28V, Low-Power, High-Voltage,
Boost or Inverting DC-DC Converter
MAX629
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (V
CC
to GND) ..................................-0.3V to +6V
SHDN
to GND...........................................................-0.3V to +6V
ISET, REF, FB, POL to GND .......................-0.3V to (V
CC
+ 0.3V)
LX to GND ..............................................................-0.3V to +30V
Continuous Power Dissipation (T
A
= +70°C)
SO (derate 5.88mW/°C above +70°C) ..........................471mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +165°C
Lead Temperature (soldering, 10sec) .............................+300°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.
ELECTRICAL CHARACTERISTICS
(V
CC
= +5V, C
REF
= 0.1µF, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note1)
PARAMETER
V
CC
Input Voltage (Note 2)
V
CC
Supply Current
V
CC
Shutdown Current
V
CC
Undervoltage Lockout
Input Supply Voltage (Note 2)
SHDN,
POL, ISET Logic Levels
Positive Output Voltage
Negative Output Voltage
LX Switch-Current Limit
LX On-Resistance
LX Leakage Current
Maximum LX On-Time
POL = GND
Minimum LX Off-Time
POL = V
CC
POL = GND, V
FB
< 1V
POL = V
CC,
V
FB
> 0.25V
POL = GND
(positive output)
FB Set Point
POL = V
CC
(negative output)
FB Input Bias Current
REF Output Voltage
V
CC
= 2.7V to 5.5V,
no load on REF
T
A
= 0°C to +85°C
T
A
= -40°C to +85°C
1.225
1.218
T
A
= 0°C to +85°C
T
A
= -40°C to +85°C
T
A
= 0°C to +85°C
T
A
= -40°C to +85°C
V
FB
= 1.3V
SHDN
= GND
100mV hysteresis
Voltage applied to L1 (V
IN
)
V
IH
V
IL
Circuit of Figure 2
Circuit of Figure 3
ISET = V
CC
ISET = GND
V
CC
= 5V
V
CC
= 3.3V
V
LX
= 28V, T
A
= +85°C
6.5
0.7
2.0
3.0
3.0
1.225
1.218
-15
-25
5
1.250
0
-
V
IN
0.39
0.20
0.45
0.25
0.6
0.7
0.05
8.5
1.0
3.2
4.5
4.5
1.250
2.3
0.8
2.4
0.4
28
-28
0.51
0.33
1.2
1.4
2.5
10.0
1.3
3.8
6.0
6.0
1.275
1.282
15
25
50
1.275
1.282
V
mV
nA
V
µs
CONDITIONS
MIN
2.7
80
0.04
2.5
TYP
MAX
5.5
120
1
2.65
V
OUT
UNITS
V
µA
µA
V
V
V
V
V
A
Ω
µA
µs
2
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MAXIM [ MAXIM INTEGRATED PRODUCTS ]
