Low-Cost Multichemistry Battery Chargers
ELECTRICAL CHARACTERISTICS (continued)
(V
DCIN
= V
BST
= V
= 18V, V
= V
= V
= 12V, V
= 3V, V
= V
= 0.75 x V
, CELLS = FLOAT, CLS =
REFIN
CSSP
CSSN
BATT
CSIP
CSIN
REFIN
VCTL
ICTL
REF, V
- V = 4.5V, ACIN = GND = PGND = 0, C
= 1µF, LDO = DLOV, C
= 1µF; CCI, CCS, and CCV are compensated
LX
LDO
REF
per Figure 1a; T = -40°C to +85°C, unless otherwise noted.) (Note 2)
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
SUPPLY AND LDO REGULATOR
DCIN Input Voltage Range
DCIN Quiescent Current
V
8
28
6
V
DCIN
I
8V < V
< 28V
mA
DCIN
DCIN
V
V
= 19V, V
= 0
1
BATT
BATT
DCIN
BATT Input Current
I
µA
BATT
= 2V to 19V, V
= 19.3V
500
5.55
100
DCIN
LDO Output Voltage
LDO Load Regulation
REFERENCE
8V < V
< 28V, no load
5.25
V
DCIN
0 < I
< 10mA
mV
LDO
REF Output Voltage
TRIP POINTS
0 < I
< 500µA
4.065
4.120
V
REF
BATT Power-Fail Threshold
ACIN Threshold
V
V
falling, referred to V
rising
50
150
mV
V
DCIN
ACIN
CSIN
2.007
2.089
SWITCHING REGULATOR
V
V
= 16V, V
= 19V,
BATT
DCIN
DHI Off-Time
0.35
0.24
0.45
µs
µs
= V
CELLS
REFIN
V
V
= 16V, V
= 17V,
BATT
DCIN
DHI Minimum Off-Time
0.33
7.5
= V
CELLS
REFIN
DHI Maximum On-Time
2.5
99
ms
%
DHI Maximum Duty Cycle
Battery Undervoltage Charge
Current
V
= 3V per cell (RS2 = 15mΩ),
BATT
150
450
mA
MAX1908 only, V
rising
BATT
CELLS = GND, MAX1908 only, V
rising
rising
6.09
9.12
6.30
9.45
12.6
7
BATT
Battery Undervoltage Current
Threshold
CELLS = float, MAX1908 only, V
CELLS = V
V
BATT
, MAX1908 only, V
rising 12.18
BATT
REFIN
DHI On-Resistance High
DHI On-Resistance Low
DLO On-Resistance High
DLO On-Resistance Low
ERROR AMPLIFIERS
V
V
V
V
- V = 4.5V, I
= +100mA
= -100mA
Ω
Ω
Ω
Ω
BST
LX
DHI
DHI
- V = 4.5V, I
LX
3.5
7
BST
= 4.5V, I
= +100mA
= -100mA
DLOV
DLOV
DLO
DLO
= 4.5V, I
3.5
V
= V
, V = 16.8V,
VCTL
LDO BATT
GMV Amplifier Transconductance
GMV
0.0625
0.250
µA/mV
CELLS = V
REFIN
GMI Amplifier Transconductance
GMS Amplifier Transconductance
CCI, CCS, CCV Clamp Voltage
LOGIC LEVELS
GMI
V
V
= V
, V
- V = 75mV
CSIN
0.5
0.5
150
2.0
2.0
600
µA/mV
µA/mV
mV
ICTL
CLS
REFIN CSIP
GMS
= V
, V
- V
CSSN
= 75mV
REF CSSP
0.25V < V
< 2V
CCV,CCS,CCI
CELLS Input Low Voltage
0.4
V
_______________________________________________________________________________________
7
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
