pin is to input chip select, has a pull-down resistor. Communication is available when this pin is in "H". If not using
communication, set this pin "L" or open.
2. SCK (input for serial clock) pin
This pin is to input a clock pulse for serial interface. When the CS pin is in "H", the SIO pin inputs / outputs data by
synchronizing with the clock pulse. When the CS pin is in "L" or open, the SCK pin does not accept inputting a clock
pulse.
3. SIO (I/O for serial data) pin
This pin is a data input / output pin of serial interface. When the CS pin is in "H", the SIO pin inputs / outputs data by
synchronizing with a clock pulse from the SCK pin. The status is in "High-Z" when the CS pin is in "L" or open, so
that the S-35192A does not transmit data. Setting the CS pin to "H" from "L" or open, this SIO pin goes in the input
status so that it receives the command data. This pin has CMOS input and Nch open drain output.
4. XIN, XOUT (quartz crystal connect) pins
Connect a quartz crystal between XIN and XOUT.
5. 32KO (constant output of 32.768 kHz) pin
This is an output pin for 32.768 kHz. This pin constantly outputs a clock pulse after power-on.
6. VDD (positive power supply) pin
Connect this VDD pin with a positive power supply. Regarding the values of voltage to be applied, refer to
" Recommended Operation Conditions".
7. VSS pin
Connect this VSS pin to GND.
Equivalent Circuits of Pins
SIO
SCK
Figure 3
SCK pin
Figure 4
SIO pin
CS
32KO
Figure 5
CS pin
Figure 6 32KO pin
5
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
Absolute Maximum Ratings
Table 3
Item
Symbol
Power supply voltage
VDD
Input voltage
VIN
Applied Pin
CS, SCK , SIO
Absolute Maximum Rating
Unit
VSS 0.3 to VSS 6.5
V
VSS 0.3 to VSS 6.5
V
Output voltage
VOUT
SIO, 32KO
VSS 0.3 to VSS 6.5
V
Operating ambient
Topr
40 to 85
C
*1
temperature
Storage temperature
Tstg
55 to 125
C
*1. Conditions with no condensation or frost. Condensation or frost causes short-circuiting between pins, resulting in a
malfunction.
Caution
The absolute maximum ratings are rated values exceeding which the product could suffer physical
damage. These values must therefore not be exceeded under any conditions.
Recommended Operation Conditions
Table 4
(VSS = 0 V)
Item
Symbol
Condition
Min.
Typ.
Max.
Unit
Power supply voltage*1
Ta = 40C to 85C
1.3
3.0
5.5
V
VDD
VDDT
Time keeping power
5.5
V
Ta = 40C to 85C
VDET 0.15
*2
supply voltage
Quartz crystal CL value
CL
6
7
pF
*1. The power supply voltage that allows communication under the conditions shown in Table 9 of " AC Electrical
Characteristics"
*2. The power supply voltage that allows time keeping. For the relationship with VDET (low power supply voltage detection
voltage), refer to " Characteristics (Typical Data)".
Oscillation Characteristics
Table 5
(Ta = 25C, VDD = 3.0 V, VSS = 0 V, VT-200 quartz crystal (CL = 6 pF, 32.768 kHz) manufactured by Seiko Instruments Inc.)
Item
Symbol
Condition
Min.
Typ.
Max.
Unit
Oscillation start voltage
VSTA
Within 10 seconds
1.1
5.5
V
Oscillation start time
tSTA
1
s
IC-to-IC frequency deviation*1
IC
10
10
ppm
Frequency voltage deviation
V
VDD = 1.3 V to 5.5 V
3
3
ppm/V
External capacitance
Cg
Applied to XIN pin
9.1
pF
Internal oscillation capacitance Cd
Applied to XOUT pin
8
pF
*1. Reference value
6
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
DC Electrical Characteristics
Table 6
DC Characteristics (VDD = 3.0 V)
(Ta 40C to85C, VSS = 0 V, VT-200 quartz crystal (CL = 6 pF, 32.768 kHz, Cg = 9.1 pF) manufactured by Seiko Instruments Inc.)
Item
Symbol
Applied Pin
Condition
Min.
Typ.
Max.
Unit
Current consumption 1
IDD1
Out of communication
During communication
0.45
1.13
A
3.3
8
A
Current consumption 2
IDD2
Input current leakage 1
IIZH
SCK , SIO
VIN = VDD
0.5
0.5
A
Input current leakage 2
IIZL
SCK , SIO
VIN = VSS
0.5
0.5
A
Input current 1
Input current 2
Input current 3
Output current leakage 1
Output current leakage 2
IIH1
IIH2
IIH3
IOZH
IOZL
CS
CS
CS
SIO, 32KO
SIO, 32KO
VIN = VDD
VIN = 0.4 V
VIN = 1.0 V
VOUT = VDD
VOUT = VSS
2
40
0.5
0.5
6
100
215
16
300
0.5
0.5
A
A
A
A
A
Input voltage 1
VIH
CS, SCK , SIO
0.8 VDD
VSS 5.5
V
Input voltage 2
VIL
CS, SCK , SIO
VSS 0.3
0.2 VDD
V
Output current 1
Output current 2
Power supply voltage
detection voltage
IOL1
IOL2
32KO
SIO
3
5
5
10
mA
mA
0.65
1
1.35
V
( SCK = 100 kHz)
VOUT = 0.4 V
VOUT = 0.4 V
VDET
DC Characteristics (VDD = 5.0 V)
Table 7
(Ta = 40C to 85C, VSS = 0 V, VT-200 quartz crystal (CL = 6 pF, 32.768 kHz, Cg = 9.1 pF) manufactured by Seiko Instruments Inc.)
Item
Symbol
Applied Pin
Condition
Min.
Typ.
Max.
Unit
Current consumption 1
IDD1
0.6
1.4
A
6
14
A
VIN = VDD
0.5
0.5
A
Out of communication
During communication
Current consumption 2
IDD2
Input current leakage 1
IIZH
SCK , SIO
Input current leakage 2
IIZL
SCK , SIO
VIN = VSS
0.5
0.5
A
Input current 1
Input current 2
Input current 3
Output current leakage 1
Output current leakage 2
IIH1
IIH2
IIH3
IOZH
IOZL
CS
CS
CS
SIO, 32KO
SIO, 32KO
VIN = VDD
VIN = 0.4 V
VIN = 2.0V
VOUT = VDD
VOUT = VSS
8
40
0.5
0.5
16
150
610
50
350
0.5
0.5
A
A
A
A
A
Input voltage 1
VIH
CS, SCK , SIO
0.8 VDD
VSS 5.5
V
Input voltage 2
VIL
CS, SCK , SIO
VSS 0.3
0.2 VDD
V
Output current 1
Output current 2
Power supply voltage
detection voltage
IOL1
IOL2
32KO
SIO
5
6
8
13
mA
mA
0.65
1
1.35
V
VDET
( SCK = 100 kHz)
VOUT = 0.4 V
VOUT = 0.4 V
7
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
AC Electrical Characteristics
Table 8
VDD
Measurement Conditions
Input pulse voltage
Input pulse rise / fall time
Output determination voltage
Output load
VIH = 0.8 VDD, VIL = 0.2 VDD
20 ns
VOH = 0.8 VDD, VOL = 0.2 VDD
80 pF pull-up resistor 10 k
R = 10 k
SIO
C = 80 pF
Remark
The power supplies of the IC
and load have the same
electrical potential.
