MAX17040G+T ,Compact, Low-Cost 1S/2S Fuel GaugesELECTRICAL CHARACTERISTICS(2.5V ≤ V≤ 4.5V, T = -20°C to +70°C, unless otherwise noted. Contact Maxi ..
MAX17040G+U ,Compact, Low-Cost 1S/2S Fuel GaugesELECTRICAL CHARACTERISTICS RECOMMENDED DC OPERATING CONDITIONS(2.5V ≤ V≤ 4.5V, T = -20°C to +70°C, ..
MAX17041G+T ,Compact, Low-Cost 1S/2S Fuel GaugesFeatures♦ Host-Side or Battery-Side Fuel GaugingThe MAX17040/MAX17041 are ultra-compact, low-cost,1 ..
MAX17041G+U ,Compact, Low-Cost 1S/2S Fuel GaugesApplicationsMAX17040X+T10 -20°C to +70°C 9 UCSP Smart Phones Portable DVD PlayersMAX17041G+U -20°C ..
MAX17043G+T ,Compact, Low-Cost 1S/2S Fuel Gauges with Low-Battery AlertFeaturesThe MAX17043/MAX17044 are ultra-compact, low-cost, ♦ Host-Side or Battery-Side Fuel Gauging ..
MAX17047G+T10 ,ModelGauge m3 Fuel GaugeApplicationsPackage or Tiny 0.4mm Pitch 9-Bump WLP Package2.5G/3G/4G Wireless Portable Game Players ..
MAX4523CSE ,Quad / Low-Voltage / SPST Analog SwitchesMAX4521/MAX4522/MAX452319-1136; Rev 1; 1/97Quad, Low-Voltage, SPST Analog Switches_______________
MAX4523EEE ,Quad / Low-Voltage / SPST Analog SwitchesApplications______________Ordering InformationBattery-Operated EquipmentPART TEMP. RANGE PIN-PACKAG ..
MAX4523EEE+ ,Quad / Low-Voltage / SPST Analog SwitchesELECTRICAL CHARACTERISTICS—Dual Supplies(V+ = +4.5V to +5.5V, V- = -4.5V to -5.5V, T = T to T , unl ..
MAX4523ESE ,Quad / Low-Voltage / SPST Analog SwitchesGeneral Description ________
MAX4523EUE+ ,Quad, Low-Voltage SPST Analog SwitchesFeaturesThe MAX4521/MAX4522/MAX4523 are quad, low-volt-
MAX17040G+T-MAX17040G+U-MAX17041G+T-MAX17041G+U
Compact, Low-Cost 1S/2S Fuel Gauges
MAX17040/MAX17041
Compact, Low-Cost 1S/2S Fuel GaugesEVALUATION KIT AVAILABLE
General DescriptionThe MAX17040/MAX17041 are ultra-compact, low-cost,
host-side fuel-gauge systems for lithium-ion (Li+) batter-
ies in handheld and portable equipment. The MAX17040
is configured to operate with a single lithium cell and the
MAX17041 is configured for a dual-cell 2S pack.
The MAX17040/MAX17041 use a sophisticated Li+ bat-
tery-modeling scheme, called ModelGauge™ to track
the battery’s relative state-of-charge (SOC) continuously
over a widely varying charge/discharge profile. Unlike
traditional fuel gauges, the ModelGauge algorithm elim-
inates the need for battery relearn cycles and an exter-
nal current-sense resistor. Temperature compensation
is possible in the application with minimal interaction
between a µC and the device.
A quick-start mode provides a good initial estimate of
the battery’s SOC. This feature allows the IC to be
located on system side, reducing cost and supply
chain constraints on the battery. Measurement and esti-
mated capacity data sets are accessed through an I2C
interface. The MAX17040/MAX17041 are available in
either a 0.4mm pitch 9-bump UCSP™or 2mm x 3mm,
8-pin TDFN lead-free package.
