MAX618
28V, PWM, Step-Up DC-DC Converter
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
IN
= +6V, PGND = GND, CVL= 4.7µF, TA= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +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 to GND ...............................................................-0.3V to +30V
LX to GND ..............................................................-0.3V to +30V
VL to GND ................................................................-0.3V to +6V
SHDN, COMP, FB to GND ............................-0.3V to (VL + 0.3V)
PGND to GND.....................................................................±0.3V
Continuous Power Dissipation (T
A
= +70°C) (Note 1)
16-Pin QSOP (derate 15mW/°C above +70°C)...................1W
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10sec) .............................+300°C
Note 1: With part mounted on 0.9 in.
2
of copper.
Shutdown Supply Current I
IN
38
µA
VIN= 28V, VFB= 1.6V, SHDN = GND
Maximum Duty Cycle DC 90 95 %
PARAMETER SYMBOL MIN TYP MAX UNITS
VL Output Voltage V
VL
2.9 3.05 3.2
V
Supply Current, Full Load I
IN
2.5 3.5
mA
Supply Current, Full Load, VL
Connected to IN
I
IN
5 6.5
mA
VL Load Regulation ∆V
VL
25 40
mV
VL Undervoltage Lockout
2.58 2.7 2.8
V
FB Set Voltage V
FB
1.47 1.5 1.53
V
FB Input Bias Current I
FB
150
nA
Supply Current, No Load
Input Voltage V
IN
328
V
I
IN
500 700
µA
Line Regulation ∆V
OUT
0.01 0.08
%/V
Load Regulation ∆V
OUT
0.2
%
LX Voltage V
LX
28 V
LX Switch Current Limit I
LXON
1.7 2.2 2.7
A
Idle Mode Current-Limit
Threshold
0.25 0.35 0.45
A
LX On-Resistance R
LXON
0.3 0.6 Ω
LX Leakage Current I
LXOFF
0.02 10 µA
COMP Maximum Output Current I
COMP
100 200 µA
COMP Current vs. FB Voltage
Transconductance
0.8 1 mmho
SHDN Input Logic Low
V
IL
0.8 V
SHDN Input Logic High
V
IH
2.0 V
Shutdown Input Current 1 µA
Switching Frequency f 200 250 300 kHz
CONDITIONS
VIN= 3V to 6V, V
OUT
= 12V
VIN= 3.5V or 28V, no load
V
OUT
= 12V, I
LOAD
= 10mA to 500mA
VIN= 3.4V to 28V, VFB= 1.4V, SHDN = VL,
V
VL
< V
IN
V
IN
= 3V to 5.5V, VFB= 1.4V, SHDN = VL = IN
I
LOAD
= 0 to 2mA, VFB= 1.6V
Rising edge, 1% hysteresis
PWM mode
VFB= 1.6V
VLX= 28V
FB = GND
VIN= 3V to 28V, VFB= 1.6V, SHDN = VL
∆FB = 0.1V
SHDN = GND or VL