MAX6782_技术文档

19-0541; Rev 1; 10/06

Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level

Battery Monitors in Small TDFN and TQFN Packages

82–MAX6790

General Description

Features

The MAX6782–MAX6790 are low-power, 1% accurate,

dual-/triple-/quad-level battery monitors offered in small

TDFN and TQFN packages. These devices are ideal for

monitoring single lithium-ion (Li+) cells, or multicell alka-

line/NiCd/NiMH power sources. These devices feature

fixed and adjustable hysteresis options to eliminate out-

put chattering associated with battery-voltage monitors.

o

1% Accurate Threshold Specified Over Full

Temperature Range

o

Dual-/Triple-/Quad, Low-Battery Output Options

Low 5.7µA Battery Current

Open-Drain or Push-Pull Outputs

Fixed or Adjustable Hysteresis

Low Input Bias Current

The MAX6782/MAX6783 offer four battery monitors in a

single package with factory-set (0.5%, 5%, 10%) or

adjustable hysteresis. The MAX6784/MAX6785 provide

three battery monitors with factory-set (0.5%, 5%, 10%)

or adjustable hysteresis. The MAX6786/MAX6787/

MAX6788 offer two battery monitors with external inputs

for setting the rising and falling thresholds, allowing

external hysteresis control. The MAX6789/MAX6790 fea-

ture quad-level overvoltage detectors with complemen-

tary outputs.

Guaranteed Valid Low-Battery-Output Logic State

Down to V

= 1.05V

BATT

Reverse-Battery Protection

o

Immune to Short Battery Transients

Fully Specified from -40°C to +85°C

Small TDFN and TQFN Packages

The MAX6782–MAX6790 are offered with either open-drain

or push-pull outputs. The MAX6782/MAX6784/MAX6786/

MAX6789 are available with push-pull outputs while the

MAX6783/MAX6785/MAX6787/MAX6790 are available with

open-drain outputs. The MAX6788 is available with one

open-drain output and one push-pull output (see the

Selector Guide). This family of devices is offered in space-

saving TDFN and TQFN packages and is fully specified

over the -40°C to +85°C extended temperature range.

Ordering Information

PIN-

PACKAGE

PKG

CODE

PART

TEMP RANGE

MAX6782TE_+

MAX6783TE_+

MAX6784TC_+

MAX6785TC_+

-40°C to +85°C 16 TQFN-EP* T1633-4

-40°C to +85°C 12 TQFN-EP* T1233-1

Ordering Information continued at end of data sheet.

+Denotes lead-free package.

Applications

Battery-Powered Systems

(Single-Cell Li+ or

Multicell NiMH, NiCd,

Alkaline)

Cell Phones/Cordless

Phones

Pagers

Portable Medical Devices

PDAs

Electronic Toys

MP3 Players

*EP = Exposed paddle.

The MAX6782/MAX6783/MAX6784/MAX6785 are available with

factory-trimmed hysteresis. Specify trim by replacing “_” with

“A” for 0.5%, “B” for 5%, or “C” for 10% hysteresis.

Pin Configuration and Typical Operating Circuit appear at

end of data sheet.

Selector Guide

PART

MONITOR LEVEL

LBO OUTPUT

Quad

Triple

Dual

OV

—

OV

—

OUTPUT TYPE

Push-Pull

HYSTERESIS

Fixed/Adj

Adj

MAX6782TE_+

MAX6783TE_+

MAX6784TC_+

MAX6785TC_+

MAX6786TA+

MAX6787TA+

MAX6788TA+

MAX6789TB+

MAX6790TB+

4

3

2

4

—

Open Drain

Push-Pull

—

Open Drain

Push-Pull

—

Dual

—

Open Drain

Push-Pull/Open Drain

Push-Pull

Adj

Dual

—

Adj

—

Single

—

Open Drain

—

Note: All devices are available in tape and reel in 2.5k increments. For tape and reel orders, add a “T” after the “+” to complete the part

number.

________________________________________________________________ Maxim Integrated Products

1

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level

Battery Monitors in Small TDFN and TQFN Packages

ABSOLUTE MAXIMUM RATINGS

(All voltages referenced to GND.)

Continuous Power Dissipation (T = +70°C)

A

BATT.........................................................................-0.3V to +6V

IN1–IN4, LBH1, LBL1,

8-Pin TDFN (derate 23.8mW/°C above +70°C) ..........1905mW

10-Pin TDFN (derate 24.4mW/°C above +70°C) ........1951mW

12-Pin Thin QFN (derate 16.7mW/°C above +70°C) ..1333mW

16-Pin Thin QFN (derate 20.8mW/°C above +70°C) ..1667mW

Operating Temperature Range ...........................-40°C to +85°C

Junction Temperature………………………………………+150°C

Storage Temperature Range.............................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

LBH2, LBL2..................-0.3V to Min ((V

HADJ1–HADJ4, REF .......-0.3V to Min ((V

LBO1–LBO4 (push-pull)..-0.3V to Min ((V

+ 0.3V) and +6V)

BATT

LBO1–LBO4 (open drain).........................................-0.3V to +6V

Input Current (all pins) ........................................................20mA

Output Current (all pins) .....................................................20mA

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.

