PT7C4337A/4337AC 2 Real-time Clock Module (I C Bus) Description Features The PT7C4337A/4337AC serial real-time clock is a Using external 32.768kHz quartz crystal for low-power clock/calendar with two programmable time- PT7C4337A of-day alarms and a programmable square-wave output. Using internal 32.768kHz quartz crystal for Address and data are transferred serially via a 2-wire, PT7C4337AC bidirectional bus. The clock/calendar provides seconds, 2 Supports I C-Bus s high speed mode (400 kHz) minutes, hours, day, date, month, and year information. Includes time (Hour/Minute/Second) and calendar The date at the end of the month is automatically (Year/Month/Date/Day) counter functions (BCD adjusted for months with fewer than 31 days, including code) corrections for leap year. The clock operates in either the Programmable square wave output signal 24-hour or 12-hour format with AM/PM indicator. Two Time-of-Day Alarms The device is fully accessible through the serial interface Oscillator Stop Flag while VCC is between 1.8V and 5.5V. I2C operation is Operating range: 1.8V to 5.5V not guaranteed below 1.8V. Timekeeping operation is Timekeeping range: 1.2V to 1.8V maintained with VCC as low as 1.2V. Table 1 shows the basic functions of PT7C4337A/ 4337AC. More details are shown in section: overview of functions. Table 1. Basic functions of PT7C4337A/4337AC Item Function PT7C4337A PT7C4337AC Source Crystal(32.768KHz) External crystal Integrated Crystal 1 Oscillator Oscillator enable/disable Oscillator fail detect 12-hour Time display 24-hour 2 Time Century bit Time count chain enable/disable 3 Interrupt Alarm interrupt output 2 2 1, 4.096k, 8.192k, 1, 4.096k, 8.192k, 4 Programmable square wave output (Hz) 32.768k 32.768k 2 5 Communication 2-wire I C bus 2014-10-0002 PT0480-2 11/03/14 1 PT7C4337A/4337AC 2 Real-time Clock Module (I C Bus) Pin Assignment PT7C4337A PT7C4337AC PT7C4337AC 1 X1 VCC 8 1 SCL SDA 16 1 8 VCC NC 2 7 2 SQW/INTB GND 15 X2 SQW/INTB 7 NC 2 SQW/INTB 3 SCL 6 3 INTA 14 INTA VCC 6 3 INTA SCL 4 5 4 13 GND SDA NC NC 4 5 SDA GND 12 5 NC NC SOIC-8, MSOP-8, DFN4x4-8L TDFN-8, TSSOP-8 6 NC NC 11 7 NC NC 10 8 9 NC NC SOIC-16 Pin Description Pin No. 4337AC 4337AC Pin Type Description 4337A SOIC DFN Oscillator Circuit Input. Together with X1, 32.768kHz crystal is connected 1 / / X1 I between them. Or external clock input. Oscillator Circuit Output. Together with X1, 32.768kHz crystal is connected 2 / / X2 O between them. When 32.768kHz external input, X2 must be float. 2 Serial Clock Input. SCL is used to synchronize data movement on the I C serial 6 1 6 SCL I interface. Serial Data Input/Output. SDA is the input/output pin for the 2-wire serial 5 16 5 SDA I/O interface. The SDA pin is open-drain output and requires an external pull-up resistor. Interrupt Output. When enabled, INTA is asserted low when the time matches the INTA values set in the alarm registers. This pin is an open-drain output and requires an 3 14 3 O external pull up resistor. Square-Wave/Interrupt Output. Programmable square-wave or interrupt output SQW/ 7 2 7 O signal. It is an open-drain output and requires an external pull up resistor. INTB 8 3 8 VCC P Power. Primary power for PT7C4337A. 4 15 4 GND P Ground. No Connect. These pins are not connected internally, but must be grounded for / 5-13 1, 2 NC proper operation. 2014-10-0002 PT0480-2 11/03/14 2