Applications
FeaturesHost-Side or Battery-Side Fuel Gauging
1 Cell (MAX17040)2 Cell (MAX17041)Precision Voltage Measurement
±12.5mV Accuracy to 5.00V (MAX17040)
±30mV Accuracy to 10.00V (MAX17041)Accurate Relative Capacity (RSOC) Calculatedfrom ModelGauge AlgorithmNo Offset Accumulation on MeasurementNo Full-to-Empty Battery Relearning NecessaryNo Sense Resistor Required2-Wire InterfaceLow Power ConsumptionTiny, Lead(Pb)-Free, 8-pin, 2mm x 3mm TDFNPackage or Tiny 0.4mm Pitch 9-Bump UCSP
Package
Ordering InformationCELL
1µF
1kΩ
10nF
150Ω
GNDEP
CTG
SCL
SDA
SEO
VDDSYSTEM
I2C BUS
MASTER
Li+
PROTECTION
CIRCUIT
MAX17040
MAX17041
Simplified Operating Circuit
PARTTEMP RANGEPIN-PACKAGE
MAX17040G+U -20°C to +70°C 8 TDFN-EP*
MAX17040G+T -20°C to +70°C 8 TDFN-EP*
MAX17040X+U -20°C to +70°C 9 UCSP
MAX17040X+T10 -20°C to +70°C 9 UCSP
MAX17041G+U -20°C to +70°C 8 TDFN-EP*
MAX17041G+T -20°C to +70°C 8 TDFN-EP*
MAX17041X+ -20°C to +70°C 9 UCSP
MAX17041X+T10 -20°C to +70°C 9 UCSP
+Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
*EP= Exposed pad.
Pin Configurations appear at end of data sheet.Smart Phones
MP3 Players
Digital Still Cameras
Digital Video Cameras
Portable DVD Players
GPS Systems
Handheld and PortableApplications
ModelGauge is a trademark of Maxim Integrated Products, Inc.
UCSP is a trademark of Maxim Integrated Products, Inc.
Visit www.maximintegrated.com/products/patentsfor
product patent marking information.
MAX17040/MAX17041
Compact, Low-Cost 1S/2S Fuel Gauges
ABSOLUTE MAXIMUM RATINGS
DC ELECTRICAL CHARACTERISTICS(2.5V ≤VDD≤4.5V, TA= -20°C to +70°C, unless otherwise noted. Contact Maxim for VDDgreater than 4.5V.)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
Voltage on CTG Pin Relative to GND.....................-0.3V to +12V
Voltage on CELL Pin Relative to GND....................-0.3V to +12V
Voltage on All Other Pins Relative to GND...............-0.3V to +6V
Operating Temperature Range...........................-40°C to +85°C
Power Dissipation..........1333mW at +70°C (derate 16.7mW/°C)
Storage Temperature Range
(TA= 0°C to +70°C (Note 10))........................-55°C to +125°C
Lead Temperature (TDFN only, soldering, 10s)..............+300°C
Soldering Temperature (reflow).......................................+260°C
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSWith on-chip clock in use 50 75 Active Current IACTIVEWith external 32kHz clock 40 65 µA
VDD = 2.0V 0.5 1.0 Sleep-Mode Current (Note 2) ISLEEP 1 3 µA
VDD = 3.6V at +25°C -1 +1
TA = 0°C to +70°C (Note 10) -2 +2 Time-Base Accuracy (Note 3) tERR
TA = -20°C to +70°C -3 +3
TA = +25°C, VIN= VDD -12.5 +12.5 MAX17040 Voltage-
Measurement Error -30 +30
TA = +25°C, 5.0V < VIN< 9.0V -30 +30 MAX17041 Voltage-
Measurement Error
VGERR
5.0V < VIN< 9.0V -60 +60
mV
CELL Pin Input Impedance RCELL 15 M
Input Logic-High:
SCL, SDA, EO, SEO VIH (Note 1) 1.4 V
Input Logic-Low:
SCL, SDA, EO, SEO VIL (Note 1) 0.5 V
Output Logic-Low: SDA VOL IOL = 4mA (Note 1) 0.4 V
Pulldown Current: SCL, SDA IPD VDD = 4.5V, VPIN = 0.4V 0.2 µA
Input Capacitance: EO CBUS 50 pF
Bus Low Timeout tSLEEP (Note 4) 1.75 2.5 s
ELECTRICAL CHARACTERISTICS RECOMMENDED DC OPERATING CONDITIONS(2.5V ≤VDD≤4.5V, TA= -20°C to +70°C, unless otherwise noted.)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSSupply Voltage VDD (Note 1) +2.5 +4.5 V
Data I/O Pins SCL, SDA,
EO, SEO (Note 1) -0.3 +5.5 V
MAX17040 CELL Pin VCELL (Note 1) -0.3 +5.0 V
MAX17041 CELL Pin VCELL (Note 1) -0.3 +10.0 V
MAX17040/MAX17041
Compact, Low-Cost 1S/2S Fuel Gauges
Note 1:All voltages are referenced to GND.
