LTC4150CMSPBF_技术文档

LTC4150

Coulomb Counter/

Battery Gas Gauge

FEATURES

DESCRIPTION

The LTC^®4150 measures battery depletion and charging

in handheld PC and portable product applications. The

devicemonitorscurrentthroughanexternalsenseresistor

between the battery’s positive terminal and the battery’s

load or charger. A voltage-to-frequency converter trans-

forms the current sense voltage into a series of output

pulses at the interrupt pin. These pulses correspond to a

ﬁxed quantity of charge ﬂowing into or out of the battery.

The part also indicates charge polarity as the battery is

depleted or charged.

n

Indicates Charge Quantity and Polarity

n

±±50m Sense moltage Range

n

Precision Timer Capacitor or Crystal Not Required

n

2.7V to 8.5V Operation

High Side Sense

32.55Hz/V Charge Count Frequency

1.5μA Shutdown Current

10-Pin MSOP Package

n

APPLICATIONS

The LTC4150 is intended for 1-cell or 2-cell Li-Ion and

3-cell to 6-cell NiCd or NiMH applications.

L, LT, LTC, LTM, Linear Technology, the Linear logo, Burst Mode are registered trademarks and

ThinSOT and PowerPath are trademarks of Linear Technology Corporation. All other trademarks

are the property of their respective owners.

n

Battery Chargers

n

Palmtop Computers and PDAs

n

Cellular Telephones and Wireless Modems

TYPICAL APPLICATION

Integral Nonlinearity, % of Full Scale

0.5

0.4

CHARGER

R

SENSE

LOAD

0.3

+

0.2

4.7μF

0.1

R

L

0

–

+

SENSE SENSE

V

DD

+

–0.1

–0.2

–0.3

–0.4

–0.5

C

INT

F

4.7μF

CLR

LTC4150

GND

μP

CHG

–

DISCHG

F

POL

SHDN

4150 TA01a

–50

–25

0

25

50

CURRENT SENSE VOLTAGE (mV)

4150 TA01b

4150fc

1

LTC4150

ABSOLUTE MAXIMUM RATINGS

PIN CONFIGURATION

(Note 1)

Supply Voltage (V ) .................................. –0.3V to 9V

DD

Input Voltage Range

TOP VIEW

+

–

+

–

Digital Inputs (CLR, SHDN) ........–0.3V to (V + 0.3)

DD

SENSE

1

2

3

4

5

10 INT

–

+

–

+

SENSE , SENSE , C , C .........–0.3V to (V + 0.3)

9

8

7

6

CLR

F

DD

C

V

GND

POL

F

DD

Output Voltage Range

SHDN

Digital Outputs (INT, POL) ....................... –0.3V to 9V

Operating Temperature Range

MS PACKAGE

10-LEAD PLASTIC MSOP

LTC4150CMS........................................... 0°C to 70°C

LTC4150IMS .......................................–40°C TO 85°C

Storage Temperature Range................... –65°C to 150°C

Lead Temperature (Soldering, 10 sec) .................. 300°C

T

= 125°C, θ = 160°C/W

JA

JMAX

ORDER INFORMATION

LEAD FREE FINISH

LTC4150CMS#PBF

LTC4150IMS#PBF

TAPE AND REEL

PART MARKING*

LTQW

PACKAGE DESCRIPTION

10-Lead Plastic MSOP

TEMPERATURE RANGE

0°C to 70°C

LTC4150CMS#TRPBF

LTC4150IMS#TRPBF

LTQW

–40°C to 85°C

Consult LTC Marketing for parts speciﬁed with wider operating temperature ranges. *The temperature grade is identiﬁed by a label on the shipping container.

Consult LTC Marketing for information on non-standard lead based ﬁnish parts.

For more information on lead free part marking, go to: http://www.linear.com/leadfree/

For more information on tape and reel speciﬁcations, go to: http://www.linear.com/tapeandreel/

ELECTRICAL CHARACTERISTICS ^Thel denotes the speciﬁcations which apply over the full operating

te0perature range, otherwise speciﬁcations are at T_A= 2±°C. m_DD= 2.7m and 8.±m unless otherwise noted.

