DS1500YE+ ,Y2K-Compliant Watchdog RTC with NV ControlELECTRICAL CHARACTERISTICS (V < V < V , T = Over the Operating Range.) CCMIN CCI CCMAX APARAMETER S ..
DS1500YEN ,Y2K Watchdog RTC with Nonvolatile ControlAPPLICATIONS Accuracy Better than ±1 Minute/Month at +25°C Remote Systems Day-of-Week/Date Al ..
DS1501W , Y2K-Compliant Watchdog Real-Time Clocks
DS1501W , Y2K-Compliant Watchdog Real-Time Clocks
DS1501W+ ,Y2K-Compliant Watchdog Real-Time Clocks DS1501/DS1511 Y2K-Compliant Watchdog Real-Time Clocks
DS1501WE ,Y2K-Compliant Watchdog Real-Time ClocksFEATURES BCD-Coded Century, Year, Month, Date, Day, The DS1501/DS1511 are full-function, year 200 ..
DTC144VKA , 100mA / 50V Digital transistor (with built-in resistors)
DTC144VKA , 100mA / 50V Digital transistor (with built-in resistors)
DTC144VKA T146 , Only the on/off conditions need to be set for operation, making the circuit design easy.
DTC144VKA T146 , Only the on/off conditions need to be set for operation, making the circuit design easy.
DTC144VKAT146 , Only the on/off conditions need to be set for operation, making the circuit design easy.
DTC144VKA-T146 , Only the on/off conditions need to be set for operation, making the circuit design easy.
DS1500WE+-DS1500YE+
Y2K-Compliant Watchdog RTC with NV Control
GENERAL DESCRIPTION The DS1500 is a full-function, year 2000-compliant
real-time clock/calendar (RTC) with an alarm,
watchdog timer, power-on reset, battery monitors,
256 bytes of on-board nonvolatile (NV) SRAM, NV
control for backing up an external SRAM, and a
32.768kHz output. User access to all registers within
the DS1500 is accomplished with a byte-wide
interface, as shown in Figure 7. The RTC registers
contain century, year, month, date, day, hours,
minutes, and seconds data in 24-hour binary-coded
decimal (BCD) format. Corrections for day of month
and leap year are made automatically.
APPLICATIONS Remote Systems
Battery-Backed Systems
Telecom Switches
Office Equipment
Consumer Electronics
Pin Configuration and Typical Operating Circuit appear at
end of data sheet.
FEATURES
BCD-Coded Century, Year, Month, Date, Day,
Hours, Minutes, and Seconds with Automatic
Leap-Year Compensation Valid Up to the Year
2100
Programmable Watchdog Timer and RTC
Alarm
Century Register; Y2K-Compliant RTC
Automatic Battery Backup and Write
Protection to External SRAM
+5V or +3.3V Operation
Precision Power-On Reset
Power-Control Circuitry Supports System
Power-On from Date/Day/Time Alarm or Key
Closure
256 Bytes User NV RAM
Auxiliary Battery Input
Accuracy Better than ±1 Minute/Month at
+25°C
Day-of-Week/Date Alarm Register
Battery Voltage-Level Indicator Flags
Optional Industrial Temperature Range: -40°C
to +85°C
ORDERING INFORMATION
PART TEMP RANGE VOLTAGE (V) PIN-PACKAGE 0BTOP MARK*
DS1500WE+ 0°C to +70°C 3.3 32 TSOP DS1500W
DS1500WEN+ -40°C to +85°C 3.3 32 TSOP DS1500WN
DS1500YE+ 0°C to +70°C 5.0 32 TSOP DS1500Y
DS1500YEN+ -40°C to +85°C 5.0 32 TSOP DS1500YN
+Denotes a lead(Pb)-free/RoHS-compliant device.
*A “+” anywhere on the top mark indicates a lead(Pb)-free/RoHS-compliant device. An “N” indicates an industrial temperature range device.
