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General Description

The low-voltage serial-peripheral interface (SPI™)

DS1390/DS1391/DS1394 and the low-voltage 3-wire

DS1392/DS1393 real-time clocks (RTCs) are clocks/

calendars that provide hundredths of a second, seconds,

minutes, hours, day, date, month, and year information.

The date at the end of the month is automatically adjusted

for months with fewer than 31 days, including corrections

for leap year. The clock operates in either the 24-hour or

12-hour format with an AM/PM indicator. One program-

mable time-of-day alarm is provided. A temperature-com-

pensated voltage reference monitors the status of V

and automatically disables the bus interface and switches

to the backup supply if a power failure is detected. On the

DS1390, a single open-drain output provides a CPU inter-

rupt or a square wave at one of four selectable frequen-

cies. The DS1391 replaces the SQW/INT pin with a RST

output/debounced input.

The DS1390, DS1391, and DS1394 are programmed

serially through an SPI-compatible, bidirectional bus. The

DS1392 and DS1393 communicate over a 3-wire serial

bus, and the extra pin is used for either a separate inter-

rupt pin or a RST output/debounced input.

All five devices are available in a 10-pin µSOP package,

and are rated over the industrial temperature range.

Applications

● Hand-Held Devices

● GPS/Telematics Devices

● Embedded Time Stamping

● Medical Devices

Features

● Real-Time Clock Counts Hundredths of Seconds,

Seconds, Minutes, Hours, Day, Date, Month, and

Year with Leap-Year Compensation Valid Up to 2100

● Output Pin Configurable as Interrupt or Square

Wave with Programmable Frequency of 32.768kHz,

8.192kHz, 4.096kHz, or 1Hz (DS1390/DS1393/

DS1394 Only)

● One Time-of-Day Alarm

● Power-Fail Detect and Switch Circuitry

● Reset Output/Debounced Input (DS1391/DS1393)

● Separate SQW and INT Output (DS1392)

● Trickle-Charge Capability

● SPI Supports Modes 0 and 2 (DS1394)

● SPI Supports Modes 1 and 3 (DS1390/DS1391)

● 3-Wire Interface (DS1392/DS1393)

● 4MHz at 3.0V and 3.3V

● 1MHz at 1.8V

● Three Operating Voltages: 1.8V ±5%, 3.0V ±10%,

and 2.97 to 5.5V (DS1394: 3.3V ±10%)

● Industrial Temperature Range: -40°C to +85°C

● Underwriters Laboratories (UL) Recognized

19-4898; Rev 5; 7/19

Typical Operating Circuits appear at end of the data sheet.

Ordering Information appears at end of the data sheet.

SPI is a trademark of Motorola, Inc.

DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs

with Trickle Charger

Click here for production status of specic part numbers.

Summary of content (27 pages)

