MAX8600AETD+T Maxim Integrated Products, MAX8600AETD+T Datasheet - Page 7

• Manufacturer Part Number: MAX8600AETD+T
• Description: IC BATTERY CHARGER SGL 14TDFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX8600AETD+T

• Function: Charge Management
• Battery Type: Lithium-Ion (Li-Ion)
• Voltage - Supply: 0 V ~ 14 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 14-WFDFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The MAX8600A is a single-cell Li+ battery charger.
Charging is optimized for Li+ cells using a control algo-
rithm that includes low-battery precharging, charging
with simultaneous voltage and current compliance, and
top-off charging. The battery is continuously monitored
for over/under temperature, and charging is suspended
if the temperature is out of range. Charging is also ter-
minated when the input source voltage is greater than
6.5V, or after excess charging time (fault). Charger
timeout protection is programmable. Charger status is
indicated by three-open drain outputs: POK, CHG, and
FLT. An input overvoltage protection circuit prevents
charging from improper input sources.
The MAX8600A reduces charging time by continuously
adjusting the charge rate to accommodate the thermal
characteristics of a given application. There is no need to
reduce the maximum charge current based on worst-case
supply voltage, temperature, and thermal resistance.
The MAX8600A is designed to charge a single-cell Li+
battery from a DC source voltage between 4.1V and
6.0V. The precharge current, charge current, and top-
off threshold are programmable with R
EN is a logic input (active low) that enables the charger.
Drive EN high to disable the charger-control circuitry.
Drive EN low or connect to GND for normal operation.
To prevent input transients, the rate of change of
charging current is limited. When the charger is turned
on or when the input source is changed, charge current
is ramped from 0 to the set current value in typically
1.2ms. This is done to ensure that the DC source is not
subjected to a severe load current step.
Charge-current ramp-up is also limited when transition-
ing from prequal to fast-charge. There is no dI/dt limit-
ing, however, if I
switch at R
The MAX8600A features a thermal limit that reduces the
charge current when the die temperature exceeds
+100°C. As the temperature increases above +100°C, the
IC lowers the fast-charge current compliance by 5%/°C.
CHG is an open-drain output that indicates charger sta-
tus. CHG goes low during charge cycles where V
greater than 2.5V and I
OVP Protection and Programmable Charge Timer
SETI
.
CHG Charge-Indicator Output
_______________________________________________________________________________________
SET
Detailed Description
is changed suddenly using a
EN Charger-Enable Input
BAT
Thermal-Limit Control
is greater than 6% of the
Single-Input 1-Cell Li+ Charger with
SETI
DC Charging
.
Soft-Start
BAT
is
maximum charge current set by R
MAX8600A is used in conjunction with a microproces-
sor (µP), connect a pullup resistor between CHG and
the logic I/O voltage to indicate charge status to the µP.
Alternatively, CHG can sink up to 20mA for an LED
charge indicator.
The MAX8600A contains an open-drain FLT output to
signal the user when a fault occurs. FLT goes low if the
charger is in prequal and the prequal timer expires, or
if the charger is in fast-charge and the fast-charge time
expires. FLT does not go low if the THM thermistor tem-
perature is out of range. Toggle EN or the input power
to reset the FLT indicator.
The MAX8600A contains an open-drain POK output
that goes low when a valid input source is detected at
DC. A valid input source is one whose voltage is
between 4.1V and 6.0V and exceeds the battery volt-
age by 350mV. After a valid input has been estab-
lished, charging is sustained with inputs as low as 3.5V
as long as the input voltage remains above the battery
voltage by at least 75mV (typ). Figure 2 shows POK
being used to drive an external p-channel MOSFET to
create a node called SAFE DC. SAFE DC is an overvolt-
age-protected version of DC.
Figure 2. Typical operating circuit. An R
mum charge current of 750mA.
4.1V TO 6.0V
DC INPUT
OFF
ON
0.068μF
1μF
C1
R
C
2kΩ
SETI
CT
DC
EN
CT
SETI
GND
Power-OK Indicator ( POK )
MAX8600A
Fault Indicator ( FLT )
470kΩ
CHG
THM
POK
D2
BAT
FLT
R1
SETI
of 2kΩ sets a maxi-
SETI
C2
2.2μF
Q1
T1
10kΩ AT
+25°C
R2
100kΩ
. When the
D1
LOGIC
SUPPLY
SAFE DC
+
Li+
R3
330Ω
LED
7