ELECTRICAL CHARACTERISTICS

(V

= 1.6V to 5.5V, T = -40°C to +85°C, unless otherwise specified. Typical values are at T = +25°C.) (Note 1)

A A

BATT

PARAMETER

SYMBOL

CONDITIONS

= 0°C to +70°C

MIN

1.05

1.2

TYP

MAX

5.5

UNITS

82–MAX6790

T

A

Operating Voltage Range

(Note 2)

V

BATT

= -40°C to +85°C

5.5

A

V

= 3.7V, no load

6.3

5.7

10

µA

ms

BATT

Supply Current

I

Q

= 1.8V, no load

Startup Time (Note 3)

rising from 0 to 1.6V

5

MAX6782/MAX6783/MAX6784/MAX6785

0.5% hysteresis (A version)

5% hysteresis (B version)

10% hysteresis (C version)

0.5994 0.6055 0.6115

0.5723 0.5781 0.5839

0.5422 0.5477 0.5531

0.6024 0.6085 0.6146

IN_ Falling Threshold (Note 4)

V

INF

IN_ Rising Threshold (Note 4)

V

INR

IN_, HADJ_ Input Leakage

Current

V

≥ 0.3V

5

nA

IN_, HADJ_

Reference Output

V

0.6024 0.6085 0.6146

0.3

V

REF

Reference Load Regulation

I

= 0 to 1mA

mV/mA

REF

Reference Temperature

Coefficient

TEMPCO

15

20

ppm/°C

Reference Short-Circuit Current

Hysteresis Adjustment Range

Hysteresis Adjustment Logic Low

mA

V

0.4

V

REF

V

0.07

V

HALL

Hysteresis Adjustment Logic

High

V

0.17

V

HALH

MAX6786/MAX6787/MAX6788

LBL_, LBH_ Threshold

V

0.6024 0.6085 0.6146

5

V

TH

LBL_, LBH_ Input Leakage

Current

V

, V

≥ 0.3V

nA

LBL LBH_

2

_______________________________________________________________________________________

Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level

Battery Monitors in Small TDFN and TQFN Packages

82–MAX6790

ELECTRICAL CHARACTERISTICS (continued)

(V

= 1.6V to 5.5V, T = -40°C to +85°C, unless otherwise specified. Typical values are at T = +25°C.) (Note 1)

A A

BATT

PARAMETER

MAX6782–MAX6788

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

LBO_ Propagation Delay

t

100mV overdrive

30

µs

V

PD

V

≥ 1.2V, I

≥ 2.7V, I

≥ 4.5V, I

= 100µA

= 1.2mA

= 3.2mA

0.3

0.4

BATT

SINK

LBO_ Output Low Voltage (Push-

Pull or Open Drain)

V

OL

V

0.8 x

V

≥ 1.6V, I

≥ 2.7V, I

≥ 4.5V, I

= 10µA

V

BATT

SOURCE

V

BATT

LBO_ Output High Voltage

(Push-Pull) (Note 5)

0.8 x

V

= 500µA

= 800µA

OH

V

BATT

0.8 x

V

BATT

LBO_ Output Leakage Current

(Open Drain)

Output not asserted, V

= 0 or 5V

500

nA

LBO_

MAX6789/MAX6790

IN_ Rising Threshold

IN_ Hysteresis

V

0.6024 0.6085 0.6146

V

TH+

31

mV

nA

µs

IN_ Input Leakage Current

OV, OV Delay Time

V

≥ 0.3V

5

IN_

t

100mV overdrive

30

PD

≥ 1.6V, I

= 100µA, output

= 1.2mA, output

= 3.2mA, output

BATT

SINK

0.3

asserted

V ≥ 2.7V, I

BATT

OV Output Low Voltage (Push-

Pull or Open Drain)

SINK

V

OL

asserted

V

≥ 4.5V, I

BATT

SINK

0.4

asserted

V

≥ 1.2V, I

= 10µA, output not

= 500µA, output not

0.8 x

V

BATT

SOURCE

asserted

OV Output High Voltage (Push-

Pull) (Note 5)

V

≥ 2.7V, I

0.8 x

BATT

SOURCE

V

nA

V

OH

asserted

V

BATT

V

≥ 4.5V, I

= 800µA, output not

SINK

0.8 x

V

BATT

asserted

OV Output Leakage Current

(Open Drain)

