DS3232M Datasheet, PDF (8/23 Pages) Maxim Integrated Products – ±5ppm, I2C Real-Time Clock with SRAM

DS3232M
±5ppm, I²C Real-Time Clock with SRAM
Pin Configuration
TOP VIEW
32KHZ 1 ⁺
V_CC 2
INT/SQW 3
DS3232M
RST 4
SO
8 SCL
7 SDA
6 VBAT
5 GND
Pin Description
PIN
NAME
FUNCTION
32.768KHZ Output (Push-Pull Output, 50% Duty Cycle). If enabled (EN32KHZ = 1), the 32kHz output is
1
32KHZ active on V_CC. If enabled for battery operation (BB32KHZ = 1), the output is also active on V_BAT. When
disabled, the output is forced low. This pin can be left unconnected if not used.
2
V_CC
DC Power Pin for Primary Power Supply. This pin should be decoupled using a 0.1FF to 1.0FF capacitor.
Connect to ground if not used.
Active-Low Interrupt or 1Hz Square-Wave Output. This open-drain pin requires an external pullup resistor
connected to a supply at 4.5V or less. It can be left open if not used. This multifunction pin is determined
3
INT/
SQW
by the state of the INTCN bit in the Control register (0Eh). When INTCN is set to logic 0, this pin outputs
a 1Hz square wave. When INTCN is set to logic 1, a match between the timekeeping registers and either
of the alarm registers activates the INT/SQW pin (if the alarm is enabled). Because the INTCN bit is set to
logic 1 when power is first applied, the pin defaults to an interrupt output with alarms disabled.
Active-Low Reset. This pin is an open-drain input/output. It indicates the status of V_CC relative to the V_PF
specification. As V_CC falls below V_PF, the RST pin is driven low. When V_CC exceeds V_PF, for t_RST, the
4
RST
RST pin is pulled high by the internal pullup resistor. The active-low, open-drain output is combined with
a debounced pushbutton input function. This pin can be activated by a pushbutton reset request. It has
an internal 50kI (R_PU) nominal value pullup resistor to V_CC. No external pullup resistors should be con-
nected. If the oscillator is disabled, t_REC is bypassed and RST immediately goes high.
5
GND Ground
Backup Power-Supply Input. When using the device with the V_BAT input as the primary power source, this
pin should be decoupled using a 0.1FF to 1.0FF low-leakage capacitor. When using the device with the V_BAT
6
V_BAT input as the backup power source, the capacitor is not required. If V_BAT is not used, connect to ground. The
device is UL recognized to ensure against reverse charging when used with a primary lithium battery. Go to
www.maxim-ic.com/qa/info/ul for more information.
7
SDA
Serial-Data Input/Output. This pin is the data input/output for the I²C serial interface. This open-drain pin
requires an external pullup resistor. The pullup voltage can be up to 4.5V, regardless of the voltage on V_CC.
8
SCL
Serial-Clock Input. This pin is the clock input for the I²C serial interface and is used to synchronize data
movement on the serial interface. The pullup voltage can be up to 4.5V, regardless of the voltage on V_CC.
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