Figure 7
Table 9
Output Load Circuit
AC Electrical Characteristics
(Ta = 40C to 85C)
VDD*2 1.3 V
VDD*2 3.0 V
Item
Symbol
Unit
Min.
Typ.
Max.
Min.
Typ.
Max.
Clock pulse width
tSCK
5
250000
1
250000
s
Setup time before CS rise
tDS
1
0.2
s
Hold time after CS rise
tCSH
1
0.2
s
Input data setup time
tISU
1
0.2
s
Input data hold time
tIHO
1
0.2
s
Output data definition time*1
3.5
1
s
tACC
Setup time before CS fall
tCSS
1
0.2
s
Hold time after CS fall
tDH
1
0.2
s
Input rise / fall time
tR, tF
0.1
0.05
s
*1. Since the output format of the SIO pin is Nch open-drain output, output data definition time is determined by the
values of the load resistance (RL) and load capacity (CL) outside the IC. Therefore, use this value only as a reference
value.
*2. Regarding the power supply voltage, refer to " Recommended Operation Conditions".
8
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
CS
tDS
tCSH
tCSS
tDH
SCK
tDS
tDH
SIO
Figure 8
Timing Diagram 1 during 3-wire Communication
tISU
tR
80%
SCK
tF
80%
20%
20%
tIHO
Input data
Figure 9
80%
80%
20%
20%
Timing Diagram 2 during 3-wire Communication
tSCK
SCK
50%
20%
tSCK
50%
50%
tACC
Output data
Figure 10
80%
80%
20%
20%
Timing Diagram 3 during 3-wire Communication
9
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
Configuration of Data Communication
1. Data communication
After setting the CS pin "H", transmit the 4-bit fixed code "0110", after that, transmit a 3-bit command and 1-bit read /
write command. Next, data is output or input from B7. Regarding details, refer to " Serial Interface".
Read / write bit
Fixed code
0
1
1
Command
0
C2
C1
C0
R/W
B2
B1
B0
1-byte data
B7
B6
B5
B4
Figure 11
10
B3
Data Communication
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
2. Configuration of command
8 types of command are available for the S-35192A. The S-35192A reads / writes the various registers by inputting
these fixed codes and commands. The S-35192A does not perform any operation with any codes and commands other
than those below. However, in case that the fixed codes or the commands are failed to be recognized in the 1st byte but
are successfully recognized in the 2nd and higher bytes, the commands are executed.
Table 10
List of Commands
Command
Fixed
Code C2 C1 C0
Description
Data
B7
B6
*1
B5
B4
*2
0
0
0 Status register 1 access
RESET
0
0
1 Status register 2 access
*2
INT1FE INT1ME INT1AE SC2
Y1
M1
0
0
1
1
0110
0
1
Real-time data 1 access
(year data to)
Real-time data 2 access
(hour data to)
INT register 1 access
(alarm time 1: week / hour / minute)
(INT1AE = 1, INT1ME = 0,
1
0
0 INT1FE = 0)
12 / 24
Y2
M2
SC0
B3
*2
Y4
M4
SC1
Y8
M8
B2
*3
B1
*3
B0
*4
INT2
SC3*2
SC4*2 INT2AE TEST*5
Y10
M10
Y20
*6
BLD
POC*4
INT1
Y40
Y80
*6
*6
*6
*6
*6
*6
D1
D2
D4
D8
D10
W1
W2
W4
*6
*6
H1
H2
H4
H8
H10
H20
AM / PM
*6
m1
m2
m4
m8
m10
m20
m40
*6
s1
s2
s4
s8
s10
s20
s40
*6
H1
H2
H4
H8
H10
H20
AM / PM
*6
m1
m2
m4
m8
m10
m20
m40
*6
s1
s2
s4
s8
s10
s20
s40
*6
W1
W2
W4
*6
*6
*6
*6
A1WE
H1
H2
H4
H8
H10
H20
m1
m2
m4
m8
m10
m20
SC5*2
SC6*2
SC7*2
SC8*2
SC9*2
W1
W2
W4
*6
*6
*6
H1
H2
H4
H8
H10
H20
m1
m2
m4
m8
m10
m20
m40
A2mE
V0
V1
V2
V3
V4
V5
V6
V7
D20
*6
AM / PM A1HE
m40
A1mE
INT register 1 access
(free register function)
SC10*2 SC11*2 SC12*2
(settings other than alarm time 1)
INT register 2 access
1
0
1 (alarm time 2: week / hour / minute)
1
1
0 Clock correction register access
(INT2AE = 1)
*6
A2WE
AM / PM A2HE
1 1 1 Free register access
F0
F1
F2
F3
F4
F5
F6
F7
*1. Write-only flag. The S-35192A initializes by writing "1" in this register.
*2. Scratch bit. This is a register which is available for read / write operations and can be used by users freely.
*3. Read-only flag. Valid only when using the alarm function. When the alarm time matches, this flag is set to "1", and it is
cleared to "0" when reading.
*4. Read-only flag. "POC" is set to "1" when power is applied. It is cleared to "0" when reading. Regarding "BLD", refer to
" Low Power Supply Voltage Detection Circuit".
*5. Test bit for ABLIC Inc. Be sure to set to "0" in use.
*6. No effect when writing. It is "0" when reading.
11
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
Configuration of Registers
1. Real-time data register
The real-time data register is a 7-byte register that stores the data of year, month, day, day of the week, hour, minute,
and second in the BCD code. To write / read real-time data 1 access, transmit / receive the data of year in B7, month,
day, day of the week, hour, minute, second in B0, in 7-byte. When you skip the procedure to access the data of year,
month, day, day of the week, read / write real-time data 2 access. In this case, transmit / receive the data of hour in B7,
minute, second in B0, in 3-byte.
The S-35192A transfers a set of data of time to the real-time data register when it recognizes a reading instruction.
Therefore, the S-35192A keeps precise time even if time-carry occurs during the reading operation of the real-time data
register.
Year data (00 to 99)
Start bit of real-time data 1 data access
Y1
Y2
Y4
Y8
Y10
Y20
Y40
B7
Y80
B0
Month data (01 to 12)
M1
M2
M4
M8
M10
0
0
B7
0
B0
Day data (01 to 31)
D1
D2
D4
D8
D10
D20
0
B7
0
B0
Day of the week data (00 to 06)
W1
W2
W4
0
0
0
0
B7
0
B0
Hour data (00 to 23 or 00 to 11)
Start bit of real-time data 2 data access
H1
H2
H4
H8
H10
H20 AM / PM
B7
0
B0
Minute data (00 to 59)
m1
m2
m4
m8
m10
m20
m40
B7
0
B0
Second data (00 to 59)
s1
s2
s4
s8
s10
s20
s40
B7
B0
Figure 12
12
0
Real-time Data Register
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
Year data (00 to 99): Y1, Y2, Y4, Y8, Y10, Y20, Y40, Y80
Sets the lower two digits of the Western calendar year (00 to 99) and links together with the auto calendar
function until 2099.