Output not asserted, V , V = 0 or 5V

500

0.3

0.4

OV OV

V

≥ 1.2V, I

= 100µA, output not

= 1.2mA, output not

= 3.2mA, output not

BATT

SINK

asserted

V ≥ 2.7V, I

BATT

OV Output Low Voltage

(Push-Pull or Open Drain)

V

OL

asserted

V

≥ 4.5V, I

BATT

asserted

_______________________________________________________________________________________

3

Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level

Battery Monitors in Small TDFN and TQFN Packages

ELECTRICAL CHARACTERISTICS (continued)

(V

= 1.6V to 5.5V, T = -40°C to +85°C, unless otherwise specified. Typical values are at T = +25°C.) (Note 1)

A A

BATT

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

V

≥ 1.6V, I

= 10µA, output

0.8 x

BATT

SOURCE

asserted

V

BATT

OV Output High Voltage (Push-

Pull ) (Note 5)

V

≥ 2.7V, I

= 500µA, output

= 800µA, output

0.8 x

BATT

V

OH

asserted

V

BATT

V

≥ 4.5V, I

0.8 x

BATT

asserted

V

BATT

OV Output Leakage Current

(Open Drain)

Output asserted, V = 0 or 5V

500

nA

V

OV

0.3 x

CLEAR Input Low Voltage

CLEAR Input High Voltage

V

IL

V

BATT

0.7 x

V

IH

V

BATT

82–MAX6790

CLEAR Pullup Resistance

CLEAR Minimum Pulse Width

CLEAR Delay Time

25

80

kΩ

µs

ns

1

t

300

CLD

Note 1: Devices are tested at T = +25°C and guaranteed by design for T = T

to T

as specified.

MAX

A

MIN

Note 2: Operating voltage range ensures low battery output is in the correct state. Minimum battery voltage for electrical specifica-

tion is 1.6V.

Note 3: Reference and threshold accuracy is only guaranteed after the startup time. Startup time is guaranteed by design.

Note 4: The rising threshold is guaranteed to be higher than the falling threshold.

Note 5: The source current is the total source current from all outputs.

4

_______________________________________________________________________________________

Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level

Battery Monitors in Small TDFN and TQFN Packages

82–MAX6790

Typical Operating Characteristics

(V

= 3.6V, T = +25°C, unless otherwise noted.)

A

BATT

PROPAGATION DELAY

vs. TEMPERATURE

SUPPLY CURRENT

vs. TEMPERATURE

70

MAXIMUM TRANSIENT DURATION

vs. THRESHOLD OVERDRIVE

8.0

7.5

7.0

6.5

6.0

5.5

5.0

4.5

4.0

1000

900

800

700

600

500

400

300

200

100

0

V

= 5V

BATT

V

=

100mV OVERDRIVE

OUTPUT ASSERTED ABOVE THIS LINE

IN_

V

= 3.6V

BATT

60

50

40

30

20

10

0

V

= 1.8V

60

BATT

-40

-15

10

35

85

-40

-15

10

35

60

85

1

10

100

1000

TEMPERATURE (°C)

THRESHOLD OVERDRIVE (mV)

NORMALIZED THRESHOLD VOLTAGES

vs. TEMPERATURE (MAX6782TEA)

NORMALIZED THRESHOLD VOLTAGES

vs. TEMPERATURE (MAX6782TEB)

NORMALIZED THRESHOLD VOLTAGES

vs. TEMPERATURE (MAX6782TEC)

1.005

1.004

1.003

1.002

1.001

1.000

0.999

0.998

0.997

0.996

0.995

1.005

1.004

1.003

1.002

1.001

1.000

0.999

0.998

0.997

0.996

0.995

1.005

1.004

1.003

1.002

1.001

1.000

0.999

0.998

0.997

0.996

0.995

NORMALIZED AT T = +25°C

A

FALLING

RISING

FALLING

RISING

-40

-15

10

35

60

85

-40

-15

10

35

60

85

-40

-15

10

35

60

85

TEMPERATURE (°C)

_______________________________________________________________________________________

5

Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level

Battery Monitors in Small TDFN and TQFN Packages

Typical Operating Characteristics (continued)

(V

= 3.6V, T = +25°C, unless otherwise noted.)

