ds2775 Maxim Integrated Products, Inc., ds2775 Datasheet
ds2775
Related parts for ds2775
ds2775 Summary of contents
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... The DS2775–DS2778 operate from +4.0V to +9.2V for direct integration into battery packs with two Li+ or Li- Poly cells. In addition to nonvolatile storage for cell compensation and application parameters, the DS2775– ...
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Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication ABSOLUTE MAXIMUM RATINGS Voltage Range on PLS, CP, CC, DC Pins Relative to V .....................................................-0.3V to +18V SS Voltage Range SRC Pins ...
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Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication ELECTRICAL CHARACTERISTICS (continued +4.0V to +9.2V -20°C to +70°C, unless otherwise noted. Typical values are PARAMETER SYMBOL DQ, PIO, SDA Output ...
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... Recovery Time Write-Zero Low Time t Write-One Low Time t Read Data Valid Reset Time High Reset Time Low Presence-Detect High Presence-Detect Low ELECTRICAL CHARACTERISTICS: 1-Wire INTERFACE, OVERDRIVE (DS2775/DS2776 ONLY +4.0V to +9.2V -20°C to +70°C PARAMETER SYMBOL Time Slot Recovery Time Write-Zero Low Time ...
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Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication ELECTRICAL CHARACTERISTICS: 2-WIRE INTERFACE (DS2777/DS2778 ONLY +4.0V to +9.2V -20°C to +70°C PARAMETER SYMBOL SCL Clock Frequency Bus-Free Time Between a STOP and ...
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... DC FET GATE DC FET SOURCE V DC FET GS V 25mΩ SNS SENSE RESISTOR WITH SHORT-CIRCUIT THRESHOLD = 150mV 100 120 140 160 180 200 TIME (μs) MODE ( LOAD ON PK+) DD DS2775/6/7/8 toc06 12.6V 2.75V 100 TIME (ms) ...
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Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication (T = +25°C, unless otherwise noted.) A CURRENT MEASUREMENT ACCURACY 125 75 -20°C +25°C 25 -25 +70°C -75 125 -0.052 -0.032 -0.012 0.008 0.028 0.048 V (mV) SNS PIN ...
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... CONTROL TEMPERATURE CURRENT PRECISION ANALOG FuelPack™ OSCILLATOR ALGORITHM CONTROL AND STATUS REGISTERS PIO LOGIC 32-BYTE PARAMETER EEPROM COMMUNICATION INTERFACE 16-BYTE USER EEPROM DS2775–DS2778 Block Diagram V IN2 10-BIT + SIGN ADC/MUX V IN1 SNS 15-BIT + SIGN ADC VREF V SS PIN SDA/DQ DRIVERS ...
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... Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication PK+ 1kΩ 150Ω DATA 5.1V 0.1μF PK- PK+ 1kΩ 150Ω SDA SCL 150Ω 5.1V 5.1V 0.1μF PK- _______________________________________________________________________________________ DS2775/DS2776 Typical Application Circuit 1kΩ 1kΩ CC SRC DC PLS IN2 V DS2775 IN1 DS2776 PIO CP VB 0.47μF ...
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... Power Modes The DS2775–DS2778 have two power modes: active and sleep. On initial power-up, the DS2775–DS2778 default to active mode. In active mode, the DS2775– DS2778 are fully functional with measurements and capacity estimation registers continuously updated. The protector circuit monitors battery pack, cell volt- ages, and battery current for safe conditions ...
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... Table 1 summarizes the conditions that activate the protection circuit, the response of the DS2775–DS2778, and the thresholds that release the DS2775–DS2778 from a protection state. Figure 3 shows Li+ protection circuitry example waveforms. ______________________________________________________________________________________ ...
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... Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication Table 1. Li+ Protection Conditions and DS2775/DS2776 Responses CONDITION THRESHOLD Overvoltage (OV) (Note 1) V CELL Undervoltage (UV) (Note 1) V CELL Overcurrent, Charge (COC) V SNS Overcurrent, Discharge V SNS (DOC) Short Circuit (SC) V SNS Note defined as (V ...
