MAXIM MAX6427, MAX6438 User Manual

General Description

The MAX6427–MAX6438 are single/dual-level battery monitors with internal hysteresis. These devices are offered with single (MAX6427/MAX6428/MAX6429, MAX6433/ MAX6434/MAX6435) or dual (MAX6430/MAX6431/ MAX6432, MAX6436/MAX6437/MAX6438) low-battery output indicators, which can be used to indicate three battery conditions: battery is good (operate system in normal mode), battery is weak (operate system in low-power mode), or battery is empty (disable the system).

These devices are ideal for monitoring single lithium-ion (Li+) cells or multicell alkaline/NiCd/NiMH power supplies. When the power-supply voltage drops below the specified low threshold, the low-battery output asserts. When the voltage rises above the specified high threshold, the lowbattery output is deasserted following a 140ms minimum timeout period. The timeout period ensures that the supply voltages have stabilized before power-converter or microprocessor activity is enabled.

The MAX6427–MAX6438 family is available with several monitoring options. The MAX6427/MAX6428/MAX6429 offer factory-trimmed battery-monitor thresholds, with a single low-battery output. The MAX6430/MAX6431/MAX6432 also feature factory-trimmed thresholds, but have two lowbattery outputs.

The MAX6433–MAX6438 have user-adjustable threshold voltages permitting the user to select the hysteresis range, and consequently the sensitivity of the system to noise. A wide hysteresis range also prevents chattering that can result due to battery recovery after load removal. Single low-battery outputs are supplied by the MAX6433/ MAX6434/MAX6435 and dual low-battery outputs by the MAX6436/MAX6437/MAX6438.

The MAX6427–MAX6438 family is available with three output logic options for convenient interface with system power circuitry or microprocessors. The family is offered in small SOT23 and SOT143 packages and is fully specified over temperature.

________________________Applications

Battery-Powered Systems (Single-Cell Li+ or Two/Three-Cell NiMH, NiCd, Alkaline)

Cell Phones/Cordless Phones Pagers

Portable Medical Devices PDAs

Electronic Toys MP3 Players

Features

♦ Factory-Trimmed or User-Adjustable Threshold

Options

Factory-Trimmed Low Thresholds from 1.6V to

2.1V or 2.6V to 3.1V in 100mV Increments (MAX6427–MAX6432) Factory-Trimmed High Thresholds from 2.3V to

2.6V or 3.3V to 3.6V in 100mV Increments (MAX6427–MAX6432) User-Adjustable Low/High Thresholds with 615mV Internal Reference (MAX6433–MAX6438)

♦ Low Current (1µA, typ) ♦ Single or Dual Low-Battery Outputs ♦ Push-Pull LBO, Open-Drain LBO, and Open-Drain

LBO Options

♦ 140ms Minimum LBO Timeout Period ♦ Immune to Short Battery Voltage Transients ♦ Guaranteed Valid LBO Logic State to BATT = 1.0V ♦ -40°C to +85°C Operating Temperature Range ♦ Small 3, 4, 5 and 6-Pin SOT Packages ♦ No External Components Required

(MAX6427–MAX6432)

MAX6427–MAX6438

Low-Power, Single/Dual-Level Battery Monitors

with Hysteresis

________________________________________________________________ Maxim Integrated Products 1

19-2323; Rev 1; 9/03

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.

Ordering Information

Typical Operating Circuit appears at end of data sheet.

Ordering Information continued at end of data sheet.

Pin Configurations continued at end of data sheet.

†

The MAX6427–MAX6432 are available with factory-trimmed battery-monitor thresholds. Select the desired thresholds using Tables 1 or 2 and enter the corresponding letters in the part number by replacing “_ _”.

Note: There are 26 standard versions with a required order minimum of 2500 pieces. Sample stock is generally held on the standard versions only (see Standard Versions Table). Required order increment is 10,000 pieces for nonstandard versions. Contact factory for availability. All devices available in tape-and-reel only.