A

BATT

LBO OUTPUT VOLTAGE LOW

vs. SINK CURRENT

5.5

LBO OUTPUT VOLTAGE HIGH

vs. SOURCE CURRENT

REFERENCE VOLTAGE

vs. TEMPERATURE

0.6

0.5

0.4

0.3

0.2

0.1

0

0.620

0.616

0.612

0.608

0.604

0.600

MAX6782TEA

V

= 1.8V

BATT

V

= 3.3V

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5

1.0

BATT

V

= 5.0V

BATT

V

= 3.3V

BATT

V

= 5.0V

BATT

V

= 1.8V

BATT

PUSH-PULL

VERSIONS

0

3

6

9

12

15

0

1

2

3

4

5

-40

-15

10

35

60

85

82–MAX6790

SINK CURRENT (mA)

SOURCE CURRENT (mA)

TEMPERATURE (°C)

REFERENCE VOLTAGE

vs. REFERENCE CURRENT

REFERENCE VOLTAGE

vs. SUPPLY VOLTAGE

CLEAR LATCH CIRCUIT

MAX6782 toc12

0.65

0.64

0.63

0.62

0.61

0.60

0.59

0.58

0.57

0.56

0.55

0.6095

0.6094

0.6093

0.6092

0.6091

0.6090

0.6089

0.6088

0.6087

0.6086

0.6085

MAX6782TEB

IN_

5V/div

CLEAR

5V/div

OV

5V/div

0

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

REFERENCE CURRENT (mA)

1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5

SUPPLY VOLTAGE (V)

100µs/div

6

_______________________________________________________________________________________

Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level

Battery Monitors in Small TDFN and TQFN Packages

82–MAX6790

Pin Description

MAX6782/MAX6783/MAX6784/MAX6785

NAME

FUNCTION

MAX6782/

MAX6783

MAX6784/

MAX6785

Battery Monitor Input 2. Connect to an external resistive divider to set the trip

threshold for monitor 2.

1

2

3

4

1

2

IN2

IN3

IN4

REF

Battery Monitor Input 3. Connect to an external resistive divider to set the trip

threshold for monitor 3.

Battery Monitor Input 4. Connect to an external resistive divider to set the trip

threshold for monitor 4.

—

3

Reference Output. REF can source up to 1mA. REF does not require an external

bypass capacitor for stability. Keep the capacitance from REF to GND below 50pF.

Hysteresis Adjustment Input 1.

Connect HADJ1 to GND to select an internal preset hysteresis option.

Connect a resistive divider from REF to HADJ1 and to GND to externally adjust the

hysteresis for IN1 from its internal preset hysteresis (see Figure 6).

5

6

7

8

4

5

HADJ1

HADJ2

HADJ3

HADJ4

Hysteresis Adjustment Input 2.

Connect HADJ2 to GND to select an internal preset hysteresis option.

Connect a resistive divider from REF to HADJ2 and to GND to externally adjust the

hysteresis for IN2 from its internal preset hysteresis (see Figure 6).

Hysteresis Adjustment Input 3.

Connect HADJ3 to GND to select an internal preset hysteresis option.

Connect a resistive divider from REF to HADJ3 and to GND to externally adjust the

hysteresis for IN3 from its internal preset hysteresis (see Figure 6).

6

Hysteresis Adjustment Input 4.

Connect HADJ4 to GND to select an internal preset hysteresis option.

Connect a resistive divider from REF to HADJ4 and to GND to externally adjust the

hysteresis for IN4 from its internal preset hysteresis (see Figure 6).

—

Active-Low, Low-Battery Output 4. LBO4 asserts when V

falls below the falling

IN4

9

—

7

LBO4

LBO3

LBO2

LBO1

BATT

threshold voltage. LBO4 deasserts when V

exceeds the rising threshold voltage.

IN4

Active-Low, Low-Battery Output 3. LBO3 asserts when V

falls below the falling

IN3

10

11

12

13

threshold voltage. LBO3 deasserts when V

exceeds the rising threshold voltage.

IN3

Active-Low, Low-Battery Output 2. LBO2 asserts when V

falls below the falling

IN2

8

threshold voltage. LBO2 deasserts when V

exceeds the rising threshold voltage.

IN2

Active-Low, Low-Battery Output 1. LBO1 asserts when V

falls below the falling

IN1

9

threshold voltage. LBO1 deasserts when V

exceeds the rising threshold voltage.

IN1

Battery Input. Power supply to the device. For better noise immunity, bypass BATT

to GND with a 0.1µF capacitor as close to the device as possible.

10

14

15

11

—

GND

N.C.

Ground

No Connection. Not internally connected.

Battery Monitor Input 1. Connect to an external resistive divider to set the trip

threshold for monitor 1.

16

12

IN1

_______________________________________________________________________________________

7

Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level

Battery Monitors in Small TDFN and TQFN Packages

Pin Description (continued)

MAX6786/MAX6787/MAX6788

1

NAME

LBL1

LBH1

LBL2

LBH2

GND

FUNCTION

Falling Trip Level Input 1. Connect to an external resistive divider to set the falling trip level.

Rising Trip Level Input 1. Connect to an external resistive divider to set the rising trip level.

Falling Trip Level Input 2. Connect to an external resistive divider to set the falling trip level.

Rising Trip Level Input 2. Connect to an external resistive divider to set the rising trip level.

Ground

2

3

4

5

Active-Low, Low-Battery Output 2. LBO2 asserts when V

falls below the falling threshold voltage. LBO2

LBL2

6

7

8

LBO2

LBO1

BATT

deasserts when V

exceeds the rising threshold voltage.