Example: 2053 (Y1, Y2, Y4, Y8, Y10, Y20, Y40, Y80) = (1, 1, 0, 0, 1, 0, 1, 0)
Month data (01 to 12): M1, M2, M4, M8, M10
Example: December (M1, M2, M4, M8, M10, 0, 0, 0) = (0, 1, 0, 0, 1, 0 ,0 ,0)
Day data (01 to 31): D1, D2, D4, D8, D10, D20
The count value is automatically changed by the auto calendar function.
1 to 31: Jan., Mar., May, July, Aug., Oct., Dec., 1 to 30: April, June, Sep., Nov.
1 to 29: Feb. (leap year), 1 to 28: Feb. (non-leap year)
Example: 29 (D1, D2, D4, D8, D10, D20, 0, 0) = (1, 0, 0, 1, 0, 1, 0, 0)
Day of the week data (00 to 06): W1, W2, W4
A septenary up counter. Day of the week is counted in the order of 00, 01, 02, …, 06, and 00. Set up day of the
week and the count value.
Hour data (00 to 23 or 00 to 11): H1, H2, H4, H8, H10, H20, AM / PM
In 12-hour mode, write 0; AM, 1; PM in the AM / PM bit. In 24-hour mode, users can write either 0 or 1. 0 is
read when the hour data is from 00 to 11, and 1 is read when from 12 to 23.
Example (12-hour mode): 11 p.m.
(H1, H2, H4, H8, H10, H20, AM / PM , 0) = (1, 0, 0, 0, 1, 0, 1, 0)
Example (24-hour mode): 22
(H1, H2, H4, H8, H10, H20, AM / PM , 0) = (0, 1, 0, 0, 0, 1, 1, 0)
Minute data (00 to 59): m1, m2, m4, m8, m10, m20, m40
Example: 32 minutes (m1, m2, m4, m8, m10, m20, m40, 0) = (0, 1, 0, 0, 1, 1, 0, 0)
Example: 55 minutes (m1, m2, m4, m8, m10, m20, m40, 0) = (1, 0, 1, 0, 1, 0, 1, 0)
Second data (00 to 59): s1, s2, s4, s8, s10, s20, s40
Example: 19 seconds (s1, s2, s4, s8, s10, s20, s40, 0) = (1, 0, 0, 1, 1, 0, 0, 0)
13
3-WIRE REAL-TIME CLOCK
S-35192A
2.
Rev.3.2_04
Status register 1
Status register 1 is a 1-byte register that is used to display and set various modes. The bit configuration is shown below.
B7
B6
B5
B4
B3
B2
B1
B0
RESET
12 / 24
SC0
SC1
INT1
INT2
BLD
POC
W
R/W
R/W
R/W
R
R
R
R
R:
W:
R / W:
Read
Write
Read / write
Figure 13
Status Register 1
B0: POC
This flag is used to confirm whether the power is on. The power-on detection circuit operates at power-on and B0 is
set to "1". This flag is Read-only. Once it is read, it is automatically set to "0". When this flag is "1", be sure to initialize.
Regarding the operation after power-on, refer to " Power-on Detection Circuit and Register Status".
B1: BLD
This flag is set to "1" when the power supply voltage decreases to the level of detection voltage (VDET) or less. Users
can detect a drop in the power supply voltage. Once this flag is set to "1", it is not set to "0" again even if the power
supply increases to the level of detection voltage (VDET) or more. This flag is read-only. When this flag is "1", be sure
to initialize. Regarding the operation of the power supply voltage detection circuit, refer to " Low Power Supply
Voltage Detection Circuit".
B2: INT2, B3: INT1
This flag indicates the time set by alarm and when the time has reached it. This flag is set to "1" when the time that
users set by using the alarm function has come. The INT1 flag in the alarm 1 function and the INT2 flag in the alarm
2 function are set to "1". Set "0" in INT1AE (B5 in the status register 2) or in INT2AE (B1 in the status register 2) after
reading "1" in the INT1 flag or in the INT2 flag. This flag is read-only. Once this flag is read, it is set to "0"
automatically.
B4: SC1, B5: SC0
These are SRAM type registers, they are 2 bits as a whole, can be freely set by users.
B6: 12 / 24
This flag is used to set 12-hour or 24-hour mode. Set the flag ahead of write operation of the real-time data register in
case of 24-hour mode.
0: 12-hour mode
1: 24-hour mode
B7: RESET
The internal IC is initialized by setting this bit to "1". This bit is write-only. It is always "0" when reading. When
applying the power supply voltage to the IC, be sure to write "1" to this bit to initialize the circuit. Regarding each
status of registers after initialization, refer to " Register Status After Initialization".
14
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
3. Status register 2
Status register 2 is a 1-byte register that is used to display and set various modes. The bit configuration is shown below.
B7
B6
B5
B4
B3
B2
B1
B0
INT1FE
INT1ME
INT1AE
SC2
SC3
SC4
INT2AE
TEST
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R / W: Read / write
Figure 14
Status Register 2
B0: TEST
This is a test flag for ABLIC Inc. Be sure to set this flag to "0" in use. If this flag is set to "1", be sure to initialize to set
"0".
B1: INT2AE
To use the alarm 2 function, access the INT register 2 after setting this flag enable. Disable when this flag is in "0",
enable when this flag is in "1".
B2: SC4, B3: SC3, B4: SC2
These flags are SRAM type registers, they are 3 bits as a whole, can be freely set by users.
B5: INT1AE, B6: INT1ME, B7: INT1FE
To use the alarm 1 function, access the INT register 1 after setting INTA1AE = "1", INT1ME = "0", and INT1FE = "0".
In other settings than this, these flags are disable for setting the alarm time (free registers).
15
3-WIRE REAL-TIME CLOCK
S-35192A
4.
Rev.3.2_04
INT register 1 and INT register 2
The INT register 1 and the INT register 2 are to set up the alarm time. The alarm output mode gets enable by using the
status register 2, these registers work as data registers for alarm time. When disable, the INT register 1 works as a
1-byte free register. Users are able to make sure the alarm output by reading the INT1 / INT2 flag (B3 or B2 in the status
register 1).
4. 1
Alarm function
Users can set the alarm time (the data of day of the week, hour, minute) by using the INT register 1 and 2 which are
3-byte data registers. The configuration of register is as well as the data register of day of the week, hour, minute, in
the real-time data register; is expressed by the BCD code. Do not set a nonexistent day. Users are necessary to set
up the alarm-time data according to the 12 / 24 hour mode that they set by using the status register 1.
