LT3471_15 Datasheet, PDF (1/16 Pages) Linear Technology – Dual 1.3A, 1.2MHz Boost/Inverter

FEATURES
n _{1.2MHz Switching Frequency}
n _{Low VCESAT Switches: 330mV at 1.3A}
n _{High Output Voltage: Up to 40V}
n _{Wide Input Range: 2.4V to 16V}
n _{Inverting Capability}
n _{5V at 630mA from 3.3V Input}
n _{12V at 320mA from 5V Input}
n _{–12V at 200mA from 5V Input}
n _{Uses Tiny Surface Mount Components}
n _{Low Shutdown Current: < 1μA}
n _{Low Profile (0.75mm) 10-Lead 3mm × 3mm}
DFN Package
APPLICATIONS
n _{Organic LED Power Supply}
n _{Digital Cameras}
n _{White LED Power Supply}
n _{Cellular Phones}
n _{Medical Diagnostic Equipment}
n _{Local ±5V or ±12V Supply}
n _{TFT-LCD Bias Supply}
n _{xDSL Power Supply}
LT3471
Dual 1.3A, 1.2MHz
Boost/Inverter in
3mm × 3mm DFN
DESCRIPTION
The LT^®3471 dual switching regulator combines two 42V,
1.3A switches with error amplifiers that can sense to
ground providing boost and inverting capability. The low
V_CESAT bipolar switches enable the device to deliver high
current outputs in a small footprint. The LT3471 switches
at 1.2MHz, allowing the use of tiny, low cost and low profile
inductors and capacitors. High inrush current at start-up
is eliminated using the programmable soft-start function,
where an external RC sets the current ramp rate. A constant
frequency current mode PWM architecture results in low,
predictable output noise that is easy to filter.
The LT3471 switches are rated at 42V, making the device
ideal for boost converters up to ±40V as well as SEPIC
and flyback designs. Each channel can generate 5V at
up to 630mA from a 3.3V supply, or 5V at 510mA from
four alkaline cells in a SEPIC design. The device can be
configured as two boosts, a boost and inverter or two
inverters.
The LT3471 is available in a low profile (0.75mm) 10-lead
3mm × 3mm DFN package.
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
CONTROL 1 _4.7k
0.33μF
V_IN
CONTROL 2
10μF
4.7k
0.33μF
OLED Driver
2.2μH
V_IN
3.3V
SW1
SHDN/SS1
V_IN
LT3471
FB1N
FB1P
V_REF
SHDN/SS2
GND
V_IN
FB2N
FB2P
SW2
3471 TA01
10μH ^1μF
90.9k
15k
0.1μF
15k
4.7μF
V_OUT1
7V
350mA
105k
75pF
15μH
10μF
V_OUT2
–7V
250mA
OLED Driver Efficiency
95
90
V_OUT1 = 7V
85
80
V_OUT1 = –7V
75
70
65
60
55
50
0
100
200
300
400
I_OUT (mA)
3471 TA01b
3471fb
1