Datasheet

MAX618
28V, PWM, Step-Up DC-DC Converter
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS
(V
IN
= +6V, PGND = GND, C
VL
= 4.7μF, T
A
= -40°C to +85°C, unless otherwise noted.) (Note 2)
100
0
0.1 1 10 100 1000
EFFICIENCY vs. OUTPUT CURRENT
(V
OUT
= 12V)
20
30
10
MAX618 toc01
OUTPUT CURRENT (mA)
EFFICIENCY (%)
40
50
60
70
80
90
V
IN
= 8V
V
IN
= 5V
V
IN
= 3V
100
0
0.1 1 10 100 1000
EFFICIENCY vs. OUTPUT CURRENT
(V
OUT
= 28V)
20
30
10
MAX618 toc02
OUTPUT CURRENT (mA)
EFFICIENCY (%)
40
50
60
70
80
90
V
IN
= 12V
V
IN
= 5V
V
IN
= 3V
Typical Operating Characteristics
(Circuit of Figure 1, T
A
= +25°C.)
Note 2: Specifications to -40°C are guaranteed by design, not production tested.
PARAMETER SYMBOL MIN TYP MAX UNITS
Supply Current, Full Load I
IN
4
mA
Supply Current, Full Load,
VL Connected to IN
I
IN
7.5
mA
Supply Current Shutdown I
IN
10
μA
VL Output Voltage V
VL
2.85 3.3
V
Supply Current, No Load
Input Voltage V
IN
328
V
I
IN
800
μA
VL Undervoltage Lockout V
VL
2.55 2.85
V
FB Set Voltage V
FB
1.455 1.545
V
LX Voltage Range V
LXON
28
V
LX Switch Current Limit I
LXON
1.4 3
A
LX On-Resistance R
LXON
0.6
Ω
Switching Frequency f
188 312
kHz
CONDITIONS
Rising edge, 1% hysteresis
V
IN
= 3.4V to 28V, V
FB
= 1.4V, SHDN = VL,
VL < V
IN
V
IN
= 3V to 5.5, V
FB
= 1.4V, SHDN = VL = IN
V
IN
= 28V, V
FB
= 1.6V, SHDN = GND
PWM mode
V
IN
= 3.5V or 28V, no load
V
IN
= 3V to 28V, V
FB
= 1.6V, SHDN = VL