DS2776G+ Maxim Integrated Products, DS2776G+ Datasheet

IC FUEL GAUGE LI+ 2CELL 14-TDFN

DS2776G+

Manufacturer Part Number
DS2776G+
Description
IC FUEL GAUGE LI+ 2CELL 14-TDFN
Manufacturer
Maxim Integrated Products
Datasheet

Specifications of DS2776G+

Function
Fuel, Gas Gauge/Monitor
Battery Type
Lithium-Ion (Li-Ion), Lithium-Polymer (Li-Pol)
Voltage - Supply
4 V ~ 9.2 V
Operating Temperature
-20°C ~ 70°C
Mounting Type
Surface Mount
Package / Case
14-TDFN
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
The DS2775–DS2778 report available capacity for
rechargeable lithium-ion (Li+) and Li+ polymer (Li-Poly)
batteries in mAh and as a percentage of full. Safe oper-
ation is ensured by the integrated Li+ protector. The
DS2776/DS2778 support SHA-1-based challenge-
response authentication in addition to all other DS2775/
DS2777 features.
Precision measurements of voltage, temperature, and
current, along with a cell characteristics table and
application parameters, are used for capacity estima-
tion calculations. The capacity registers report a con-
servative estimate of the amount of charge that can be
removed given the current temperature, discharge rate,
stored charge, and application parameters.
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–DS2778 offer
16 bytes of EEPROM for use by the host system and/or
pack manufacturer to store battery lot and date tracking
information. The EEPROM can also be used for non-
volatile storage of system and/or battery usage statis-
tics. A Maxim 1-Wire
(DS2777/DS2778) interface provides serial communica-
tion to access measurement and capacity data regis-
ters, control registers, and user memory. The
DS2776/DS2778 use the SHA-1 hash algorithm in a
challenge-response pack authentication protocol for
battery-pack verification.
19-4688; Rev 3; 5/10
Selector Guide appears at end of data sheet.
1-Wire is a registered trademark of Maxim Integrated Products, Inc.
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
Low-Cost Notebooks
UMPCs
DSLR Cameras
Video Cameras
Commercial and Military Radios
Portable Medical Equipment
Protector and Optional SHA-1 Authentication
2-Cell, Stand-Alone, Li+ Fuel-Gauge IC with
________________________________________________________________ Maxim Integrated Products
®
General Description
(DS2775/DS2776) or 2-wire
Applications
♦ High-Side nFET Drivers and Protection Circuitry
♦ Precision Voltage, Temperature, and Current
♦ Cell-Capacity Estimation from Coulomb Count,
♦ Estimates Cell Aging Between Learn Cycles
♦ Uses Low-Cost Sense Resistor
♦ Allows Calibration of Gain and Temperature
♦ Programmable Thresholds for Overvoltage and
♦ Pack Authentication Using SHA-1 Algorithm
♦ 32-Byte Parameter EEPROM
♦ 16-Byte User EEPROM
♦ Maxim 1-Wire Interface with 64-Bit Unique ID
♦ 2-Wire Interface with 64-Bit Unique ID
♦ 3mm x 5mm, 14-pin TDFN Lead-Free Package
Note: All devices are specified over the -20°C to +70°C oper-
ating temperature range.
+ Denotes a lead(Pb)-free/RoHS-compliant package.
T&R = Tape and reel.
* EP = Exposed pad.
DS2775G+
DS2775G+T&R
DS2776G+
DS776G+T&R
DS2777G+
DS2777G+T&R
DS2778G+
DS2778G+T&R
Measurement System
Discharge Rate, Temperature, and Cell
Characteristics
Coefficient
Overcurrent
(DS2776/DS2778)
(DS2775/DS2776)
(DS2777/DS2778)
PART
PIN-PACKAGE
14 TDFN-EP*
14 TDFN-EP*
14 TDFN-EP*
14 TDFN-EP*
14 TDFN-EP*
14 TDFN-EP*
14 TDFN-EP*
14 TDFN-EP*
Ordering Information
TOP MARK
Features
D2775
D2775
D2776
D2776
D2777
D2777
D2778
D2778
1