LBH2

Active-Low, Low-Battery Output 1. LBO1 asserts when V

deasserts when V

falls below the falling threshold voltage. LBO1

LBL1

exceeds the rising threshold voltage.

LBH1

Battery Input. Power supply to the device. For better noise immunity, bypass BATT to GND with a 0.1µF

capacitor as close to the device as possible.

82–MAX6790

MAX6789/MAX6790

1

NAME

IN1

FUNCTION

Overvoltage Monitor Input 1

Overvoltage Monitor Input 2

Overvoltage Monitor Input 3

Overvoltage Monitor Input 4

Ground

2

IN2

3

IN3

4

IN4

5

GND

Active-Low Clear Input. OV and OV do not latch when an overvoltage fault is detected if CLEAR is held low.

CLEAR has an internal pullup resistor to BATT.

6

7

CLEAR

N.C.

No Connection. Not internally connected.

Active-Low Overvoltage Output. When any of the inputs (V ) exceeds its respective rising threshold

IN_

8

OV

voltage, OV asserts and stays asserted until CLEAR is pulled low or the power to the device is cycled. OV

does not latch when an overvoltage fault is detected if CLEAR is held low.

9

OV

Active-High Overvoltage Output. Inverse of OV.

Battery Input. Power supply to the device. For better noise immunity, bypass BATT to GND with a 0.1µF

capacitor as close to the device as possible.

10

BATT

lighter loads. The MAX6782–MAX6785 also feature ref-

erence outputs that can source up to 1mA.

Detailed Description

The MAX6782–MAX6788 are designed to monitor two

to four battery levels (1% accuracy) and assert an

active-low output indicator when the monitored voltage

level falls below the user-set threshold. Each battery

level is associated with an independent open-drain or

push-pull output. Each of these independent outputs

can be used to provide low battery warnings at differ-

ent voltage levels. Each of these monitored levels offers

fixed or adjustable hysteresis in order to prevent the

output from chattering as the battery recovers from the

The MAX6789/MAX6790 monitor four overvoltage con-

ditions and assert the complementary overvoltage out-

puts when any voltage at the inputs exceeds its

respective threshold. The MAX6789/MAX6790 allow

each trip threshold to be set with external resistors.

These devices also feature a latch and a clear function.

Figures 1, 2, and 3 show the simplified block diagrams

for the MAX6782–MAX6790. See the Selector Guide.

8

_______________________________________________________________________________________

Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level

Battery Monitors in Small TDFN and TQFN Packages

82–MAX6790

BATT

REF

IN1

COMPARATOR

SECTION 1

REFERENCE

HADJ1

LBO1

IN2

COMPARATOR

SECTION 2

HADJ2

LBO2

INTERNAL

HYSTERESIS

LADDER

IN3

COMPARATOR

SECTION 3

HADJ3

LBO3

MAX6782

MAX6783

MAX6784

MAX6785

IN4

COMPARATOR

SECTION 4

HADJ4

LBO4

HYSTERESIS

SELECT

GND

(

) MAX6782/MAX6783 ONLY

Figure 1. MAX6782–MAX6785 Block Diagram

BATT

MAX6786

MAX6787

MAX6788

REF

R

1

LBO_

LBL_

LBH_

R

HYST

R

2

GND

Figure 2. MAX6786/MAX6787/MAX6788 Block Diagram

_______________________________________________________________________________________

9

Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level

Battery Monitors in Small TDFN and TQFN Packages

BATT

IN_

MAX6789

MAX6790

REF

OV

LATCH

CONTROL

CLEAR

82–MAX6790

GND

Figure 3. MAX6789/MAX6790 Block Diagram

Low-Battery/Overvoltage Output

Hysteresis

All devices are offered with either push-pull or open-

drain outputs (see the Selector Guide). The MAX6788

has one push-pull output and one open-drain output,

configured as shown in Table 1.

Input hysteresis defines two thresholds, separated by

the hysteresis voltage, configured so the output asserts

when the input falls below the falling threshold, and

deasserts only when the input rises above the rising

threshold. Figures 4 and 5 show this graphically.

Hysteresis removes, or greatly reduces, the possibility

of the output changing state in response to noise or

battery-terminal voltage recovery after load removal.

Table 1. MAX6788 Outputs

DEVICE

LBO1

LBO2

MAX6788

Push-Pull

Open Drain

All open-drain outputs require an external pullup resis-

tor. The open-drain pullup resistor may be connected

to an external voltage up to +6V, regardless of the volt-

age at BATT.

10 ______________________________________________________________________________________

Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level

Battery Monitors in Small TDFN and TQFN Packages

82–MAX6790

V

INR

INTERNAL HYSTERESIS

INF

IN_

V

HALL

V

HADJ_

t

PD

t

PD

LBO_

A) NORMAL OPERATION FOR V

< V

HALL

.