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

l

V

Digital Input Low Voltage, CLR, SHDN

Digital Input High Voltage, CLR, SHDN

Digital Output Low Voltage, INT, POL

Digital Output Leakage Current, INT, POL

Differential Offset Voltage (Note 4)

0.7

V

IL

1.9

IH

I

= 1.6mA, V = 2.7V

0.5

1

V

OL

DD

I

V

= V = 8.5V

POL

0.01

μA

LEAK

INT

DD

V

= 4.0V

100

150

μV

OS

l

V

= 8.0V

100

150

μV

DD

= 2.7V to 8.5V

150

200

μV

l

V

Sense Voltage Common Mode Input Range

Sense Voltage Differential Input Range

Average Differential Input Resistance,

V

– 0.06

V + 0.06

DD

V

SENSE(CM)

DD

+

–

SENSE – SENSE

–0.05

155

0.05

390

SENSE

R

V

= 4.1V (Note 3)

Rising

270

2.5

kΩ

IDR

DD

+

–

Across SENSE and SENSE

l

V

Undervoltage Lockout Threshold

V

2.7

V

UVLO

DD

4150fc

2

LTC4150

The l denotes the speciﬁcations which apply over the full operating

ELECTRICAL CHARACTERISTICS

te0perature range, otherwise speciﬁcations are at T_A= 2±°C. m_DD= 2.7m and 8.±m unless otherwise noted.

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Power Supply Current

l

I

Supply Current, Operating

Supply Current, Shutdown

V

= 8.5V

= 2.7V

115

80

140

100

μA

DD

l

V

= 8.5V

= 5.5V

= 2.7V

10

22

10

1.5

μA

DD(SD)

DD

AC Characteristics

G

VF

Voltage to Frequency Gain

V

= 50mV to –50mV,

SENSE

32.0

31.8

32.55

33.1

33.3

Hz/V

l

2.7V ≤ V ≤ 8.5V

DD

Gain Variation with Supply

Gain Variation with Temperature

Integral Nonlinearity

2.7V ≤ V ≤ 8.5V

0

0.5

%/V

ΔG

DD

VF(VDD)

l

(Note 2)

–0.03

0.03

%/ºC

VF(TEMP)

INL

–0.4

–0.5

0.4

0.5

%

t

CLR Pulse Width to Reset INT,

INT and CLR Not Connected

Figure 2

20

μs

CLR

INT

l

INT Low Time, INT Connected to CLR

Figure 3, C = 15pF

L

1

μs

Note 1: Stresses beyond those listed under Absolute Maximum Ratings

may cause permanent damage to the device. Exposure to any Absolute

Maximum Rating condition for extended periods may affect device

reliability and lifetime.

Note 2: Guaranteed by design and not tested in production.

Note 3: Measured at least 20ms after power on.

Note 4: Tested in feedback loop to SENSE and SENSE .

+

–

4150fc

3

LTC4150

TYPICAL PERFORMANCE CHARACTERISTICS ^T_A^{= 2±°C, unless otherwise noted.}

moltage to Frequency Gain

vs Supply moltage

moltage to Frequency Gain

vs Te0perature

Operating I_DDvs m_DD

+1.00

+0.75

+0.50

+0.25

0

+1.00

+0.75

+0.50

+0.25

0

140

120

100

80

V

= 50mV

SENSE

V

= 2.7V

DD

V

= 25mV

SENSE

V

= 8.5V

DD

V

= 50mV

SENSE

–0.25

–0.50

–0.75

–1.00

–0.25

–0.50

–0.75

–1.00

60

2

3

4

5

6

7

8

9

-50 -25

0

25

50

75 100 125

2

3

4

5

6

7

8

9

10

V

(V)

TEMPERATURE (°C)

V

(V)

