DS2751+025 datasheet, PDF - EEWORLD Datasheet

DS2751

Multichemistry Battery

Fuel Gauge

www.maxim-ic.com

FEATURES

§

Available in Two Configurations

- Internal 25mW Sense Resistor

- External User-Selectable Sense Resistor

Current Measurement

- 12-Bit Bidirectional Measurement

- Internal Sense Resistor Configuration:

0.625mA LSB and ±1.9A Dynamic Range

- External Sense Resistor Configuration:

15.625mV LSB and ±64mV Dynamic

Range

Current Accumulation

- Internal Sense Resistor: 0.25mAhr LSB

- External Sense Resistor: 6.25mVhr LSB

Voltage Measurement with 4.88mV

Resolution

Temperature Measurement Using Integrated

Sensor with 0.125°C Resolution

32 Bytes of Lockable EEPROM

16 Bytes of General-Purpose SRAM

Dallas 1-Wire

®

Interface with Unique 64-Bit

Device Address

Supports 1-Cell Li+/Polymer or 3-Cell Ni

Battery Packs

3mm Dimension of 8-Pin TSSOP Package

Allows Mounting on Side of Thin Li+ and

Li+/Polymer Cells (Lead Free available)

Low Power Consumption:

- Active Current: 60mA (typ), 90mA (max)

- Sleep Current:

1mA (typ), 2mA (max)

PIN CONFIGURATION

V

IN

V

SS

PIO

V

DD

1

2

3

2

4

8

7

6

5

DQ

SNS

IS2

IS1

§

DS2751E

8-Pin TSSOP Package

(Lead Free Available)

PIN DESCRIPTION

V

IN

V

SS

PIO

V

DD

IS1

IS2

SNS

DQ

Voltage-Sense Input

Device Ground

Programmable I/O Pin

Power-Supply Input (2.5V to 5.5V)

Current-Sense Input

Sense Resistor Connection

Data Input/Output

§

1-Wire is a registered trademark of Dallas Semiconductor.

1 of 19

020105

DS2751

ORDERING INFORMATION

MARKING

TEMP RANGE

DESCRIPTION

8-Pin TSSOP, External Sense Resistor

2751E

-20°C to +70°C

2751E

8-Pin Lead Free TSSOP, External Sense

DS2751E+

-20°C to +70°C

(Note 1)

Resistor

DS2751E-025

2751R

-20°C to +70°C

8-Pin TSSOP, 25mW Sense Resistor

2751R

8-Pin Lead Free TSSOP, 25mW Sense

DS2751E+025

-20°C to +70°C

(Note 1)

Resistor

DS2751E on Tape-and-Reel

DS2751E/T&R

2751E

-20°C to +70°C

2751E

DS2751E+ on Tape-and-Reel (Lead Free)

DS2751E+T&R

-20°C to +70°C

(Note 1)

DS2751E-025 on Tape-and-Reel

DS2751E-025/T&R

2751R

-20°C to +70°C

2751R

DS2751E+025 on Tape-and-Reel (Lead

DS2751E+025/T&R

-20°C to +70°C

(Note 1)

Free)

Note 1: A “+” will be marked on the package near the Pin 1 indicator.

PART

DS2751E

DESCRIPTION

The DS2751 multichemistry battery fuel gauge is a data-acquisition and information-storage device

tailored for cost-sensitive and space-constrained 1-cell Li+/polymer or 3-cell Ni battery-pack

applications. The DS2751 provides the key hardware components required to accurately estimate

remaining capacity by integrating low-power, precision measurements of temperature, voltage, current,

and current accumulation, as well as nonvolatile (NV) data storage, into the small footprint of a 3.0mm x

4.4mm 8-pin TSSOP package.

Through its 1-Wire interface, the DS2751 gives the host system read/write access to status and control

registers, instrumentation registers, and general-purpose data storage. Each device has a unique factory-

programmed 64-bit net address that allows it to be individually addressed by the host system, supporting

multibattery operation.

The DS2751 performs temperature, voltage, and current measurement to a resolution sufficient to support

process-monitoring applications such as battery charge control and remaining capacity estimation.

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.

Three types of memory are provided on the DS2751 for battery information storage: EEPROM, lockable

EEPROM, and SRAM. EEPROM memory saves important battery data in true NV memory that is

unaffected by severe battery depletion, accidental shorts, or ESD events. Lockable EEPROM becomes

ROM when locked to provide additional security for unchanging battery data. SRAM provides

inexpensive storage for temporary data.

2 of 19

DS2751

ABSOLUTE MAXIMUM RATINGS*

Voltage on PIO Pin, Relative to V

SS

Voltage on All Other Pins, Relative to V

SS

Continuous Internal Sense Resistor Current

Pulsed Internal Sense Resistor Current

Operating Temperature Range

Storage Temperature Range

Soldering Temperature

-0.3V to +12V

-0.3V to +6V

±2.5A

±50A

for <100µs/s, <1000 Pulses

-40°C to +85°C

-55°C to +125°C

See J-STD-020A Specification

*

This is a stress rating only and functional operation of the device at these or any other conditions above

those indicated in the operation sections of this specification is not implied. Exposure to absolute

maximum rating conditions for extended periods of time may affect reliability.

RECOMMENDED DC OPERATING CONDITIONS

(T

A

= 2.5V

£

V

DD

£

5.5V, -20°C to +70°C.)

