MAXIM MAX6846 Technical data

General Description

The MAX6846–MAX6849 are a family of ultra-low-power
battery monitors with integrated microprocessor (µP)
supervisors. The user-adjustable battery monitors are
offered with single or dual low-battery output options that
can be used to signal when the battery is OK (enabling
full system operation), when the battery is low (for low­power system operation), and when the battery is dead
(to disable system operation). These devices also have
an independent µP supervisor that monitors VCCand
provides an active-low reset output. A manual reset
function is available to reset the µP with a pushbutton.

The MAX6846–MAX6849 are ideal for single-cell lithium­ion (Li+) or multicell alkaline/NiCd/NiMH applications.
When the battery voltage drops below each adjusted low
threshold, the low-battery outputs are asserted to alert
the system. When the voltage rises above the adjusted
high thresholds, the outputs are deasserted after a
150ms minimum timeout period, ensuring the voltages
have stabilized before power circuitry is activated or pro­viding microprocessor reset timing.

These devices have user-adjustable battery threshold
voltages, providing a wide hysteresis range to prevent
chattering that can result due to battery recovery after
load removal. Single low-battery outputs are supplied
by the MAX6846/MAX6847 and dual low-battery out­puts are supplied by the MAX6848/MAX6849. All bat­tery monitors have open-drain low-battery outputs.

The MAX6846–MAX6849 monitor system voltages
(VCC) from 1.8V to 3.3V with seven fixed reset threshold
options. Each device is offered with two minimum reset
timeout periods of 150ms or 1200ms. The MAX6846/
MAX6848 are offered with an open-drain RESET output
and the MAX6847/MAX6849 are offered with a push­pull RESET output.

The MAX6846–MAX6849 are offered in a SOT23 pack­age and are fully specified over a -40°C to +85°C temp­erature range.

Applications

Battery-Powered Systems (Single-Cell Li+ or
Multicell NiMH, NiCd, Alkaline)

Cell Phones/Cordless Phones

Portable Medical Devices

Digital Cameras

Pagers

PDAs

MP3 Players

Electronic Toys

Features

♦ User-Adjustable Thresholds for Monitoring

Single-Cell Li+ or Multicell Alkaline/NiCd/NiMH
Applications

♦ Single and Dual Low-Battery Output Options

♦ Independent µP Reset with Manual Reset

♦ Factory-Set Reset Thresholds for Monitoring 1.8V

to 3.3V Systems

♦ Available with 150ms (min) or 1.2s (min) V

CC

Reset Timeout Period Options

♦ 150ms (min) LBO Timeout Period

♦ Immune to Short-Battery Voltage Transients

♦ Low Current (2.5µA, typ at 3.6V)

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

♦ Small 8-Pin SOT23 Packages

MAX6846–MAX6849

Low-Power, Adjustable Battery Monitors with

Hysteresis and Integrated µP Reset

________________________________________________________________ Maxim Integrated Products 1

Pin Configurations

Ordering Information

19-2947; Rev 0; 7/03

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.

Note: The first “_” is the VCCreset threshold level, suffix found

in Table 1. The “_” after the D is a placeholder for the reset
timeout period suffix found in Table 2. All devices are available
in tape-and-reel only. There is a 2500 piece minimum order
increment for standard versions (see Standard Versions table).
Sample stock is typically held on standard versions only. Non­standard versions require a minimum order increment of
10,000 pieces. Contact factory for availability.

查询MAX6846KARD3供应商

PART TEMP RANGE PIN-PACKAGE

MAX6846KA_D_-T -40°C to +85°C 8 SOT23-8

MAX6847KA_D_-T -40°C to +85°C 8 SOT23-8

MAX6848KA_D_-T -40°C to +85°C 8 SOT23-8

MAX6849KA_D_-T -40°C to +85°C 8 SOT23-8

TOP VIEW

V

LTHIN

1

DD

2

MAX6846

3

MAX6847

4

87V

6

5

CC

HTHINGND

MR

RESETLBO

LTHIN

LBOL

DD

2

MAX6848

3

MAX6849

4

1

V

SOT23

SOT23

87V

6

5

CC

HTHINGND

LBOH

RESET

MAX6846–MAX6849

Low-Power, Adjustable Battery Monitors with
Hysteresis and Integrated µP Reset

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

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.