DD

4150 G01

4150 G02

4150 G03

Undervoltage Lockout Threshold

vs Te0perature

Shutdown I_DDvs m_DD

Digital Output Low moltage vs m_DD

2.60

2.59

2.58

2.57

2.56

2.55

2.54

2.53

2.52

6

5

4

3

2

1

0

400

350

300

250

200

150

100

50

RISING EDGE

I

= 1.6mA

OL

POL PIN

INT PIN

0

-50 -25

0

25

50

75 100 125

2

3

4

5

6

7

8

9

10

2

3

4

5

6

7

8

9

TEMPERATURE (°C)

V

(V)

V

(V)

DD

4150 G06

4150 G04

4150 G05

4150fc

4

LTC4150

PIN FUNCTIONS

+

SENSE (Pin 1): Positive Sense Input. This is the nonin-

POL (Pin 6): Battery Current Polarity Open-Drain Output.

POLindicatesthemostrecentbatterycurrentpolaritywhen

INT is high. A low state indicates the current is ﬂowing out

of the battery while high impedance means the current

is going into the battery. POL latches its state when INT

is asserted low. POL is an open-drain output and can be

pulled up to any logic supply up to 9V. In shutdown, POL

is high impedance.

+

verting current sense input. Connect SENSE to the load

and charger side of the sense resistor. Full-scale current

+

sense input is 50mV. SENSE must be within 60mV of

V

for proper operation.

DD

–

SENSE (Pin2):NegativeSenseInput.Thisistheinverting

–

current sense input. Connect SENSE to the positive bat-

tery terminal side of the sense resistor. Full-scale current

–

sense input is 50mV. SENSE must be within 60mV of V

for proper operation.

GND (Pin 7): Ground. Connect directly to the negative

battery terminal.

DD

+

C

(Pin 3): Filter Capacitor Positive Input. A capacitor

m

(Pin 8): Positive Power Supply. Connect to the load

F

DD

+

–

+

connected between C and C ﬁlters and averages

and charger side of the sense resistor. SENSE also con-

F

noise and fast battery current variations. A 4.7μF value

nects to V . V operating range is 2.7V to 8.5V. Bypass

V

DD DD

with 4.7μF capacitor.

DD

+

is recommended. If ﬁltering is not desired, leave C and

F

–

C

unconnected.

F

CLR (Pin 9): Clear Interrupt Digital Input. When asserted

low for more than 20μs, CLR resets INT high. Charge

counting is unaffected. INT may be directly connected to

CLR. In this case the LTC4150 will capture each assertion

ofINTandwaitatleast1μsbeforeresettingit.Thisensures

that INT pulses low for at least 1μs but gives automatic

–

C

(Pin 4): Filter Capacitor Negative Input. A capacitor

F

+

–

connected between C and C ﬁlters and averages

F

noise and fast battery current variations. A 4.7μF value

+

is recommended. If ﬁltering is not desired, leave C and

F

–

C

unconnected.

F

INT reset. In applications with a logic supply V > V ,

CC

DD

SHDN(Pin±):Shutdown Digital Input. When asser ted low,

SHDNforcestheLTC4150intoitslowcurrentconsumption

power-down mode and resets the part. In applications

a resistive divider must be used between INT and CLR.

See the Applications Information section.

with logic supply V > V , a resistive divider must be

INT (Pin 15): Charge Count Interrupt Open-Drain Output.

INT latches low every 1/(V

reset by a low pulse at CLR. INT is an open-drain output

and can be pulled up to any logic supply of up to 9V. In

shutdown INT is high impedance.

CC

DD

used between SHDN and the logic which drives it. See the

• G ) seconds and is

SENSE VF

Applications Information section.

