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DS3232M

High-Accuracy Time Base

The temperature sensor, oscillator, and digital adjust-

ment controller logic form the highly accurate time base.

The controller reads the output of the on-board tempera-

ture sensor and adjusts the final 1Hz output to maintain

the required accuracy. The device is trimmed at the

factory to maintain a tight accuracy over the operating

the adjustment occurs once a second. When the device

10s to conserve power. Adjusting the 1Hz time base less

often does not affect the device’s long-term timekeeping

accuracy. The device also contains an Aging Offset reg-

ister that allows a constant offset (positive or negative) to

be added to the factory-trimmed adjustment value.

Power-Supply Configurations

The DS3232M can be configured to operate on a single

supply configuration, which provides a backup supply

source to keep the timekeeping circuits alive during

absence of primary system power.

Figure 4 illustrates a single-supply configuration using

the RST output is asserted (active low). Temperature con-

versions are executed once per second.

Figure 5 illustrates a single-supply configuration using

is disabled and is held at ground through the connection

of the internal pullup resistor. Temperature conversions

are executed once every 10s.

Figure 6 illustrates a dual-supply configuration, using

power-selection function is provided by a temperature-

compensated voltage reference and a comparator circuit

temperature conversions are executed once per second.

perature conversions are executed once every 10s.

Figure 6. Dual Power Supply

+3.3V

+3.3V