LT3469 Datasheet, PDF (1/8 Pages) Linear Technology – Piezo Microactuator Driver with Boost Regulator

LT3469
Piezo Microactuator Driver
with Boost Regulator
FEATURES
Amplifier
s _{Current Limit: ±40mA Typical}
s _{Input Common Mode Range: 0V to 10V}
s _{Output Voltage Range: 1V to (VCC – 1V)}
s _{Differential Gain Stage with High Impedance Output}
(g_m Stage)
s _{Quiescent Current (from VCC): 2mA}
s _{Unloaded Gain: 30,000 Typical}
Switching Regulator
s _{Generates VCC Up to 35V}
s _{Wide Operating Supply Range: 2.5V to 16V}
s _{High Switching Frequency: 1.3MHz}
s _{Internal Schottky Diode}
s _{Tiny External Components}
s _{Current Mode Switcher with Internal Compensation}
s _{Low Profile (1mm) SOT-23 Package}
U
APPLICATIO S
s _{Piezo Speakers}
s _{Piezo Microactuators}
s _{Varactor Bias}
DESCRIPTIO
The LT^®3469 is a transconductance (g_m) amplifier that can
drive outputs up to 33V from a 5V or 12V supply. An
internal switching regulator generates a boosted supply
voltage for the g_m amplifier. The amplifier can drive
capacitive loads in the range of 5nF to 300nF. Slew rate is
limited only by the maximum output current. The 35V
output voltage capability of the switching regulator, along
with the high supply voltage of the amplifier, combine to
allow the wide output voltage range needed to drive a
piezoceramic microactuator.
The LT3469 switching regulator switches at 1.3MHz,
allowing the use of tiny external components. The output
capacitor can be as small as 0.22µF, saving space and cost
versus alternative solutions.
The LT3469 is available in a low profile ThinSOT^TM package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
ThinSOT is a trademark of Linear Technology Corporation.
TYPICAL APPLICATIO
Piezo Microactuator Driver
5V OR 12V
47µH
3
5
1µF
16V
V_IN
SW
V_CC ⁶
9.09k
+
INPUT
0V TO 3V
– ^10k
7
+IN
8
–IN
LT3469
+
–
2
FB
4
GND
1
OUT
100k
453k
16.5k
0.47µF
50V
V_OUT
1V TO 33V
PIEZO
ACTUATOR
5nF < C < 300nF
3469 TA03
I_OUT
100mA/DIV
Response Driving a 33nF Load
V_OUT
10V/DIV
INPUT
5V/DIV
50µs/DIV
3469 TA04
3469f
1