DS1673 Maxim, DS1673 Datasheet
DS1673
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DS1673 Summary of contents
Page 1
... GENERAL DESCRIPTION The DS1673 portable system controller is a circuit that incorporates many of the functions necessary for low-power portable products integrated into one chip. The device provides a real-time clock (RTC), NV RAM controller, microprocessor monitor, and a 3-channel, 8-bit analog-to-digital converter (ADC). ...
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... The DS1673 debounces a pushbutton input and guarantees an active reset pulse width of 250 ms. The third function is a watchdog timer. The DS1673 has an internal timer that forces the reset signals to the active state if the strobe input is not driven low prior to watchdog timeout. ...
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... AIN0 Connections for Standard 32.768kHz Quartz Crystal. For greatest accuracy, the DS1673 must be used with a crystal that has a specified load capacitance of 6pF. There is no need for external capacitors or resistors. Note: X1 and X2 are very high- impedance nodes recommended that they and the crystal be guard-ringed with ...
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... Bits 0 through 6 specify the address of the registers to be accessed. The MSB (bit 7) is the Read/Write bit. This bit specifies whether the accessed byte will be read or written. A read operation is selected if bit and a write operation is selected if bit one. The address map for the DS1673 is shown in Figure 3. ...
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... The contents of the time, calendar, and alarm registers are in the Binary-Coded Decimal (BCD) format. The DS1673 can run in either 12-hour or 24-hour mode. Bit 6 of the hours register is defined as the 12- or 24-hour mode select bit. When high, the 12-hour mode is selected. In the 12-hour mode, bit 5 is the AM/PM bit with logic 1 being PM ...
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... Oscillator). This bit, when set to logic 0 will start the oscillator. When this bit is set to a EOSC logic 1, the oscillator is stopped and the DS1673 is placed into a low-power standby mode with a current drain of less than 200nA when in battery-backup mode. When the DS1673 is powered by V ...
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... The DS1673 was specifically designed with the Intel 80186 and 386EX microprocessors in mind. As such, the DS1673 has the capability to provide access to the external SRAM in either byte-wide or word- wide format. This capability is provided by the chip enable scheme. Three input signals and two output signals are used for enabling the external SRAM(s) (see Figure 4) ...
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... After the internal 250ms timer has expired, the DS1673 will continue RST to monitor the line. If the line is still low, the DS1673 will continue to monitor the line looking for a RST rising edge. Upon detecting release, the DS1673 will force the The third microprocessor monitoring function provided by the DS1673 is a watchdog timer ...
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... ADC into 256 codes (8 bits). The FSV range is bounded by an upper limit equal to the reference voltage and the lower limit, which is ground. The DS1673 has a FSV of 2.55V (typical) that provides a resolution of 10mV. An input voltage equal to the reference voltage converts to FFh while an input voltage equal to ground converts to 00h. The relative linearity of the ADC is ...
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... Data transfers can occur 1 byte at a time or in multiple byte burst mode. After CS is driven high an address is written to the DS1673. After the address more data bytes can be read or written. For a single-byte transfer 1 byte is read or written and then CS is driven low. For a multiple-byte transfer, multiple bytes can be read or written to the DS1673 after the address has been written ...
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... SINGLE-BYTE DATA TRANSFER Figure 7 MULTIPLE-BYTE BURST TRANSFER Figure DS1673 ...
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... MAX UNITS NOTES 5.0 5.5 V 3.0 3 +0 0C to +70C.) A TYP MAX UNITS NOTES A +1 A 150 V 0.4 V 1.5 2.0 mA A 500 A 300 300 500 nA 200 k 4.35 4.50 V 2.70 2.80 V 2.55 2.63 V 2.0 V 0.3 0 150 mA A 150 DS1673 ...
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... A TYP MAX UNITS NOTES A +1 A 150 V 0.4 V 0.75 1.0 mA A 200 A 100 300 500 nA 200 k 2.6 2.7 V 2.40 2.50 V 2.55 2.63 V 2.0 V 0.3 0 A 100 (T = +25C) A TYP MAX UNITS NOTES DS1673 ...
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... CWH t CDZ RPD t 250 RST PB 250 DB t 250 RPU CED t 200 DS1673 = 0C to 70C.) A MAX UNITS NOTES 200 2.0 MHz 8 500 ns ...
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... CWH t CDZ t 300 RPD t 250 RST PB 250 DB t 250 RPU CED t 300 DS1673 = 0C to +70C.) A MAX UNITS NOTES 600 0.667 MHz 8 1500 ns s 8 210 ns 8 s ...
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... TIMING DIAGRAM: READ DATA Figure 9 TIMING DIAGRAM: WRITE DATA Figure DS1673 ...
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... PUSHBUTTON RESET Figure 11 POWER-UP Figure 12 POWER-DOWN Figure DS1673 ...
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... V occurs when V CC BAT CC output pin. CCO output pin. CCO DOCUMENT NO. 21-0066 21-0042 © 2005 Maxim Integrated Products for capacitive loads. Excludes CC drops below the lower of V CCSW is equal to 250ms plus the startup RPU DS1673 pin RST and V . BAT ...