AEEM View Datasheet(PDF) - Maxim Integrated

Part Name

Description

Manufacturer

AEEM

Low-Power, Single-/Dual-Level Battery Monitors with Hysteresis and Integrated µP Reset

Maxim Integrated 

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

with Hysteresis and Integrated µP Reset

Pin Description

PIN

MAX6439/ MAX6441/

MAX6440 MAX6442

1

1

2

3

3

—

4

5

5

2

6

8

—

6

—

7

—

4

NAME

FUNCTION

VBATT

MR

Battery Voltage Input. Input for battery voltage threshold monitors and device power supply

if VBATT is greater than VCC.

Manual Reset Input, Active-Low, Internal 1.5kΩ Pullup to VCC. Pull low to assert a one-shot

edge-triggered RESET output for the MR reset timeout period. Leave unconnected or

connect to VCC if unused. The MR input is debounced for MR rising edges to prevent false

reset events.

LBO

Low-Battery Output, Active Low, Open Drain. LBO is asserted when VBATT drops below the

LTH specification and remains asserted until VBATT rises above the HTH specification for at

least 150ms.

RESET

GND

VCC

LBOH

Reset Output, Active Low, Push-Pull or Open Drain. RESET changes from high to low when

the VCC input drops below the selected reset threshold and remains low for the VCC reset

timeout period after VCC exceeds the reset threshold. RESET is one-shot edge-trigger

pulsed low for the MR reset timeout period when the MR input is pulled low. RESET is an

open-drain output for the MAX6439/MAX6441, and a push-pull output for the

MAX6440/MAX6442. The push-pull outputs are referenced to VCC. RESET is guaranteed to

be in the correct logic state for VBATT or VCC > 1.0V.

Ground

VCC Voltage Input. Input for VCC reset threshold monitor and device power supply if VCC is

greater than VBATT.

Low-Battery Output High, Active Low, Open Drain. LBOH is asserted when VBATT drops

below the HTH- specification. LBOH is deasserted when VBATT rises above the HTH+

specification for at least 150ms.

LBOL

Low-Battery Output Low, Active Low, Open Drain. LBOL is asserted when VBATT drops

below the LTH- specification. LBOL is deasserted when VBATT rises above the LTH+

specification for at least 150ms.

LBOLH

Low-Battery Output Low/High, Active Low, Open Drain. LBOLH is asserted when VBATT

drops below the LTH- specification. LBOLH is deasserted when VBATT rises above the

HTH+ specification for at least 150ms.

Detailed Description

The MAX6439–MAX6442 family is available with several

monitoring options. The factory-trimmed thresholds

eliminate the requirement for external components. The

MAX6439/MAX6440 have single low-battery outputs

and the MAX6441/MAX6442 have dual low-battery out-

puts (see Figure 1a and Figure 1b).

The MAX6439–MAX6442 combine a 1.23V reference

with two comparators, logic, and timing circuitry to pro-

vide the user with information about the charge state of

the power-supply batteries. The MAX6441/MAX6442

monitor separate high-voltage and low-voltage thresh-

olds to determine battery status. The output(s) can be

used to signal when the battery is charged, when the

battery is low, and when the battery is empty. Factory-

trimmed thresholds are ideal for monitoring single-cell

Li+ or multicell alkaline/NiCd/NiMH power supplies.

When the power-supply voltage drops below the speci-

fied low threshold, the low-battery output asserts. When

the voltage rises above the specified high threshold fol-

lowing a 150ms (min) timeout period, the low-battery

output is deasserted. This ensures the supply voltage

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