LT3495 Datasheet, PDF (1/16 Pages) Linear Technology – 650mA/350mA Micropower Low Noise Boost Converter with Output Disconnect

FEATURES
n _{Low Quiescent Current}
60μA in Active Mode
0.1μA in Shutdown Mode
n _{Low Noise Control Scheme (Switching Frequency}
Always Stays Above Audible Range for LT3495/-1)
n _{Integrated Power NPN:}
650mA Current Limit (LT3495/B)
350mA Current Limit (LT3495-1/B-1)
n _{Integrated Output Disconnect}
n _{Integrated Output Dimming}
n _{Wide input range: 2.3V to 16V}
n _{Wide output range : Up to 40V}
n _{Integrated feedback resistor}
n _{Tiny 10-Lead 3mm × 2mm DFN Package}
APPLICATIONS
n _{OLED Power}
n _{Low Noise Power}
n _{MP3 Player}
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners. *Patent pending.
LT3495/LT3495B/
LT3495-1/LT3495B-1
650mA/350mA Micropower
Low Noise Boost Converter
with Output Disconnect
DESCRIPTION
The LT^®3495/LT3495B/LT3495-1/LT3495B-1 are low noise
boost converters with integrated power switch, feedback
resistor and output disconnect circuitry. The parts control
power delivery by varying both the peak inductor current
and switch off-time. This novel* control scheme results
in low output voltage ripple as well as high efficiency
over a wide load range. For the LT3495/LT3495-1, the
off-time of the switch is not allowed to exceed a fixed
level, guaranteeing the switching frequency stays above
the audio band for the entire load range. The parts feature
a high performance NPN power switch with a 650mA
and 350mA current limit for the LT3495/LT3495B and
LT3495-1/LT3495B-1 respectively. The quiescent current
is a low 60μA, which is further reduced to 0.1μA in shut-
down. The internal disconnect circuitry allows the output
voltage to be isolated from the input during shutdown. An
auxiliary reference input (CTRL pin) overrides the internal
1.235V feedback reference with any lower value allowing
full control of the output voltage during operation. The
LT3495 series are available in a tiny 10-lead 3mm × 2mm
DFN package.
TYPICAL APPLICATION
OLED Power Supply from One Li-Ion Cell
ONE
Li-Ion
CELL
10μH
4.7μF
SW CAP
V_CC V_OUT
LT3495
SHDN FB
CTRL GND
2.2μF
909k
V_OUT
16V
70mA
1μF
3495 TA01a
Output Voltage Ripple
vs Load Current
50
1.0μF 0603
40 ^{CAPACITOR AT V}OUT
30
20
10
2.2μF 1206
CAPACITOR AT V_OUT
0
0
1
10
100
LOAD CURRENT (mA)
3495 TA01b
Efficiency vs Load Current
90
V_IN = 3.6V
80
400
LOAD FROM CAP
LOAD FROM V_OUT 320
70
240
60
160
50
80
40
0.1
1
10
LOAD CURRENT (mA)
0
100
3495 TA01c
3495b1b1f
1