4150fc

5

LTC4150

BLOCK DIAGRAM

CHARGER

LOAD

REFHI

1.7V

V

DD

+

INT

10

S3

8

1

+

–

OFLOW/

UFLOW

S

Q

100pF

SENSE

R

S1

2k

COUNTER

200k

CLR

9

6

–

+

200k

C

F

UP/DN

CONTROL

LOGIC

AMPLIFIER

CHARGE

3

4

R

SENSE

C

F

+

POL

POLARITY

DETECTION

+

–

C

F

DISCHARGE

200k

S2

I

BAT

2

7

SENSE

GND

REFLO

0.95V

5

SHDN

4150 F01

Figure 1. Block Diagra0

TIMING DIAGRAMS

50% 50%

CLR

INT

t

CLR

50% 50%

INT

t

4150 F02

INT

4150 F03

Figure 2. CLR Pulse Width to Reset INT,

CLR and INT Not Connected

Figure 3. INT Mini0u0 Pulse Width, CLR and INT Connected

4150fc

6

LTC4150

OPERATION

Charge is the time integral of current. The LTC4150 mea-

suresbatterycurrentbymonitoringthevoltagedeveloped

acrossasenseresistorandthenintegratesthisinformation

inseveralstagestoinfercharge.TheBlockDiagramshows

the stages described below. As each unit of charge passes

into or out of the battery, the LTC4150 INT pin interrupts

an external microcontroller and the POL pin reports the

polarity of the charge unit. The external microcontroller

then resets INT with the CLR input in preparation for the

next interrupt issued by the LTC4150. The value of each

charge unit is determined by the sense resistor value and

CHARGE COUNTING

First, the current measurement is ﬁltered by capacitor C

F

+

–

connected across pins C and C . This averages fast

F

changes in current arising from ripple, noise and spikes

in the load or charging current.

Second, the ﬁlter’s output is applied to an integrator with

the ampliﬁer and 100pF capacitor at its core. When the

integratoroutputrampstoREFHIorREFLOlevels,switches

S1 and S2 reverse the ramp direction. By observing the

condition of S1 and S2 and the ramp direction, polarity is

determined. The integrating interval is trimmed to 600μs

at 50mV full-scale sense voltage.

the sense voltage to interrupt frequency gain G of the

VF

LTC4150.

Third, a counter is incremented or decremented every

time the integrator changes ramp direction. The counter

effectively increases integration time by a factor of 1024,

greatly reducing microcontroller overhead required to

service interrupts from the LTC4150.

Power-On and Start-Up Initialization

When power is ﬁrst applied to the LTC4150, all internal

circuitryisreset.Afteraninitializationinterval,theLTC4150

begins counting charge. This interval depends on V and

DD

the voltage across the sense resistor but will be at least

5ms. It may take an additional 80ms for the LTC4150 to

accuratelytrackthesensevoltage.Aninternalundervoltage

At each counter under or overﬂow, the INT output latches

low, ﬂagging a microcontroller. Simultaneously, the POL

output is latched to indicate the polarity of the observed

charge. With this information, the microcontroller can

total the charge over long periods of time, developing

an accurate estimate of the battery’s condition. Once the

interruptisrecognized,themicrocontrollerresetsINTwith

a low going pulse on CLR and awaits the next interrupt.

Alternatively, INT can drive CLR.

lockout circuit monitors V and resets all circuitry when

DD

V

falls below 2.5V.

DD

Asserting SHDN low also resets the LTC4150’s internal

circuitry and reduces the supply current to 1.5μA. In this

condition, POL and INT outputs are high impedance. The

LTC4150 resumes counting after another initialization

interval. Shutdown minimizes battery drain when both

the charger and load are off.

4150fc

7

LTC4150

APPLICATIONS INFORMATION

SENSE mOLTAGE INPUT AND FILTERS

Coulo0b Counting

The LTC4150’s transfer function is quantiﬁed as a volt-

Since the overall integration time is set by internally trim-

mingtheLTC4150,noexternaltimingcapacitorortrimming

is necessary. The only external component that affects

the transfer function of interrupts per coulomb of charge

age to frequency gain G , where output frequency is the

VF

number of interrupts per second and input voltage is the

+

–

differential drive V

across SENSE and SENSE . The

SENSE

number of interrupts per second will be:

is the sense resistor, R

. The common mode range

SENSE

+

–

for the SENSE and SENSE pins is V

60mV, with a

DD

f = G • ⏐V

⏐

SENSE

(2)

(3)

(4)

VF

+

maximum differential voltage range of 50mV. SENSE is

where

normally tied to V , so there is no common mode issue

DD

–

when SENSE operates within the 50mV differential limit

V

= I

• R

SENSE

BATTERY SENSE

+

relative to SENSE .

