MAX6439 Maxim, MAX6439 Datasheet - Page 7

• Manufacturer Part Number: MAX6439
• Description: Low-Power / Single-/Dual-Level Battery Monitors with Hysteresis and Integrated P Reset
• Manufacturer: Maxim

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
Low-Power, Single-/Dual-Level Battery Monitors
MAX6439/
MAX6440
—
—
—
1
2
3
4
5
6
PIN
MAX6441/
MAX6442
—
with Hysteresis and Integrated µP Reset
1
3
5
2
8
6
7
4
_______________________________________________________________________________________
Detailed Description
LBOLH
RESET
NAME
V
LBOH
LBOL
GND
LBO
V
BATT
MR
CC
Battery Voltage Input. Input for battery voltage threshold monitors and device power supply
if V
Manual Reset Input, Active-Low, Internal 1.5kΩ Pullup to V
edge-triggered RESET output for the MR reset timeout period. Leave unconnected or
connect to V
reset events.
Low-Battery Output, Active Low, Open Drain. LBO is asserted when V
LTH specification and remains asserted until V
least 150ms.
Reset Output, Active Low, Push-Pull or Open Drain. RESET changes from high to low when
the V
timeout period after V
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 V
be in the correct logic state for V
Ground
V
greater than V
Low-Battery Output High, Active Low, Open Drain. LBOH is asserted when V
below the HTH- specification. LBOH is deasserted when V
specification for at least 150ms.
Low-Battery Output Low, Active Low, Open Drain. LBOL is asserted when V
below the LTH- specification. LBOL is deasserted when V
specification for at least 150ms.
Low-Battery Output Low/High, Active Low, Open Drain. LBOLH is asserted when V
drops below the LTH- specification. LBOLH is deasserted when V
HTH+ specification for at least 150ms.
CC
BATT
Voltage Input. Input for V
CC
is greater than V
input drops below the selected reset threshold and remains low for the V
CC
BATT
if unused. The MR input is debounced for MR rising edges to prevent false
.
CC
CC
exceeds the reset threshold. RESET is one-shot edge-trigger
.
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
CC
BATT
reset threshold monitor and device power supply if V
or V
FUNCTION
CC
> 1.0V.
BATT
rises above the HTH specification for at
BATT
CC
BATT
. Pull low to assert a one-shot
CC
rises above the LTH+
rises above the HTH+
Pin Description
. RESET is guaranteed to
BATT
BATT
rises above the
drops below the
BATT
BATT
CC
drops
drops
BATT
reset
CC
is
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