DS1500
Y2K Watchdog RTC with Nonvolatile Control 19-6130; Rev 11/11
DS1500 Y2KC Watchdog RTC with Nonvolatile Control
ABSOLUTE MAXIMUM RATINGS Voltage Range on Any Pin Relative to Ground……………………………………………………………..-0.5V to +6.0V
Operating Temperature Range (Industrial)...……………………………………………-40°C to +85°C (Note 1)
Operating Temperature Range (Commercial)…………….………………………………...……-0°C to +70°C
Storage Temperature Range………………………………………………………………….-55°C to +125°C
Lead Temperature (soldering, 10s)……….……………………….…………………………………… +300°C
Soldering Temperature (reflow)………………………………….…………………………………… +260°C
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 the absolute maximum rating conditions for extended periods may affect device reliability.
RECOMMENDED DC OPERATING CONDITIONS (TA = Over the Operating Range.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Power Supply Voltage (Note 2) VCC 5V (Y) 4.5 5.0 5.5 V 3.3V (W) 3.0 3.3 3.6
Logic 1 Voltage All Inputs (Note 2) VIH 2.2 VCC +
0.3 V 2.0 VCC +
0.3
Pullup Voltage, IRQ, PWR, and RST Outputs VPU (Note 2) 5.5 V
Logic 0 Voltage All Inputs (Note 2) VIL Y -0.3 +0.8 V W -0.3 +0.6
Battery Voltage (Note 2) VBAT 2.5 3.0 3.7 V
Auxiliary Battery Voltage (Note 2) VBAUX Y 2.5 3.0 5.3 V W 2.5 3.0 3.7
DC ELECTRICAL CHARACTERISTICS (VCCMIN < VCCI < VCCMAX, TA = Over the Operating Range.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Active Supply Current (Note 3) ICC Y 15 mA W 10
TTL Standby Current (CS = VIH) ICC1 Y 5 mA W 4
CMOS Standby Current
(CS ≥ VCCI - 0.2V) ICC2 Y 5 mA W 4
Input Leakage Current (Any Input) IIL -1 +1 µA
Output Leakage Current (Any Output) IOL -1 +1 µA
Output Logic 1 Voltage (IOUT = -1.0mA) VOH (Note 2) 2.4 V
Output Logic 0 Voltage (IOUT = 2.1mA,
DQ0–7, CEO IOUT = 5.0mA, IRQ,
IOUT = 7.0mA PWR, and RST)
VOL1 (Note 2) 0.4 V
VOL2 (Notes 2, 4) 0.4 V
Battery Low, Flag Trip Point (Note 2) VBLF Y 2.0 V W 1.9
Output Voltage (ICCO1 = 85mA ) (Note 5) VCCO1 Y VCCI -
0.3 V W
Power-Fail Voltage (Note 2) VPF Y 4.20 4.50 V W 2.75 2.97
Battery Switchover Voltage VSO (Notes 2, 6)
VBAT,
VBAUX, V
DS1500 Y2KC Watchdog RTC with Nonvolatile Control
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Output Voltage (ICCO2 = 50μA) VCCO2 (Note 7) VBAT -
0.3 V
Battery Leakage Current ILKG 10 100 nA
DC ELECTRICAL CHARACTERISTICS (VCC = 0V, TA = Over the Operating Range.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Battery Current, BB32 = 0, EOSC = 0 IBAT1 (Notes 8, 9) 0.27 1.0 µA
Battery Current, BB32 = 0, EOSC = 1 IBAT2 (Notes 8, 9) 0.01 0.1 µA
VBAUX Current BB32 = 1, SQW Open IBAUX (Notes 8, 9) 2 µA
CRYSTAL SPECIFICATIONS
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Nominal Frequency fO 32.768 kHz
Series Resistance ESR 45 kΩ
Load Capacitance CL 6 pF
Note: The crystal, traces, and crystal input pins should be isolated from RF generating signals. Refer to Application Note 58: Crystal Considerations for Maxim Real-Time Clocks (RTCs) for additional specifications.
