Rainbow Electronics MAX1774 User Manual
Page 2
MAX1774
Dual, High-Efficiency, Step-Down
Converter with Backup Battery Switchover
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
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.
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
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
CONDITIONS
MIN
TYP
MAX
UNITS
Input Voltage
V
IN
2.7
28
V
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
SHDNM = SHDNC = GND
8
40
µA
MAIN REGULATOR
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
1.21
1.25
1.29
V
FBM Input Current
I
FBM
V
FBM
= +1.3V
-0.1
0.1
µA
Current-Limit Threshold
V
CS+
- V
CS-
60
80
100
mV
Minimum Current-Limit
Threshold
V
CS+
- V
CS-
5
15
25
mV
Valley Current Threshold
V
CS+
- V
CS-
40
50
60
mV
Zero Current Threshold
V
CS+
- V
CS-
0
5
15
mV
PDRV, NDRV Gate Drive
Resistance
V
CS-
= +3.3V, I
PDRV
, I
NDRV
= 50mA
2
5.5
Ω
CS- to CVL Switch Resistance
I
CVL
= 50mA
4.5
9.5
Ω
PDRV, NDRV Dead Time
50
ns