User Manual
MAX1908/MAX8724
Low-Cost Multichemistry Battery Chargers
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(V
DCIN
= V
CSSP
= V
CSSN
= 18V, V
BATT
= V
CSIP
= V
CSIN
= 12V, V
REFIN
= 3V, V
VCTL
= V
ICTL
= 0.75 x V
REFIN
, CELLS = float, CLS =
REF, V
BST
- V
LX
= 4.5V, ACIN = GND = PGND = 0, C
LDO
= 1µF, LDO = DLOV, C
REF
= 1µF; CCI, CCS, and CCV are compensated
per Figure 1a; T
A
= 0°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V
DCIN
= 5V, V
REFIN
= 3V -1 +1
REFIN Input Bias Current
V
REFIN
= 5V -1 +1
µA
ICHG Transconductance
G
ICHG
V
CSIP
- V
CSIN
= 45mV 2.7 3 3.3
µA/mV
V
CSIP
- V
CSIN
= 75mV -6 +6
V
CSIP
- V
CSIN
= 45mV -5 +5 ICHG Accuracy
V
CSIP
- V
CSIN
= 5mV -40
+40
%
ICHG Output Current V
CSIP
- V
CSIN
= 150mV, V
ICHG
= 0
350
µA
ICHG Output Voltage V
CSIP
- V
CSIN
= 150mV, ICHG
= float 3.5 V
INPUT CURRENT REGULATION
CSSP-to-CSSN Full-Scale
Current-Sense Voltage
72 75 78 mV
V
CLS
= V
REF
-4 +4
Input Current-Limit Accuracy
V
CLS
= V
REF
/ 2
-7.5
+7.5
%
CSSP, CSSN Input Voltage
Range
8 28 V
V
DCIN
= 0 0.1 1
CSSP, CSSN Input Current
V
CSSP
= V
CSSN
= V
DCIN
> 8V
350
600
µA
CLS Input Range 1.6
REF
V
CLS Input Bias Current V
CLS
= 2V -1 +1 µA
IINP Transconductance G
IINP
V
CSSP
- V
CSSN
= 75mV 2.7 3 3.3
µA/mV
V
CSSP
- V
CSSN
= 75mV -5 +5
IINP Accuracy
V
CSSP
- V
CSSN
= 37.5mV
-7.5
+7.5
%
IINP Output Current V
CSSP
- V
CSSN
= 150mV, V
IINP
= 0
350
µA
IINP Output Voltage V
CSSP
- V
CSSN
= 150mV,V
IINP
= float 3.5 V
SUPPLY AND LDO REGULATOR
DCIN Input Voltage Range V
DCIN
8 28 V
V
DCIN
falling 7 7.4
DCIN Undervoltage-Lockout Trip
Point
V
DCIN
rising 7.5
7.85
V
DCIN Quiescent Current I
DCIN
8.0V < V
DCIN
< 28V 3.2 6 mA
V
BATT
= 19V, V
DCIN
= 0 1
BATT Input Current I
BATT
V
BATT
= 2V to 19V, V
DCIN
= 19.3V
200
500
µA
LDO Output Voltage 8V < V
DCIN
< 28V, no load
5.25
5.4
5.55
V
LDO Load Regulation 0 < I
LDO
< 10mA 34 100 mV
LDO Undervoltage-Lockout Trip
Point
V
DCIN
= 8V
3.20
4
5.15
V
REFERENCE
REF Output Voltage 0 < I
REF
< 500µA
4.072 4.096 4.120
V