Note 2:SDA, SCL = GND; EO, SEO idle.
Note 3:External time base on EO pin must meet this specification.
Note 4:The MAX17040/MAX17041 enter Sleep mode 1.75s to 2.5s after (SCL < VIL) AND (SDA < VIL).
Note 5:fSCLmust meet the minimum clock low time plus the rise/fall times.
Note 6:The maximum tHD:DAThas only to be met if the device does not stretch the low period (tLOW) of the SCL signal.
Note 7:This device internally provides a hold time of at least 75ns for the SDA signal (referred to the VIHMINof the SCL signal) to
bridge the undefined region of the falling edge of SCL.
Note 8:Filters on SDA and SCL suppress noise spikes at the input buffers and delay the sampling instant.
Note 9:CB—total capacitance of one bus line in pF.
Note 10:Applies to 8-pin TDFN-EP package type only.
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSSCL Clock Frequency fSCL (Note 5) 0 400 kHz
Bus Free Time Between a STOP
and START Condition tBUF 1.3 µs
Hold Time (Repeated)
START Condition tHD:STA(Note 5) 0.6 µs
Low Period of SCL Clock tLOW 1.3 µs
High Period of SCL Clock tHIGH 0.6 µs
Setup Time for a Repeated
START Condition tSU:STA 0.6 µs
Data Hold Time tHD:DAT (Notes 6, 7) 0 0.9 µs
Data Setup Time tSU:DAT (Note 6) 100 ns
Rise Time of Both SDA
and SCL Signals tR20 +
0.1CB 300 ns
Fall Time of Both SDA
and SCL Signals tF20 +
0.1CB 300 ns
Setup Time for STOP Condition tSU:STO 0.6 µs
Spike Pulse Widths Suppressed
by Input Filter tSP(Note 8) 0 50 ns
Capacitive Load for Each
Bus Line CB(Note 9) 400 pF
SCL, SDA Input Capacitance CBIN 60 pF
ELECTRICAL CHARACTERISTICS: 2-WIRE INTERFACE(2.5V ≤VDD≤4.5V, TA= -20°C to +70°C.)
MAX17040/MAX17041
Compact, Low-Cost 1S/2S Fuel Gauges
Typical Operating Characteristics(TA = +25°C, unless otherwise noted.)
QUIESCENT CURRENT vs. SUPPLY VOLTAGEMAX17040 toc01
VDD (V)
QUIESCENT CURRENT (2451
TA = +70°CTA = +25°C
TA = -20°C
SIMPLE C/2 RATE CYCLES*
SOC ACCURACYMAX17040 toc02
TIME (hr)
STATE OF CHARGE (%)
SOC ERROR (%)106842
ERROR (%)
MAX17040/
MAX17041 SOC:
DASHED LINE
REFERENCE SOC:
SOLID LINE
C/2 RATE ZIGZAG PATTERN*
SOC ACCURACYMAX17040 toc05
TIME (hr)
STATE OF CHARGE (%)
SOC ERROR (%)81622204
ERROR (%)
MAX17040/MAX17041 SOC:
DASHED LINE
REFERENCE SOC:
SOLID LINE
SIMPLE C/4 RATE CYCLES*
SOC ACCURACYMAX17040 toc03
TIME (hr)
STATE OF CHARGE (%)
SOC ERROR (%)1068181622201442
ERROR (%)
MAX17040/
MAX17041 SOC:
DASHED LINE
REFERENCE SOC:
SOLID LINE
MAX17040 VOLTAGE ADC ERROR
vs. TEMPERATUREMAX17040 toc04
TEMPERATURE (°C)
VOLTAGE ADC ERROR (mV)106085-15
VCELL = 3.0V
VCELL = 4.2V
VCELL = 3.6V
MAX17040/MAX17041
Compact, Low-Cost 1S/2S Fuel GaugesSDA
SCL
tLOW
tHD:STA
tHD:DAT
tSU:STAtSU:STO
tSU:DATtHD:STA
tSPtRtBUF
SSrPS
Figure 1. 2-Wire Bus Timing Diagram
Pin Description
PIN
UCSPTDFNNAMEFUNCTION A1 8 SDA Serial Data Input/Output. Open-drain 2-wire data line. Connect this pin to the DATA signal of the
2-wire interface. This pin has a 0.2µA typical pulldown to sense disconnection.
