DS3232S#T&R Maxim Integrated Products, DS3232S#T&R Datasheet - Page 9

• Manufacturer Part Number: DS3232S#T&R
• Description: IC RTC W/TCXO 20-SOIC
• Manufacturer: Maxim Integrated Products
• Type: Clock/Calendar/TCXO/Crystalr

Specifications of DS3232S#T&R

• Memory Size: 236B
• Time Format: HH:MM:SS (12/24 hr)
• Date Format: YY-MM-DD-dd
• Interface: I²C, 2-Wire Serial
• Voltage - Supply: 2.3 V ~ 5.5 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 20-SOIC (7.5mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

power failures and to automatically switch to the back-
up supply when necessary. The RST pin provides an
external pushbutton function and acts as an indicator of
a power-fail event. Also available are 236 bytes of gen-
eral-purpose battery-backed SRAM.
The block diagram shows the main elements of the
DS3232. The eight blocks can be grouped into four
functional groups: TCXO, power control, pushbutton
function, and RTC. Their operations are described sep-
arately in the following sections.
7–14, 19
18, 20
1, 2,
PIN
15
16
17
3
4
5
6
NAME
32kHz
GND
V
N.C.
SDA
SCL
V
/SQW
BAT
CC
No Connection. Not connected internally. Must be connected to ground.
32kHz Push-Pull Output. If disabled with either EN32kHz = 0 or BB32kHz = 0, the state of the 32kHz pin
will be low.
DC Power Pin for Primary Power Supply. This pin should be decoupled using a 0.1μF to 1.0μF capacitor.
Active-Low Interrupt or Square-Wave Output. This open-drain pin requires an external pullup resistor. It can
be left open if not used. This multifunction pin is determined by the state of the INTCN bit in the Control
Register (0Eh). When INTCN is set to logic 0, this pin outputs a square wave and its frequency is
determined by RS2 and RS1 bits. When INTCN is set to logic 1, then a match between the timekeeping
registers and either of the alarm registers activates the
INTCN bit is set to logic 1 when power is first applied, the pin defaults to an interrupt output with alarms
disabled. The pullup voltage can be up to 5.5V, regardless of the voltage on V
be left unconnected.
Active-Low Reset. This pin is an open-drain input/output. It indicates the status of V
V
pushbutton input function. This pin can be activated by a pushbutton reset request. It has an internal 50k
nominal value pullup resistor to V
oscillator is disabled, t
Ground
Backup Power-Supply Input. When using the device with the V
pin should be decoupled using a 0.1μF to 1.0μF low-leakage capacitor. When using the device with the
V
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.
Serial-Data Input/Output. This pin is the data input/output for the I
requires an external pullup resistor. The pullup voltage can be up to 5.5V, regardless of the voltage on V
Serial-Clock Input. This pin is the clock input for the I
movement on the serial interface. A connection to only one of the pins is required. The other pin must be
connected to the same signal or be left unconnected. Up to 5.5V can be used for this pin, regardless of the
voltage on V
PF
BAT
specification. As V
pin is driven high impedance. The active-low, open-drain output is combined with a debounced
input as the backup power source, the capacitor is not required. If V
CC
.
Extremely Accurate I
_____________________________________________________________________
Operation
CC
RST
falls below V
is bypassed and
Integrated Crystal and SRAM
CC
. No external pullup resistors should be connected. If the crystal
PF
, the
The temperature sensor, oscillator, and control logic
form the TCXO. The controller reads the output of the
on-chip temperature sensor and uses a lookup table to
determine the capacitance required, adds the aging
correction in AGE register, and then sets the capaci-
tance selection registers. New values, including
changes to the AGE register, are loaded only when a
change in the temperature value occurs. The tempera-
ture is read on initial application of V
64 seconds (default, see the description for CRATE1
and CRATE0 in the control/status register) afterwards.
FUNCTION
immediately goes high.
pin is driven low. When V
2
C serial interface and is used to synchronize data
/SQW pin (if the alarm is enabled). Because the
BAT
2
C serial interface. This open-drain pin
input as the primary power source, this
BAT
2
CC
is not used, connect to
C RTC with
CC
exceeds V
Pin Description
. If not used, this pin can
CC
CC
relative to the
PF
32kHz TCXO
and once every
, for t
RST
, the
CC
.
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