MAX6429FJUR+T Maxim Integrated Products, MAX6429FJUR+T Datasheet - Page 7

• Manufacturer Part Number: MAX6429FJUR+T
• Description: IC MONITOR BAT LP SOT23-3
• Manufacturer: Maxim Integrated Products

Specifications of MAX6429FJUR+T

• Function: Battery Monitor
• Battery Type: Alkaline, Li-Ion, NiCd, NiMH
• Voltage - Supply: 1 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: TO-236-3, SC-59, SOT-23-3
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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 (see Figure 1). The
MAX6430/MAX6431/MAX6432 also feature factory-
trimmed thresholds, but have two low-battery outputs
(see Figure 2). The factory-trimmed thresholds of the
MAX6427–MAX6432 eliminate the requirement for
external components.
The user sets the threshold voltages for the
MAX6433–MAX6438, which permit the user to select
the hysteresis range, and consequently the sensitivity
of the system to noise. A wide hysteresis range pre-
vents chattering that can result during battery recovery
or load removal. The MAX6433/MAX6434/ MAX6435
have single low-battery outputs and the MAX6436/
MAX6437/MAX6438 have dual low-battery outputs (see
Figures 3 and 4).
The MAX6427–MAX6438 combine a 615mV 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 MAX6427–MAX6438
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-
Figure 1. MAX6427/MAX6428/MAX6429 Functional Diagram
Low-Power, Single/Dual-Level Battery Monitors
( ) ARE FOR THE MAX6429
_______________________________________________________________________________________
Detailed Description
V
BATT
615
mV
V
BATT
+
-
trimmed thresholds are ideal for monitoring single-cell
Li+ or multicell alkaline/NiCd/NiMH power supplies.
User-programmable versions are also available with
thresholds determined using an external resistor-
divider (see Resistor-Value Selection).The adjustable
versions can monitor down to 0.62V, making them suit-
able for monitoring single-cell alkaline, NiMH, and NiCd
applications (V
When the power-supply voltage drops below the speci-
fied low threshold, the low-battery output asserts (see
Low-Battery Output). When the voltage rises above the
specified high threshold following a 140ms (min) time-
out period, the low-battery output is deasserted (see
Threshold Monitoring). This ensures the supply voltage
has stabilized before power-converter or microproces-
sor activity is enabled.
The low-battery outputs are available in active-low
(LBO, LBOH, LBOL, push-pull and open-drain) and
active-high (LBO, LBOL, LBOH, open-drain) configura-
tions. Push-pull outputs are referenced to BATT (for
factory-trimmed versions) or V
old versions).
The open-drain devices can be pulled to a voltage inde-
pendent of V
LBO TIMEOUT
PERIOD
DD
DD
or BATT, up to 5.5V. This allows the
R
S
with Hysteresis
≥ 1.6V).
Q
Q
Low-Battery Output
DD
LBO
(LBO)
(for adjustable thresh-
7