DS1670 Maxim, DS1670 Datasheet
DS1670
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DS1670 Summary of contents
Page 1
... GENERAL DESCRIPTION The DS1670 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 DS1670 debounces a pushbutton input and guarantees an active-reset pulse width of 250ms. The third function is a watchdog timer. The DS1670 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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... For more information on crystal selection and crystal layout considerations, refer to Application Note 58: Crystal Considerations with Dallas Real Time Clocks. The DS1670 does not function without a crystal. +3.3V Input DC Power. When 3.3V is applied within nominal limits, the device is fully accessible and data can be written and read ...
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... Bits 0 through 6 specify the addresses 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 The address map for the DS1670 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 DS1670 can run in either 12-hour or 24-hour mode. Bit 6 of the hours register is defined as the 12-hour 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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... The DS1670 was specifically designed with the Intel 80186 and 386EX microprocessors in mind. As such, the DS1670 can 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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... The second monitoring function is pushbutton reset control. The DS1670 provides for a pushbutton switch to be connected to the RST output pin. When the DS1670 is not in a reset cycle, it continuously monitors the signal for a low-going edge edge is detected, the DS1670 will debounce the RST ...
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... The FSV range is bounded by an upper limit equal to the reference voltage and the lower limit, which is ground. The DS1670 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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... ADC Register to ensure that the contents are stable during a read cycle. Once a read cycle to the ADC Register has been started, the DS1670 will not update that register until the read cycle has been completed. It should also be mentioned that taking CS low will abort the read cycle and will allow the ADC Register to be updated ...
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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 DS1670. After the address, one or 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 DS1670 after the address has been written ...
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... Exposure to absolute maximum rating conditions for extended periods of time may affect device reliability. RECOMMENDED DC OPERATING CONDITIONS PARAMETER Power-Supply Voltage Input Logic 1 Input Logic 0 Battery Voltage SYMBOL MIN TYP V 2. 2.5 BAT DS1670 (T = 0C to +70C) A MAX UNITS NOTES ...
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... 0C to +70C) A MAX UNITS A +1 A 150 V 0.4 V 0.75 1.0 mA A 200 A 100 300 500 nA 200 k 2.88 2.97 V 2.70 2.78 V 2.55 2.63 V 2.0 V 0.3 0 100 mA A 150 (T A MAX UNITS DS1670 NOTES +25C) NOTES ...
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... DB t 250 RPU CED t 200 3.3V ±10 0C to +70C.) A MAX UNITS ns ns 400 1.0 MHz 1000 ns s ns s 140 ns 140 ns s ns 100 s DS1670 NOTES 15, 16 ...
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... TIMING DIAGRAM: READ DATA Figure 9 TIMING DIAGERAM: WRITE DATA Figure DS1670 ...
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... PUSHBUTTON RESET Figure 11 RST POWER-UP Figure RST POWER-DOWN Figure RST CCTP t RPU CCTPMAX V CCTP V CCSWMIN RPD RST DS1670 ...
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... V occurs when V drops below the lower BAT CC output pin. CCO output pin. CCO DOCUMENT NO. 21-0066 21-0042 © 2005 Maxim Integrated Products for capacitive loads. Excludes CC CCSW is equal to 250ms plus the startup time RPU DS1670 pin. RST and V . BAT ...