M
Dual, High-Effic ienc y, S tep-Down
Converter with Bac kup Battery S witc hover
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
IN,
SHDNM
,
MDRV
, DBI, LBI, ACI,
CVH to GND .......................................................-0.3V to +30V
IN to CVH, PDRV ......................................................-0.3V to +6V
BIN to CS-.................................................................-0.3V to +6V
LXB to GND ................................................-0.3V to (V
BIN
+ 0.7V)
PDRV to GND..................................(V
CVH
- 0.3V) to (V
IN
+ 0.3V)
All Other Pins to GND...............................................-0.3V to +6V
ELECTRICAL CHARACTERISTICS
(Figure 1, V
IN
= V
INS
+12V, V
INC
= V
CS-
= V
CS+
= +3.3V, V
CORE
= +1.8V,
T
A
= 0°C to +85°C,
unless otherwise noted. Typical values are at
T
A
= +25°C.)
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.
PGND to GND .......................................................-0.3V to +0.3V
Continuous Power Dissipation
28-Pin QSOP (derate 10.8mW/°C above +70°C)........860mW
32-Pin QFN (derate 23.2mW/°C above +70°C) ........1860mW
Operating Temperature.......................................-40°C to +85°C
Storage Temperature.........................................-65°C to +150°C
Temperature (soldering, 10s) ..........................................+300°C
PARAMETER
SYMBOL
V
IN
CONDITIONS
MIN
2.7
TYP
MAX
28
UNITS
V
Input Voltage
Input Quiescent Supply Current
I
IN
V
FBM
= +1.5V, V
FBC
= +1.5V,
V
SHDNM
= V
SHDNC
= +3.3V
18
40
μA
CS- Quiescent Supply Current
I
CS-
V
FBM
= +1.5V, V
FBC
= +1.5V,
V
SHDNM
= V
SHDNC
= +3.3V
110
220
μA
Core Regulator Quiescent
Supply Current
I
INC
V
FBM
= +1.5V, V
FBC
= +1.5V,
V
SHDNM
= V
SHDNC
= +3.3V
60
105
μA
Backup Mode BIN Quiescent
Supply Current
I
BIN
V
BIN
= +3.3V, CS- open
V
FBM
= +1.5V, V
SHDNM
= +3.3V,
V
BKOFF
= +1.5V,
SHDNC
= GND
60
105
μA
IN Shutdown Supply Current
MAIN REGULATOR
SHDNM
=
SHDNC
= GND
8
40
μA
Main Output Voltage Adjust
Range
1.25
5.5
V
FBM Regulation Threshold
V
FBM
V
(CS+ - CS-)
= 0 to +60mV,
V
IN
= +3.5V to +28V
V
FBM
= +1.3V
V
CS+
- V
CS-
1.21
1.25
1.29
V
FBM Input Current
Current-Limit Threshold
I
FBM
-0.1
60
0.1
100
μA
mV
80
Minimum Current-Limit
Threshold
V
CS+
- V
CS-
5
15
25
mV
Valley Current Threshold
Zero Current Threshold
V
CS+
- V
CS-
V
CS+
- V
CS-
40
0
50
5
60
15
mV
mV
PDRV, NDRV Gate Drive
Resistance
V
CS-
= +3.3V, I
PDRV
, I
NDRV
= 50mA
2
5.5
CS- to CVL Switch Resistance
PDRV, NDRV Dead Time
I
CVL
= 50mA
4.5
50
9.5
ns