BATT

3 GND

( ) ARE FOR THE MAX6429.

MAX6427 MAX6428 MAX6429

SOT23-3

TOP VIEW

LBO

(LBO)

Pin Configurations

查询MAX6427供应商

PART TEMP RANGE PIN-PACKAGE

MAX6427_ _UR-T -40°C to +85°C 3 SOT23-3

MAX6427–MAX6438

Low-Power, Single/Dual-Level Battery Monitors with Hysteresis

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(BATT = 1.0V to 5.5V or VDD= 1.6V to 5.5V, TA= -40°C to +85°C, unless otherwise specified. Typical values are at TA= +25°C.) (Note 1)

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.

BATT, VDDto GND ................................................-0.3V to +6.0V

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

+ 0.3V)

Open-Drain LBO/LBO, LBOH/LBOH,

LBOL/LBOL to GND .........................................-0.3V to +6.0V

Push-Pull LBO/LBO, LBOH/LBOH,

LBOL/LBOL to GND ................-0.3V to (BATT or V

+ 0.3V)

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

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

Continuous Power Dissipation (T

= +70°C)

3-Pin SOT23-3 (derate 4.0mW/°C above +70°C) .......320mW

4-Pin SOT143-4 (derate 4.0mW/°C above +70°C) .....320mW

5-Pin SOT23-5 (derate 7.1mW/°C above +70°C) .......571mW

6-Pin SOT23-6 (derate 8.7mW/°C above +70°C) .......696mW

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

Operating Voltage Range V

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

BATT

TA = -40°C to +85°C

TA = 0°C to +70°C

TA = -40°C to +85°C 1.6 5.5 V

1.2 5.5

1.0 5.5

BATT Supply Current I

VDD Supply Current I

FACTORY-FIXED THRESHOLDS (MAX6427–MAX6432)

HTH Threshold (Note 2)

LTH Threshold (Note 2)

HTH- Threshold (Note 2)

HTH+ Threshold (Note 3)

LTH- Threshold (Note 2)

LTH+ Threshold (Note 3)

BATT

HTH-

HTH+

LTH+

HTH

LTH

LTH-

= 3.7V, no load (MAX6427–MAX6432) 1 1.5 µA

BATT

= 3.7V, no load

(MAX6433–MAX6438)

Factory-fixed options, BATT rising, LBO deasserted when BATT rises above V

(MAX6427/MAX6428/MAX6429)

HTH

Factory-fixed options, BATT falling, LBO asserted when BATT falls below V (MAX6427/MAX6428/MAX6429)

Factory-fixed options, BATT falling, LBOH asserted when BATT falls below V (MAX6430/MAX6431/MAX6432)

Factory-fixed options, BATT rising, LBOH deasserted when BATT rises above V

(MAX6430/MAX6431/MAX6432)

HTH+

Factory-fixed options, BATT falling, LBOL asserted when BATT falls below V (MAX6430/MAX6431/MAX6432)

Factory-fixed options, BATT rising, LBOL deasserted when BATT rises above V

(MAX6430/MAX6431/MAX6432)

LTH+

HTH-

LTH

LTH-

1 1.5 µA

-2.5 +2.5 %

MAX6427–MAX6438

Low-Power, Single/Dual-Level Battery Monitors

with Hysteresis

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(BATT = 1.0V to 5.5V or VDD= 1.6V to 5.5V, TA= -40°C to +85°C, unless otherwise specified. Typical values are at TA= +25°C.) (Note 1)

USER-ADJUSTABLE THRESHOLDS (MAX6433–MAX6438)

HTHIN Threshold (Note 4)

LTHIN Threshold (Note 4)

HTHIN+ Threshold (Note 4)

HTHIN- Threshold (Note 5)

LTHIN+ Threshold (Note 4)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

User-adjustable options, HTHIN rising,

HTHIN

LTHIN

HTHIN+

HTHIN-

LTHIN+

LBO is deasserted when HTHIN rises above V

, V

HTHIN-

(MAX6433/MAX6434/MAX6435)

