MAX1501ZETE Maxim Integrated Products, MAX1501ZETE Datasheet - Page 12

• Manufacturer Part Number: MAX1501ZETE
• Description: IC BATT CHRGR LI+ 1CELL 16-TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX1501ZETE

• Function: Charge Management
• Battery Type: Li-Ion, NiCd, NiMH
• Voltage - Supply: 4.5 V ~ 13 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-WQFN Exposed Pad
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Highly Integrated, Linear Battery Charger with
Thermal Regulation for Portable Applications
Table 3. RLED and GLED Behavior
The MAX1501 precharges the NiMH/NiCd battery with
10% of the user-programmed fast-charge current at the
start of a charge cycle. Precharge ends and fast
charge begins when the battery voltage exceeds 2.8V.
Set the fast-charge current with a resistor between SETI
and GND (see the Charge-Current Selection section).
The MAX1501 enters constant-voltage mode and
decreases the charge current when the battery voltage
reaches 4.5V.
The thermal-regulation loop limits the MAX1501 die
temperature to the value selected by the TEMP input by
reducing the charge current as necessary (see the
Thermal-Regulation Selection section). This feature pro-
tects the MAX1501 from overheating when supplying
high charge currents, or while operating from high input
voltages.
Set the top-off-current threshold with the three-state
FULLI input (see the Top-Off-Current Selection section).
RLED goes high impedance and GLED asserts low
when the top-off current threshold is reached. The
MAX1501 automatically initiates recharging when the
battery voltage drops below 4V. (The MAX1501Z does
not time out.)
Connect CHGEN and MODE to VL to place the MAX1501
in no-battery mode. An external load can be connected to
BATT in this mode. V
mode, regardless of the state of SELV.
The current-control loop, voltage-control loop, and
thermal-control loop all function in no-battery mode.
The loop gain of the voltage-control loop decreases to
ensure stability with no battery present. Connect a 10µF
ceramic capacitor to BATT for stability. RLED and
GLED are both high impedance in no-battery mode.
The ACOK output asserts low when V
≤ V
open-drain output requires an external 100kΩ pullup
12
Li+ Mode or
NiMH/NiCd Mode
Disable Mode
No Battery Mode
IN
______________________________________________________________________________________
MODE
≤ 6.25V, and V
• 10% current-limited precharge
• Current-limited charge
• Voltage-limited charge before top-off
• Temperature-limited charge before top-off
• Voltage-limited charge after top-off
• Safety timer expires (MAX1501 only)
BATT
IN
- V
regulates to 4V in no-battery
BATT
> 100mV. The ACOK
No-Battery Mode
IN
is present, 4.2V
STATE
—
—
ACOK
resistor to an external supply voltage. The external
supply voltage must be less than 5.5V.
RLED and GLED serve as visual indicators that power
is applied as well as the charge status of a battery.
RLED asserts low when a wall adapter is connected
and a battery is charging, regardless of cell chemistry.
GLED asserts low when power is applied and the bat-
tery is fully charged. Both outputs go high-impedance
in shutdown. Connect the anode of each LED to IN,
and the cathode to RLED or GLED. Table 3 summa-
rizes the behavior of RLED and GLED under normal
operating conditions. Connect pullup resistors to the µP
I/O supply when interfacing RLED and GLED with a
µP’s logic inputs.
A ten-step, soft-start algorithm activates when entering
fast-charge mode. The charging current ramps up in
10% increments, 20ms per step, to the full charging
current when V
Program the charging current using an external resistor
between SETI and GND. Set the charge-current resistor
with the following equation:
If V
battery charging. If V
control loop or the thermal-control loop operates.
Measure the charging current by monitoring V
using the following equation:
SETI
= 1.4V, the current-control loop controls the
BATT
Applications Information
R
V
SETI
SETI
High impedance
High impedance
High impedance
exceeds 2.8V.
Sinks 10mA
RLED and GLED Indicators
=
SETI
Charge-Current Selection
=
RLED
1000
I
1000
BATT
< 1.4V, either the voltage-
×
×
I
1 4
BATT
R
.
SETI
V
High impedance
High impedance
High impedance
Sinks 20mA
GLED
Soft-Start
SETI
and