DS2751 Maxim Integrated Products, DS2751 Datasheet
DS2751
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DS2751 Summary of contents
Page 1
... DS2751E 8-Pin TSSOP Package (Lead Free Available) PIN DESCRIPTION V Voltage-Sense Input IN V Device Ground SS PIO Programmable I/O Pin V Power-Supply Input (2.5V to 5.5V) DD IS1 Current-Sense Input IS2 Current-Sense Input SNS Sense Resistor Connection DQ Data Input/Output DS2751 Fuel Gauge DQ 8 SNS 7 IS2 6 IS1 5 020105 ...
Page 2
... Temperature is measured using an on-chip sensor, eliminating the need for a separate thermistor. Bidirectional current measurement and accumulation are accomplished using either an internal 25mW sense resistor or an external device. The DS2751 also features a programmable I/O pin that allows the host system to sense and control other electronics in the pack, including switches, vibration motors, speakers, and LEDs ...
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ABSOLUTE MAXIMUM RATINGS* Voltage on PIO Pin, Relative to V Voltage on All Other Pins, Relative to V Continuous Internal Sense Resistor Current Pulsed Internal Sense Resistor Current Operating Temperature Range Storage Temperature Range Soldering Temperature * This is a ...
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ELECTRICAL CHARACTERISTICS: TEMPERATURE, VOLTAGE, CURRENT = 2.5V £ V £ 5.5V, -20°C to +70°C PARAMETER SYMBOL Temperature Resolution Temperature Full-Scale Magnitude Temperature Error Voltage Resolution Voltage Full-Scale Magnitude Voltage Offset Error Voltage Gain Error Current Resolution Current ...
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... Note 10: Current gain-error specification applies to gain error in converting the voltage difference at IS1 and IS2, and excludes any error remaining after the DS2751 compensates for the internal sense-resistor’s temperature coefficient of 3700ppm/° accuracy of ±500ppm/°C. The DS2751 does not compensate for external sense resistor characteristics, and any error terms arising from the use of an external sense resistor should be taken into account when calculating total current measurement error ...
Page 6
... ADDRESS THERMAL SENSE IS1 - IS2 SNS 1-WIRE AND VOLTAGE REFERENCE MUX ADC INTERNAL SENSE RESISTOR CONFIGURATION ONLY IS2 REGISTERS AND USER MEMORY LOCKABLE EEPROM SRAM TEMPERATURE VOLTAGE CURRENT TIMEBASE ACCUM. CURRENT STATUS/CONTROL 25mW CHIP GROUND IS1 DS2751 PIO V SS ...
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... UVEN bit in the Status Register is set to 1 and the voltage on V threshold V for t UV UVD The DS2751 returns to active mode when the DQ line is pulled from a low-to-high state and the voltage above V . The factory default for the DS2751 is UVEN = PMOD = The DS2751 defaults to active mode when power is first applied ...
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... CURRENT MEASUREMENT In the active mode of operation, the DS2751 continually measures the current flow into and out of the battery by measuring the voltage drop across a current-sense resistor. The DS2751 is available in two configurations: 1) internal 25mW current-sense resistor, and 2) external user-selectable sense resistor. In either configuration, the DS2751 considers the voltage difference between pins IS1 and IS2 ( the filtered voltage drop across the sense resistor ...
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... Figure 5. CURRENT OFFSET BIAS VOLTAGE MEASUREMENT The DS2751 continually measures the voltage between pins V Voltage Register is updated in two’s-complement format every 3.4ms with a resolution of 4.88mV. Voltages above the maximum register value are reported as the maximum value. The Voltage Register format is shown in Figure 6 ...
Page 10
... PIO bit disables the output driver, allowing the PIO pin to be pulled high or used as an input. To sense the value on the PIO pin, read the PIO bit. The DS2751 turns off the PIO output driver and sets the PIO bit high when in sleep mode or when DQ is low for more than t the PMOD bit ...
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... X X PMOD—Sleep Mode Enable. A value this bit enables the DS2751 to enter sleep mode when the DQ line goes low for greater than t This bit is read-only. The desired default value should be set in bit 5 of address 31h. The factory default is 0. ...
Page 12
... UVEN—Undervoltage Sleep Enable. A value UVEN along with a value PMOD enables the DS2751 to enter sleep mode when the voltage (cell depletion). A value of 0 disables the DS2751 from entering the sleep mode due to undervoltage UVD events. This bit is read-only. The desired default value should be set in bit 3 of address 31h. The factory default is 0. X— ...
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... Each DS2751 has a unique, factory-programmed 1-Wire net address that is 64 bits in length. The first 8 bits are the 1-Wire family code (51h for DS2751). The next 48 bits are a unique serial number. The last 8 bits are a CRC of the first 56 bits (see Figure 11). The 64-bit net address and the 1-Wire I/O circuitry built into the device enable the DS2751 to communicate through the 1-Wire protocol detailed in the 1-Wire Bus System section of this data sheet ...
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... To facilitate this, each device attached to the 1-Wire bus must connect to the bus with open-drain or tri-state output drivers. The DS2751 uses an open-drain output driver as part of the bidirectional interface circuitry shown in Figure 13 bidirectional pin is not available on the bus master, separate output, and input pins can be connected together ...
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... available to be read immediately after the MSb of the data at address XX. If the bus master continues to read beyond address FFh, the DS2751 outputs logic 1 until a reset pulse occurs. Addresses labeled “reserved” in the memory map contain undefined data. The Read Data command can be terminated by the bus master with a reset pulse at any bit boundary ...
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... LSb to be stored at address can be written immediately after the MSb to be stored at address XX. If the bus master continues to write beyond address FFh, the DS2751 ignores the data. Writes to read- only addresses, reserved addresses and locked EEPROM blocks are ignored. Incomplete bytes are not written ...
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... NO MATCH SEARCH YES MASTER Tx DS2751 Tx BIT 0 BIT 0 DS2751 Tx BIT 0 MASTER Tx BIT 0 BIT BIT 0 MATCH ? MATCH ? YES MASTER Tx DS2751 Tx BIT 1 BIT 1 DS2751 Tx BIT 1 MASTER Tx BIT 1 BIT BIT 1 MATCH ? MATCH ? YES MASTER Tx DS2751 Tx BIT 63 BIT 63 DS2751 Tx BIT 63 MASTER Tx BIT 63 YES BIT 63 ...
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... DS2751 to present valid data. The bus master can then sample the data t read time slot. By the end of the read time slot, the DS2751 releases the bus line and allows pulled high by the external pullup resistor. All read time slots must be t ...
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... BUS MASTER ACTIVE LOW BOTH BUS MASTER AND DS2751 ACTIVE LOW WRITE 1 SLOT t SLOT t LOW1 DS2751 SAMPLE WINDOW MIN TYP MAX 15ms 15ms 30ms READ 1 SLOT t SLOT t REC MASTER SAMPLE WINDOW t RDV DS2751 ACTIVE LOW RESISTOR PULLUP PACK+ PACK– PACK+ PACK– ...