User-adjustable options, LTHIN falling, LBOH is asserted when LTHIN falls below V

LTHIN-

(MAX6433/MAX6434/MAX6435)

User-adjustable options, HTHIN rising, LBOH is deasserted when HTHIN rises above V (MAX6436/MAX6437/MAX6438)

User-adjustable options, HTHIN falling, LBOH is asserted when HTHIN falls below V

HTHIN-

(MAX6436/MAX6437/MAX6438)

User-adjustable options, LTHIN rising, LBOL is deasserted when LTHIN rises above V (MAX6436/MAX6437/MAX6438)

REF

, V

REF

HTHIN+

, V

REF

LTHIN+

= 615mV

, V

REF

= 585mV

, V

= 615mV

REF

= 615mV

-2.5 +2.5 %

LTHIN- Threshold (Note 5)

HTHIN/LTHIN Leakage Current (Note 6)

LTHIN-

LKG

User-adjustable options, LTHIN falling, LBOL is asserted when LTHIN falls below

, V

or V

= 585mV

REF

> 400mV 20 nA

LTHIN

LTHIN-

(MAX6436/MAX6437/MAX6438)

HTHIN

-2.5 +2.5 %

MAX6427–MAX6438

Low-Power, Single/Dual-Level Battery Monitors with Hysteresis

4 _______________________________________________________________________________________

Note 1: Production testing done at TA= +25°C, limits over temperature guaranteed by design only. Note 2: Percentage of selected factory-fixed HTH- or LTH- threshold voltage. Note 3: Percentage of 1.05

(selected factory-fixed threshold voltage).

Note 4: Percentage of 615mV voltage reference. Note 5: Percentage of 585mV voltage reference. Note 6: Guaranteed by design. Note 7: V

SUPPLY

is BATT or VDD.

ELECTRICAL CHARACTERISTICS (continued)

(BATT = 1.0V to 5.5V or VDD= 1.6V to 5.5V, TA= -40°C to +85°C, unless otherwise specified. Typical values are at TA= +25°C.) (Note 1)

LOW-BATTERY OUTPUTS (LBO, LBO, LBOH, LBOH, LBOL, LBOL )

Timeout Period t

Delay t

LBO/LBOL/LBOH Output LOW (Push-Pull or Open-Drain)

LBO Output HIGH (Push-Pull Only) (Note 7)

LBO Output Leakage Current (Open-Drain Only)

LBO/LBOL/LBOH Output LOW (Open-Drain Only)

LBO Output Leakage Current (Open-Drain Only)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

LBOP

LBOD

LKG

BATT or VDD/HTHIN/LTHIN rising above threshold

BATT or VDD/HTHIN/LTHIN falling below threshold

BATT or V

≥ 1.6V, I

SINK

= 100µA,

asserted low

BATT or V

≥ 2.7V, I

SINK

= 1.2mA,

asserted low

BATT or V

≥ 4.5V, I

SINK

= 3.2mA,

asserted low

BATT or V

≥ 1.6V, I

SOURCE

= 200µA,

deasserted

BATT or V

≥ 2.7V, I

SOURCE

= 500µA,

deasserted

BATT or V

≥ 4.5V, I

SOURCE

= 800µA,

deasserted

LBO deasserted 500 nA

BATT or V

≥ 1.6V, I

SINK

= 100µA,

deasserted low

BATT or V

≥ 2.7V, I

SINK

= 1.2mA,

deasserted low

BATT or V

≥ 4.5V, I

SINK

= 3.2mA,

deasserted low

LBO asserted 500 nA

140 210 280 ms

100 µs

0.3

0.4

0.8 × V

SUPPLY

0.8 × V

SUPPLY

0.8 × V

SUPPLY

0.3

0.4

0.6

0.3

1.2

0.9

1.5

1.8

-40 20 40-20 0 60 80

SUPPLY CURRENT

vs. TEMPERATURE

MAX6427 toc01

TEMPERATURE (°C)

