M
Dual, High-Efficiency, Step-Down
Controller with Accurate Current Limit
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS (Note 1)
V+ to AGND..............................................................-0.3 to +30V
V
CC
to AGND............................................................-0.3V to +6V
V
DD
to PGND............................................................-0.3V to +6V
AGND to PGND.....................................................-0.3V to +0.3V
PGOOD, OUT_ to AGND..........................................-0.3V to +6V
OVP, UVP, ILIM_, FB_, REF,
SKIP
, TON, ON_ to AGND......................-0.3V to (V
CC
+ 0.3V)
DL_ to PGND..............................................-0.3V to (V
DD
+ 0.3V)
BST_ to AGND........................................................-0.3V to +36V
CS_ to AGND.............................................................-6V to +30V
DH1 to LX1 ..............................................-0.3V to (V
BST1
+ 0.3V)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
LX_ to BST_..............................................................-6V to +0.3V
DH2 to LX2 ..............................................-0.3V to (V
BST2
+ 0.3V)
REF Short Circuit to GND...........................................Continuous
Continuous Power Dissipation (T
A
= +70°C)
28-Pin QSOP (derate 10.8mW/°C above +70°C)........860mW
36-Pin 6mm
6mm Thin QFN
(derate 26.3mW/°C above +70°C).............................2105mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 1, V
DD
= V
CC
= 5V,
SKIP
= AGND, V+ = 15V,
T
A
= 0
°
C to +85
°
C
, typical values are at +25°C, unless otherwise
noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
PWM CONTROLLERS
V+
Battery voltage, V+
V
CC
, V
DD
2
28
5.5
1.818
1.515
1.01
1.827
1.523
1.015
Input Voltage Range
V
CC
/V
DD
4.5
1.782
1.485
0.99
1.773
1.477
0.985
V
FB1 to AGND
FB1 to V
CC
FB1 to OUT1
FB1 to AGND
FB1 to V
CC
FB1 to OUT1
1.8
1.5
1
1.8
1.5
1
V+ = 2V to 28V, I
LOAD
= 0 to 8A,
SKIP
= V
CC
,
+25
°
C to +85
°
C
DC Output Voltage OUT1
(Note 2)
V
OUT1
V+ = 2V to 28V, I
LOAD
= 0 to 8A,
SKIP
= V
CC
,
0
°
C to +85
°
C
V
FB2 to AGND
2.475
2.5
2.525
V+ = 4.5V to 28V,
I
LOAD
= 0 to 4A,
SKIP
= V
CC
,
+25
°
C to +85
°
C
FB2 to OUT2
0.99
1
1.01
FB2 to AGND
2.463
2.5
2.537
DC Output Voltage OUT2
(Note 2)
V
OUT2
V+ = 4.5V to 28V,
I
LOAD
= 0 to 4A,
SKIP
= V
CC
,
0
°
C to +85
°
C
FB2 to OUT2
0.985
1
1.015
V
Output Voltage Adjust Range
Dual-Mode Threshold, Low
OUT1, OUT2
OVP, FB_
1
5.5
0.15
V
V
0.05
0.1
OVP, ILIM_
V
CC
-
1.5
V
CC
-
0.4
Dual-Mode Threshold, High
FB1
V
OUT1
= 1.5V
V
OUT2
= 2.5V
1.9
75
100
-0.1
2.0
2.1
V
R
OUT1
R
OUT2
I
FB
OUT_ Input Resistance
k
FB_ Input Bias Current
Soft-Start Ramp Time
0.1
μA
μs
Zero to full ILIM
1700
Note 1:
For the MAX1845EEI, AGND and PGND refer to a single pin designated GND.