INT register 2
INT register 1
W1
W2
W4
0
0
B7
H1
H2
H4
H8
0
A1WE
W1
B0
B7
/ A1HE
H10 H20 AM
PM
B7
m1
0
H1
B0
m2
m4
m8
m1
B0
B7
Figure 15
W4
0
0
0
0
A2WE
B0
H2
H4
H8
B7
m10 m20 m40 A1mE
B7
W2
H10 H20 AM / A2HE
PM
B0
m2
m4
m8
m10 m20 m40 A2mE
B0
INT Register 1 and INT Register 2 (Alarm-Time Data)
The INT register 1 has A1WE, A1HE, A1mE at B0 in each byte. It is possible to make data valid; the data of day of
the week, hour, minute which are in the corresponding byte; by setting these bits to "1". This is as well in A2WE,
A2HE, A2mE in the INT register 2.
Setting example: alarm time "7:00 pm" in the INT register 1
(1)
12-hour mode (status register 1 B6 = 0)
set up 7:00 PM
Data written to INT register 1
*1
*1
*1
*1
*1
Day of the week
Hour
1
1
1
0
0
Minute
0
0
0
0
0
B7
*1. Don't care (both of 0 and 1 are acceptable).
(2)
*1
1
0
0
1
1
B0
*1
0
0
*1
1*2
0
0
1
1
B0
24-hour mode (status register 1 B6 = 1)
set up 19:00 PM
Data written to INT register 1
*1
*1
*1
*1
*1
Day of the week
Hour
1
0
0
1
1
Minute
0
0
0
0
0
B7
*1. Don't care (both of 0 and 1 are acceptable).
*2.
16
*1
0
0
Set up AM / PM flag along with the time setting.
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
4. 2
Free register
The INT register 1 is a 1-byte SRAM type register that can be set freely by users.
B7
B6
B5
B4
B3
B2
B1
B0
SC5
SC6
SC7
SC8
SC9
SC10
SC11
SC12
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R / W: Read / write
Figure 16
INT Register 1 (Free register)
5. Clock correction register
The clock correction register is a 1-byte register that is used to correct advance / delay of the clock. When not using this
function, set this register to "00h". Regarding the register values, refer to " Function of Clock Correction".
B7
B6
B5
B4
B3
B2
B1
B0
V0
V1
V2
V3
V4
V5
V6
V7
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R / W: Read / write
Figure 17
Clock Correction Register
6. Free register
The free register is a 1-byte SRAM type register that can be set freely by users.
B7
B6
B5
B4
B3
B2
B1
B0
F0
F1
F2
F3
F4
F5
F6
F7
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R / W: Read / write
Figure 18
Free Register
17
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
Power-on Detection Circuit and Register Status
The power-on detection circuit operates by power-on the S-35192A, as a result each register is cleared; each register is
set as follows.
Real-time data register:
Status register 1:
Status register 2:
INT register 1:
INT register 2:
Clock correction register:
Free register:
00 (Y), 01 (M), 01 (D), 0 (day of the week), 00 (H), 00 (M), 00 (S)
"01h"
"80h"
"80h"
"00h"
"00h"
"00h"
"1" is set in the POC flag (B0 in the status register 1) to indicate that power has been applied. In this case, be sure to
initialize. The POC flag is set to "0" due to initialization. (Refer to " Register Status After Initialization".)
For the regular operation of power-on detection circuit, as seen in Figure 19, the period to power-up the S-35192A is that
the voltage reaches 1.3 V within 10 ms after setting the IC’s power supply voltage at 0 V. When the power-on detection
circuit is not working normally is; the POC flag (B0 in the status register 1) is not in "1", or 1 Hz is not output from the INT
pin. In this case, power-on the S-35192A once again because the internal data may be in the indefinite status.
Moreover, regarding the processing right after power-on, refer to " Flowchart of Initialization and Example of
Real-time Data Set-up".
Within 10 ms
1.3 V
0V
*1
*1. 0 V indicates that there are no potential differences between the VDD
pin and VSS pin of the S-35192A.
Figure 19
18
How to Raise the Power Supply Voltage
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
Register Status After Initialization
The status of each register after initialization is as follows.
Real-time data register:
Status register 1:
00 (Y), 01 (M), 01 (D), 0 (day of the week), 00 (H), 00 (M), 00 (S)
"0 B6 B5 B4 0 0 0 0 b"
(In B6, B5, B4, the data of B6, B5, B6 in the status register 1 at initialization is set.
Refer to Figure 20.)
"00h"
"00h"
"00h"
"00h"
"00h"
Status register 2:
INT register 1:
INT register 2:
Clock correction register:
Free register:
Write to status register 1
Read from status register 1
CS
SCK
SIO
X
0 1 1 0 0 0 0 0 1 0 1 0 0 0 0 0
Fixed code
command
B7 B5
0 1 1 0 0 0 0 1 0 0 1 0 0 0 00
Fixed code
command
B5: Not reset
Write "1" to reset flag
and SC0.
Figure 20
Status Register 1 Data At Initialization
19
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
Low Power Supply Voltage Detection Circuit
The S-35192A has a low power supply voltage detection circuit, so that users can monitor drops in the power supply
voltage by reading the BLD flag (B1 in the status register 1). There is a hysteresis width of approx. 0.15 V (typ.) between
detection voltage and release voltage (refer to " Characteristics (Typical Data)"). The low power supply voltage
detection circuit does the sampling operation only once in one sec for 15.6 ms.
If the power supply voltage decreases to the level of detection voltage (VDET) or less, "1" is set to the BLD flag so that
sampling operation stops. Once "1" is detected in the BLD flag, no sampling operation is performed even if the power
supply voltage increases to the level of release voltage or more, and "1" is held in the BLD flag.
Furthermore, the S-35192A does not initialize the internal circuit even if "1" is set to the BLD flag. If the BLD flag is "1"
even after the power supply voltage is recovered, the internal circuit may be in the indefinite status. In this case, be sure to
initialize the circuit. Without initializing, if the next BLD flag reading is done after sampling, the BLD flag gets reset to "0". In
this case, be sure to initialize although the BLD flag is in "0" because the internal circuit may be in the indefinite status.
VDD
Hysteresis width
0.15 V approximately
Detection voltage
Release
voltage
Time keeping power
supply voltage (min.)
BLD flag reading
Sampling pulse
15.6 ms
1s
1s
Stop
Stop
Stop
BLD flag
Figure 21
Timing of Low Power Supply Voltage Detection Circuit
Circuits Power-on and Low Power Supply Voltage Detection
Figure 22 shows the changes of the POC flag and BLD flag due to VDD fluctuation.
Low power supply voltage
detection voltage
VDD
POC flag
BLD flag
Status register 1
reading
Figure 22
20
POC Flag and BLD Flag
Low power supply voltage
detection voltage
VSS
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
Correction of Nonexistent Data and End-of-Month
When users write the real-time data, the S-35192A checks it. In case that the data is invalid, the S-35192A does the
following procedures.