Therefore,

f = G • ⏐I

ChooseR

to provide 50mV drop at maximum charge

SENSE

• R ⏐

SENSE

VF

BATTERY

or discharge current, whichever is greater. Calculate

from:

R

SENSE

Since I • t = Q, coulombs of battery charge per INT pulse

can be derived from Equation 4:

50mV

I_MAX

R_SENSE

=

(1)

1

One INT =

Coulombs

(5)

G_VF•R_SENSE

The sense input range is small ( 50mV) to minimize the

loss across R . To preserve accuracy, use Kelvin

SENSE

Battery capacity is most often expressed in ampere-

hours.

connections at R

.

SENSE

The external ﬁlter capacitor, C , operates against a total

F

1Ah = 3600 Coulombs

(6)

(7)

(8)

on-chip resistance of 4k to form a lowpass ﬁlter that

averages battery current and improves accuracy in the

presence of noise, spikes and ripple. 4.7μF is recom-

mended for general applications but can be extended to

higher values as long as the capacitor’s leakage is low.

A 10nA leakage is roughly equivalent to the input offset

error of the integrator. Ceramic capacitors are suitable

for this use.

Combining Equations 5 and 6:

1

One INT =

[Ah]

3600 •G_VF•R_SENSE

or

1Ah = 3600 • G • R

Interrupts

VF

SENSE

The charge measurement may be further scaled within

the microcontroller. However, the number of interrupts,

coulombs or Ah all represent battery charge.

Switching regulators are a particular concern because

they generate high levels of current ripple which may ﬂow

+

through the battery. The V and SENSE connection to

DD

the charger and load should be bypassed by at least 4.7μF

at the LTC4150 if a switching regulator is present.

The LTC4150’s transfer function is set only by the value

of the sense resistor and the gain G . Once R

is

VF

SENSE

selected using Equation 1, the charge per interrupt can

The LTC4150 maintains high accuracy even when Burst

Mode^®switching regulators are used. Burst pulse “on”

levels must be within the speciﬁed differential input volt-

be determined from Equation 5 or 7.

Note that R

is not chosen to set the relationship

SENSE

+

–

age range of 50mV as measured at C and C . To retain

between ampere-hours of battery charge and number of

interruptsissuedbytheLTC4150.Rather,R ischosen

F

accurate charge information, the LTC4150 must remain

SENSE

enabled during Burst Mode operation. If the LTC4150

to keep the maximum sense voltage equal to or less than

the LTC4150’s 50mV full-scale sense input.

shuts down or V drops below 2.5V, the part resets and

DD

charge information is lost.

4150fc

8

LTC4150

APPLICATIONS INFORMATION

INT, POL and CLR

Interfacing to INT, POL, CLR and SHDN

INT asserts low each time the LTC4150 measures a unit

of charge. At the same time, POL is latched to indicate

the polarity of the charge unit. The integrator and counter

continuerunning,sothemicrocontrollermustserviceand

clear the interrupt before another unit of charge accumu-

lates. Otherwise, one measurement will be lost. The time

available between interrupts is the reciprocal of

The LTC4150 operates directly from the battery, while in

most cases the microcontroller supply comes from some

separate, regulatedsource. ThisposesnoproblemforINT

and POL because they are open-drain outputs and can

be pulled up to any voltage 9V or less, regardless of the

voltage applied to the LTC4150’s V .

DD

CLR and SHDN inputs require special attention. To drive

them, the microcontroller or external logic must generate

a minimum logic high level of 1.9V. The maximum input

Equation 2:

1

G_VF•⏐V_SENSE

level for these pins is V + 0.3V. If the microcontroller’s

Time per INT Assertion =

(9)

DD

⏐

supply is more than this, resistive dividers must be used

on CLR and SHDN. The schematic in Figure 6 shows an

At 50mV full scale, the minimum time available is 596ms.

To be conservative and accommodate for small, unex-

pectedexcursionsabovethe50mVsensevoltagelimit,the

microcontroller should process the interrupt and polarity

information and clear INT within 500ms.

application with INT driving CLR and microcontroller V

CC

> V . The resistive dividers on CLR and SHDN keep the

DD

voltages at these pins within the LTC4150’s V range.