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... MSb “S”: SIGN BITS(S), “X”: RESERVED Figure 4. Voltage Register Format ______________________________________________________________________________________ until the voltage on PLS rises above ( DS2775–DS2778 provide a test current of value I IN2 IN1 from V DD removal of the offending low-impedance load. , UVD If V SNS period longer than short-circuit delay, t > ...
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... Temperature measurements are updated every 440ms and placed in the Temperature register in two’s complement form. Current Measurement In active mode, the DS2775–DS2778 continuously mea- sure the current flow into and out of the battery by mea- suring the voltage drop across a low-value current-sense resistor, R ...
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... NBEN bit in the Control register. See the Control regis- ter description for additional information. The DS2775–DS2778’s current measurement gain can be adjusted through the RSGAIN register, which is facto- ry calibrated to meet the data sheet specified accuracy. ...
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... The 16-bit FRSGAIN value is readable from addresses B0h and B1h. Sense-Resistor Temperature Compensation The DS2775–DS2778 can temperature compensate the current-sense resistor to correct for variation in a sense resistor’s value over temperature. The DS2775–DS2778 are factory programmed with the sense-resistor temper- ature coefficient, RSTC, set to zero, which turns off the temperature compensation function ...
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... Gauging with Maxim Battery Monitor ICs. To facilitate efficient implementation in hardware, a modified version of the method outlined in Application Note 131 is used to store cell characteristics in the DS2775–DS2778. Full and empty points are retrieved in a lookup process that retraces a piecewise linear model consisting of three model curves named full, active empty, and standby empty ...
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... The application’s charge termination method should be used to determine the table values. The DS2775–DS2778 reconstruct the full line from cell char- acteristic table values to determine the full capacity of the battery at each temperature. Reconstruction occurs in one-degree temperature increments ...
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... IN2 standby-load current and voltage are used for deter- mining the cell characteristics but are not programmed into the DS2775–DS2778. The DS2775–DS2778 recon- struct the standby-empty line from the cell characteris- tic table to determine the standby-empty capacity of the battery at each temperature. Reconstruction occurs Standby Empty in one-degree temperature increments ...
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Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication -10 full with a resolution Standby empty at +40°C is, by definition, zero and therefore no storage is required. The slopes (derivatives) of the four segments ...
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Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication Minimum Charge Current (IMIN) IMIN stores the charge-current threshold used to detect a fully charged state stored as a 1-byte value with units of 50µV (IMIN x ...
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... Note: Do not confuse the active-empty point with the active-empty flag. The active-empty flag is set only when the VAE threshold is passed. The DS2775–DS2778 process measurement and cell characteristics on a 3.5s interval and yield seven result registers. The result registers are sufficient for direct display to the user in most applications ...
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Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication MSB—ADDRESS 02h MSb Figure 16. Remaining Active Absolute Capacity (RAAC) [mAh] The RAAC register reports the capacity available under ...
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Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication The Protection register reports events detected by the Li+ safety circuit on bits [7:2]. Bits 0 and 1 are used to disable the charge and discharge FET gate drivers. ...
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Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication The Status register contains bits that report the device status. All bits are set internally. The CHGTF, AEF, SEF, LEARNF, and VER bits are read-only. The UVF and PORF ...
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... V and V IN1 disables transitions to sleep mode during an undervoltage condition. Bit 5: Power-Mode Enable (PMOD). A value of 1 allows the DS2775–DS2778 to enter sleep mode when DQ is low for value of 0 disables DQ-related transitions to sleep mode. SLEEP Bit 4: Read Net Address Op Code (RNAOP). A value of 0 selects 33h as the op code value for the Read Net Address command ...
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Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication The 8-bit Overvoltage Threshold register (VOV) sets the overvoltage threshold for the protection circuitry. An over- voltage condition is detected if either of the voltages on V the VOV ...
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... The overcurrent thresholds are set in the upper nibble of the RSGAIN register. The OC1 and OC0 bits set the over- current thresholds for the charge and discharge thresholds. The short-circuit threshold is set by the SC0 bit (see Tables 6 and 7, respectively, for overcurrent and short-circuit threshold values). The DS2775–DS2778 have a built-in fixed delay of t ...
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Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication The EEPROM register provides access control of the EEPROM blocks. EEPROM blocks can be locked to prevent alteration of data within the block. Locking a block disables write access ...
