MAX1501EVKIT Maxim Integrated, MAX1501EVKIT Datasheet - Page 4

• Manufacturer Part Number: MAX1501EVKIT
• Description: Battery Management Evaluation Kit for the MAX1501
• Manufacturer: Maxim Integrated
• Series: MAX1501r

Specifications of MAX1501EVKIT

• Battery Type: Li-Ion, Li-Pol, NiCD, NiMH
• Operating Supply Voltage: 0 V to 13 V
• Charge Safety Timers: Yes
• Operating Supply Current: 5 mA
• Product Type: Charge Management
• Temperature Monitoring: Yes
• Uvlo Start Threshold: 4 V
• Uvlo Stop Threshold: 4.25 V

JU1), the green LED turns on and the red LED turns off,
signaling that charging is complete. While the charger
is in top-off, it continues to charge until the timer
expires. Once the timer has expired, the charger auto-
matically reinitiates fast charging if the cell voltage
drops below 95% of target voltage. If, at any point while
charging the battery, the die temperature approaches
the user-selected temperature setting (TEMP pin, JU3),
the MAX1501 reduces the charging current so that the
die temperature does not exceed the temperature reg-
ulation set point.
In NiMH/NiCd charge mode, the MAX1501 charges 3-
cell NiMH/NiCd batteries using voltage, current, and
thermal-control loops. When a 3-cell NiMH/NiCd battery
pack with a voltage below 2.8V is inserted, the
MAX1501 charger enters the prequalification stage
where it precharges the battery pack with 10% of the
user-programmed fast-charge current. Once the cell
has passed 2.8V, the charger enters the fast-charge
stage where it increases the charging current by 10%
steps every 20ms until the charger reaches 100% fast-
charge current programmed by resistor R1. During
precharge and fast charge, the red LED is on and the
green LED is off. As the battery voltage approaches the
4.5V user-selected regulation voltage (SELV pin, JU6),
the charging current is reduced. If the charging current
drops below the top-off current setting (FULLI pin, JU2)
or if the charge timer expires (TMAX pin, JU1), the
green LED turns on and the red LED turns off, signaling
that charging is complete. While the charger is in top-
off, it continues to charge until the timer expires. Once
the timer has expired, the charger automatically reiniti-
ates fast charging if the cell voltage drops below 4V. If,
at any point while charging the battery, the die temper-
ature approaches the user-selected temperature set-
ting (TEMP pin, JU3), the MAX1501 reduces the charg-
ing current so that the die temperature does not
exceed the temperature regulation set point. When the
voltage regulation setting of 4.95V is used, a micro-
processor must be used to terminate the charging
sequence using -∆V or -∆T/∆t methods. Use an input of
5.5V when the regulation voltage is set to 4.95V.
Without microprocessor controls, the 4.95V regulation
voltage should not be used.
Disable mode disables the charger and terminates the
charging cycle. However, the VL node is still valid at
3V. The red and green LEDs are off in this mode.
MAX1501 Evaluation Kit
4
_______________________________________________________________________________________
NiMH/NiCd Charge Mode
Disable Mode
In no-battery mode, an external load can be connected
across the BATT+ and BATT- pads. In this mode, the
charger regulates the output to 4.0V, regardless of the
state of jumper JU6 (SELV), and can supply the maximum
load current set by resistor R1. The red and green LEDs
are off.
The red D1 and green D2 LEDs are visual indicators
that power is connected to the EV kit and the status of a
connected battery. Table 5 describes the state of the
LEDs during normal operation. LED brightness can be
reconfigured by cutting open the PC board shorts
across the R3 and R4 PC board pads and installing
desired resistors.
The ACOK output indicates when a supply is present at
VIN and the voltage is in the safe range for charging
batteries. ACOK asserts low when VIN is in the safe
range of 4.5V and 6.5V and (VIN-BATT+) ≥ 100mV.
ACOK asserts high when VIN is out of this range. The
ACOK pin is an open-drain output, and resistor R2 is
used to pull the output up to the external voltage con-
nected at the VLOGIC pad.
Table 5. LED States
Li+ mode
or
NiMH/NiCd
mode
Disable
mode
No-battery
mode
CHARGE
MODE
GREEN
LED
OFF
OFF
OFF
ON
RED
LED
OFF
OFF
OFF
ON
• Prequalification
• Fast charge
• Top-off charge
• Timeout
• Charger is off
• V
BATT+
No-Battery Mode
CONDITIONS
= 4.0V
ACOK Output
LEDs