1. Processing of nonexistent data
Table 11
Processing of Nonexistent Data
Register
Normal Data
Nonexistent Data
Result
Year data
00 to 99
XA to XF, AX to FX
00
Month data
01 to 12
00, 13 to 19, XA to XF
01
Day data
01 to 31
00, 32 to 39, XA to XF
01
Day of the week data
0 to 6
7
0
24-hour
0
to
23
24
to
29,
3X,
XA
to
XF
00
Hour data*1
12-hour
0 to 11
12 to 20, XA to XF
00
Minute data
00 to 59
60 to 79, XA to XF
00
2
Second data
00 to 59
60 to 79, XA to XF
00
*1. In 12-hour mode, write the AM / PM flag (B1 in hour data in the real-time data register).
In 24-hour mode, the AM / PM flag in the real-time data register is omitted. However in the flag of reading, users are
able to read 0; 0 to 11, 1; 12 to 23.
*2. Processing of nonexistent data, regarding second data, is done by a carry pulse which is generated in 1 second, after
writing. At this point the carry pulse is sent to the minute-counter.
2. Correction of end-of-month
A nonexistent day, such as February 30 and April 31, is set to the first day of the next month.
21
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
Alarm Function
By this alarm function, the INT1 flag or the INT2 flag (B2 or B3 in the status register1) is set to "H" when the time that
users set has come.
Set up the data of day of the week, hour and minute as alarm time in the INT register 1 / 2. Refer to "4. INT register 1
and INT register 2" in " Configuration of Registers".
1.
Alarm setting of "W (day of the week), H (hour), m (minute)"
Status register 2 setting
Alarm 1 function
INT1ME = INT1FE = 0
Alarm 2 function
None
INT register x alarm enable flag
AxHE = AxmE = AxWE = "1"
INT register 1
INT register 2
mx
Hx
Wx
Alarm output to INT1 flag / INT2 flag
(B3 or B2 in status register 1)
Comparator
Second Minute
Hour Day of Day Month Year
Minute Hour
Second
the week
Real-time data
W (day of the week)
Real-time data
H h (m 1) m 59 s
Change by program
H h m m 00 s
01 s
Change by program
59 s
Change by program
INT1AE / INT2AE
INT1 flag / INT2 flag
Alarm time matches
Read status register 1
Period when alarm time matches
Figure 23
22
H h (m 1) m 00 s
Output Timing of INT1 Flag and INT2 Flag
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
2. Alarm setting of "H (hour)"
Status register 2 setting
Alarm 1 function
INT1ME = INT1FE = 0
Alarm 2 function
None
INT register x alarm enable flag
AxWE = AxmE = "0", AxHE = "1"
INT register 1
INT register 2
mx Hx Wx Dx Mx Yx
Alarm output to INT1 flag / INT2 flag
(B3 or B2 in status register 1)
Comparator
Second Minute Hour Day of Day Month Year
the week
Real-time data
Real-time data (H 1) h 59 m 59 s
H h 00 m 00 s 01 s
Change by program
59 s H h 01 m 00 s
H h 59 m 59 s (H 1) h 00 m 00 s
Change by program Change by program Change by program
INT1AE / INT2AE
Read status register 1
Read status register 1
INT1 flag / INT2 flag
Period when alarm time matches
Figure 24
Output Timing of INT1 Flag and INT2 Flag
Function of Clock Correction
The function of clock correction is to correct advance / delay of the clock due to the deviation of oscillation frequency, in
order to make a high precise clock. For correction, the S-35192A adjusts the clock pulse by using a certain part of the
dividing circuit, not adjusting the frequency of the quartz crystal. Correction is performed once every 20 seconds (or 60
seconds). The minimum resolution is approx. 3 ppm (or approx. 1 ppm) and the S-35192A corrects in the range of 195.3
ppm to +192.2 ppm (or of 65.1 ppm to +64.1 ppm). (Refer to Table 12.) Users can set up this function by using the clock
correction register. Regarding how to calculate the setting data, refer to "1. How to calculate". When not using this
function, be sure to set "00h".
Table 12
Item
Correction
Minimum resolution
Correction range
Function of Clock Correction
B0 = 0
Every 20 seconds
3.052 ppm
195.3 ppm to 192.2 ppm
B0 = 1
Every 60 seconds
1.017 ppm
65.1 ppm to 64.1 ppm
23
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
1. How to calculate
1. 1
If current oscillation frequency > target frequency (in case the clock is fast)
*1
Correction value = 128 Integral value
Caution
(Current oscillation frequency
*3
*2
actual measurement value ) (Target oscillation frequency )
(Current oscillation frequency
*2
actual measurement value )
The figure range which can be corrected is that the calculated value is from 0 to 64.
*1. Convert this value to be set in the clock correction register. For how to convert, refer to "(1)
example 1".
*2. Measurement value of a clock pulse output from the 32KO pin.
*3. Target value of average frequency when the clock correction function is used.
*4. Refer to "Table 12 Function of Clock Correction".
(1)
*4
(Minimum resolution )
Calculation
Calculation example 1
In case of current oscillation frequency actual measurement value = 32.771 [kHz], target oscillation frequency =
32.768 [kHz], B0 = 0 (Minimum resolution = 3.052 ppm)
(32771) (32768)
Correction value = 128 Integral value
(32771) (3.052 106)
= 128 Integral value (29.99) = 128 29 = 99
Convert the correction value "99" to 7-bit binary and obtain "01100011 b".
Reverse the correction value "01100011 b" and set it to B7 to B1 of the clock correction register.
Thus, set the clock correction register:
(B7, B6, B5, B4, B3, B2, B1, B0) = (1, 1, 0, 0, 0, 1, 1, 0)
1. 2
If current oscillation frequency < target frequency (in case the clock is slow)
Correction value = Integral value
Caution
(1)
(Current oscillation frequency
(Target oscillation frequency) actual measurement value)
(Current oscillation frequency
actual measurement value)
1
(Minimum resolution)
The figure range which can be corrected is that the calculated value is from 0 to 62.
Calculation example 2
In case of current oscillation frequency actual measurement value = 32.765 [kHz], target oscillation frequency =
32.768 [kHz]. B0 = 0 (Minimum resolution = 3.052 ppm)
(32768) (32765)
1
Correction value = Integral value
(32765) (3.052 10-6)
= Integral value (30.00) 1 = 30 1 = 31
Thus, set the clock correction register:
(B7, B6, B5, B4, B3, B2, B1, B0) = (1, 1, 1, 1, 1, 0, 0, 0)
(2)
Calculation example 3
In case of current oscillation frequency actual measurement value = 32.765 [kHz], target oscillation frequency =
32.768 [kHz], B0 = 1 (Minimum resolution = 1.017 ppm)
(32768) (32765)
1
Correction value = Integral value
(32765) (1.017 10-6)
= Integral value (90.03) 1
This calculated value exceeds the correctable range 0 to 62.
B0 = "1" (minimum resolution = 1.017 ppm) indicates the correction is impossible.
