MAX8900A MAXIM [Maxim Integrated Products], MAX8900A Datasheet - Page 27
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MAX8900A
Manufacturer Part Number
MAX8900A
Description
Manufacturer
MAXIM [Maxim Integrated Products]
Datasheet
1.MAX8900A.pdf
(35 pages)
PVL is a 5V linear regulator that the MAX8900_ uses to
power the gate drivers for its step-down charger. PVL
also charges the BST capacitor. The PVL linear regulator
is on when CEN is low, V
is above V
off. Bypass PVL with a 1FF ceramic capacitor to GND.
Powering external loads from PVL is not recommended.
As shown in Figure 3, AVL is a filtered output from the
PVL linear regulator that the MAX8900_ uses to power its
internal analog circuits. The filter consists of an internal
12.5I resistor and the AVL external bypass capacitor
(0.1FF). This filter creates a 127kHz lowpass filter that
cleans the 3.25MHz switching noise from the analog por-
tions of the MAX8900_. Connect a 0.1FF ceramic capaci-
tor from AVL to GND. Powering external loads with AVL
is not recommended.
STAT1, STAT2, and STAT3 are open-drain outputs that
indicate the status of the MAX8900B as shown in Table 3.
When the status outputs are used to communicate with a
FP, pull them up to the system logic voltage (V
create a signal that has a logic-high and logic-low state
that the FP can easily interpret (Figure 2). Since more
than one status signal may change when the MAX8900B
changes states, the FP must implement a deglitching
routine for the interpretation of the status signals.
When the status outputs are used to drive LED indicators,
a series resistor should limit the LED current to be less
Table 3. 3-Pin Status Output Truth Table
Note: STAT1, STAT2, and STAT3 are open-drain outputs. “0”
indicates that the output device is pulling low. “1” indicates
that the output is high impedance.
Rating and JEITA Battery Temperature Monitoring
STAT1
0
0
0
0
1
1
1
1
1.2A Switch-Mode Li+ Chargers with ±22V Input
STAT2
BAT
0
0
1
1
0
0
1
1
by the V
Charge Status Outputs (3 Pin)
STAT3
0
1
0
1
0
1
0
1
IN2BAT
IN
PVL and AVL Regulator
Charging (dead-battery state or
state or prequalification state or
dead battery + prequalification
is greater than ~2V, and V
V
V
IN
Battery cold (THM < T1)
IN
Battery hot (THM >T4)
threshold, otherwise it is
< V
< (V
fast-charge state)
thermal shutdown
INDICATION
V
UVLO
Done state
Undefined
Timer fault
IN
BAT
> V
+ V
or CEN = 1 or
OVLO
IN2BAT
LOGIC
) or
) to
IN
than 30mA (Figure 1). The STAT1 and STAT2 typical pull-
down resistance is 25I and the absolute maximum rating
is +30V. This +30V rating allows IN to be used to bias
STAT1 and STAT2. The STAT3 typical pulldown resis-
tance is 10I and the absolute maximum rating is +6V.
STAT1 and STAT2 are open-drain outputs that indicate
the status of the MAX8900A as shown in Table 4.
When the status outputs are used to communicate with a
FP, pull them up to the system logic voltage (V
create a signal that has a logic-high and logic-low state
that the FP can easily interpret (Figure 2). Since more
than one status signal may change when the MAX8900A
changes states, the FP must implement a deglitching
routine for the interpretation of the status signals.
When the status outputs are used to drive LED indica-
tors, a series resistor should limit the LED current to
be less than 30mA (Figure 1). Note that the STAT1 and
STAT2 typical pulldown resistance is 25I and the abso-
lute maximum rating is +30V. This +30V rating allows IN
to be used to bias STAT1 and STAT2.
STAT3 pulls low when the battery temperature moni-
tor detects that the battery temperature is greater than
the T4 threshold, otherwise, STAT3 is high impedance.
Some systems may want to reduce the battery loading
when STAT3 pulls low to prevent the battery from getting
excessively hot.
Table 4. 2-Pin Status Output Truth Table
Note: STAT1 and STAT2 are open-drain outputs. “0” indicates
that the output device is pulling low. “1” indicates that the out-
put is high impedance.
STAT1
0
0
1
1
Charge Status Outputs (2 Pin + > T4)
STAT2
0
1
0
1
dead battery + prequalification state
V
tery cold (THM < T1) or battery hot
Timer fault or V
UVLO
Charging (dead-battery state or
Done state or CEN = 1 or V
or prequalification state or fast-
or V
thermal shutdown
IN
charge state)
INDICATION
(THM > T4)
Undefined
< (V
IN
BAT
> V
OVLO
+ V
IN2BAT
LOGIC
or bat-
IN
<
) or
) to
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