Related parts for DS2776G+

DS2776G+ Summary of contents

Page 1

... Interface with 64-Bit Unique ID (DS2777/DS2778) ♦ 3mm x 5mm, 14-pin TDFN Lead-Free Package PART Applications DS2775G+ DS2775G+T&R DS2776G+ DS776G+T&R DS2777G+ DS2777G+T&R DS2778G+ DS2778G+T&R Note: All devices are specified over the -20°C to +70°C oper- ating temperature range. + Denotes a lead(Pb)-free/RoHS-compliant package. ...

Page 2

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 ...

Page 3

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 ...

Page 4

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication EEPROM RELIABILITY SPECIFICATION (V = +4.0V to +9.2V -20°C to +70°C, unless otherwise noted PARAMETER SYMBOL EEPROM Copy Time EEPROM Copy Endurance ELECTRICAL CHARACTERISTICS: 1-Wire ...

Page 5

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 ...

Page 6

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication (T = +25°C, unless otherwise noted.) A DISCHARGE-OVERCURRENT PROTECTION DELAY 2V/div 0V 2V/div 0V 1V/div 0V 20mV/div TIME (ms) DC ...

Page 7

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 _______________________________________________________________________________________ ...

Page 8

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication PIN NAME 1 CC Charge Control. Charge FET control output Chip-Supply Input. Bypass with 0.1μ Discharge Control. Discharge FET control output. Battery ...

Page 9

... Protector and Optional SHA-1 Authentication Li+ PLS PROTECTOR CC FET DRIVERS DC CP CHARGE V DD PUMP VOLTAGE REGULATOR VB VB INTERNAL FuelPack is a trademark of Maxim Integrated Products, Inc. _______________________________________________________________________________________ VOLTAGE POWER-MODE CONTROL TEMPERATURE CURRENT PRECISION ANALOG FuelPack™ OSCILLATOR ALGORITHM CONTROL AND STATUS REGISTERS PIO LOGIC 32-BYTE PARAMETER ...

Page 10

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication PK+ 150Ω DATA 5.1V 0.1μF PK- PK+ 150Ω SDA SCL 150Ω 5.1V 5.1V PK- 10 ______________________________________________________________________________________ DS2775/DS2776 Typical Application Circuit 1kΩ 1kΩ 1kΩ CC SRC DC PLS V DD ...

Page 11

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication Detailed Description The DS2775–DS2778 function as an accurate fuel gauge, Li+ protector, and SHA-1-based authentication token (SHA-1-based authentication available only on the DS2776/DS2778). The fuel gauge provides accu- rate ...

Page 12

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication ACTIVE RISING EDGE ON DQ PMOD = 0 UVEN = 0 CHARGER DETECT PULL DQ LOW ACTIVE < V IN1 IN2 UV PMOD = 0 UVEN ...

Page 13

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 ...

Page 14

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication Undervoltage (UV) If the average of the voltages drops below the undervoltage threshold, IN1 for a period longer than undervoltage ...

Page 15

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication Temperature Measurement The DS2775–DS2778 use an integrated temperature sensor to measure battery temperature with a resolution of 0.125°C. Temperature measurements are updated every 440ms and placed in the Temperature ...

Page 16

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication Current Offset Correction Every 1024th conversion, the ADC measures its input offset to facilitate offset correction. Offset correction occurs approximately once per hour. The resulting cor- rection factor is ...

Page 17

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication FRSGAIN value is provided to preserve the factory cali- bration value only and is not used to calibrate the current measurement. The 16-bit FRSGAIN value is readable from addresses ...

Page 18

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication Accumulation Bias In some designs a systematic error or an application preference requires the application of an arbitrary bias to the current accumulation process. The Current Accumulation Bias register ...

