LT3469 Piezo Microactuator Driver with Boost Regulator FEATURES DESCRIPTIO Amplifier The LT 3469 is a transconductance (g ) amplifier that can m n Current Limit: 40mA Typical drive outputs up to 33V from a 5V or 12V supply. An n Input Common Mode Range: 0V to 10V internal switching regulator generates a boosted supply n Output Voltage Range: 1V to (V 1V) voltage for the g amplifier. The amplifier can drive CC m n Differential Gain Stage with High Impedance Output capacitive loads in the range of 5nF to 300nF. Slew rate is (g Stage) limited only by the maximum output current. The 35V m n Quiescent Current (from V ): 2mA output voltage capability of the switching regulator, along CC n Unloaded Gain: 30,000 Typical with the high supply voltage of the amplifier, combine to allow the wide output voltage range needed to drive a Switching Regulator piezoceramic microactuator. n Generates V Up to 35V CC n Wide Operating Supply Range: 2.5V to 16V The LT3469 switching regulator switches at 1.3MHz, n High Switching Frequency: 1.3MHz allowing the use of tiny external components. The output n Internal Schottky Diode capacitor can be as small as 0.22m F, saving space and cost n Tiny External Components versus alternative solutions. n Current Mode Switcher with Internal Compensation TM The LT3469 is available in a low profile ThinSOT package. n Low Profile (1mm) SOT-23 Package , LTC and LT are registered trademarks of Linear Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation. U APPLICATIO S n Piezo Speakers n Piezo Microactuators n Varactor Bias TYPICAL APPLICATIO Piezo Microactuator Driver 47H 5V OR 12V Response Driving a 33nF Load 35 1F V SW IN 16V I OUT 6 V 100mA/DIV CC 453k 2 0.47F FB 50V V OUT LT3469 16.5k 10V/DIV 4 GND 9.09k 7 +IN + 1 V + OUT OUT INPUT 8 1V TO 33V IN INPUT 5V/DIV 0V TO 3V 50m s/DIV 3469 TA04 10k PIEZO ACTUATOR 100k 5nF < C < 300nF 3469 TA03 3469f 1 U ULT3469 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) ORDER PART V Voltage ............................................................. 16V IN TOP VIEW NUMBER SW Voltage ............................................................. 40V OUT 1 8 IN V Voltage............................................................. 38V CC FB 2 7 +IN LT3469ETS8 V 3 6 V +IN, IN Voltage ..................................................... 10V IN CC GND 4 5 SW FB Voltage ................................................................ 3V TS8 PART MARKING TS8 PACKAGE Current Into SW Pin ................................................. 1A 8-LEAD PLASTIC TSOT-23 LTACA Operating Temperature Range (Note 2) .. 40 C to 85 C T = 125 C, q = 250 C/W JMAX JA Storage Temperature Range ................ 65 C to 150 C Lead Temperature (Soldering, 10 sec)................. 300 C Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25 C. (Note 2) V = 5V, V = 35V, unless otherwise noted. A IN CC PARAMETER CONDITIONS MIN TYP MAX UNITS g Amplifier m Input Offset Voltage V = V /2 l 310 mV OUT CC Input Offset Current l 10 100 nA Input Bias Current l 150 500 nA Input ResistanceDifferential Mode 1MW Input ResistanceCommon Mode 200 MW Common Mode Rejection Ratio V = 0V to 10V 70 100 dB CM Power Supply Rejection RatioV V = 2.5V to 16V 80 120 dB IN IN Power Supply Rejection RatioV V = 15V to 35V 65 85 dB CC CC Gain No Load, V = 2V to 33V 15 30 V/mV OUT R = 200k, V = 2V to 33V 10 20 V/mV L OUT Transconductance I = 100m A 160 220 260 m A/mV OUT l 140 300 m A/mV Maximum Output Current V = V /2 30 40 55 mA OUT CC l 23 58 mA Maximum Output Voltage, Sourcing V = 35V, I = 10mA 34.0 34.5 V CC OUT V = 35V, I = 0mA 34.5 34.9 V CC OUT Minimum Output Voltage, Sinking I = 10mA 200 1000 mV OUT I = 0mA 10 500 mV OUT Output Resistance V = 35V, V = 2V to 33V 100 kW CC OUT Supply CurrentV V = 35V 1.5 2 2.5 mA CC CC Switching Regulator Minimum Operating Voltage 2.5 V Maximum Operating Voltage 16 V Feedback Voltage l 1.19 1.23 1.265 V FB Pin Bias Current l 45 200 nA FB Line Regulation 2.5V < V < 16V 0.03 %/V IN Supply CurrentV 1.9 2.6 mA IN Switching Frequency l 0.8 1.3 1.7 MHz Maximum Duty Cycle l 88 91 % Switch Current Limit (Note 3) l 165 220 mA Switch V I = 100mA 350 500 mV CESAT SW 3469f 2 U WWW