24
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
2. Setting values for registers and correction values
Table 13
Table 14
Setting Values for Registers and Correction Values (Minimum Resolution: 3.052 ppm (B0 = 0))
B7
B6
B5
B4
B3
B2
B1
B0
1
0
1
1
1
0
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
1
0
1
0
1
1
0
0
1
1
0
0
0
0
1
1
1
0
0
0
1
1
1
0
0
0
1
1
1
0
0
0
1
1
1
0
0
0
0
0
0
0
1
0
1
0
0
0
0
0
0
0
0
1
1
1
0
0
0
1
1
1
0
0
0
0
0
0
1
1
1
0
0
0
Correction Value
[ppm]
192.3
189.2
186.2
6.1
3.1
0
3.1
6.1
9.2
189.2
192.3
195.3
Rate
[s / day]
16.61
16.35
16.09
0.53
0.26
0
0.26
0.53
0.79
16.35
16.61
16.88
Setting Values for Registers and Correction Values (Minimum Resolution: 1.017 ppm (B0 = 1))
B7
B6
B5
B4
B3
B2
B1
B0
1
0
1
1
1
0
1
1
1
1
1
1
1
1
1
0
0
0
1
1
1
0
1
0
1
0
1
1
0
0
1
1
0
0
0
0
1
1
1
0
0
0
1
1
1
0
0
0
1
1
1
0
0
0
1
1
1
1
1
1
1
1
1
0
1
0
1
0
0
0
0
0
0
0
0
1
1
1
0
0
0
1
1
1
0
0
0
0
0
0
1
1
1
1
1
1
Correction Value
[ppm]
64.1
63.1
62.0
2.0
1.0
0
1.0
2.0
3.0
63.1
64.1
65.1
Rate
[s / day]
5.54
5.45
5.36
0.18
0.09
0
0.09
0.18
0.26
5.45
5.54
5.62
25
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
Serial Interface
The S-35192A receives various commands via a 3-wire serial interface to read / write data. Regarding transmission is as
follows.
1. Data reading
When data is input from the SIO pin in synchronization with the falling of the SCK clock after setting the CS pin to "H",
the data is loaded internally in synchronization with the next rising of the SCK clock. When R / W bit = "1" is loaded at
the eighth rising of the SCK clock, the status of data reading is entered. Data corresponding to each command is then
output in synchronization with the falling of the subsequent SCK clock input. When the SCK clock is less than 8, the
IC is in the clock-wait status, and no processing is performed.
2. Data writing
When data is input from the SIO pin in synchronization with the falling of the SCK clock after setting the CS pin to "H",
the data is loaded internally in synchronization with the next rising of the SCK clock. When R / W bit = "0" is loaded at
the eighth rising of the SCK clock, the status of data writing is entered. In this status, the data, which is input in
synchronization with the falling of the subsequent SCK clock input, is written to registers according to each command.
In data writing, input a clock pulse which is equivalent to the byte of the register. As well as reading, when the SCK clock
is less than 8, the IC is in the clock-wait status, and no processing is performed.
3. Data access
3. 1
Real-time data 1 access
CS
1
8
16
56
64
B7
B0
SCK
R/W
SIO
X 0110010
B7
Fixed code
command
B0
Year data
When reading: Output mode switching
Figure 25
26
Real-Time Data 1 Access
Second data
When reading:
Input mode switching
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
3. 2
Real-time data 2 access
CS
16
8
1
24
32
SCK
R/W
SIO
X 01100 11
B7
Fixed code
command
B0 B7
B0 B7
B0
Minute data
Hour data
Second data
When reading: Output mode switching
Figure 26
3. 3
When reading:
Input mode switching
Real-Time Data 2 Access
Status register 1 access and status register 2 access
CS
1
16
8
SCK
*1
R/W
X 011000
SIO
B7
Fixed code
command
B0
Status data
When reading:
Input mode switching
When reading: Output mode switching
*1. 0: Status register 1 selected
1: Status register 2 selected
Figure 27
Status Register 1 Access and Status Register 2 Access
27
3-WIRE REAL-TIME CLOCK
S-35192A
3. 4
Rev.3.2_04
INT register 1 access and INT register 2 access
In read / write the INT register 1, data varies depending on the setting of the status register 2. Be sure to read / write
the INT register 1 after setting the status register 2. When setting the alarm by using the status register 2, these
registers work as 3-byte alarm-time data registers, in other statuses, they work as 1-byte free registers.
Read / write the INT register 2 after setting INT2AE in the status register 2. When INT2AE is in "1", the INT register 2
works as for setting the 3-byte alarm-time data. Regarding details of each data, refer to "4. INT register 1 and INT
register 2" in " Configuration of Register".
Caution
Users cannot use both functions of alarm 1 function and the free register data simultaneously.
CS
1
8
16
24
32
SCK
R/W
*1
SIO
X 011010
B7
Fixed code
command
When reading: Output mode switching
B0 B7
Day of the
week data
B0 B7
Hour data
B0
Minute data
When reading:
Input mode switching
*1. 0: INT register 1 selected
1: INT register 2 selected
Figure 28
INT Register 1 Access and INT Register 2 Access
CS
1
8
16
SCK
R/W
SIO
X 0110100
B7
Fixed code
command
B0
Free register data
When reading: Output mode switching
Figure 29
28
INT Register 1 (Free Register Data) Access
When reading:
Input mode switching
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
3. 5
Clock correction register access
CS
1
8
16
SCK
R/W
X 011 0110
SIO
B7
Fixed code
command
B0
Clock correction
data
When reading:
Input mode switching
When reading: Output mode switching
Figure 30
3. 6
Clock Correction Register Access
Free register access
CS
1
8
16
SCK
R/W
SIO
X 0110111
B7
Fixed code
command
B0
Free register data
When reading: Input
mode switching
When reading: Output mode switching
Figure 31
Free Register Access
29
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
Flowchart of Initialization and Example of Real-time Data Set-up
Figure 32 is a recommended flowchart when the master device shifts to a normal operation status and initiates
communication with the S-35192A. Regarding how to apply power, refer to " Power-on Detection Circuit and Register
Status". It is unnecessary for users to comply with this flowchart of real-time data strictly. And if using the default data at
initializing, it is also unnecessary to set up again.
START
Read status register 1
NO
POC = 1
YES
Wait for 0.5 s
*1
NO
BLD = 0
YES
Initialize
(status register 1 B7 = 1)
Read real-time data 1
Read status register 1
NO
POC = 0
YES
NO
BLD = 0
YES
Set 24-hour / 12-hour mode
to status register 1
Read status register 1
Confirm data in status
register 1
NG
OK
Set real-time data 1
Read real-time data 1
*2
Confirm data in real-time
data 1
NG
OK
END
*1.
*2.
Do not communicate for 0.5 seconds since the power-on detection circuit is in operation.
Reading the real-time data 1 should be completed within 1 second after setting the real-time data 1.
Figure 32
30
Example of Initialization Flowchart
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
Examples of Application Circuits
VCC
10 k
VCC
32KO
VDD
10 k
CS
S-35192A
System
power supply
CPU
SIO
VSS
SCK
VSS
XOUT
XIN
Cg
Caution
1.
