DS1390-DS1393 MAXIM [Maxim Integrated Products], DS1390-DS1393 Datasheet - Page 10

• Manufacturer Part Number: DS1390-DS1393
• Description: Low-Voltage SPI/3-Wire RTCs with Trickle Charger
• Manufacturer: MAXIM [Maxim Integrated Products]

Low-Voltage SPI/3-Wire RTCs with
Trickle Charger
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DS1390 DS1391 DS1392 DS1393
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V
SQW/INT
NAME
BACKUP
DOUT
SCLK
SQW
GND
RST
V
DIN
INT
CS
CE
I/O
X1
X2
CC
Connections for Standard 32.768kHz Quartz Crystal. The internal oscillator
circuitry is designed for operation with a crystal having a 6pF specified load
capacitance (C
connected to an external 32.768kHz oscillator. The output of the internal
oscillator, pin X2, is floated if an external oscillator is connected to pin X1.
DC Backup Power Input for Primary Cell. This pin is a rechargeable
battery/super cap or a secondary supply. UL recognized to ensure against
reverse charging current when used with a lithium battery.
SPI Chip-Select Input. This pin is used to select or deselect the part.
Chip Enable for 3-Wire Interface
Ground
SPI Data Input. This pin is used to shift address and data into the part.
Interrupt Output. This pin is used to output the interrupt signal, if enabled by
the control register. The maximum voltage on this pin is 5.5V, independent
of V
by either V
Reset. This active-low, open-drain output indicates the status of V
to the V
When Vcc exceeds V
This pin is combined with a debounced pushbutton input function. This pin
can be activated by a pushbutton reset request. This pin has an internal,
50k
connected. If the crystal oscillator is disabled, the startup time of the
oscillator is added to the t
SPI Data Output. Data is output on this pin when the part is in read mode.
CMOS push-pull driver.
Input/Output for 3-Wire Interface. CMOS push-pull driver.
Serial Clock Input. This pin is used to control the timing of data into and out
of the part.
Square-Wave/Interrupt Output. This pin is used to output the programmable
square wave or interrupt signal. When enabled by setting the ESQW bit to
logic 1, the SQW/INT pin outputs one of four frequencies: 32.768kHz,
8.192kHz, 4.096kHz, or 1Hz. This pin is open drain and requires an external
pullup resistor. The maximum voltage on this pin is 5.5V, independent of
V
powered by either V
Square-Wave Output. This pin is open drain and requires an external pullup
resistor. The maximum voltage on this pin is 5.5V, independent of V
V
V
DC Power Pin for Primary Power Supply
CC
BACKUP
CC
CC
or V
or V
(typ) pullup resistor to V
or V
PF
BACKUP
BAT
. If enabled, SQW functions when the device is powered by either
specification. As Vcc falls below V
CC
BACKUP
.
or V
L
). Pin X1 is the input to the oscillator and can optionally be
. If enabled, SQW/INT functions when the device is
BAT
. If enabled, INT functions when the device is powered
CC
PF
.
or V
, for t
RST
BAT
RST
CC
delay.
.
, the RST pin is driven high impedance.
. No external pullup resistors should be
FUNCTION
PF
, the RST pin is driven low.
Pin Description
CC
CC
relative
or