PARAMETER

SYMBOL

CONDITIONS

Supply Voltage

V

DD

(Note 1)

Data Pin

DQ

(Note 1)

V

DD

³

4.2V (Notes 1, 2)

V

IN

V

IN

2.5V

<

V

DD

<

4.2V

(Notes 1, 2)

MIN

2.5

-0.3

TYP

MAX

5.5

+5.5

+4.5

V

DD

+

0.3

UNITS

V

DC ELECTRICAL CHARACTERISTICS

(T

A

= 2.5V

£

V

DD

£

5.5V, -20°C to +70°C.)

PARAMETER

SYMBOL

CONDITIONS

DQ = V

DD

,

Active Current

I

ACTIVE

normal operation

DQ = 0V,

Sleep-Mode Current

I

SLEEP

no activity

Input Logic High:

V

IH

(Note 1)

DQ, PIO

Input Logic Low:

V

IL

(Note 1)

DQ, PIO

Output Logic Low:

I

OL

= 4mA (Note 1)

V

OL

DQ, PIO

DQ Pulldown Current

I

PD

Input Resistance: V

IN

R

IN

Internal Current-Sense

R

SNS

+25°C

Resistor

DQ Low-to-Sleep

t

SLEEP

Time

Undervoltage Detect

V

UV

(Note 1)

Undervoltage Delay

T

UVD

MIN

TYP

60

1

1.5

0.4

1

5

20

2.2

2.5

90

2.6

100

2.7

110

25

30

MAX

90

2

UNITS

mA

V

mA

MW

mW

s

V

ms

3 of 19

DS2751

ELECTRICAL CHARACTERISTICS: TEMPERATURE, VOLTAGE, CURRENT

(T

A

= 2.5V

£

V

DD

£

5.5V, -20°C to +70°C.)

PARAMETER

SYMBOL

CONDITIONS

Temperature Resolution

T

LSB

Temperature Full-Scale

T

FS

Magnitude

Temperature Error

T

ERR

(Note 3)

Voltage Resolution

V

LSB

Voltage Full-Scale

(Note 4)

V

FS

Magnitude

Voltage Offset Error

V

OERR

(Note 5)

Voltage Gain Error

Current Resolution

Current Full-Scale

Magnitude

Current Offset Error

Current Gain Error

Accumulated Current

Resolution

Current Sampling

Frequency

Internal Timebase

Accuracy

V

GERR

I

LSB

I

FS

I

OERR

I

GERR

q

CA

f

SAMP

t

ERR

0°C to +50°C

(Note 11)

-20°C to +70°C

(Note 6)

(Note 7)

(Notes 6, 7)

(Note 8)

(Note 9)

(Notes 6, 10)

(Note 7)

(Note 6)

(Note 7)

0.625

15.625

2.56

64

1

3

1

0.25

6.25

1456

±1

±3

±5

MIN

127

4.88

4.5

1

3

±3

TYP

0.125

MAX

UNITS

°C

mV

V

LSB

%V

reading

mA

m

V

A

mV

LSB

%I

reading

mAhr

µVhr

Hz

%

1.9

ELECTRICAL CHARACTERISTICS—1-WIRE INTERFACE

(T

A

= 2.5V

£

V

DD

£

5.5V, -20°C to +70°C.)

PARAMETER

SYMBOL

CONDITIONS

Time Slot

t

SLOT

Recovery Time

t

REC

Write 0 Low Time

t

LOW0

Write 1 Low Time

t

LOW1

Read Data Valid

t

RDV

Reset Time High

t

RSTH

Reset Time Low

t

RSTL

Presence-Detect High

t

PDH

Presence-Detect Low

t

PDL

DQ Capacitance

C

DQ

MIN

60

1

60

1

480

15

60

TYP

MAX

120

119

15

960

60

240

60

UNITS

m

s

m

s

m

s

m

s

m

s

m

s

m

s

m

s

m

s

pF

4 of 19

DS2751

EEPROM RELIABILITY SPECIFICATION

(T

A

= 2.5V

£

V

DD

£

5.5V, -20°C to +70°C.)

PARAMETER

SYMBOL

CONDITIONS

Copy to EEPROM Time

t

EEC

EEPROM Copy

(Note 12)

N

EEC

Endurance

MIN

25,000

TYP

2

MAX

10

UNITS

ms

cycles

Note 1:

Note 2:

Note 3:

Note 4:

Note 5:

Note 6:

Note 7:

Note 8:

Note 9:

Note 10:

Note 11:

Note 12:

All voltages are referenced to V

SS

.

Operating V

IN

> 4.5V relative to V

SS

, or V

IN

> V

DD

+ 0.3V can induce errors in voltage,

temperature, or current measurements.

Self heating due to output pin loading and sense resistor power dissipation can alter the

reading from ambient conditions.

Although the Voltage Register is large enough to report values larger than 4.75V, the internal

compensation for circuit variations can reduce the maximum reportable voltage to as low as

4.75V.

Voltage offset measurement is with respect to 4.35V at +25°C.

Internal current-sense resistor configuration.

External current-sense resistor configuration.

The Current Register supports measurement magnitudes up to 2.56A using the internal sense-

resistor option and 64mV with the external resistor option. Compensation of the internal

sense-resistor value for process and temperature variation may reduce the maximum

reportable magnitude to 1.9A.

Current offset error null to ±1 LSb typically requires a one time 3.5s in-system calibration by

user.

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/°C to an 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.

Typical value for t

ERR

valid at 3.6V and +25°C.

Four year data retention at +70°C.

5 of 19

DS2751+025

DS2751+025 Overview

Preview

Recommended Resources