Document
S-35392A
www.sii-ic.com © SII Semiconductor Corporation, 2006-2016
2-WIRE REAL-TIME CLOCK
Rev.3.2_02
The S-35392A is a CMOS 2-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-35392A can be used for various power supplies from main supply to backup battery. Due to the 0.45 μA current consumption and wide range of power supply voltage at time keeping, the S-35392A 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-35392A 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 μA typ. (VDD = 3.0 V, Ta = +25°C)
• 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 • 2-wire (I2C-bus) CPU interface
• Built-in alarm interrupter
• 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 oscillator (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
2-WIRE REAL-TIME CLOCK S-35392A
Block Diagram
Rev.3.2_02
XIN XOUT
Oscillation circuit
Divider, timing generator
VDD VSS
Clock correction register
Status register 1
Status register 2
Free register
Low power supply voltage detector
Power-on detection circuit
Constantvoltage circuit
INT1 register
INT1 controller
Comparator 1
Real-time data register
Second Minute
Hour
Day of the week
Day
Month
Year
Comparator 2
INT2 register Shift register
INT2 controller
Serial interface
32KO
INT2 SDA SCL
Figure 1
2
Rev.3.2_02
2-WIRE REAL-TIME CLOCK S-35392A
Product Name Structure
1. Product name
S-35392A - 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
Package Name SNT-8A
Table 1 Package Drawing Codes
Dimension PH008-A-P-SD
Tape PH008-A-C-SD
Reel PH008-A-R-SD
Land PH008-A-L-SD
3
2-WIRE REAL-TIME CLOCK S-35392A
Rev.3.2_02
Pin Configuration
1. SNT-8A
Top view 18 27 36 45
Figure 2 S-35392A-I8T1U
Table 2 List of Pins
Pin No. Symbol Description
I/O
Configuration
Pin for constant 1 32KO output of 32.768 Output
kHz
Nch open-drain output (no protective diode at VDD)
2 XOUT Connection pins 3 XIN for crystal oscillator
−
−
4 VSS GND pin
−
−
5
INT2
Output pin for interrupt signal 2
Output
Nch open-drain output (no protective diode at VDD)
6 SCL
Input pin for serial clock
Input
CMOS input (no protective diode at VDD)
7 SDA
I/O pin for serial data
Nch open-drain output Bi-directional (no protective diode at VDD)
CMOS input
8 VDD
Pin for positive power supply
−
−
4
Rev.3.2_02
2-WIRE REAL-TIME CLOCK S-35392A
Pin Functions
1. SDA (I/O for serial data) pin
This pin is a data input / output pin of I2C-bus interface. This pin inputs / outputs data by synchronizing with a clock pulse from the SCL pin. This pin has CMOS input and Nch open drain output. Generally in use, pull up this pin to the VDD potential via a resistor, and connect it to any other device having open drain or open collector output with wired-OR connection.
2. SCL (input for serial clock) pin
This pin is to input a clock pulse for I2C-bus interface. The SDA pin inputs / outputs data by synchronizing with the clock pulse.
3. XIN, XOUT (crystal oscillator connect) pins
Connect a crystal oscillator between XIN and XOUT.
4. 32KO (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.
5. INT2 (output for interrupt signal 2) pin
This pin outputs a signal of interrupt, or a clock pulse. By using the status register 2, users can select either of; alarm interrupt, output of user-set frequency, or minute-periodical interrupt 1. This pin has Nch open drain output.
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 Co.