2.
Because the I/O pin has no protective diode on the VDD side, the relation of VCC VDD is possible.
But pay careful attention to the specifications.
Start communication under stable condition after power-on the power supply in the system.
Figure 33
Application Circuit 1
System power
supply
10 k
VCC
32KO
CS
VDD
10 k
S-35192A
CPU
SIO
SCK
VSS
XIN
VSS
XOUT
Cg
Caution Start communication under stable condition after power-on the power supply in the system.
Figure 34
Caution
Application Circuit 2
The above connection diagrams do not guarantee operation. Set the constants after performing
sufficient evaluation using the actual application.
31
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
Adjustment of Oscillation Frequency
1. Configuration of crystal oscillation circuit
Since the crystal oscillation circuit is sensitive to external noise (the clock accuracy is affected), the following measures
are essential for optimizing the configuration.
Place the S-35192A, quartz crystal, and external capacitor (Cg) as close to each other as possible.
Increase the insulation resistance between pins and the substrate wiring patterns of XIN and XOUT.
Do not place any signal or power lines close to the crystal oscillation circuit.
Locating the GND layer immediately below the crystal oscillation circuit is recommended.
Locate the bypass capacitor adjacent to the power supply pin of the S-35192A.
Parasitic capacitance*3
XIN
Rf
Cg
Quartz crystal: 32.768 kHz
CL = 6 pF*1
Cg = None*2 to 9.1 pF
Parasitic capacitance*3
Rd
XOUT
Rf = 100 M (typ.)
Rd = 100 k (typ.)
Cd = 8 pF (typ.)
Cd
S-35192A
*1. When setting the value for the quartz crystal's CL as 7 pF, connect Cd externally if necessary.
*2. The crystal oscillation circuit operates even when Cg is not connected. Note that the oscillation frequency is in the
direction that it advances.
*3. Design the board so that the parasitic capacitance is within 5 pF.
Figure 35
Connection Diagram 1
1
Quartz crystal
Cg
Figure 36
Caution
32
S-35192A
8
2 XOUT
7
3 XIN
6
4 VSS
5
Locate the GND layer in the
layer immediately below
Connection Diagram 2
1. When using the quartz crystal with a CL exceeding the rated value (7 pF) (e.g : CL = 12.5 pF),
oscillation operation may become unstable. Use a quartz crystal with a CL value of 6 pF or 7 pF.
2. Oscillation characteristics are subject to the variation of each component such as substrate
parasitic capacitance, parasitic resistance, quartz crystal, and Cg. When configuring a crystal
oscillaiton circuit, pay sufficient attention for them.
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
2. Measurement of oscillation frequency
When the S-35192A is turned on, a signal of 32.768 Hz is output from the 32KO pin. Turn the power on and measure the
signal with a frequency counter following the circuit configuration shown in Figure 37.
Remark If the error range is 1 ppm in relation to 32.768 kHz, the time is shifted by approximately 2.6 seconds per
month (calculated using the following expression).
10–6 (1 ppm) 60 seconds 60 minutes 24 hours 30 days 2.592 seconds
VDD
10 kΩ
10 kΩ
XIN
SIO
SCK
Cg
S-35192A
10 kΩ
XOUT
32KO
Open
Frequency
counter
CS
VSS
Figure 37
Caution
Configuration of Oscillation Frequency Measurement Circuit
Use a high-accuracy frequency counter of 7 digits or more.
33
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
3. Adjustment of oscillation frequency
3. 1
Adjustment by setting Cg
Matching of the quartz crystal with the nominal frequency must be performed with the parasitic capacitance on the
board included. Select a quartz crystal and optimize the Cg value in accordance with the flowchart below.
START
Select a quartz crystal*1
Variable
capacitance
YES
Trimmer capacitor
NO
Fixed capacitor
Set to center
of variable
capacitance*3
Set Cg
NO
Frequency
Cg in
specification
YES
Optimal
value*2
Change Cg
NO
NO
YES
Make fine adjustment
of frequency using
variable capacitance
YES
END
*1. Request a quartz crystal manufacturer for a matching evaluation between the IC and the quartz crystal. The
recommended quartz crystal characteristic values are, CL value (load capacitance) = 6 pF, R1 value (equivalent
serial resistance) = 50 k max.
*2. The Cg value must be selected on the actual PCB since it is affected by parasitic capacitance. Select the
external Cg value in a range of 0 pF to 9.1 pF.
*3. Adjust the rotation angle of the variable capacitance so that the capacitance value is slightly smaller than the
center, and confirm the oscillation frequency and the center value of the variable capacitance. This is done in
order to make the capacitance of the center value smaller than one half of the actual capacitance value because
a smaller capacitance value increases the frequency variation.
Figure 38
Caution
34
Quartz Crystal Setting Flow
1. The oscillation frequency varies depending on the ambient temperature and power supply
voltage. Refer to " Characteristics (Typical Data)".
2. The 32.768 kHz quartz crystal operates more slowly at an operating temperature higher or
lower than20C to 25C. Therefore, it is recommended to set the oscillator to operate
slightly faster at normal temperature.
Rev.3.2_04
3-WIRE REAL-TIME CLOCK
S-35192A
Precautions
Do not apply an electrostatic discharge to this IC that exceeds the performance ratings of the built-in electrostatic
protection circuit.
ABLIC Inc. claims no responsibility for any disputes arising out of or in connection with any infringement by products
including this IC of patents owned by a third party.
35
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
Characteristics (Typical Data)
1. Standby current vs. VDD characteristics
2. Current consumption
vs. Input clock characteristics
Ta = 25C, CL = 6 pF
IDD1
[A]
Ta = 25C, CL = 6 pF
1.0
30
0.8
25
VDD = 5.0 V
20
0.6
IDD2
[A]
0.4
15
VDD = 3.0 V
10
0.2
5
0
0
2
1
3
VDD [V]
4
5
0
6
3. Standby current
vs. Temperature characteristics
0
200
400
600
800
SCK frequency [kHz]
4. Standby current vs. Cg characteristics
Ta = 25C, CL = 6 pF
CL = 6 pF
1.0
1.0
0.9
0.9
0.8
0.8
VDD = 5.0 V
0.7
0.6
IDD1
0.5
[A]
0.4
VDD = 3.0 V
0.7
VDD = 5.0 V
0.6
IDD1
0.5
[A]
0.4
VDD = 3.0 V
0.3
0.3
0.2
0.2
0.1
0.1
0
－40 －25
0
25
Ta [C]
50
0
75 85
5. Oscillation frequency vs. Cg characteristics
0
2
50
80
40
60
30
0
10
0
10
–40
20
–60
30
–80
40
–100
36
f/f
[ppm]
VDD = 3.0 V
–20
0
2
4
6
Cg [pF]
8
10
20
VDD = 5.0 V
20
8
Ta = 25C, Cg = 7.5 pF
100
40
4
6
Cg [pF]
6. Oscillation frequency vs. VDD characteristics
Ta = 25C, CL = 6 pF
f/f
[ppm]
1000
10
50
0
1
2
3
VDD [V]
4
5
6
3-WIRE REAL-TIME CLOCK
S-35192A
Rev.3.2_04
7. Oscillation frequency
vs. Temperature characteristics
8. Oscillation start time vs. Cg characteristics
Ta = 25C
Cg = 7.5 pF
20
500
VDD = 5.0 V
0
450
400
–20
350
VDD = 3.0 V
–40
300
tSTA
250
[ms]
200
f/f
–60
[ppm]
–80
VDD = 5.0 V
VDD = 3.0 V
150
–100
100
–120
50
–140
–40 –25
0
25
Ta [C]
0
75 85
50
0
2
8
4
6
Cg [pF]
10
9. Output current characteristics 1 (VOUT vs. IOL1) 10. Output current characteristics 2 (VOUT vs. IOL2)
32KO pin, Ta = 25C
SIO pin, Ta = 25C
50
50
40
40
VDD = 5.0 V
IOL1
[mA]
30
IOL2
[mA]
VDD = 3.0 V
20
10
0
VDD = 5.0 V
30
20
VDD = 3.0 V
10
0
1
2
3
4
0
0
0.5
1
1.5
VOUT [V]
VOUT [V]