AC OPERATING CHARACTERISTICS (VCCI = 5.0V ±10%, TA = Over the Operating Range.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Read Cycle Time tRC 70 ns
Address Access Time tAA 70 ns
CS to DQ Low-Z tCSL (Note 10) 5 ns
CS Access Time tCSA 70 ns
CS Data Off Time tCSZ (Note 10) 25 ns
OE to DQ Low-Z (0°C to +85°C) tOEL (Note 10) 5 ns
OE to DQ Low-Z (-40°C to 0°C) tOEL (Note 10) 2 ns
OE Access Time tOEA 35 ns
OE Data Off Time tOEZ (Note 10) 25 ns
Output Hold from Address tOH 5 ns
Write Cycle Time tWC 70 ns
Address Setup Time tAS 0 ns
WE Pulse Width tWEW 50 ns
CS Pulse Width tCSW 55 ns
Data Setup Time tDS 30 ns
Data Hold Time tDH 5 ns
Address Hold Time tAH 0 ns
WE Data Off Time tWEZ (Note 10) 25 ns
Write Recovery Time tWR 15 ns
CEI to CEO Propagation Delay tCEPD 10 ns
Pulse Width, OE, WE, or CS High PWHIGH 20 ns
Pulse Width, OE, WE, or CS Low PWLOW 70 ns
DS1500 Y2KC Watchdog RTC with Nonvolatile Control
AC OPERATING CHARACTERISTICS (continued) (VCCI = 3.3V ±10%, TA = Over the Operating Range.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Read Cycle Time tRC 120 ns
Address Access Time tAA 120 ns
CS to DQ Low-Z tCSL (Note 10) 5 ns
CS Access Time tCSA 120 ns
CS Data Off Time tCSZ (Note 10) 40 ns
OE to DQ Low-Z (0°C to +85°C) tOEL (Note 10) 5 ns
OE to DQ Low-Z (-40°C to 0°C) tOEL (Note 10) 2 ns
OE Access Time tOEA 100 ns
OE Data Off Time tOEZ (Note 10) 35 ns
Output Hold from Address tOH 5 ns
Write Cycle Time tWC 120 ns
Address Setup Time tAS 0 ns
WE Pulse Width tWEW 100 ns
CS Pulse Width tCSW 110 ns
Data Setup Time tDS 80 ns
Data Hold Time tDH 5 ns
Address Hold Time tAH 0 ns
WE Data Off Time tWEZ (Note 10) 40 ns
Write Recovery Time tWR 15 ns
CEI to CEO Propagation Delay tCEPD 10 ns
Pulse Width, OE, WE, or CS High PWHIGH 40 ns
Pulse Width, OE, WE, or CS Low PWLOW 100 ns
Figure 1. Read Cycle Timing tRC
tCSA
tOEA
tCSL
tOEL
tOH
tOEZ
tAA
VALIDDQ0-DQ7
A0-A4
tCSZ
DS1500 Y2KC Watchdog RTC with Nonvolatile Control
Figure 2. Write Cycle Timing, Write-Enable-Controlled
Figure 3. Write Cycle Timing, Chip-Select-Controlled tWC
tAH
tDS
tAS
tWEZtDH
tWR
tAS
DATA INPUTDQ0-DQ7
A0-A4
DATA OUTPUTDATA INPUT
tWEW
VALIDVALID
tWC
tAH
tDS
tAS
tDH
tWR
tAS
DATA INPUTDQ0-DQ7
A0-A4
DATA INPUT
tCSW
VALIDVALID
DS1500 Y2KC Watchdog RTC with Nonvolatile Control
Figure 4. Burst Mode Timing Waveform A0–A4
DQ0–DQ7
OE, WE, OR CS
13h
PWHIGH PWLOW
POWER-UP/DOWN CHARACTERISTICS (Figure 5)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS CS, CEI, or WE at VIH Before Power-Fail tPF 0 µs
VCCI Fall Time: VPF(MAX) to VPF(MIN) tF 300 µs
VCCI Fall Time: VPF(MIN) to VSO tFB 10 µs
