Typical operating characteristics (continued), Pin description – Rainbow Electronics MAX8922L User Manual
Page 5
100
200
300
400
500
600
0
CHARGE CURRENT (mA)
MAX8922 toc10
CHARGE CURRENT vs.
AMBIENT TEMPERATURE
60
35
10
-15
-40
85
AMBIENT TEMPERATURE (°C)
400mA PRESET
V
IN
= 5V
V
BATT
= 4V
CHARGE CURRENT vs.
AMBIENT TEMPERATURE (1A CHARGE)
MAX8922 toc11
AMBIENT TEMPERATURE (°C)
CHARGE CURRENT (mA)
60
35
10
-15
100
200
300
400
500
600
700
800
900
1000
0
-40
85
R
SETI
= 1.5k
I
V
IN
= 5V
V
BATT
= 4V
BAT REGULATION VOLTAGE ACCURACY
vs. AMBIENT TEMPERATURE
MAX8922 toc09
AMBIENT TEMPERATURE (°C)
V
BAT
REGULATION ACCURACY (%)
60
35
10
-15
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1.0
-1.0
-40
85
V
IN
= 5V
NO BATTERY
MAX8922L
30V Li+ Linear Battery Charger
with GSM Test Mode in 3mm x 2mm TDFN
_______________________________________________________________________________________
5
Typical Operating Characteristics (continued)
(V
IN
= 5V, V
EN/SET
= 0V. V
BAT
= 4V, MAX8922L Evaluation Kit. T
A
= +25°C, unless otherwise noted.)
Pin Description
PIN
NAME
FUNCTION
1
IN
DC Input Supply. Connect IN to V
IN
> 4V and (V
IN
- V
BAT
) ≥ 250mV up to a 7V charging source.
Bypass IN to GND with a 1µF or larger ceramic capacitor.
2
SETI
Charge-Current Program and Fast-Charge Current Monitor. Output current from SETI is 1000µA per
ampere of battery-charging current. Set the charging current by connecting a resistor (R
SETI
in Figure
1) from SETI to GND. I
FAST-CHARGE
= 1500V/R
SETI
. Connect to GND if pulse 1 mode (external SETI)
is not used.
3
GND
Ground
4
LDO
4.94V Regulated LDO Output with Input Overvoltage Protection. Bypass LDO to GND with a 1µF or
larger ceramic capacitor. LDO can be used to supply low-voltage-rated USB systems.
5
MIN
Top-Off Current Threshold Programmable Input. I
MIN
= 150V/R
MIN.
Connect to GND if pulse 1 mode
(external SETI) is not used.
6
EN/SET
Active-Low Enable Input. EN/SET is used for programming fast-charge current and GSM test mode. For
detailed descriptions, see the Charger-Enable and Program Input (EN/SET) section.
7
TEST
Factory Test Input. Connect to GND.
8
CHG
Charging-Status Output. CHG is internally pulled low when the charger is in prequalification or fast-
charge mode. CHG is high impedance when the charger is in top-off or disabled.
9
POK
Input Power-OK Monitor. POK is an open-drain output that is internally pulled low when V
IN
is greater
than V
UVLO
and lower than V
OVP
and V
IN
> V
BAT
+ 250mV. POK is high impedance when V
IN
is less
than V
UVLO
or greater than V
OVP
or V
IN
< V
BAT
+ 100mV.
10
BAT
Battery Connection. The IC delivers charging current and monitors battery voltage using BAT. Bypass
BAT to GND with a 2.2µF or larger ceramic capacitor. BAT is high impedance when the IC is disabled.
—
EP
Exposed Pad. Connect to the GND plane for increased thermal dissipation.