HADJ_

V

INR

INTERNAL HYSTERESIS

V

INF

IN_

V

HADJ_

V

HALH

t

PD

t

PD

LBO_

B) NORMAL OPERATION FOR V

> V

HALH

.

HADJ_

Figure 4. MAX6782–MAX6785 Timing

______________________________________________________________________________________ 11

Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level

Battery Monitors in Small TDFN and TQFN Packages

V

TH+

V

TH-

IN_

CLEAR

OV

t

PD

t

CLD

82–MAX6790

Figure 5. MAX6789/MAX6790 Timing

Externally Adjusted Hysteresis

The MAX6782–MAX6785 can also be configured for

externally adjustable hysteresis. Connect a resistive

divider from REF to HADJ_ and to GND (Figure 6) to set

the hysteresis voltage. The hysteresis adjustment range

MAX6782–MAX6785 Hysteresis

Factory-Set Hysteresis

The MAX6782–MAX6785 have factory-set hysteresis for

ease of use and reduced external parts count. For

these devices the absolute hysteresis voltage is a per-

centage of the internally generated reference. The

amount depends on the device option. “A” devices

have 0.5% hysteresis, “B” devices have 5% hysteresis,

and “C” devices have 10% hysteresis. Table 2 presents

the threshold voltages for devices with factory-set hys-

teresis. For factory-set hysteresis, connect HADJ_ to

GND.

is from 0.4V to V

, and the voltage at HADJ_

REF

(V

) must be set higher than Hysteresis

Adjustment Logic High (V

is lower than Hysteresis Adjustment Logic Low

), these devices switch back to the internal fac-

tory-set hysteresis (Figure 4a).

HADJ_

) (Figure 4b). Note that if

HALH

V

HADJ_

(V

HALL

MAX6786/MAX6787/MAX6788 Adjustable

Hysteresis

Table 2. Typical Falling and Rising

Thresholds for MAX6782–MAX6785

(HADJ_ = GND)

The MAX6786/MAX6787/MAX6788 offer external hystere-

sis control through the resistive divider that monitors bat-

tery voltage. Figure 2 shows the connections for external

hysteresis. See Calculating an External Hysteresis

Resistive Divider (MAX6786/MAX6787/MAX6788) section

for more information.

PERCENT

FALLING

RISING

DEVICE

OPTION

HYSTERESIS THRESHOLD

THRESHOLD

(%)

(V ) (V)

INF

(V ) (V)

INR

A

B

C

0.5

5

0.6055

0.5781

0.5477

0.6085

10

12 ______________________________________________________________________________________

Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level

Battery Monitors in Small TDFN and TQFN Packages

82–MAX6790

old (V ) on the associated IN_ (the rising threshold

INF

Reference Output

The reference output can provide up to 1mA of output

current. The output is not buffered. Excessive loading

affects the accuracy of the thresholds. An external

capacitor is not required for stability and is stable for

capacitive loads up to 50pF. In applications where the

load or the supply can experience step changes, a

capacitor reduces the amount of overshoot (under-

shoot) and improves the circuit’s transient response.

Place the capacitor as close to the device as possible

for best performance.

(V ) is fixed). See Table 2. Calculate R using:

INR

3

e

× V

REF

A

R =

3

I

L

where e is the fraction of the maximum acceptable

A

absolute resistive divider error attributable to the input

leakage current (use 0.01 for 1%), V

is the refer-

REF

ence output voltage, and I is the worst-case HADJ_

L

leakage current. Calculate R using:

4

V

×R

3

INF

Applications Information

R

=

4

V

− V

REF

INF

Resistor-Value Selection

Choosing the proper external resistors is a balance

between accuracy and power use. The input to the volt-

age monitor, while high impedance, draws a small cur-

rent, and that current travels through the resistive

divider, introducing error. If extremely high resistor val-

ues are used, this current introduces significant error.

With extremely low resistor values, the error becomes

negligible, but the resistive divider draws more power

from the battery than necessary, and shortens battery

life. See Figure 6 and calculate the optimum value for

R1 using:

where V

is the desired falling voltage threshold. To

INF

calculate the percent hysteresis, use:

V

− V

INF

INR

V

Hysteresis % = 100 ×

(

)

INR

where V

is the rising voltage.

INR

Calculating an External

Hysteresis Resistive Divider

(MAX6786/MAX6787/MAX6788)

Setting the hysteresis externally requires calculating

three resistor values, as indicated in Figure 2. First cal-

e

× V

BATT

A

culate R using:

1

R =

1

I

L

e

× V

BATT

A

R =

1

where e is the fraction of the maximum acceptable

A

absolute resistive divider error attributable to the input

I

L

leakage current (use 0.01 for 1%), V

is the battery

BATT

and R using:

20

voltage at which LBO should activate, and I is the

L

worst-case IN_ leakage current, from the Electrical

Characteristics. For example, for 0.5% error, a 2.8V

V

×R

1

TH

R

=

(as in the above example)

20

V

− V

BATT

TH

battery minimum, and 5nA leakage, R = 2.80MΩ.