A2 7 SCL Serial Clock Input. Input only 2-wire clock line. Connect this pin to the CLOCK signal of the
2-wire interface. This pin has a 0.2µA typical pulldown to sense disconnection.
A3 1 CTG Connect to Ground. Connect to GND during normal operation.
B1 6 EO External 32kHz Clocking Signal. Input for external clocking signal to be the primary system
clock. Configured to implement interrupt feature with a pulldown set on SEO pin.
B2 — N.C. No Connect. Do not connect.
B3 2 CELL Battery-Voltage Input. The voltage of the cell pack is measured through this pin.
C1 5 SEO
External 32kHz Clocking Signal Enable Input. Input to enable external clocking signal on EO pin
with a pullup state; a pulldown state to configure the interrupt feature. External 32kHz clock
enable. Connects logic-low to enable external interrupt.
C2 3 VDDPower-Supply Input. 2.5V to 4.5V input range. Connect to system power through a decoupling
network. Connect a 10nF typical decoupling capacitor close to pin.
C3 4 GND Ground. Connect to the negative power rail of the system. — EP Exposed Pad (TDFN Only). Connect to ground.
STATE
MACHINE
(SOC, RATE)
2-WIRE
INTERFACE
GROUND
TIME BASE
(32kHz)
ADC (VCELL)
VOLTAGE
REFERENCE
BIAS
GND
CELL
VDD
SCL
SDA
CTG
SEO
MAX17040
MAX17041
Detailed DescriptionFigure 1 shows the 2-wire bus timing diagram, and
Figure 2 is the MAX17040/MAX17041 block diagram.
ModelGauge Theory of OperationThe MAX17040/MAX17041 use a sophisticated battery
model, which determines the SOC of a nonlinear Li+
battery. The model effectively simulates the internal
dynamics of a Li+ battery and determines the SOC. The
model considers the time effects of a battery caused by
the chemical reactions and impedance in the battery.
The MAX17040/MAX17041 SOC calculation does not
MAX17040/MAX17041
Compact, Low-Cost 1S/2S Fuel Gaugescomparedto traditional coulomb counters, which suffer
from SOC drift caused by current-sense offset and cell
self-discharge. This model provides good performance
for many Li+ chemistry variants across temperature
and age. To achieve optimum performance, the
MAX17040/MAX17041 must be programmed with con-
figuration data custom to the application. Contact the
factory for details.
Fuel-Gauge PerformanceThe classical coulomb-counter-based fuel gauges suf-
fer from accuracy drift due to the accumulation of the
offset error in the current-sense measurement. Although
the error is often very small, the error increases over
time in such systems, cannot be eliminated, and
requires periodic corrections. The corrections are usu-
ally performed on a predefined SOC level near full or
empty. Some other systems use the relaxed battery
voltage to perform corrections. These systems deter-
mine the true SOC based on the battery voltage after a
long time of no activity. Both have the same limitation: if
the correction condition is not observed over time in the
actual application, the error in the system is boundless.
In some systems, a full charge/discharge cycle is
required to eliminate the drift error. To determine the
true accuracy of a fuel gauge, as experienced by end
users, the battery should be exercised in a dynamic
manner. The end-user accuracy cannot be understood
with only simple cycles. The MAX17040/MAX17041 do
not suffer from the drift problem since they do not rely
on the current information.
IC Power-UpWhen the battery is first inserted into the system, there is
no previous knowledge about the battery’s SOC. The IC
assumes that the battery has been in a relaxed state for
the previous 30min. The first A/D voltage measurement is
translated into a best “first guess” for the SOC. Initial error
caused by the battery not being in a relaxed state fades
over time, regardless of cell loading following this initial
conversion. Because the SOC determination is conver-
gent rather than divergent (as in a coulomb counter), this
initial error does not have a long-lasting impact.
Quick-StartA quick-start allows the MAX17040/MAX17041 to restart
fuel-gauge calculations in the same manner as initial
power-up of the IC. For example, if an application’s
power-up sequence is exceedingly noisy such that
excess error is introduced into the IC’s “first guess” of
SOC, the host can issue a quick-start to reduce the
error. A quick-start is initiated by a rising edge on the
EO pin when SEO is logic-low, or through software by
writing 4000h to the MODE register.
