DS1390DS1394
Low-Voltage SPI/3-Wire RTCs with
Trickle Charger
Reset Output/Debounced Input (DS1391/DS1393)
General Description
Separate SQW and INT Output (DS1392)
The low-voltage serial-peripheral interface (SPI)
DS1390/DS1391/DS1394 and the low-voltage 3-wire
Trickle-Charge Capability
DS1392/DS1393 real-time clocks (RTCs) are clocks/cal-
SPI Supports Modes 0 and 2 (DS1394)
endars that provide hundredths of a second, seconds,
minutes, hours, day, date, month, and year information. SPI Supports Modes 1 and 3 (DS1390/DS1391)
The date at the end of the month is automatically
3-Wire Interface (DS1392/DS1393)
adjusted for months with fewer than 31 days, including
4MHz at 3.0V and 3.3V
corrections for leap year. The clock operates in either
the 24-hour or 12-hour format with an AM/PM indicator. 1MHz at 1.8V
One programmable time-of-day alarm is provided. A
Three Operating Voltages: 1.8V 5%, 3.0V 10%,
temperature-compensated voltage reference monitors
and 2.97 to 5.5V (DS1394: 3.3V 10%)
the status of V and automatically disables the bus
CC
Industrial Temperature Range: -40C to +85C
interface and switches to the backup supply if a power
failure is detected. On the DS1390, a single open-drain
Underwriters Laboratories (UL) Recognized
output provides a CPU interrupt or a square wave at
one of four selectable frequencies. The DS1391
replaces the SQW/INT pin with a RST output/
Ordering Information
debounced input.
TYP
The DS1390, DS1391, and DS1394 are programmed
PIN-
PART OPERATING TOP MARK
serially through an SPI-compatible, bidirectional bus.
PACKAGE
VOLTAGE (V)
The DS1392 and DS1393 communicate over a 3-wire
serial bus, and the extra pin is used for either a sepa-
DS1390U-18+ 1.8 10 SOP 1390 rr-18
rate interrupt pin or a RST output/debounced input.
DS1390U-3+ 3.0 10 SOP 1390 rr-3
All five devices are available in a 10-pin SOP package,
DS1390U-33+ 3.3 10 SOP 1390 rr-33
and are rated over the industrial temperature range.
DS1391U-18+ 1.8 10 SOP 1391 rr-18
DS1391U-3+ 3.0 10 SOP 1391 rr-3
Applications
DS1391U-33+ 3.3 10 SOP 1391 rr-33
Hand-Held Devices
DS1392U-18+ 1.8 10 SOP 1393 rr-18
GPS/Telematics Devices
DS1392U-3+ 3.0 10 SOP 1392 rr-3
Embedded Time Stamping
DS1392U-33+ 3.3 10 SOP 1392 rr-33
Medical Devices DS1393U-18+ 1.8 10 SOP 1393 rr-18
DS1393U-3+ 3.0 10 SOP 1393 rr-3
Features
DS1393U-33+ 3.3 10 SOP 1393 rr-33
Real-Time Clock Counts Hundredths of Seconds,
DS1394U-33+ 3.3 10 SOP 1394 rr-33
Seconds, Minutes, Hours, Day, Date, Month, and
Note: All devices are rated for the -40C to +85C operating
Year with Leap-Year Compensation Valid Up to
temperature range.
2100
+Denotes a lead(Pb)-free/RoHS-compliant package.
Output Pin Configurable as Interrupt or Square
A + anywhere on the top mark denotes a lead(Pb)-
Wave with Programmable Frequency of
free/RoHS-compliant package.
32.768kHz, 8.192kHz, 4.096kHz, or 1Hz rr = Revision code on second line of top mark.
(DS1390/DS1393/DS1394 Only)
One Time-of-Day Alarm
Power-Fail Detect and Switch Circuitry
Typical Operating Circuits and Pin Configurations appear at
end of the data sheet.
SPI is a trademark of Motorola, Inc.
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxims website at www.maximintegrated.com. 19-4898; Rev 4; 10/12DS1390DS1394
Low-Voltage SPI/3-Wire RTCs with
Trickle Charger
ABSOLUTE MAXIMUM RATINGS
Voltage Range on V Pin Relative to Ground .....-0.3V to +6.0V Storage Temperature Range .............................-55C to +125C
CC
Voltage Range on Inputs Relative Soldering Temperature...........................Refer to the IPC/JEDEC
to Ground ...............................................-0.3V to (V + 0.3V) J-STD-020 Specification.
CC
Operating Temperature Range ...........................-40C to +85C
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
RECOMMENDED DC OPERATING CONDITIONS
(V = V to V , T = -40C to +85C, unless otherwise noted. Typical values are at nominal supply voltage and T = +25C,
CC CC(MIN) CC(MAX) A A
unless otherwise noted.) (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
DS139x-33 2.97 3.3 5.50
Supply Voltage (Note 2) V DS139x-3 2.7 3.0 3.3 V
CC
DS139x-18 1.71 1.8 1.89
0.7 x V +
CC
Logic 1 V (Note 2) V
IH
V 0.5
CC
+0.3 x
Logic 0 V (Note 2) -0.3 V
IL
V
CC
Supply Voltage, Pullup
V (Note 2) 5.5 V
PU
SQW/INT, SQW, INT, V = 0V
CC
-33 1.3 3.0 V
CC(MAX)
V Voltage (Note 2) V V
BACKUP BACKUP -3 1.3 3.0 3.7
-18 1.3 3.0 3.7
-33 2.70 2.88 2.97
Power-Fail Voltage (Note 2) V V
PF -3 2.45 2.6 2.70
-18 1.51 1.6 1.71
R1 (Notes 3, 4) 250
Trickle-Charge Current-Limiting
R2 (Notes 3, 5) 2000
Resistors
R3 (Notes 3, 6) 4000
Input Leakage I (Note 7) -1 +1 A
LI
I/O Leakage I (Note 8) -1 +1 A
LO
RST Pin I/O Leakage I (Note 9) -200 +10 A
LORST
-33, -3 (V = 0.85 x V) -1
OH CC
DOUT Logic 1 Output I mA
OHDOUT
-18 (V = 0.80 x V) 0.750
OH CC
-33, -3 (V = 0.15 x V) 3
OL CC
DOUT Logic 0 Output I mA
OHDOUT
-18 (V = 0.20 x V) 2
OL CC
Logic 0 Output
V > 1.71V; V = 0.4V 3.0 mA
CC OL
(DS1390/DS1393/DS1394
I
OLSIR
SQW/INT; DS1392 SQW, INT;
1.3V < V < 1.71V; V = 0.4V 250 A
CC OL
DS1391/DS1393 RST)
-33 2
mA
V Active Supply Current
CC
I
CCA-3 2
(Note 10)
-18 500 A
2
Maxim Integrated