DS1846 MAXIM [Maxim Integrated Products], DS1846 Datasheet
DS1846
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DS1846 Summary of contents
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... DS1846E-010/T&R (Tape-and-Reel Version) OVERVIEW The DS1846 NV tri-potentiometer, memory, and MicroMonitor™ consists of two 10kW, 100-position linear taper potentiometers, one 100kW, 256-position linear taper potentiometer; 256 bytes of EEPROM memory; and a MicroMonitor. The device provides an ideal method for setting bias voltages and currents in control applications using a minimum of circuitry ...
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... Access to this EEPROM is through an industry-standard 2-wire bus. The interface I/O pins consist of SDA and SCL. The wiper positions of the DS1846, as well as EEPROM data, can be hardware write-protected using the WP input pin. The MicroMonitor is a precision temperature-compensated reference and comparator that monitors certain vital status conditions for a microprocessor ...
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... SDA—2-Wire Serial Data Interface. The serial data pin is for serial data transfer to and from the DS1846. The pin is open drain and can be wire-ORed with other open-drain or open-collector interfaces. SCL—2-Wire Serial Clock Interface. The serial clock input is used to clock data into the DS1846 on rising edges and clock data out on falling edges. ...
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... MEMORY ORGANIZATION The EEPROM of the DS1846 contains 256 bytes. Bytes 00h to F7h are general-purpose user memory. The next three bytes, F8h, F9h, and FAh, contain the wiper settings for each of the potentiometers (see Table 1). The last five bytes, FBh to FFh, are reserved and should not be used. ...
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... The DS1846 is capable of an 8-byte page write. A page write is initiated the same way as a byte write, but the master does not send a stop condition after the first data byte. Instead, after the slave acknowledges the data byte has been received, the master can send up to seven more data bytes using the same nine- clock sequence ...
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... For detailed information concerning page operations, see the MEMORY ORGANIZATION section. The DS1846 is capable of an 8-byte page write. A page write is initiated the same way as a byte write, but the master does not send a stop condition after the first data byte. Instead, after the slave acknowledges receipt of the data byte, the master can send up to seven more data bytes using the same nine-clock sequence ...
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... The bus must be controlled by a master device that generates the serial clock (SCL), controls the bus access, and generates the start and stop conditions. The DS1846 operates as a slave on the 2-wire bus. Connections to the bus are made through the open-drain I/O lines, SDA and SCL. ...
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... Slave Transmitter Mode: The first byte is received and handled as in the slave receiver mode. However, in this mode the direction bit indicates that the transfer direction is reversed. Serial data is transmitted on SDA by the DS1846 while the serial clock is input on SCL. Start and stop conditions are recognized as the beginning and end of a serial transfer. ...
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WRITE PROTECT The WP pin protects EEPROM data and potentiometer position from alteration in an application. This pin must be open or connected high to protect data from alteration. WP has an internal pullup (R READING AND WRITING THE POTENTIOMETER ...
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... R1 and R2 can be determined by the equation as shown TP in Figure 4. Proper operation of the DS1846 requires that the voltage at the IN pin be limited to V Therefore, the maximum allowable voltage at the supply being monitored (V shown in Figure 4. A simple approach to solving the equation is to select a value for R2 high enough to keep power consumption low, and solve for R1 ...
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... Figure 4. NMI The following equations are used to calculate the resistor values when using V V SENSE V Optional, see note . CC SDA Vcc SCL A0 /PBRST WP /RST /NMI RST L0 DS1846 GND R1 TPmin Vsense V Vcc CC ...
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TIMING DIAGRAM: PUSHBUTTON RESET Figure 5 TIMING DIAGRAM: NONMASKABLE INTERRUPT Figure 6 t NMI ...
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TIMING DIAGRAM: POWER-DOWN Figure 7 TIMING DIAGRAM: POWER-UP Figure ...
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ABSOLUTE MAXIMUM RATINGS* Voltage on Any Pin Relative to Ground Operating Temperature Range Programming Temperature Range Storage Temperature Range Soldering Temperature * This is a stress rating only and functional operation of the device at these or any other conditions ...
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DC ELECTRICAL CHARACTERISTICS PARAMETER SYMBOL Input Leakage I IL Current Standby Current I STBY V OL1 Low-Level Output Voltage (SDA) V OL2 I/O Capacitance C I/O Output at 2. Output at NMI OH 2.4V Output at 0.4V ...
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AC ELECTRICAL CHARACTERISTICS PARAMETER SYMBOL SCL Clock Frequency f Bus Free Time t Between Stop and Start Condition Hold Time (Repeated) t HD:STA Start Condition Low Period of SCL t Clock High Period of SCL t HIGH Clock Data Hold ...
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ANALOG RESISTOR CHARACTERISTICS (-40°C to +85°C; V PARAMETER SYMBOL Wiper Resistance R W End-to-End Resistance Absolute Linearity Relative Linearity -3dB Cutoff f cutoff Frequency Temperature Coefficient CONDITION MIN TYP 7 10kW pot 70 100kW pot -1 10kW pot -3 100kW ...
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NOTES: 1) All voltages are referenced to ground. 2) I/O pins of fast-mode devices must not obstruct the SDA and SCL lines specified with V = 5.0V and control port logic pins are driven to the ...