Page 19

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication VOLTAGE (R) TEMPERATURE (R) CURRENT (R) ACCUMULATED CURRENT (ACR) (RW) AVERAGE CURRENT (R) CELL MODEL PARAMETERS (EEPROM) AGING CAPACITY (AC) (2 BYTES EE) AGE SCALAR (AS) (1 BYTE EE) ...

Page 20

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication SEGMENT 1 100% DERIVATIVE (ppm/°C) Figure 14. Cell Model Example Diagram read from the Current register. The specified minimum voltage, or active-empty voltage (VAE), should be a 110ms average ...

Page 21

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 ...

Page 22

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 ...

Page 23

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication count-based estimation is reset after a learn cycle. The cycle-count-based estimation is used only in the absence of a learn cycle. ACR Housekeeping The ACR value is adjusted occasionally ...

Page 24

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 ...

Page 25

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 [3:2]. Bits 0 and 1 are used to disable the charge and discharge FET gate drivers. ...

Page 26

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, and LEARNF bits are read-only. BIT 7 BIT 6 BIT ...

Page 27

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication All Control register bits are read and write accessible. The Control register is recalled from parameter EEPROM memory at power-up. Register bit values can be modified in shadow RAM ...

Page 28

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 ...

Page 29

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication 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. ...

Page 30

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 ...

Page 31

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 ...

Page 32

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) ...

Page 33

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication Table 9. Memory Map (continued) ADDRESS (HEX) 13h Accumulated Current Register LSB - 2 14h Age Scalar Register 15h Special Feature Register 16h Full Register MSB 17h Full Register ...

Page 34

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 ...

Page 35

... CRC value from the first 56 bits of the address and compare it to the CRC from the DS2775/DS2776. MSb Figure 23. 1-Wire CRC Generation Block Diagram iButton is a registered trademark of Maxim Integrated Products, Inc. ______________________________________________________________________________________ HEX 5Ah Clears the 64-bit secret to 0000 0000 0000 0000h. ...

Page 36

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication also used to provide verification of error-free data trans- fer as each EEPROM page is sent to the master during a Read Data/Generate CRC command and for the 8 ...

Page 37

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication Match Net Address [55h] This command allows the bus master to specifically address one DS2775/DS2776 on the 1-Wire bus. Only the addressed DS2775/DS2776 responds to any sub- sequent function ...

Page 38

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication register, address 1Fh, bit the LOCK bit setting the LOCK bit to 1 does not immediately precede the Lock command, ...

Page 39

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 Command 1-Wire SKIP-ROM RESET COMMAND PRESENCE COMPUTE PULSE NEXT SECRET COMMAND Figure 26. Compute Next Secret ...

Page 40

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication 1-Wire SKIP-ROM RESET COMMAND PRESENCE PULSE Figure 28. Clear/Lock Secret, Set/Clear Overdrive Commands DQ LINE TYPE LEGEND: Figure 29. 1-Wire Initialization Sequence 1-Wire Signaling The 1-Wire bus requires strict ...

Page 41

Stand-Alone, Li+ Fuel-Gauge IC with Protector and Optional SHA-1 Authentication Write Time Slots A write time slot is initiated when the bus master pulls the 1-Wire bus from a logic-high (inactive) level to a logic-low level. There are two ...

Page 42

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 ...

Page 43

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 ...

Page 44

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 ...

Page 45

... Read ROM — 39h ID Selector Guide PART INTERFACE DS2775G+ 1-Wire DS2775G+T&R 1-Wire DS2776G+ 1-Wire DS2776G+T&R 1-Wire DS2777G+ 2-Wire DS2777G+T&R 2-Wire DS2778G+ 2-Wire DS2778G+T&R 2-Wire + Denotes a lead(Pb)-free/RoHS-compliant package. T&R = Tape and reel. ______________________________________________________________________________________ DESCRIPTION This command copies the shadow RAM to the target EEPROM block. Copy data commands that target locked blocks are ignored ...

Page 46

... Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 46 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2010 Maxim Integrated Products ...

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