11. CS pin input current characteristics
2
2.5
12. BLD detection, release voltage, VDDT (min.)
vs. temperature characteristics
CS pin, Ta = 25C
CL = 6 pF
1.4
800
700
600
Release voltage
1.2
VDD = 5.0 V
1.0
500
Detection voltage
0.8
BLD
[V] 0.6
IIH
400
[A]
300
VDDT (min.)
VDD = 3.0 V
200
0.4
0.2
100
0
0
1
2
3
VIN [V]
4
5
6
0
40 25
0
25
Ta [C]
50
75 85
37
1.97±0.03
8
7
6
5
3
4
+0.05
1
0.5
2
0.08 -0.02
0.48±0.02
0.2±0.05
No. PH008-A-P-SD-2.1
TITLE
SNT-8A-A-PKG Dimensions
No.
PH008-A-P-SD-2.1
ANGLE
UNIT
mm
ABLIC Inc.
+0.1
ø1.5 -0
2.25±0.05
4.0±0.1
2.0±0.05
ø0.5±0.1
0.25±0.05
0.65±0.05
4.0±0.1
4 321
5 6 78
Feed direction
No. PH008-A-C-SD-2.0
TITLE
SNT-8A-A-Carrier Tape
No.
PH008-A-C-SD-2.0
ANGLE
UNIT
mm
ABLIC Inc.
12.5max.
9.0±0.3
Enlarged drawing in the central part
ø13±0.2
(60°)
(60°)
No. PH008-A-R-SD-1.0
TITLE
SNT-8A-A-Reel
No.
PH008-A-R-SD-1.0
QTY.
ANGLE
UNIT
mm
ABLIC Inc.
5,000
0.52
2.01
2
0.52
0.2 0.3
1.
2.
1
(0.25 mm min. / 0.30 mm typ.)
(1.96 mm ~ 2.06 mm)
1.
2.
3.
4.
0.03 mm
SNT
1. Pay attention to the land pattern width (0.25 mm min. / 0.30 mm typ.).
2. Do not widen the land pattern to the center of the package (1.96 mm to 2.06mm).
Caution 1. Do not do silkscreen printing and solder printing under the mold resin of the package.
2. The thickness of the solder resist on the wire pattern under the package should be 0.03 mm
or less from the land pattern surface.
3. Match the mask aperture size and aperture position with the land pattern.
4. Refer to "SNT Package User's Guide" for details.
1.
2.
(0.25 mm min. / 0.30 mm typ.)
(1.96 mm ~ 2.06 mm)
TITLE
No. PH008-A-L-SD-4.1
SNT-8A-A
-Land Recommendation
PH008-A-L-SD-4.1
No.
ANGLE
UNIT
mm
ABLIC Inc.
Disclaimers (Handling Precautions)
1.
All the information described herein (product data, specifications, figures, tables, programs, algorithms and
application circuit examples, etc.) is current as of publishing date of this document and is subject to change without
notice.
2.
The circuit examples and the usages described herein are for reference only, and do not guarantee the success of
any specific mass-production design.
ABLIC Inc. is not liable for any losses, damages, claims or demands caused by the reasons other than the products
described herein (hereinafter "the products") or infringement of third-party intellectual property right and any other
right due to the use of the information described herein.
3.
ABLIC Inc. is not liable for any losses, damages, claims or demands caused by the incorrect information described
herein.
4.
Be careful to use the products within their ranges described herein. Pay special attention for use to the absolute
maximum ratings, operation voltage range and electrical characteristics, etc.
ABLIC Inc. is not liable for any losses, damages, claims or demands caused by failures and / or accidents, etc. due to
the use of the products outside their specified ranges.
5.
Before using the products, confirm their applications, and the laws and regulations of the region or country where they
are used and verify suitability, safety and other factors for the intended use.
6.
When exporting the products, comply with the Foreign Exchange and Foreign Trade Act and all other export-related
laws, and follow the required procedures.
7.
The products are strictly prohibited from using, providing or exporting for the purposes of the development of
weapons of mass destruction or military use. ABLIC Inc. is not liable for any losses, damages, claims or demands
caused by any provision or export to the person or entity who intends to develop, manufacture, use or store nuclear,
biological or chemical weapons or missiles, or use any other military purposes.
8.
The products are not designed to be used as part of any device or equipment that may affect the human body, human
life, or assets (such as medical equipment, disaster prevention systems, security systems, combustion control
systems, infrastructure control systems, vehicle equipment, traffic systems, in-vehicle equipment, aviation equipment,
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ABLIC, Inc. Do not apply the products to the above listed devices and equipments.
ABLIC Inc. is not liable for any losses, damages, claims or demands caused by unauthorized or unspecified use of
the products.
9.
In general, semiconductor products may fail or malfunction with some probability. The user of the products should
therefore take responsibility to give thorough consideration to safety design including redundancy, fire spread
prevention measures, and malfunction prevention to prevent accidents causing injury or death, fires and social
damage, etc. that may ensue from the products' failure or malfunction.
The entire system in which the products are used must be sufficiently evaluated and judged whether the products are
allowed to apply for the system on customer's own responsibility.
10. The products are not designed to be radiation-proof. The necessary radiation measures should be taken in the
product design by the customer depending on the intended use.
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metals and should therefore not be put in the mouth. The fracture surfaces of wafers and chips may be sharp. Be
careful when handling these with the bare hands to prevent injuries, etc.
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13. The information described herein contains copyright information and know-how of ABLIC Inc. The information
described herein does not convey any license under any intellectual property rights or any other rights belonging to
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representative.
15. This Disclaimers have been delivered in a text using the Japanese language, which text, despite any translations into
the English language and the Chinese language, shall be controlling.
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