
M
28V, PWM, S tep-Up DC-DC Converter
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
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
ELECTRICAL CHARACTERISTICS
(V
IN
= +6V, PGND = GND, C
VL
= 4.7μF,
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.
Operating Temperature Range ...........................-40°C to +85°C
J unction 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
VL Output Voltage
VL Load Regulation
VL Undervoltage Lockout
FB Set Voltage
FB Input Bias Current
Line Regulation
Load Regulation
LX Voltage
LX Switch Current Limit
I
IN
V
VL
V
VL
3
8
μA
V
mV
V
V
nA
%/V
%
V
A
V
IN
= 28V, V
FB
= 1.6V,
SHDN
= GND
V
IN
= 3.5V or 28V, no load
I
LOAD
= 0 to 2mA, V
FB
= 1.6V
Rising edge, 1% hysteresis
Maximum Duty Cycle
DC
90
95
%
PARAMETER
SYMBOL
V
IN
I
IN
MIN
3
TYP
MAX
28
700
UNITS
V
μA
2.9
3.05
25
2.7
1.5
1
0.01
0.2
3.2
40
2.8
1.53
50
0.08
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
2.58
1.47
V
FB
I
FB
V
OUT
V
OUT
V
LX
I
LXON
Supply Current, No Load
Input Voltage
500
28
2.7
1.7
2.2
Idle Mode Current-Limit
Threshold
0.25
0.35
0.45
A
LX On-Resistance
LX Leakage Current
COMP Maximum Output Current
R
LXON
I
LXOFF
I
COMP
0.3
0.02
200
0.6
10
μA
μA
100
COMP Current vs. FB Voltage
Transconductance
0.8
1
mmho
SHDN
Input Logic Low
SHDN
Input Logic High
Shutdown Input Current
Switching Frequency
V
IL
V
IH
0.8
V
V
2.0
1
μA
kHz
f
200
250
300
CONDITIONS
V
IN
= 3V to 6V, V
OUT
= 12V
V
OUT
= 12V, I
LOAD
= 10mA to 500mA
V
IN
= 3.4V to 28V, V
FB
= 1.4V,
SHDN
= VL,
V
VL
< V
IN
V
IN
= 3V to 5.5V, V
FB
= 1.4V,
SHDN
= VL = IN
PWM mode
V
FB
= 1.6V
V
LX
= 28V
FB = GND
V
IN
= 3V to 28V, V
FB
= 1.6V,
SHDN
= VL
FB = 0.1V
SHDN
= GND or VL