PAGE 1
Click here for production status of specific part numbers. DS1390–DS1394 General Description The low-voltage serial-peripheral interface (SPI™) DS1390/DS1391/DS1394 and the low-voltage 3-wire DS1392/DS1393 real-time clocks (RTCs) are clocks/ calendars that provide hundredths of a second, seconds, minutes, hours, day, date, month, and year information. The date at the end of the month is automatically adjusted for months with fewer than 31 days, including corrections for leap year.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger Absolute Maximum Ratings Voltage Range on VCC Pin Relative to Ground....-0.3V to +6.0V Voltage Range on Inputs Relative to Ground............................................... -0.3V to (VCC + 0.3V) Operating Temperature Range............................ -40°C to +85°C Storage Temperature Range............................. -55°C to +125°C Soldering Temperature...........................Refer to the IPC/JEDEC J-STD-020 Specification.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger Recommended DC Operating Conditions (continued) (VCC = VCC(MIN) to VCC(MAX), TA = -40°C to +85°C, unless otherwise noted. Typical values are at nominal supply voltage and TA = +25°C, unless otherwise noted.) (Note 1) PARAMETER VCC Standby Current (Note 11) VBACKUP Leakage Current (VBACKUP = 3.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger CS tCC tR SCLK tCL tCDH tDC tCDZ tCDD W/R DIN tF tCH A6 DOUT A0 D7 HIGH IMPEDANCE D0 CPHA = 1 WRITE ADDRESS BYTE READ DATA BYTE NOTE: SCLK CAN BE EITHER POLARITY SHOWN FOR CPOL = 1. Figure 1a.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger CPHA = 1 tCWH CS tCC tR tCCH tF tCL SCLK tDC DIN tCH tCDH A6 W/R A0 D7 WRITE ADDRESS BYTE D0 READ DATA BYTE DOUT HIGH IMPEDANCE NOTE: SCLK CAN BE EITHER POLARITY SHOWN FOR CPOL = 1. Figure 2a.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger AC Electrical Characteristics—3-Wire Interface (VCC = VCC(MIN) to VCC(MAX), TA = -40°C to +85°C.
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DS1390–DS1394 CE Low-Voltage SPI/3-Wire RTCs with Trickle Charger tCC tR tF SCLK tCL tCDH tCDZ tCH tCDD tDC I/O A0 A1 R/W D0 D7 READ DATA BYTE WRITE ADDRESS BYTE Figure 3. Timing Diagram—3-Wire Read Transfer tCWH CE tCC tR tCCH tF SCLK tCDH tCL tCH tDC I/O A0 A1 WRITE ADDRESS BYTE R/W D0 D7 WRITE DATA BYTE Figure 4. Timing Diagram—3-Wire Write Transfer www.maximintegrated.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger Power-Up/Power-Down Characteristics (TA = -40°C to +85°C) (Figures 5, 6) PARAMETER SYMBOL VCC Detect to Recognize Inputs (VCC Rising) CONDITIONS MIN (Note 17) tRST TYP MAX UNITS 160 200 ms VCC Fall Time; VPF(MAX) to VPF(MIN) tF 300 µs VCC Rise Time; VPF(MIN) to VPF(MAX) tR 0 µs VCC VPF(MAX) VPF VPF VPF(MIN) tF tR tRPU tRST RST INPUTS RECOGNIZED DON'T CARE RECOGNIZED HIGH IMPEDANCE OUTPUTS VALID VALID Figure 5
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger Capacitance (TA = +25°C) PARAMETER Capacitance on All Input Pins Capacitance on All Output Pins (High Impedance) SYMBOL CIN CIO CONDITIONS MIN TYP MAX 10 UNITS pF 10 pF WARNING: Negative undershoots below -0.3V while the part is in battery-backed mode can cause loss of data. Note 1: Limits at -40°C are guaranteed by design and not production tested. Note 2: All voltages are referenced to ground.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger Typical Operating Characteristics (VCC = +3.3V, TA = +25°C, unless otherwise noted.) VCC= 0 SUPPLY CURRENT (nA) 500 450 400 350 1.3 1.7 2.1 2.5 2.9 3.3 3.7 4.1 4.5 4.9 5.3 600 1.3 1.7 2.1 2.5 2.9 3.3 3.7 4.1 4.5 4.9 5.3 VBACKUP (V) IBACKUP vs. TEMPERATURE VBACKUP = 3.0V OSCILLATOR FREQUENCY vs. SUPPLY VOLTAGE VCC = 0V 550 32768.00 32767.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger Pin Configurations TOP VIEW 10 VCC X1 1 X2 2 VBACKUP 3 DS1390/ DS1394 CS 4 GND 5 1 X2 2 8 SCLK VBACKUP 3 7 DOUT CS 4 7 DOUT GND 5 6 DIN 9 SQW/ INT 6 DIN µSOP X1 1 10 VCC 8 SCLK 10 VCC X1 1 X2 2 8 SCLK VBACKUP 3 7 I/O 6 RST X2 3 CE 4 7 I/O CE 4 GND 5 6 INT GND 5 www.maximintegrated.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger Pin Description PIN DS1390/ DS1391 DS1394 DS1392 DS1393 1 1 1 1 X1 2 2 2 2 X2 3 FUNCTION NAME Connections for Standard 32.768kHz Quartz Crystal. The internal oscillator circuitry is designed for operation with a crystal having a 6pF specified load capacitance (CL). Pin X1 is the input to the oscillator and can optionally be connected to an external 32.768kHz oscillator.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger Functional Diagram X1 CL HUNDREDTHS-OFSECONDS GENERATOR CL X2 VCC GND VBACKUP VCC LEVEL DETECT, POWER SWITCH, WRITE PROTECT, TRICKLE CHARGER SQUARE-WAVE RATE SELECTOR, INT, MUX, RST OUTPUT SQW/INT (DS1390/93/94) N RST (DS1391) SQW (DS1392) REAL-TIME CLOCK WITH HUNDREDTHS OF SECONDS (DS1390/91/94) CS (DS1392/93) (CE) SCLK (DS1390/91/94) DIN ALARM REGISTERS BUS INTERFACE (DS1390/91/94) DOUT (DS1392/93) I/O CONTROL/STATUS REGISTERS T
