DS1501:Y2K-Compliant Watchdog Real-Time Clocks

The DS1501/DS1511 are full-function, year 2000-compliant real-time clock/calendars (RTCs) with an RTC alarm, watchdog timer, power-on reset, battery monitors, 256 bytes NV SRAM, and a 32.768kHz output. User access to all registers within the DS1501/DS1511 is accomplished with a byte-wide interface, as shown in Figure 8. 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.

Key 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
  • +3.3 (W) or +5V (Y) Operation
  • Precision Power-On Reset
  • Power-Control Circuitry Support System Power-On from Date/Day/Time Alarm or Key Closure/Modem-Detect Signal
  • 256 Bytes Battery-Backed SRAM
  • Auxiliary Battery Input
  • Accuracy of DS1511 Better than ±1 Minute/Month at +25°C
  • Day-of-Week/Date Alarm Register
  • Crystal Select Bit Allow RTC to Operate with 6pF or 12.6pF Crystal (DS1501)
  • Battery Voltage-Level Indicator Flags
  • Available as Chip (DS1501) or Stand-Alone Encapsulated DIP Module with Embedded Battery and Crystal (DS1511)
DS1501, DS1511: Typical Operating Circuit
DS1501, DS1511: Typical Operating Circuit
Applications/Uses
  • Battery-Backed Systems
  • Consumer Electronics
  • Office Equipment
  • Remote Systems
  • Telecom Switches
DataSheet
titleDownload file
DS1501-DS1511 Data SheetDS1501-DS1511.pdf
Errata DS15011501A6.pdf
Errata DS15011501A7.pdf
Parametrics
Part NumberInterfaceVSUPPLY
(V)
CL
(pF)
Memory TypeMemory Size
(Bytes)
Time of Day AlarmsFunctionsPackage/PinsBudgetary
Price
See Notes
DS1501Bytewide3.3
5
6
12.5
NV SRAM2561RTC
Watchdog Timekeeper
PDIP(W)/28
SOIC(W)/28
TSOP/28
$4.63 @1k
DS1511-EDIP/28$10.38 @1k
Quality and Environmental Data
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
DS1501W+NRNDPDIP(W),;28 pin;592.6 mm²0°C to +70°CLead Free
DS1501WENo Longer AvailableDS1501WE+TSOP,;28 pin;109.8 mm²0°C to +70°CNo
DS1501WE+No Longer AvailableTSOP,;28 pin;109.8 mm²0°C to +70°CLead Free
DS1501WE+T&RNo Longer AvailableTSOP,;28 pin;109.8 mm²0°C to +70°CLead Free
DS1501WE/T&RNo Longer AvailableDS1501WE+T&RTSOP,;28 pin;109.8 mm²0°C to +70°CNo
DS1501WENNo Longer AvailableDS1501WEN+TSOP,;28 pin;109.8 mm²-40°C to +85°CNo
DS1501WEN+No Longer AvailableTSOP,;28 pin;109.8 mm²-40°C to +85°CLead Free
DS1501WEN+T&RNo Longer AvailableTSOP,;28 pin;109.8 mm²-40°C to +85°CLead Free
DS1501WEN/T&RNo Longer AvailableDS1501WEN+T&RTSOP,;28 pin;109.8 mm²-40°C to +85°CNo
DS1501WN+NRNDPDIP(W),;28 pin;592.6 mm²-40°C to +85°CLead Free
Part NumberStatusRecommended ReplacementPackageTempRoHS
DS1501WSNo Longer AvailableSOIC(W),;28 pin;235 mm²0°C to +70°CNo
DS1501WS+No Longer AvailableDS1501WZ+SOIC(W),;28 pin;235 mm²0°C to +70°CSee data sheet
DS1501WS+T&RNo Longer AvailableDS1501WZ+T&RSOIC(W),;28 pin;235 mm²0°C to +70°CSee data sheet