DD

Choose R2 and R1 so that:

(R1 + R2) ≥ 50R

(12)

(13)

L

Toggling CLR low for at least 20μs resets INT high and

unlatchesPOL.SincetheLTC4150’sintegratorandcounter

operate independently of the INT and POL latches, no

charge information is lost during the latched period or

while CLR is low. Charge/discharge information contin-

ues to accumulate during those intervals and accuracy

is unaffected.

R1

1.9V ≤

V_CC≤ V_DD(Minimum)

R1+R2

Equation 13 also applies to the selection of R3 and R4.

The minimum V is the lowest supply to the LTC4150

DD

when the battery powering it is at its lowest discharged

voltage.

Once cleared, INT idles in a high state and POL indicates

real-timepolarityofthebatterycurrent.POLhighindicates

charge ﬂowing into the battery and low indicates charge

ﬂowing out. Indication of a polarity change requires at

least:

When the battery is removed in any application, the CLR

and SHDN inputs are unpredictable. INT and POL outputs

may be erratic and should be ignored until after the bat-

tery is replaced.

If desired, the simple logic of Figure 4 may be used to

derive separate charge and discharge pulse trains from

INT and POL.

2

t_POL

=

(10)

G_VF•1024 •⏐V_SENSE

⏐

where V

is the smallest sense voltage magnitude

SENSE

CHARGE

INT

before and after the polarity change.

CLR

Open-drain outputs POL and INT can sink I = 1.6mA

OL

LTC4150

at V = 0.5V. The minimum pull-up resistance for these

OL

DISCHARGE

pins should be:

POL

R > (V – 0.5)/1.6mA

(11)

L

CC

4150 F04

where V is the logic supply voltage. Because speed isn’t

Figure 4. Unravelling Polarity—

Separate Charge and Discharge Outputs

CC

an issue, pull-up resistors of 10k or higher are adequate.

4150fc

9

LTC4150

APPLICATIONS INFORMATION

AUTOMATIC CHARGE COUNT INTERRUPT AND CLEAR

use Figure 6. The resistor dividers on CLR and SHDN keep

thevoltagesatthesepinswithintheLTC4150’sV range.

DD

InapplicationswhereaCLRpulse is unavailable, it ’s easy to

Choose an R value using Equation 11 and R1-R4 values

L

maketheLTC4150runautonomously, asshowninFigures

using Equation 13. In either application, the LTC4150 will

capture the ﬁrst assertion of INT and wait at least 1μs

before resetting it. This insures that INT pulses low for at

least 1μs but gives automatic INT reset.

5 and 6. If the microcontroller V is less than or equal to

CC

the battery V , INT may be directly connected to CLR, as

DD

inFigure5.Theonlyrequirementisthatthemicrocontroller

should be able to provide a high logic level of 1.9V to SHDN.

If the microcontroller V is greater than the battery V ,

CC

DD

POWER-DOWN

SWITCH

LOAD

C

L

PROCESSOR

47μF

V

CC

R

L

R

L

1

10

+

SENSE

INT

9

8

LTC4150

R

SENSE

CLR

2

3

–

V

DD

SENSE

C2

4.7μF

+

2.7V TO 8.5V

BATTERY

+

7

C

F

GND

μP

C

F

4.7μF

4

5

–

C

F

6

SHDN

POL

4150 F05

Figure ±. Application with INT Direct Drive or CLR and Separate Microprocessor Supply m_CC≤ m_DD

POWER-DOWN

SWITCH

LOAD

C

L

PROCESSOR

47μF

V

CC

R

L

R

L

1

10

9

+

SENSE

INT

LTC4150

R

CLR

SENSE

R2

R1

8

2

3

–

V

DD

SENSE

C2

4.7μF

+

7

6

C

BATTERY

< V

F

GND

μP

V

C

BATTERY

CC

F

4.7μF

4

5

–

C

F

SHDN

POL

SHUTDOWN

R4

R3

4150 F06

Figure 6. Application with INT Driving CLR and Separate Microprocessor Supply m_CC> m_DD

