Rainbow Electronics MAX1873 - Manual (Page 5)

MAX1873
Simple Current-Limited Switch-Mode
Li+ Charger Controller
_______________________________________________________________________________________ 5
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, V
DCIN
= V
CSSP
= V
CSSN
= 18V, V
ICHG/EN
= V
REF
, V
VADJ
= V
REF
/2. MAX1873R: V
BATT
= V
CSB
= 8.4V;
MAX1873S: V BATT = V CSB = 12.6V; MAX1873T: V BATT = V CSB = 16.8V; T A = -40°C to +85°C. Typical values are at T A = +25°C,
unless otherwise noted.)
PARAMETER CONDITIONS MIN MAX UNITS
MAX1873R 4.8 5.2
MAX1873S 7.2 7.8 BATT Undervoltage Threshold
For I CHG /20 trickle
charge
MAX1873T 9.6 10.4
V
CURRENT SENSE
V ICHG/EN = V REF 190 210 mV CSB to BATT Battery Current-Sense
Voltage
V
ICHG/EN
= V
REF
/4 40 60 mV
CSB to BATT Current-Sense Voltage
when V
BATT < 2.5V per Cell
5 15 mV
CSSP to CSSN Current-Sense Voltage 6V < V
CSSP
< 28V 90 110 mV
CONTROL INPUTS/OUTPUTS
ICHG/EN Input Threshold Includes 50mV of hysteresis 500 700 mV
ICHG/EN Input Voltage Range for
Charge Current Adjustment
700 V REF mV
VADJ Input Current V VADJ = V REF /2 -100 100 nA
ICHG/EN Input Current V ICHG/EN = V REF -100 100 nA
VADJ Input Voltage Range 0 V REF V
Full scale
V CSB - V BATT = 200mV,
0 < I OUT < 500µA
3.6 4.4
25% scale
V CSB - V BATT = 50mV,
0 < I OUT < 500µA
0.9 1.1
V
Trickle charge V CSB - V BATT = 10mV 75 325
IOUT Voltage
No charge
current V CSB - V BATT = 0,
I IOUT = sinking 20µA
40 90
mV
Note 1: While it may appear possible to set the Battery Regulation Voltage higher than the Battery Overvoltage Cutoff Threshold, this
cannot happen because both parameters are derived from the same reference and track each other.
Note 2: Specifications to -40°C are guaranteed by design, not production tested.