SUPPLY CURRENT (µA)

BATT

= 5V

BATT

= 3.3V

BATT

= 2V

LBO NOT ASSERTED

1.010

1.005

1.000

0.995

0.990

-40 20-20 0 40 60 80

NORMALIZED LBO TIMEOUT PERIOD

vs. TEMPERATURE

MAX6427 toc02

TEMPERATURE (°C)

NORMALIZED LBO TIMEOUT PERIOD

10 100 1000

MAXIMUM TRANSIENT DURATION

vs. LBO COMPARATOR OVERDRIVE

MAX6427 toc03

LBO COMPARATOR OVERDRIVE (mV)

MAXIMUM TRANSIENT DURATION (µs)

OUTPUT DOES NOT ASSERT

OUTPUT ASSERTS

0.950

0.975

1.025

1.000

1.050

-40 0-20 20 40 60 80

NORMALIZED UPPER AND LOWER

TRIP VOLTAGES vs. TEMPERATURE

MAX6427 toc04

TEMPERATURE (°C)

NORMALIZED TRIP VOLTAGES (V)

LOWER TRIP VOLTAGE

UPPER TRIP VOLTAGE

100

200

150

250

300

010

MAX6427 toc05

SINK

(mA)

4268

LBO OUTPUT vs. I

SINK

LBO OUTPUT (mV)

OPEN-DRAIN LBO ASSERTED

MAX6427–MAX6438

Low-Power, Single/Dual-Level Battery Monitors

with Hysteresis

_______________________________________________________________________________________ 5

Typical Operating Characteristics

(TA = +25°C, unless otherwise noted.)

MAX6427–MAX6438

Low-Power, Single/Dual-Level Battery Monitors with Hysteresis

6 _______________________________________________________________________________________

Pin Description

M AX6427/ M AX6428/ M AX6429

1 — 4 —

23——BATT

3 1 2 2 GND Ground

M AX6430/ M AX6431/ M AX6432

M AX6433/ M AX6434/ M AX6435

M AX6436/ M AX6437/ M AX6438

— 2 — 5

— 4 — 4

NAME FUNCTION

Low-Battery Output. LBO/LBO is asserted when BATT drops

(MAX6427/MAX6428/MAX6429) or when LTHIN

LTH

(MAX6430/MAX6431/MAX6432) or when

HTH-

(MAX6430/MAX6431/MAX6432) or when

LTH-

(MAX6430/MAX6431/MAX6432) or LTHIN rises

LTH+

(MAX6436/MAX6437/MAX6438).

LTHIN+

(MAX6436/MAX6437/ MAX6438). It

HTHIN-

(MAX6436/MAX6437/

LTHIN-

LBO/

LBO

LBOH/

LBOH

LBOL/

LBOL

below V (MAX6433/MAX6434/MAX6435) drops below V remains asserted for at least 140ms after BATT exceeds V (MAX6427/MAX6428/MAX6429) or V MAX6434/MAX6435).

Battery-Voltage Input. Input for battery-voltage threshold monitors and device power supply for factory-trimmed threshold versions.

Low-Battery Output High. LBOH/LBOH is asserted when BATT drops below V HTHIN drops below V remains asserted for at least 140ms after BATT exceeds V (MAX6430/MAX6431/MAX6432) or HTHIN rises above V (MAX6436/MAX6437/MAX6438).

Low-Battery Output Low. LBOL/LBOL is asserted when BATT drops below V LTHIN drops below V MAX6438). It remains asserted for at least 140ms after BATT exceeds V above V

HTHIN

LTHIN

(MAX6433/

, and

HTH

HTH+

HTHIN+

—— 1 1 HTHIN

—— 3 3 LTHIN

—— 56V

HTH Threshold Monitor Input. A resistor-divider network sets the high threshold associated with LBOH/LBOH.

LTH Threshold Monitor Input. A resistor-divider network sets the low threshold associated with LBOL/LBOL.

VDD Supply Voltage Input. Device power supply for adjustable

threshold versions.

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