LT8415_15 Datasheet, PDF (1/12 Pages) Linear Technology – Ultralow Power Boost Converter with Dual Half-Bridge Switches

FEATURES
n _{High Voltage Switches Built in (Dual half-bridge)}
n _{Ultralow Quiescent Current}
10.5μA in Active Mode
0μA in Shutdown Mode
n _{Comparator Built into SHDN pin}
n _{Low Noise Control Scheme}
n _{Adjustable FB reference voltage}
n _{Wide Input Range: 2.5V to 16V}
n _{Wide Output Range: Up to 40V}
n _{Integrated Power NPN Switch (25mA Current Limit)}
n _{Integrated Schottky Diode}
n _{Integrated Output Disconnect}
n _{High Value (12.4M/0.4M) Feedback Resistor Integrated}
n _{Built in Soft Start (Optional Capacitor from VREF to GND)}
n _{Over Voltage Protection for CAP, VOUT, OUT1 and}
OUT2 Pins
n _{12-Pin 3mm × 2mm DFN package}
APPLICATIONS
n _{Sensor Power}
n _{RF Mems Relay Power}
n _{Low Power Actuator Bias/Control}
n _{Liquid Lens Driver}
LT8415
Ultralow Power Boost
Converter with Dual
Half-Bridge Switches
DESCRIPTION
The LT^®8415 is an ultralow power boost converter with
two integrated complementary MOSFET half-bridges
(N- and P-channel), integrated power switch, Schottky
diode and output disconnect circuitry. The N-channel and
P-channel MOSFETs in each half-bridge are synchronously
controlled by a single input pin, and never turn on at the
same time in typical applications.
The boost regulator controls power delivery by varying
both the peak inductor current and switch off-time. This
control scheme results in low output voltage ripple as well
as high efficiency over a wide load range. The quiescent
current is a low 10.5μA, which is further reduced to 0μA
in shutdown. The internal disconnect circuitry allows the
output voltage to be blocked from the input during shut-
down. High value (12.4M/0.4M) resistors are integrated
on chip for output voltage detection, significantly reducing
input referred quiescent current. The LT8415 also features a
comparator built into the SHDN pin, overvoltage protection
for the CAP, V_OUT, OUT1 and OUT2 pins, built in soft start
and comes in a tiny 12-pin 3mm × 2mm DFN package.
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Hot Swap
is a trademark of Linear Technology Corporation. All other trademarks are the property of their
respective owners. Protected by U.S. Patents including 5481178, 6580258, 6304066, 6127815,
6498466, 6611131.
TYPICAL APPLICATION
Drive External Capacitors to 34V/0V with the LT8415
V_IN
2.5V to 16V
100μH
2.2μF
SW CAP
V_CC
V_OUT
LT8415
LOGIC
LEVEL
CHIP
ENABLE
IN 1 OUT 1
IN 2 OUT 2
SHDN ^VREF
GND FBP
*HIGHER VALUE CAPACITOR IS REQUIRED
WHEN THE V_IN IS HIGHER THAN 8V
**THIS CAPACITOR IS OPTIONAL
22nF
V_OUT = 34V
0.1μF*
34V/0V
137K
34V/0V
887K
0.1μF**
8415 TA01
Response Driving External Capacitors
OUT2 VOLTAGE
20/DIV
IN2 VOLTAGE
2V/DIV
OUT1 VOLTAGE
20/DIV
IN1 VOLTAGE
2V/DIV
C_OUT1 = 1nF
C_OUT2 = 200pF
20μs/DIV
8415 TA02
8415f
1