DS1501WSNNo Longer AvailableSOIC(W),;28 pin;235 mm²-40°C to +85°CNo
DS1501WSN+No Longer AvailableDS1501WZN+SOIC(W),;28 pin;235 mm²-40°C to +85°CSee data sheet
DS1501WSN+T&RNo Longer AvailableDS1501WZN+T&RSOIC(W),;28 pin;235 mm²-40°C to +85°CSee data sheet
DS1501WSN+T&R-WNo Longer AvailableDS1685SN-5+SOIC(W),;28 pin;235 mm²-40°C to +85°CSee data sheet
DS1501WSN/T&RNo Longer AvailableSOIC(W),;28 pin;235 mm²-40°C to +85°CNo
DS1501WZ+ActiveSOIC(W),;28 pin;192.8 mm²0°C to +70°CLead Free
DS1501WZ+T&RActiveSOIC(W),;28 pin;192.8 mm²0°C to +70°CLead Free
Part NumberStatusRecommended ReplacementPackageTempRoHS
DS1501WZN+ActiveSOIC(W),;28 pin;192.8 mm²-40°C to +85°CLead Free
DS1501WZN+T&RActiveSOIC(W),;28 pin;192.8 mm²-40°C to +85°CLead Free
DS1501Y+NRNDPDIP(W),;28 pin;592.6 mm²0°C to +70°CLead Free
DS1501YENo Longer AvailableDS1501YE+TSOP,;28 pin;109.8 mm²0°C to +70°CNo
DS1501YE+No Longer AvailableTSOP,;28 pin;109.8 mm²0°C to +70°CLead Free
DS1501YE+T&RActiveTSOP,;28 pin;109.8 mm²0°C to +70°CLead Free
DS1501YENNo Longer AvailableTSOP,;28 pin;109.8 mm²-40°C to +85°CNo
DS1501YEN+No Longer AvailableTSOP,;28 pin;109.8 mm²-40°C to +85°CLead Free
DS1501YEN+T&RNo Longer AvailableTSOP,;28 pin;109.8 mm²-40°C to +85°CLead Free
DS1501YN+NRNDPDIP(W),;28 pin;592.6 mm²-40°C to +85°CLead Free
Part NumberStatusRecommended ReplacementPackageTempRoHS
DS1501YSNo Longer AvailableSOIC(W),;28 pin;235 mm²0°C to +70°CNo
DS1501YS+No Longer AvailableDS1501YZ+SOIC(W),;28 pin;235 mm²0°C to +70°CSee data sheet
DS1501YS+T&RNo Longer AvailableSOIC(W),;28 pin;235 mm²0°C to +70°CSee data sheet
DS1501YSNNo Longer AvailableDS1501YZN+SOIC(W),;28 pin;235 mm²-40°C to +85°CNo
DS1501YSN+No Longer AvailableDS1501YZN+SOIC(W),;28 pin;235 mm²-40°C to +85°CSee data sheet
DS1501YSN+T&RNo Longer AvailableDS1501YZN+T&RSOIC(W),;28 pin;235 mm²-40°C to +85°CSee data sheet
DS1501YZ+ActiveSOIC(W),;28 pin;192.8 mm²0°C to +70°CLead Free
DS1501YZ+T&RActiveSOIC(W),;28 pin;192.8 mm²0°C to +70°CLead Free
DS1501YZN+ActiveSOIC(W),;28 pin;192.8 mm²-40°C to +85°CLead Free
DS1501YZN+T&RActiveSOIC(W),;28 pin;192.8 mm²-40°C to +85°CLead Free
DS1501-DS1511.pdf DS1511
1501A6.pdf DS1511
1501A7.pdf DS1511
Tips for Writing Bulletproof Real-Time Clock Control Code DS3234
State Machine Logic in Binary-Coded Decimal (BCD)-Formatted Real-Time Clocks DS3234
Oscillator Design Considerations for Low-Current Applications DS17885
Selecting a Backup Source for Real-Time Clocks DS3234
Using the DS32kHz with Maxim Real-Time Clocks DS17885
Using the Power-Control Functions of the DS1501/DS1511 Real-Time Clock DS1511
Lithium Coin-Cell Batteries: Predicting an Application Lifetime DS9034PCX
Design Considerations for Maxim Real-Time Clocks DS3234
Crystal Considerations with Maxim Real-Time Clocks (RTCs) DS3234
DS1501.pdf DS1501
1501A7.pdf DS1511