*Applying 7V for a duration of 1ms does not damage the device.

V

DD

, VCCto GND....................................................-0.3V to +6V*

Open-Drain LBO, LBOH, LBOL to GND .................-0.3V to +6V*

Open-Drain RESET to GND ....................................-0.3V to +6V*

Push-Pull RESET to GND............................-0.3V to (V

CC

+ 0.3V)

HTHIN, LTHIN to GND................................-0.3V to (V

DD

+ 0.3V)

MR to GND .................................................-0.3V to (V

CC

+ 0.3V)

Input/Output Current, All Pins .............................................20mA

Continuous Power Dissipation (T

A

= +70°C)

8-Pin SOT23 (derate 8.9mW/°C above +70°C)............714mW

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

ELECTRICAL CHARACTERISTICS

(VDD= 1.6V to 5.5V, VCC= 1.2V to 5.5V, TA= -40°C to +85°C, unless otherwise specified. Typical values are at TA= +25°C.) (Note 1)

VDD Operating Voltage Range V

VCC Operating Voltage Range V

VCC + VDD Supply Current ICC + I

MAX6846/MAX6847 VDD THRESHOLDS

HTHIN Threshold V

LTHIN Threshold V

MAX6848/MAX6849 VDD THRESHOLDS

HTHIN+ Threshold V

HTHIN- Threshold V

LTHIN+ Threshold V

LTHIN- Threshold V

MAX6846–MAX6849

HTHIN/LTHIN Leakage Current I

LBO , LBO L, LBO H Ti m eout P er i od t
LBO, LBOL, LBOH Delay Time t

LBO, LBOL, LBOH Output Low V

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DD

CC

HTH

LTH

HTH+

HTH-

LTH+

LTH-

LKG

LBOP

LBOD

OL

TA = 0°C to +85°C 1.0 5.5

TA = -40°C to +85°C 1.2 5.5

DDVDD

= 3.6V, VCC = 3.3V, no load (Note 2) 2.5 7 µA

HTHIN rising, LBO is deasserted when
HTHIN rises above V

LTHIN falling, LBO is asserted when LTHIN
falls below V

HTHIN rising, LBOH is deasserted when
HTHIN rises above V

HTHIN falling, LBOH is asserted when
HTHIN falls below V

LTHIN rising, LBOL is deasserted when
LTHIN rises above V

LTHIN falling, LBOL is asserted when
LTHIN falls below V

V

HTHIN

HTHIN/LTHIN rising above threshold 150 225 300 ms

HTHIN/LTHIN falling below threshold 100 µs

(VDD or VCC) ≥ 1.2V, I
low

(VDD or VCC) ≥ 1.6V, I
asserted low

(VDD or VCC) ≥ 2.7V, I
asserted low

(VDD or VCC) ≥ 4.5V, I
asserted low

or V

LTH

LTHIN

HTH

HTH+

HTH-

LTH+

LTH-

≥ 400mV 20 nA

= 50µA, asserted

SINK

= 100µA,

SINK

= 1.2mA,

SINK

= 3.2mA,

SINK

1.6

600 615 630 mV

600 615 630 mV

600 615 630 mV

567 582 597 mV

600 615 630 mV

567 582 597 mV

5.5

0.3

0.3

0.3

0.3

V

V

V

MAX6846–MAX6849

Low-Power, Adjustable Battery Monitors with

Hysteresis and Integrated µP Reset

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VDD= 1.6V to 5.5V, VCC= 1.2V to 5.5V, TA= -40°C to +85°C, unless otherwise specified. Typical values are at TA= +25°C.) (Note 1)

Note 1: Production testing done at TA= +25°C; limits over temperature guaranteed by design only.
Note 2: The device is powered up by the highest voltage between V

DD

and VCC.

Note 3: MR input ignores falling input pulses, which occur within the MR debounce period (t

DEB

) after a valid MR reset assertion.

This prevents invalid reset assertion due to switch bounce.

