Datasheet

MAX1925/MAX1926
Switch-Mode 1-Cell Li+ Chargers
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(V
PGND
= V
GND
= 0, V
INP
= V
IN
= V
CHG
= 5V, V
BATT
= V
CS
= V
EN
= 4V, THRM = 10kΩ to GND, C
CT
= 100nF, T
A
= 0°C to +85°C,
unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Restart Threshold Charging restarts when BATT falls to this point 3.92 4.00 4.08 V
BATT Voltage Fault Threshold
If BATT exceeds this threshold, EXT is high
(external MOSFET is off) and CHG blinks
4.275 4.350 4.425 V
CURRENT LOOP
V
CS
- V
BATT
, average value 132 142 152
CS - BATT Sense Threshold
Rise/fall hysteresis 30
mV
Prequal1 Charge Current V
BATT
< 2V 3 4 6 mA
Average value, 2V < V
BATT
< 3V (charge current is C/10) 14
Prequal2 CS - BATT Sense
Threshold
Rise/fall hysteresis, 2V < V
BATT
< 3V 12
mV
Current Threshold for
Full-Battery Indication
I
LOAD
falling, as percentage of fast charge current 6 12 20 %
DRIVER FUNCTIONS
EXT Sink/Source Current 1 A
EXT On-Resistance EXT high or low 5 12 Ω
Nominal Switching Frequency V
BATT
= 3.6V, L =10µH 235 kHz
TIMER FUNCTIONS
Full-Time Timeout - t
FULL
C
CT
= 100nF 3.02 hours
Prequal1 Timeout C
CT
= 100nF
t
FULL/1088
(10s)
s
Prequal2 Timeout C
CT
= 100nF
t
FULL/17
(10.67 min)
min
Timer Accuracy C
CT
= 100nF for 3 hours -15 +15 %
CHG Output Low Current V
CHG
= 1V 7 10 14 mA
CHG Output High Leakage
Current
V
CHG
= 12V 1 µA
CHG Blink Rate - Fault Fault state (50% duty cycle), C
CT
= 100nF 0.5 Hz
ACON High Leakage V
ACON
= 12V 0.01 1.00 µA
ACON Sink Current V
ACON
= 0.4V 2 mA
THERMISTOR MONITOR (Note 2)
THRM Sense Current for Hot
Qualification
344.1 352.9 361.7 µA
THRM Sense Current for Cold
Qualification
47.58 48.80 50.02 µA
THRM Sense-Voltage Trip Point (Note 3) 1.386 1.400 1.414 V