1

Calculate R using:

2

where R = R + R determine the total resistive-

HYST

divider current, I

20

2

, at the trip voltage using:

TOTAL

V

×R

1

INF

R =

2

V

− V

BATT

INF

V

BATT

I

=

TOTAL

R +R

1

20

where V

is the falling threshold voltage from Table 2.

INF

Continuing the above example, and selecting V

=

INF

Then, determine R

using:

HYST

0.5477V (10% hysteresis device), R = 681kΩ. There

2

are other sources of error for the battery threshold,

including resistor and input monitor tolerances.

V

HYST

R

=

HYST

I

TOTAL

Calculating an External Hysteresis

Resistive Divider (MAX6782–MAX6785)

To set the hysteresis, place a resistive divider from REF

to HADJ_ as shown in Figure 6. The resistive divider

sets voltage on HADJ_, which controls the falling thresh-

where V

is the required hysteresis voltage.

HYST

Finally, determine R using:

2

R = R - R

HYST

2

20

______________________________________________________________________________________ 13

Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level

Battery Monitors in Small TDFN and TQFN Packages

Monitoring a Battery Voltage Higher

than the Allowable V

For monitoring higher voltages, supply a voltage to BATT,

which is within the specified supply range, and power the

input resistive divider from the high voltage to be moni-

tored. Do not exceed the Absolute Maximum Ratings.

Adding External Capacitance to Reduce

Noise and Transients

If monitoring voltages in a noisy environment, add a

bypass capacitor of 0.1µF from BATT to GND as close

as possible to the device. For systems with large tran-

sients, additional capacitance may be required.

BATT

Maintaining Reference Accuracy

Since the ground connection of the MAX6782–MAX6790

has a small series resistance, any current flowing into an

output flows to ground and causes a small voltage to

develop from the internal ground to GND. This has the

effect of slightly increasing the reference voltage. To mini-

mize the effect on the reference voltage, keep the total

output sink current below 3mA.

Reverse-Battery Protection

To prevent damage to the device during a reverse-battery

condition, connect the MAX6782–MAX6785 in the configu-

ration shown in Figure 6a or 6b. For the internal reverse-

battery protection to function correctly on the MAX6782–

MAX6790, several conditions must be satisfied:

• The connections to IN_/LBL_/LBH_ must be made to

the center node of a resistive divider going from

BATT to GND. The Thevenin equivalent impedance

of the resistive divider must not fall below 1kΩ in

order to limit the current.

• HADJ_ (MAX6782–MAX6785 only) must either be

connected to GND or to the center node of a resis-

tive divider going from REF to GND.

BATT

82–MAX6790

R

1

IN_

LBO_

• The outputs may only be connected to devices pow-

ered by the same battery as the MAX6782–

MAX6790.

2

MAX6782

MAX6783

MAX6784

MAX6785

REF

Note that the MAX6782–MAX6790 will not protect other

devices in the circuit.

HADJ_

Additional Application Circuit

Figure 7 shows the MAX6786/MAX6787/MAX6788 in a

typical two-battery-level monitoring circuit.

GND

A) FACTORY PRESET HYSTERESIS CONNECTION

BATT

LBL1

1

BATT

R

1

LBO1

LBH1

IN_

REF

LBO_

MAX6786

MAX6787

MAX6788

2

MAX6782

MAX6783

MAX6784

MAX6785

R

LBL2

3

HADJ_

LBO2

LBH2

4

GND

B) EXTERNAL HYSTERESIS ADJUST CONNECTION

Figure 6. Internal Preset or Externally Adjusted Hysteresis

Connection

Figure 7. Two-Battery-Level Monitor Configuration

14 ______________________________________________________________________________________

Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level

Battery Monitors in Small TDFN and TQFN Packages

82–MAX6790

Typical Operating Circuit

BATT

IN1

LBO1

LBO2

LBO3

DEAD BATTERY

BACKUP MEMORY

IN2

IN3

MAX6782

MAX6783

SHUT DOWN

SUBSYSTEM

SLOW DOWN

PROCESSOR SPEED

LBO4

REF

IN4

HADJ_

GND

Ordering Information (continued)

Top Marks

PIN-

PACKAGE

PKG

CODE

PART

MAX6782TEA+

TOP MARK

+AEG

+AEH

+AEI

PART

TEMP RANGE

MAX6786TA+T

MAX6787TA+T

MAX6788TA+T

MAX6789TB+T

MAX6790TB+T

-40°C to +85°C

8 TDFN-EP*

T833-3

MAX6782TEB+

MAX6782TEC+

MAX6783TEA+

MAX6783TEB+

MAX6783TEC+

MAX6784TCA+

MAX6784TCB+

MAX6784TCC+

MAX6785TCA+

MAX6785TCB+

MAX6785TCC+

MAX6786TA+

MAX6787TA+

MAX6788TA+

MAX6789TB+

MAX6790TB+

+AEJ

-40°C to +85°C 10 TDFN-EP* T1033-1

+AEK

+AEL

+Denotes lead-free package.