External Oscillator ControlWhen the SEO pin is logic-high, the MAX17040/
MAX17041 disable the 32kHz internal oscillator and rely
on external clocking from the EO pin. A precision exter-
nal clock source reduces current consumption during
normal operation.
When the SEO pin is logic-low, the EO pin becomes an
interrupt input. Any rising edge detected on EO causes
the MAX17040/MAX17041 to initiate a quick-start.
Sleep ModeHolding both SDA and SCL logic-low forces the
MAX17040/MAX17041 into Sleep mode. While in Sleep
mode, all IC operations are halted and power drain of
the IC is greatly reduced. After exiting Sleep mode,
fuel-gauge operation continues from the point it was
halted. SDA and SCL must be held low for at least 2.5s
to guarantee transition into Sleep mode. Afterwards, a
rising edge on either SDA or SCL immediately transi-
tions the IC out of Sleep mode.
Power-On Reset (POR)Writing a value of 0054h to the COMMAND register caus-
es the MAX17040/MAX17041 to completely reset as if
power had been removed. The reset occurs when the last
bit has been clocked in. The IC does not respond with an
I2C ACK after this command sequence.
RegistersAll host interaction with the MAX17040/MAX17041 is
handled by writing to and reading from register loca-
tions. The MAX17040/MAX17041 have six 16-bit regis-
ters: SOC,
VCELL, MODE, VERSION, RCOMP, and
COMMAND. Register reads and writes are only valid ifall 16 bits are transferred. Any write command that is
terminated early is ignored. The function of each regis-
ter is described as follows. All remaining address loca-
tions not listed in Table 1 are reserved. Data read from
reserved locations is undefined.
MAX17040/MAX17041
Compact, Low-Cost 1S/2S Fuel Gauges
VCELL RegisterBattery voltage is measured at the CELL pin input with
respect to GND over a 0 to 5.00V range for the
MAX17040 and 0 to 10.00V for the MAX17041 with res-
olutions of 1.25mV and 2.50mV, respectively. The A/D
calculates the average cell voltage for a period of
125ms after IC POR and then for a period of 500ms for
every cycle afterwards. The result is placed in the
VCELL register at the end of each conversion period.
Figure 3 shows the VCELL register format.
SOC RegisterThe SOC register is a read-only register that displays
the state of charge of the cell as calculated by the
ModelGauge algorithm. The result is displayed as a
percentage of the cell’s full capacity. This register
automatically adapts to variation in battery size since
the MAX17040/MAX17041 naturally recognize relative
SOC. Units of % can be directly determined by observ-
ing only the high byte of the SOC register. The low byte
provides additional resolution in units 1/256%. The
reported SOC also includes residual capacity, which
might not be available to the actual application because
of early termination voltage requirements. When SOC()
= 0, typical applications have no remaining capacity.
The first update occurs within 250ms after POR of the
IC. Subsequent updates occur at variable intervals
depending on application conditions. ModelGauge cal-
culations outside the register are clamped at minimum
and maximum register limits. Figure 4 shows the SOC
register format.
ADDRESS
(HEX)REGISTERDESCRIPTIONREAD/
WRITE
DEFAULT
(HEX)02h–03h VCELL Reports 12-bit A/D measurement of battery voltage. R —
04h–05h SOC Reports 16-bit SOC result calculated by ModelGauge algorithm. R —
06h–07h MODE Sends special commands to the IC. W —
08h–09h VERSION Returns IC version. R —
0Ch–0Dh RCOMP Battery compensation. Adjusts IC performance based on
application conditions. R/W 9700h
FEh–FFh COMMAND Sends special commands to the IC. W —
Table 1. Register SummaryMSB—ADDRESS 02h LSB—ADDRESS 03h 11 210 29 28 27 26 25 24 23 22 21 20 0 0 0 0
MSB LSB MSB LSB
0: BITS ALWAYS READ LOGIC 0 UNITS: 1.25mV FOR MAX17040
2.50mV FOR MAX17041
Figure 3. VCELL Register Format
MSB—ADDRESS 04h LSB—ADDRESS 05h
27 26 25 24 23 22 21 20 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8
MSB LSB MSB LSB
UNITS: 1.0%
Figure 4. SOC Register Format
