Rainbow Electronics MAX1797 User Manual
Page 2
MAX1795/MAX1796/MAX1797
Low Supply Current, Step-Up DC-DC Converters
with True-Shutdown
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
BATT
= +2V, OUT = FB (V
OUT
= +3.3V), SHDN = LBI = GND, 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.
OUT, LX, SHDN, LBI, LBO, BATT to GND................-0.3V to +6V
FB .............................................................-0.3V to (V
OUT
+ 0.3V)
I
LX
, I
OUT
..............................................................................±1.5A
Output Short-Circuit Duration ...................................................5s
Continuous Power Dissipation
8-Pin µMAX (derate 4.1mW/°C above +70°C) .............330mW
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
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Minimum Input Voltage
After startup
0.7
V
Operating Voltage
V
BATT
(Note 1)
1.0
5.5
V
Startup Voltage
T
A
= +25
°C, R
L
= 3k
Ω
0.85
1.0
V
Startup Voltage Tempco
-2.2
m V /
°C
V
OUT
FB = OUT
3.17
3.3
3.43
Output Voltage
FB = GND
4.80
5.0
5.20
V
Adjustable Output Voltage
Range
2.0
5.5
V
MAX1795
100
180
MAX1796
200
300
BATT = +2V,
FB = OUT
(V
OUT
= +3.3V)
MAX1797
400
550
MAX1795
50
120
MAX1796
100
200
Steady-State Output Current
I
OUT
BATT = +2V,
FB = GND
(V
OUT
= +5.0V)
MAX1797
250
370
mA
Feedback Set-Point Voltage
(Adjustable Mode)
V
FB
V
OUT
= +2V to +5.5V
1.20
1.24
1.28
V
Feedback Input Current
I
FB
V
FB
= +1.24V
4
100
nA
NFET
0.17
0.3
Internal NFET, PFET On-
Resistance
R
DS(ON)
V
OUT
= +3.3V,
I
LX
= 100mA
PFET
0.27
0.45
Ω
MAX1795
0.2
0.25
0.35
MAX1796
0.4
0.5
0.625
LX Switch Current Limit (NFET
only)
I
LIM
MAX1797
0.8
1.0
1.25
A
LX Leakage Current
I
LEAK
V
LX
= 0 and +5.5V, V
OUT
= +5.5V
0.2
µA
Synchronous Rectifier Turn-Off
Current Limit
25
mA
Damping Switch On-Resistance
R
DAMP
100
200
400
Ω
Operating Current into OUT
(Note 2)
V
FB
= +1.4V
25
45
µA