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger Power Control The power-control function is provided by a precise, temperature-compensated voltage reference and a comparator circuit that monitors the VCC level. The device is fully accessible and data can be written and read when VCC is greater than VPF. However, when VCC falls below VPF, the internal clock registers are blocked from any access.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger Address Map The first method is to synchronize enabling the device (CE or CS) with the square wave or interrupt output (DS1390–DS1394). Enabling the device, either after detecting the falling edge of the interrupt output or the rising edge of the square-wave output, ensures that the two events are not simultaneous. Table 3 shows the address map for the DS1390–DS1393 RTC and RAM registers.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger Table 3.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger Alarms All five devices contain one time-of-day/date alarm. Writing to registers 88h through 8Ch sets the alarm. The alarm can be programmed (by the alarm enable and INTCN bits of the control register) to activate the SQW/ INT or INT output on an alarm-match condition. The alarm can activate the SQW/INT or INT output while the device is running from VBACKUP if BBSQI is enabled.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger Special-Purpose Registers The DS1390–DS1394 have three additional registers (control, status, and trickle charger) that control the RTC, alarms, square-wave output, and trickle charger. Control Register (0D/8Dh) (DS1390/DS1393/DS1394 Only) BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0 EOSC 0 BBSQI RS2 RS1 INTCN 0 AIE Bit 7: Enable Oscillator (EOSC). When set to logic 0, this bit starts the oscillator.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger Control Register (0D/8Dh) (DS1392 Only) BIT 7 EOSC BIT 6 0 BIT 5 BBSQI BIT 4 RS2 BIT 3 RS1 BIT 2 ESQW BIT 1 0 BIT 0 AIE The INTCN bit used in the DS1390/DS1393/DS1394 becomes the SQW pin-enable bit in the DS1392. This bit powers up a zero, making SQW active. Status Register (0E/8Eh) BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0 OSF 0 0 0 0 0 0 AF Bit 7: Oscillator Stop Flag (OSF).
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger TRICKLE-CHARGE REGISTER (8Fh WRITE, 0Fh READ) BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0 TCS3 TCS2 TCS1 TCS0 DS1 DS0 ROUT1 ROUT0 1 0F 16 SELECT NOTE: ONLY 1010b ENABLES CHARGER TCS[3:0] = TRICKLE-CHARGE SELECT DS[1:0] = DIODE SELECT ROUT[1:0] = RESISTOR SELECT 1 OF 3 SELECT 1 OF 2 SELECT R1 250W R2 2kW VCC VBACKUP R3 4kW Figure 8. DS1390–DS1394 Programmable Trickle Charger Table 6.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger SPI Serial-Data Bus The DS1390/DS1391/DS1394 provide a 4-wire SPI serial-data bus to communicate in systems with an SPI host controller. The DS1390/DS1391 support SPI modes 1 and 3, while the DS1394 supports SPI modes 0 and 2. Both devices support single-byte and multiple-byte data transfers for maximum flexibility. The DIN and DOUT pins are the serial-data input and output pins, respectively.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger CS SCLK (MODE 0) SCLK (MODE 1) DIN W/R A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0 D4 D3 D2 D1 D0 HIGH IMPEDANCE DOUT Figure 10. SPI Single-Byte Write CS SCLK (MODE 0) SCLK (MODE 1) DIN W/R A6 A5 DOUT A4 A3 HIGH IMPEDANCE A2 A1 A0 D7 D6 D5 Figure 11. SPI Single-Byte Read www.maximintegrated.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger CS SCLK DIN WRITE ADDRESS BYTE DATA BYTE 0 DATA BYTE 1 DATA BYTE N DATA BYTE 1 DATA BYTE N DIN ADDRESS BYTE READ DOUT HIGH-IMPEDANCE DATA BYTE 0 Figure 12. SPI Multiple-Byte Burst Transfer CE SCLK I/O A0 A1 A2 A3 A4 A5 A6 W/R D0 D1 D2 D3 D4 D5 D6 D7 A3 A4 A5 A6 W/R D0 D1 D2 D3 D4 D5 D6 D7 Figure 13. 3-Wire Single-Byte Read CE SCLK I/O A0 A1 A2 Figure 14. 3-Wire Single-Byte Write www.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger 3-Wire Serial-Data Bus The DS1392/DS1393 provide a 3-wire serial-data bus, and support both single-byte and multiple-byte data transfers for maximum flexibility. The I/O pin is the serial-data input/output pin. The CE input is used to initiate and terminate a data transfer. The SCLK pin is used to synchronize data movement between the master (microcontroller) and the slave (DS1392/DS1393) devices.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger Typical Operating Circuits CRYSTAL VCC X2 VCC CRYSTAL VCC X2 VCC VCC X1 VCC X1 CS CS SCLK CPU DOUT SQW/INT SCLK CPU DS1390/ DS1394 DOUT VBACKUP DIN RST VCC X2 VCC VBACKUP DIN GND CRYSTAL DS1391 RST GND CRYSTAL VCC X2 VCC VCC X1 VCC X1 CE CE SQW SCLK CPU I/O SCLK CPU DS1392 SQW/INT DS1393 I/O INT VBACKUP VBACKUP RST GND RST GND Package Information For the latest package outline information a
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger Ordering Information PART DS1390U-18+ DS1390U-3+ DS1390U-33+ DS1391U-18+ DS1391U-3+ DS1391U-33+ DS1392U-18+ DS1392U-3+ DS1392U-33+ DS1393U-18+ DS1393U-3+ DS1393U-33+ DS1394U-33+ TYP PINOPERATING VOLTAGE (V) PACKAGE 1.8 3.0 3.3 1.8 3.0 3.3 1.8 3.0 3.3 1.8 3.0 3.3 3.
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DS1390–DS1394 Low-Voltage SPI/3-Wire RTCs with Trickle Charger Revision History REVISION NUMBER REVISION DATE 0 7/04 1 1/07 PAGES CHANGED DESCRIPTION Initial release. — Added text to the General Description section to indicate that the bus interface is disabled when the part switches to VBACKUP; replaced Ordering Information table with lead-free packages. 1 Added 0MHz (min) spec for SCLK frequency for SPI, 3-wire AC timing.