4150fc

10

LTC4150

APPLICATIONS INFORMATION

PC BOARD LAYOUT SUGGESTIONS

TO CHARGER

Keep all traces as short as possible to minimize noise

and inaccuracy. The supply bypass capacitor C2 should

be placed close to the LTC4150. The 4.7μF ﬁlter capacitor

PIN 1

R

SENSE

LTC4150

+

–

C should be placed close the C and C pins and should

F

be a low leakage, unpolarized type. Use a 4-wire Kelvin

sense connection for the sense resistor, locating it close

4150 F07

+

TO BATTERY

to the LTC4150 with short sense traces to the SENSE and

–

SENSE pins and longer force lines to the battery pack

Figure 7. Kelvin Connection on SENSE Resistor

and powered load, see Figure 7.

TYPICAL APPLICATIONS

Figure 8 shows a typical application designed for a single

celllithium-ionbatteryand500mAmaximumloadcurrent.

With a microcontroller supply = 5V, Equation 11 gives

L

R > 2.875k. The nearest standard value is 3k.

Use Equation 1 to calculate R

= 0.05V/0.5A = 0.1Ω.

SENSE

From Equation 12, R = 3k gives R1 + R2 equal to 150.5k.

L

With R

= 0.1Ω, Equation 7 shows that each interrupt

A single cell lithium-ion battery can discharge as low as

SENSE

corresponds to 0.085mAh. Equation 14, derived from

2.7V.

Equation2,givesthenumberofINTassertionsforaverage

battery current, I

From Equation 13, select R1 = 75k; the nearest standard

value for R2 is 76.8k.

, over a time, t, in seconds:

BATT

INT Assertions = G • I

• R

• t

(14)

VF BATT

SENSE

Also from Equation 13, we choose R3 = 75k and R4 =

76.8k.

Loading the battery so that 51.5mA is drawn from it over

600secondsresultsin100INTassertions.Foran800mAh

battery, this is (51.5mA • 1/6h) / 800mAh = 11% of the

battery’s capacity.

POWER-DOWN

SWITCH

LOAD

C

L

5.0V

47μF

R

L

3k

L

3k

1

10

9

+

SENSE

INT

R

SENSE

0.1Ω

R2

76.8k

LTC4150

CLR

8

2

3

–

V

DD

SENSE

C2

4.7μF

SINGLE-CELL

Li-Ion

3.0V ~ 4.2V

+

7

6

+

C

R1

75k

F

GND

μP

C

F

4.7μF

4

5

–

C

F

SHDN

POL

SHUTDOWN

R4

76.8k

R3

75k

4150 F08

Figure 8. Typical Application, Single Cell Lithiu0-Ion Battery

4150fc

11

LTC4150

PACKAGE DESCRIPTION

MS Package

15-Lead Plastic MSOP

(Reference LTC DWG # 05-08-1661 Rev E)

0.889 p 0.127

(.035 p .005)

5.23

(.206)

MIN

3.20 – 3.45

(.126 – .136)

3.00 p 0.102

(.118 p .004)

(NOTE 3)

0.497 p 0.076

(.0196 p .003)

REF

0.50

0.305 p 0.038

(.0120 p .0015)

TYP

(.0197)

10 9

8

7 6

BSC

RECOMMENDED SOLDER PAD LAYOUT

3.00 p 0.102

(.118 p .004)

(NOTE 4)

4.90 p 0.152

(.193 p .006)

DETAIL “A”

0.254

(.010)

0o – 6o TYP

GAUGE PLANE

1

2

3

4 5

0.53 p 0.152

(.021 p .006)

0.86

(.034)

REF

1.10

(.043)

MAX

DETAIL “A”

0.18

(.007)

SEATING

PLANE

0.17 – 0.27

(.007 – .011)

TYP

0.1016 p 0.0508

(.004 p .002)

0.50

(.0197)

BSC

MSOP (MS) 0307 REV E

NOTE:

1. DIMENSIONS IN MILLIMETER/(INCH)

2. DRAWING NOT TO SCALE

3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.

MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE

4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.

INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE

5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX

4150fc

12

LTC4150

REVISION HISTORY ^{(Revision history begins at Rev C)}

REm

DATE

DESCRIPTION

PAGE NUMBER

C

2/10

Added Conditions to Power Supply Current in Electrical Characteristics

3

4150fc

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.

However,noresponsibilityisassumedforitsuse.LinearTechnologyCorporationmakesnorepresenta-

t ion t h a t t he in ter c onne c t ion o f i t s cir cui t s a s de s cr ib e d her ein w ill no t in fr inge on ex is t ing p a ten t r igh t s.

13

LTC4150

TYPICAL APPLICATION

CHARGER

LOAD

+

SENSE

INT

CD40110B

LTC4150

CLR

1.2Ω

1.1Ω

100mΩ

–

SENSE

+

SENSE RESISTANCE = 0.0852Ω

= 588mA

I

MAX

10,000 PULSES = 1Ah

4150 F09

Figure 9. A0pere-Hour Gauge

RELATED PARTS

PART NUMBER

DESCRIPTION

COMMENTS

LTC1732

Lithium-Ion Linear Battery Charger Controller

Simple Charger uses External FET, Features Preset Voltages, C/10 Charger

Detection and Programmable Timer, Input Power Good Indication

LTC1733

LTC1734

LTC1734L

LTC1998

LTC4006

Monolithic Lithium-Ion Linear Battery Charger

Lithium-Ion Linear Battery Charger in ThinSOT

Lithium-Ion Low Battery Detector

Standalone Charger with Programmable Timer, Up to 1.5A Charge Current

Simple ThinSOT Charger, No Blocking Diode, No Sense Resistor Needed

Low Current Version of LTC1734

™

1% Accurate 2.5μA Quiescent Current, SOT-23

Small, High Efﬁciency, Fixed Voltage,

Lithium-Ion Battery Charger

Constant-Current/Constant Voltage Switching Regulator with Termination

Timer, AC Adapter Current Limit and Thermistor Sensor in a Small 16-Pin

Package

LTC4050

Lithium-Ion Linear Battery Charger Controller

Simple Charger uses External FET, Features Preset Voltages, C/10 Charger

Detection and Programmable Timer, Input Power Good Indication,

Thermistor Interface

LTC4052

LTC4053

LTC4054

Monolithic Lithium-Ion Battery Pulse Charger

No Blocking Diode or External Power FET Required, Safety Current Limit

USB Compatible Monolithic Lithium-Ion Battery Charger Standalone Charger with Programmable Timer, Up to 1.25A Charge Current

800mA Standalone Linear Lithium-Ion Battery Charger

with Thermal Regulation in ThinSOT

No External MOSFET, Sense Resistor or Blocking Diode Required, Charge

Current Monitor for Gas Gauging, C/10 Charge Termination

LTC4410

LTC4412

USB Power Manager

For Simultaneous Operation of USB Peripheral and Battery Charging from

USB Port, Keeps Current Drawn from USB Port Constant, Keeps Battery

Fresh, Use with the LTC4053, LTC1733, LTC4054

™

PowerPath Controller in ThinSOT

More Efﬁcient Diode OR’ing, Automatic Switching Between DC Sources,

Simpliﬁed Load Sharing, 3V ≤ V ≤ 28V

IN

4150fc

LT 0210 REV C • PRINTED IN USA

LinearTechnology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

14

●

(408) 432-1900 FAX: (408) 434-0507 www.linear.com


型号：	LTC4150CMSPBF
厂家：	Linear
描述：	Coulomb Counter/ Battery Gas Gauge 库仑计/电池电量监测计电池仪表
文件：	总14页 (文件大小：167K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

LTC4150CMSPBF [Linear]

相关型号：

LTC4150CMSTRPBF

LTC4150IMS

LTC4150IMS#PBF

LTC4150IMS#TR

LTC4150IMS#TRPBF

LTC4150IMSPBF

LTC4150IMSTRPBF

LTC4150_1

LTC4151

LTC4151-1

LTC4151CDD#PBF

LTC4151CDD-1#PBF