Max8922l, Power-ok indicator ( pok ), Is greater than v – Rainbow Electronics MAX8922L User Manual
Page 8: And lower than v, And v, Pok is high impedance
MAX8922L
Power-OK Indicator (
POK)
The MAX8922L contains an open-drain POK output that
goes low when V
IN
is greater than V
UVLO
and lower than
V
OVP
and V
IN
exceeds the battery voltage by 250mV.
Once charging has started, charging is sustained with
inputs as low as 3.5V, as long as the input voltage
remains above the battery voltage by at least 100mV.
POK status should be maintained even though the
charger is disabled by EN/SET. When V
IN
> V
OVP
, POK
is high impedance.
30V Li+ Linear Battery Charger
with GSM Test Mode in 3mm x 2mm TDFN
8
_______________________________________________________________________________________
V
BAT
< 2.5V
V
BAT
< 2.2V
V
BAT
> 2.5V
I
CHG
< I
TOP-OFF
STANDBY MODE
CHARGER = OFF
POK = LOW
CHG = HIGH IMPEDANCE
SHUTDOWN
CHARGER = OFF
POK = HIGH IMPEDANCE
CHG = HIGH IMPEDANCE
PREQUALIFICATION
PRECHARGE CURRENT
POK = LOW
CHG = LOW
FAST CHARGE
(PULSE PROGRAMMABLE)
100% CHARGER CURRENT
POK = LOW
CHG = LOW
FULL BATTERY
V
BAT
= 4.2V
POK = LOW
CHG = HIGH IMPEDANCE
ASYNCHRONOUS
FROM ANYWHERE
EN/SET = LOW
FULL BATTERY CONTINUES
TO REGULATE V
BAT
TO 4.2V
CHARGER LOOP DEFAULT IS OFF;
IF EN/SET = LOW UPON POK.
CHARGER LOOP
ACTIVATES AFTER 4ms
POR DEBOUNCE
PULSE 3
MODE DOES NOT HAVE
PRECHARGE STATE
V
UVLO
< V
IN
< V
OVP
AND
V
IN
> V
BAT
+ 250mV
V
IN
< V
UVLO
OR V
IN
> V
OVP
OR V
BAT
+ 100mV > V
IN
POK = (V
OVP
> V
IN
> V
UVLO
)
AND (V
IN
- V
BAT
) > 250mV
I
CHG
> I
TOP-OFF
+ HYSTERESIS
V
IN
< V
UVLO
OR V
IN
> V
OVP
OR V
BAT
+ 100mV > V
IN
ASYNCHRONOUS
FROM ANYWHERE
t
EN/SET
= HIGH > 4ms
Figure 2. Charger State Diagram