LBO, LBOL, LBOH Output
Open-Drain Leakage Current

VCC Reset Threshold V

VCC Reset Hysteresis 0.3 %

VCC to RESET Delay t

VCC to RESET Timeout Period t

MR Input Voltage

MR Minimum Pulse Width t
MR Glitch Rejection 100 ns
MR to RESET Delay 200 ns
MR Reset Timeout Period t
MR Pullup Resistance MR to V
MR Rising Debounce Period t

RESET Output High

(Push-Pull)

RESET Output Low V

RESET Output Leakage Current

(Open Drain)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Output deasserted 500 nA

MAX68_ _ _ _ T 3.000 3.075 3.150

MAX68_ _ _ _ S 2.850 2.925 3.000

MAX68_ _ _ _ R 2.550 2.625 2.700

TH

RD

RP

V

IL

V

IH

MPW

MRP

DEB

V

OH

OL

MAX68_ _ _ _ Z 2.250 2.313 2.375

MAX68_ _ _ _ Y 2.125 2.188 2.250

MAX68_ _ _ _ W 1.620 1.665 1.710

MAX68_ _ _ _ V 1.530 1.575 1.620

VCC falling at 10mV/µs from (VTH + 100mV)

- 100mV)

to (V

TH

MAX68_ _ _ _ _ D3 150 225 300

MAX68_ _ _ _ _ D7 1200 1800 2400

0.7 x V

1µs

150 225 300 ms

CC

(Note 3) 150 225 300 ms

VCC ≥ 1.53V, I
deasserted

VCC ≥ 2.55V, I
deasserted

VCC ≥ 1.0V, I

VCC ≥ 1.2V, I

VCC ≥ 2.12V, I
asserted

RESET deasserted 500 nA

SINK

SINK

= 100µA, RESET

SOURCE

= 500µA, RESET

SOURCE

= 50µA, RESET asserted 0.3
= 100µA, RESET asserted 0.3

= 1.2mA, RESET

SINK

750 1500 2250 Ω

0.8 x V

0.8 x V

50 µs

0.3 x V

CC

CC

CC

CC

0.3

V

ms

V

V

V

MAX6846–MAX6849

Low-Power, Adjustable Battery Monitors with
Hysteresis and Integrated µP Reset

4 _______________________________________________________________________________________

Typical Operating Characteristics

(VDD= 3.6V, VCC= 3.3V, unless otherwise specified. Typical values are at TA= +25°C.)

SUPPLY CURRENT
vs. TEMPERATURE

4

VCC = 3.3V, VDD = 3.6V

3

2

SUPPLY CURRENT (µA)

1

0

-40 80

TEMPERATURE (°C)

MAXIMUM V

TOTAL

I

DD

I

CC

6040200-20

TRANSIENT DURATION

LTH/VHTH

1.10

MAX6846-49 toc01

1.05

1.00

0.95

NORMALIZED LBO TIMEOUT PERIOD

0.90

vs. THRESHOLD OVERDRIVE

120

110

100

90

TRANSIENT DURATION (µs)

HTH

/V

80

LTH

70

MAXIMUM V

60

LBO ASSERTS ABOVE THIS LINE

10 100 1000

THRESHOLD OVERDRIVE (mV)

NORMALIZED LBO TIMEOUT PERIOD

vs. TEMPERATURE

-40 80

TEMPERATURE (°C)

MAX6846-49 toc04

6040200-20

100

90

80

70

60

TRANSIENT DURATION (µs)

50

CC

40

30

MAXIMUM V

20

NORMALIZED RESET TIMEOUT PERIOD

vs. TEMPERATURE

1.100

MAX6846-49 toc02

1.050

1.000

0.950

NORMALIZED RESET TIMEOUT PERIOD

0.900

-40 80

TEMPERATURE (°C)

MAXIMUM VCC TRANSIENT DURATION

vs. THRESHOLD OVERDRIVE

RESET OCCURS ABOVE THIS LINE

10 100 1000

THRESHOLD OVERDRIVE (mV)

MAX6846-49 toc03

6040200-20

MAX6846-49 toc05