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... Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication The DS2775–DS2778 have a 256-byte linear memory space with registers for instrumentation, status, and control, as well as EEPROM memory blocks to store parameters and user information. Byte addresses des- ignated as “reserved” typically return FFh when read. ...
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Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication Table 8. Parameter EEPROM Memory Block ADDRESS DESCRIPTION (HEX) 60h Control Register 61h Accumulation Bias Register (AB) 62h Aging Capacity Register MSB (AC) 63h Aging Capacity Register LSB (AC) ...
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... Register value is automatically saved to EEPROM during active-mode operation and recalled from EEPROM on power-up. 64-Bit Net Address (ROM ID) Each DS2775–DS2778 has a unique, factory-pro- grammed ROM ID that is 64 bits. The first 8 bits of the net address are the product family code (32h). The next 48 bits are a unique serial number ...
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Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication Challenge command. The host then issues the Compute MAC or Compute MAC with ROM ID command. The MAC is computed per FIPS 180, and then returned as a 160-bit ...
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... Sets lock bit to prevent changes to the secret. The host system is responsible for verifying the CRC value and taking action as a result. The DS2775/ DS2776 do not compare CRC values and do not pre- vent a command sequence from proceeding as a result of a CRC mismatch. Proper use of the CRC can result in a communication channel with a very high level of integrity ...
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... There is no circuitry in the DS2775/DS2776 that prevents a command sequence from proceeding if the stored or calculated CRC from the DS2775/DS2776 and the calculated CRC from the host do not match. Hardware Configuration Because the 1-Wire bus has only a single line important that each device on the bus be able to drive it at the appropriate time ...
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... Skip Net Address [CCh] This command saves time when there is only one DS2775/DS2776 on the bus by allowing the bus master to issue a function command without specifying the address of the slave. If more than one slave device is present on the bus, a subsequent function command can cause a data collision when all slaves transmit data at the same time ...
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... XXh Copies shadow RAM data to EEPROM block containing address XXh. B8h, XXh Recalls EEPROM block containing address XXh to RAM. 6Ah, XXh Permanently locks the block of EEPROM containing address XXh. BBh Resets DS2775/DS2776 (software POR). ISSUE 00h BEFORE READ (BITS) — ...
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Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication 1-Wire SKIP-ROM RESET COMMAND PRESENCE COMPUTE PULSE MAC COMMAND Figure 25. Compute MAC Function Command 1-Wire SKIP-ROM RESET COMMAND PRESENCE COMPUTE PULSE NEXT SECRET COMMAND Figure 26. Compute Next ...
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... The bus master transmits (Tx) a reset pulse for t RSTL goes into receive mode (Rx). The 1-Wire bus line is then pulled high by the pullup resistor. After detecting the rising edge on the DQ pin, the DS2775/DS2776 wait for t and then transmit the presence pulse for t PDH t ...
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... RDV By the end of the read time slot, the DS2775/DS2776 release the bus line and allow pulled high by the external pullup resistor. All read time slots must duration with a 1µs minimum recovery time, t between cycles ...
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Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication V PULLUP GND MIN MODE: 15μs 15μs STANDARD 2μs OVERDRIVE t RDV V PULLUP GND MODE: 15μs STANDARD 2μs OVERDRIVE LINE TYPE LEGEND: Figure 30. 1-Wire Write and Read ...
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Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication A byte of data consists of 8 bits ordered MSb first. The LSb of each byte is followed by the acknowledge bit. The DS2777/DS2778 registers composed of multibyte values ...
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Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication Table 14. 2-Wire Protocol Key KEY S START Bit SAddr Slave Address (7-bit) FCmd Function Command Byte MAddr Memory Address Byte Data Data Byte Written by Master A Acknowledge ...
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... No V IN1 No VB Yes V SS Yes *EXPOSED PAD DOCUMENT NO. 56-G0010-001 is a registered trademark of Maxim Integrated Products, Inc 2ms EEC Pin Configuration SRC 3 12 SCL/OVD DS2775 4 DS2776 11 SDA/DQ DS2777 5 10 PLS DS2778 6 9 PIO * SNS TDFN-EP × (3mm 5mm) ...