VCCI Rise Time: VPF(MIN) to VPF(MAX) tR 0 µs
VPF to RST High tREC 35 200 ms
CAPACITANCE (TA = +25°C)
PARAMETER SYMBOL MIN TYP MAX UNITS Capacitance on All Input Pins CIN 10 pF
Capacitance on IRQ, PWR, RST, and DQ Pins CIO 10 pF
AC TEST CONDITIONS
OUTPUT LOAD INPUT PULSE
LEVELS
TIMING MEASUREMENT
REFERENCE LEVELS
INPUT PULSE RISE
AND FALL TIMES (Y) 50pF + 1TTL Gate 0V to 3.0V for
5V operation
Input: 1.5V 5ns (W) 25pF + 1 TTL Gate Output: 1.5V
DS1500 Y2KC Watchdog RTC with Nonvolatile Control
Figure 5. 5V Power-Up/Down Waveform Timing OUTPUTS CCI V PF(MAX) PF(MIN)
INPUTS
HIGH-Z
RST
DON'T CARE
VALID
RECOGNIZED RECOGNIZED
VALID F t FB t PF t DR SO R REC
Warning: Under no circumstances are negative undershoots, of any amplitude, allowed when
device is in battery-backup mode. DS1500 Y2KC Watchdog RTC with Nonvolatile Control
WAKEUP/KICKSTART TIMING (TA = +25°C) (Figure 6)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Kickstart-Input Pulse Width tKSPW 2 µs
Wakeup/Kickstart Power-On Timeout tPOTO (Note 11) 2 s
Note: Time intervals shown above are referenced in Wakeup/Kickstart.
Figure 6. Wakeup/Kickstart Timing Diagram
Note 1: Limits at -40°C are not production tested and are guaranteed by design.
Note 2: Voltage referenced to ground.
Note 3: Outputs are open.
Note 4: The IRQ, PWR, and RST outputs are open drain.
Note 5: Value for voltage and currents is from the VCCI input pin to the VCCO pin.
Note 6: If VPF is less than VBAT and VBAUX, the device power is switched from VCC to the greater of VBAT or VBAUX when VCC drops below VPF. If VPF is greater than VBAT and VBAUX, the device power is switched from VCC to the greater of VBAT or VBAUX when VCC drops below the greater
of VBAT or VBAUX.
Note 7: Value for voltage and currents is from the VBAT or VBAUX input pin to the VCCO pin.
Note 8: IBAT1 and IBAT2 are specified with VCCO unconnected and do not include any RAM current.
Note 9: VBAT or VBAUX current. Using a 32.768kHz crystal connected to X1 and X2.
Note 10: These parameters are sampled with a 5pF load and are not 100% tested.
Note 11: Typical values are at +25°C, nominal (active) supply, unless otherwise noted.
DS1500 Y2KC Watchdog RTC with Nonvolatile Control
PIN DESCRIPTION
PIN NAME FUNCTION SQW
Square-Wave Output. When enabled, the SQW pin outputs a 32.768kHz square wave. If the square
wave (E32K) and battery-backup 32kHz (BB32) bits are enabled, power is provided by VBAUX when
VCC is absent. KS
Kickstart Input. This pin is used to wake up a system from an external event, such as a key closure.