*EP = Exposed paddle.

+AAV

+AAW

+AAX

+AAY

+AAZ

+ABA

+APU

+APV

+APW

+AQI

The MAX6782/MAX6783/MAX6784/MAX6785 are available with

factory-trimmed hysteresis. Specify trim by replacing “_” with

“A” for 0.5%, “B” for 5%, or “C” for 10% hysteresis.

+AQJ

______________________________________________________________________________________ 15

Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level

Battery Monitors in Small TDFN and TQFN Packages

Pin Configurations

TOP VIEW

9

8

7

12

11

10

9

HADJ4

8

7

6

5

BATT 13

GND 14

HADJ3

HADJ2

HADJ1

6

5

10

11

BATT

GND

IN1

HADJ3

HADJ2

HADJ1

MAX6784

MAX6785

MAX6782

MAX6783

N.C.

IN1

15

16

12

4

+

1

2

3

1

2

3

4

82–MAX6790

THIN QFN

8

7

6

5

10

9

8

7

6

MAX6786

MAX6787

MAX6788

MAX6789

MAX6790

+

1

2

3

4

1

2

3

4

5

TDFN

Chip Information

PROCESS: BiCMOS

16 ______________________________________________________________________________________

Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level

Battery Monitors in Small TDFN and TQFN Packages

82–MAX6790

Package Information

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information

go to www.maxim-ic.com/packages.)

______________________________________________________________________________________ 17

Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level

Battery Monitors in Small TDFN and TQFN Packages

Package Information (continued)

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information

go to www.maxim-ic.com/packages.)

82–MAX6790

18 ______________________________________________________________________________________

Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level

Battery Monitors in Small TDFN and TQFN Packages

82–MAX6790

Package Information (continued)

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information

go to www.maxim-ic.com/packages.)

PACKAGE OUTLINE, 6,8,10 & 14L,

TDFN, EXPOSED PAD, 3x3x0.80 mm

1

H

21-0137

2

______________________________________________________________________________________ 19

Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level

Battery Monitors in Small TDFN and TQFN Packages

Package Information (continued)

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information

go to www.maxim-ic.com/packages.)

PACKAGE VARIATIONS

COMMON DIMENSIONS

MIN. MAX.

SYMBOL

PKG. CODE

T633-1

N

6

D2

1.50±0.10 2.30±0.10 0.95 BSC

1.50±0.10 2.30±0.10

E2

e

JEDEC SPEC

MO229 / WEEA

MO229 / WEEC

b

[(N/2)-1] x e

1.90 REF

1.95 REF

2.00 REF

2.40 REF

0.40±0.05

0.30±0.05

A

0.70

2.90

0.00

0.20

0.80

3.10

0.05

0.40

T633-2

6

D

E

0.95 BSC

T833-1

8

1.50±0.10 2.30±0.10 0.65 BSC

T833-2

8

A1

L

T833-3

8

T1033-1

T1033-2

T1433-1

T1433-2

10

14

1.50±0.10 2.30±0.10 0.50 BSC MO229 / WEED-3 0.25±0.05

k

0.25 MIN.

0.20 REF.

1.50±0.10 2.30±0.10

0.25±0.05

0.20±0.05

A2

0.50 BSC MO229 / WEED-3

1.70±0.10 2.30±0.10 0.40 BSC

- - - -

82–MAX6790

PACKAGE OUTLINE, 6,8,10 & 14L,

TDFN, EXPOSED PAD, 3x3x0.80 mm

2

-DRAWING NOT TO SCALE-

H

21-0137

2

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.

20 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

is a registered trademark of Maxim Integrated Products, Inc.


型号：	MAX6782
厂家：	MAXIM INTEGRATED PRODUCTS
描述：	Low-Power, 1% Accurate, Dual-/Triple-/Quad-Level Battery Monitors in Small TDFN and TQFN Packages 低功耗， 1 ％精度，双/三/四电平电池监视器小TDFN和TQFN封装电池监视器
文件：	总20页 (文件大小：653K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

MAX6782 [MAXIM]

相关型号：

MAX6782TE

MAX6782TE+

MAX6782TEA+

MAX6782TEB+

MAX6782TEC+

MAX6782TE_+

MAX6782_10

MAX6783

MAX6783TE

MAX6783TE+

MAX6783TEA+

MAX6783TEB+