Electrical characteristics (continued) – Rainbow Electronics MAX8724 User Manual
Page 7
MAX1908/MAX8724
Low-Cost Multichemistry Battery Chargers
_______________________________________________________________________________________
7
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
= -40°C to +85°C, unless otherwise noted.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
SUPPLY AND LDO REGULATOR
DCIN Input Voltage Range
V
DCIN
8
28
V
DCIN Quiescent Current
I
DCIN
8V < V
DCIN
< 28V
6
mA
V
BATT
= 19V, V
DCIN
= 0
1
BATT Input Current
I
BATT
V
BATT
= 2V to 19V, V
DCIN
= 19.3V
500
µA
LDO Output Voltage
8V < V
DCIN
< 28V, no load
5.25
5.55
V
LDO Load Regulation
0 < I
LDO
< 10mA
100
mV
REFERENCE
REF Output Voltage
0 < I
REF
< 500µA
4.065
4.120
V
TRIP POINTS
BATT Power-Fail Threshold
V
DCIN
falling, referred to V
CSIN
50
150
mV
ACIN Threshold
V
ACIN
rising
2.007
2.089
V
SWITCHING REGULATOR
DHI Off-Time
V
BATT
= 16V, V
DCIN
= 19V,
V
CELLS
= V
REFIN
0.35
0.45
µs
DHI Minimum Off-Time
V
BATT
= 16V, V
DCIN
= 17V,
V
CELLS
= V
REFIN
0.24
0.33
µs
DHI Maximum On-Time
2.5
7.5
ms
DHI Maximum Duty Cycle
99
%
Battery Undervoltage Charge
Current
V
BATT
= 3V per cell (RS2 = 15m
Ω
),
MAX1908 only, V
BATT
rising
150
450
mA
CELLS = GND, MAX1908 only, V
BATT
rising
6.09
6.30
CELLS = float, MAX1908 only, V
BATT
rising
9.12
9.45
Battery Undervoltage Current
Threshold
CELLS = V
REFIN
, MAX1908 only, V
BATT
rising
12.18
12.6
V
DHI On-Resistance High
V
BST
- V
LX
= 4.5V, I
DHI
= +100mA
7
Ω
DHI On-Resistance Low
V
BST
- V
LX
= 4.5V, I
DHI
= -100mA
3.5
Ω
DLO On-Resistance High
V
DLOV
= 4.5V, I
DLO
= +100mA
7
Ω
DLO On-Resistance Low
V
DLOV
= 4.5V, I
DLO
= -100mA
3.5
Ω
ERROR AMPLIFIERS
GMV Amplifier Transconductance
GMV
V
V C T L
= V
LD O
, V
BAT T
= 16.8V ,
C E LLS = V
RE F IN
0.0625
0.250
µA/mV
GMI Amplifier Transconductance
GMI
V
ICTL
= V
RE F IN
, V
CSIP
- V
CSIN
= 75mV
0.5
2.0
µA/mV
GMS Amplifier Transconductance
GMS
V
CLS
= V
REF
, V
CSSP
- V
CSSN
= 75mV
0.5
2.0
µA/mV
CCI, CCS, CCV Clamp Voltage
0.25V < V
CCV,CCS,CCI
< 2V
150
600
mV
LOGIC LEVELS
CELLS Input Low Voltage
0.4
V