The KS pin is normally connected using a pullup resistor to VBAUX. If the KS function is not used,
connect to ground. VBAT
Battery input for any standard 3V lithium cell or other energy source. Battery voltage must be held
between 2.5V and 3.7V for proper operation. UL recognized to ensure against reverse charging
current when used with a lithium battery. If not used, connect to ground.* VBAUX
Auxiliary battery input for any standard 3V lithium cell or other energy source. Battery voltage must
be held between 2.5V and 3.7V for proper operation. Provides backup power to the device, and
provides power for auxiliary functions. UL recognized to ensure against reverse charging current
when used with a lithium battery. If not used, connect to ground.* CEO Chip-Enable Output. Buffered chip-enable output signal for external SRAM switches high when VCCI
falls below the power-fail point VPF. CEI Chip-Enable Input. Input for chip-enable signal for external SRAM. WE Write-Enable Input. Active-low input that enables DQ0–DQ7 for data input to the device. VCC1
DC power is applied to the device on these pins. VCC is the positive terminal. When power is applied
within the normal limits, the device is fully accessible and data can be written and read. When VCC
drops below the normal limits, reads and writes are inhibited. As VCC drops below the battery
voltage, the RAM and timekeeping circuits are switched over to the battery. VCC0 Buffered VCC output to external SRAM. Switches to either VBAT or VBAUX when in data retention
mode.
10 N.C. No Connection
11 PWR Power-On Output (Open Drain). This output, if used, is normally connected to power-supply control
circuitry. This pin requires a pullup resistor connected to a positive supply to operate correctly.
12, 13 X1, X2
Connections for a standard 32.768kHz quartz crystal. For greatest accuracy, the DS1500 must be
used with a crystal that has a specified load capacitance of either 6pF or 12.5pF. The crystal select
(CS) bit in control register B is used to select operation with a 6pF or 12.5pF crystal. The crystal is
attached directly to the X1 and X2 pins. There is no need for external capacitors or resistors. An
external 32.768kHz oscillator can also drive the DS1500. In this configuration, the X1 pin is
connected to the external oscillator signal and the X2 pin is left unconnected. For more information
about crystal selection and crystal layout considerations, refer to Application Note 58: Crystal
Considerations with Maxim Real-Time Clocks (RTCs). See Figure 8.
14 RST
Reset Output (Open Drain). This output, if used, is normally connected to a microprocessor-reset
input. This pin requires a pullup resistor connected to a positive supply to operate correctly. When
RST is active, the device is not accessible.
15 IRQ Interrupt Output (Open Drain). This output, if used, is normally connected to a microprocessor
interrupt input. This pin requires a pullup resistor connected to a positive supply to operate correctly.
16–20 A4–A0 Address Inputs. Selects one of 17 register locations.
21–23,
25–29 DQ0–DQ7 Data I/O pins for 8-bit parallel data transfer.
24, 31 GND
DC power is applied to the device on these pins. VCC is the positive terminal. When power is applied
within the normal limits, the device is fully accessible and data can be written and read. When VCC
drops below the normal limits, reads and writes are inhibited. As VCC drops below the battery
voltage, the RAM and timekeeping circuits are switched over to the battery.
30 CS Chip-Select Input. Active-low input to enable the device.
32 OE Output-Enable Input. Active-low input that enables DQ0–DQ7 for data output from the device
*See “Conditions of Acceptability” at /TechSupport/QA/ntrl.htm.
DS1500 Y2KC Watchdog RTC with Nonvolatile Control
Figure 7. Block Diagram
Figure 8. Typical Crystal Layout CRYSTAL
X1
X2
GND
LOCAL GROUND PLANE (LAYER 2) CCO
RST
PWR
CEO
256 x 8
NV SRAM
POWER CONTROL
WRITE PROTECTION,
AND POWER-ON
RESET
16 x 8
CLOCK AND CONTROL
REGISTERS BAT BAT BAUX
GND
KS
CEI
A0–A4
DQ0–DQ7
CS
WE
OE
X1
X2
32.768kHz CLOCK
OSCILLATOR IRQ
SQW
CLOCK ALARM AND WATCHDOG
COUNTDOWN
Maxim DS1500
