MAX8903A View Datasheet(PDF) - Maxim Integrated
Part Name
Description
Manufacturer
MAX8903A Datasheet PDF : 20 Pages
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2A 1-Cell Li+ DC-DC Charger for USB*
and Adapter Power
VBATT < 2.8V
RESET TIMER
ANY CHARGING
STATE
THM OK
TIMER RESUME
THM NOT OK
TIMER SUSPEND
TEMPERATURE SUSPEND
ICHG = 0mA
UOK OR DOK PREVIOUS STATE
CHG = HIGH IMPEDANCE
FLT = HIGH IMPEDANCE
NOT READY
UOK AND DOK = HIGH IMPEDANCE
CHG = HIGH IMPEDANCE
FLT = HIGH IMPEDANCE
ICHG = 0mA
CEN = HI OR
REMOVE AND RECONNECT
THE INPUT SOURCE(S)
ANY STATE
UOK AND/OR DOK = LOW
CEN = 0
RESET TIMER
PREQUALIFICATION
UOK AND/OR DOK = LOW
CHG = LOW
FLT = HIGH IMPEDANCE
0 < VBAT < 3V
ICHG ≤ ICHGMAX/10
TIMER > tPREQUAL
VBATT < 2.82V
RESET TIMER = 0
VBATT > 3.0V
RESET TIMER
TOGGLE CEN OR
REMOVE AND RECONNECT
THE INPUT SOURCE(S)
FAULT
UOK AND/OR DOK = LOW
CHG = HIGH IMPEDANCE
FLT = LOW
ICHG = 0mA
FAST-CHARGE
UOK AND/OR DOK = LOW
CHG = LOW
FLT = HIGH IMPEDANCE
3V < VBAT < 4.2V
ICHG ≤ ICHGMAX
ICHG < ITERM
ICHG > ITERM
RESET TIMER
AND VBAT = 4.2V
AND THERMAL
OR INPUT LIMIT
NOT EXCEEDED;
TOP-OFF
RESET TIMER
UOK AND/OR DOK = LOW
CHG = HIGH IMPEDANCE
FLT = HIGH IMPEDANCE
VBAT = 4.2V
ICHG = ITERM
VBAT < 4.1V
RESET TIMER
TIMER > tFSTCHG
(TIMER SLOWED BY 2x IF
ICHG < ICHGMAX/2, AND
PAUSED IF ICHG < ICHGMAX/5 WHILE VBAT < 4.2V)
TIMER > 15s
DONE
UOK AND/OR DOK = 0
CHG = HIGH IMPEDANCE
FLT = HIGH IMPEDANCE
4.1V < VBAT < 4.2V
ICHG = 0mA
Figure 6. MAX8903A Charger State Flow Chart
charging resumes and the charge timer continues from
where it left off. Connecting THM to GND disables the
thermistor monitoring function. Table 4 lists the fault
temperature of different thermistors.
Since the thermistor monitoring circuit employs an
external bias resistor from THM to VL (RTB, Figure 7),
the thermistor is not limited only to 10kΩ (at +25°C).
Any resistance thermistor can be used as long as the
value is equivalent to the thermistor’s +25°C resistance.
For example, with a 10kΩ at +25°C thermistor, use
10kΩ at RTB, and with a 100kΩ at +25°C thermistor,
use 100kΩ .
For a typical 10kΩ (at +25°C) thermistor and a 10kΩ
RTB resistor, the charger enters a temperature suspend
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