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MAXIM INTEGRATED PRODUCTS DS1603 Elapsed Time Counter Module User's Manual

Summary

The DS1603 is a precision Real-Time Clock/Elapsed Time Counter module designed for seamless integration into embedded systems. This dual-counter device accurately tracks seconds with exceptional reliability, featuring one dedicated 32-bit counter that retains data even when external power fails, alongside an integral battery backup lasting over ten years. Data communication occurs via a simple, efficient serial port protocol. It is essential for engineers developing applications that require highly accurate continuous timing measurement, monitoring equipment operational time, and deriving precise date metrics in portable or critical environments.

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DS1603

www.maxim-ic.com

Elapsed Time Counter Module

www.maxim-ic.com

FEATURES PIN ASSIGNMENT § Two 32-bit counters keep track of real-time and elapsed time VCC § Counters keep track of seconds for over 125 RST

years DQ NC

§ Battery powered counter counts seconds from

the time battery is attached until VBAT is less

than 2.5V

§ VCC powered counter counts seconds while VCC is above VTP and retains the count in the absence of VCC under battery backup power

PIN DESCRIPTION

§ Clear function resets selected counter to 0 § Read/write serial port affords low pin count RST - Reset § Powered internally by a lithium energy cell CLK - Clock that provides over 10 years of operation DQ - Data Input/Output § One-byte protocol defines read/write, counter GND - Ground address and software clear function VCC - +5V § Self-contained crystal provides an accuracy of OSC - 1Hz Oscillator Output ±2 min per month NC - No Connect § Operating temperature range of 0°C to +70°C § Low-profile SIP module § Underwriters Laboratory (UL) recognized

DESCRIPTION The DS1603 is a real-time clock/elapsed time counter designed to count seconds when VCC power is applied and continually count seconds under battery backup power with an additional counter regardless of the condition of VCC. The continuous counter can be used to derive time of day, week, month, and year by using a software algorithm. The VCC powered counter will automatically record the amount of time that VCC power is applied. This function is particularly useful in determining the operational time of equipment in which the DS1603 is used. Alternatively, this counter can also be used under software control to record real-time events. Communication to and from the DS1603 takes place via a 3-wire serial port. A 1-byte protocol selects read/ write functions, counter clear functions and oscillator trim. The device contains a 32.768k Hz crystal that will keep track of time to within ±2 min/mo. An internal lithium energy source contains enough energy to power the continuous seconds counter for over 10 years.

OPERATION The main elements of the DS1603 are shown in Figure 1. As shown, communications to and from the elapsed time counter occur over a 3-wire serial port. The port is activated by driving RST to a high state. Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device may be simultaneously available through various sales channels. For information about device errata, click here: www.maxim-ic.com/errata.

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Page Summary Contents For MAXIM INTEGRATED PRODUCTS DS1603 Elapsed Time Counter Module User's Manual

Page 1 DS1603 www.maxim-ic.com Elapsed Time Counter Module www.maxim-ic.com FEATURES PIN ASSIGNMENT § Two 32-bit counters keep track of real-time and elapsed time VCC § Counters keep track of seconds for ove...
Page 2 DS1603 With RST at high level 8 bits are loaded into the protocol shift register providing read/write, register select, register clear, and oscillator trim information. Each bit is serially input on t...
Page 3 DS1603 DATA INPUT Following the 8-bit protocol that inputs write mode, 32 bits of data are written to the selected counter on the rising edge of the next 32 CLK cycles. After 32 bits have been entered...
Page 4 DS1603 Figure 1. ELAPSED TIME COUNTER BLOCK DIAGRAM Figure 2. PROTOCOL BIT MAP 7 6 5 4 3 2 1 0 ACC AVC OSC2 OSC1 OSC0 CCC CVC RD 4 of 9
Page 5 DS1603 Table 1. VALID PROTOCOLS PROTOCOL ACTION FUNCTION ACC AVC OSC2 OSC1 OSC0 CCC CVC RD Output continuous counter on the 32 clocks following protocol. Continuous 1 0 X X X X X 1 Oscillator trim reg...
Page 6 DS1603 Figure 3. DATA TRANSFER TIMING DIAGRAM: READ/WRITE DATA TRANSFER Note: t CL, t CH, t R, and t F apply to both read and write data transfer. 6 of 9
Page 7 DS1603 ABSOLUTE MAXIMUM RATINGS Voltage Range on Any Pin Relative to Ground -0.3V to +7.0V Operating Temperature Range 0°C to +70°C Storage Temperature Range -40°C to +70°C Soldering Temperature Range...
Page 8 DS1603 AC ELECTRICAL CHARACTERISTICS (VCC = +5V ±10%; 0°C to +70°C) PARAMETER SYMBOL MIN TYP MAX UNITS NOTES Data to CLK Setup t DC 50 ns 6 CLK to Data Hold t CDH 60 ns 6 CLK to Data Delay t CDD 200 n...
Page 9 DS1603 DS1603 7-PIN MODULE PKG 7-PIN DIM MIN MAX A IN. 0.830 0.850 MM 21.08 21.59 B IN. 0.650 0.670 MM 16.51 17.02 C IN. 0.310 0.330 MM 7.87 8.38 D IN. 0.015 0.030 MM 0.38 0.76 E IN. 0.110 0.140 MM 2....

Manual Details

Brand Maxim Integrated
Pages 9
File Size 223.70 KB
Published May 26, 2026
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Frequently Asked Questions

How long can the DS1603 function using internal backup power?

The lithium energy cell contains enough energy to power the continuous seconds counter for over 10 years.

What happens when external V power drops below its minimum threshold?

The device switches to internal power, disabling the serial port while the continuous counter continues running and retaining previous counts.

What are the temperature restrictions for using this time module?

The operating temperature range is limited between 0°C and +70°C.

Are there specific cautions when soldering the DS1603 onto a circuit board?

Temperature exposure to the lithium energy source must not exceed +85°C, and ultrasonic vibration during post-solder cleaning is prohibited.