MAS6240 Piezo Driver with Multi-Mode Charge Pump

Transcription

1 MAS624 Piezo Driver with Multi-Mode Charge Pump Both Single Ended and Differential Output Three-Step Volume Adjusting Up to 8Vpp Output from 3V Supply One Wire Audio & Shutdown Control High Efficiency Solution without Inductors Low External Part Count DESCRIPTION MAS624 is a piezo driver device that can drive outputs up to 8Vpp from 3V supply. An internal three-mode charge pump generates boosted supply voltage for piezo driver. For adjusting the piezo element sound volume, the charge pump can operate in either of a x, 2x or 3x mode. In x mode the input voltage is bypassed to the output, in 2x or 3x mode the input voltage is boosted up accordingly 2 or 3 times. Charge pump mode is selected by control pins EN and EN2 (see Table at page 2). MAS624 is an easy and low-cost solution for piezo driver, since only 4 small value capacitors are needed in addition to sound element - the use of inductors can be avoided. The inductorless design also causes significantly less disturbance to the surrounding circuits making it an ideal choice for sensitive designs. Its charge pump switches at MHz, allowing to use as small as nf external capacitors. Control logic is switching the charge pump on at first FEATURES Thin.75 mm QFN 2 package Piezo Driver Three-Step Volume Adjusting Both Single Ended and Differential Output Up to 8Vpp Output from 3V Supply One Wire Audio & Shutdown Control Charge Pump Low External Part Count Solution without Inductors MHz Switching Frequency Multi-Mode Charge Pump (x/2x/3x) first rising signal of digital input (DIN) pin. The switch-off signal will be generated while the signal at DIN has been at low mostly for 5ms. The piezo driver is enabled at a second rising edge of a pulse at DIN and the signal is transferred to piezo output VO. The same signal is inverted into output VO2 for using differential output. Continuous logic high level at DIN input causes the charge pump to be turned ON but leaves the audio amplifier disabled. In that state the charge pump output can be used to power the external LEDs or any other external circuit. The output voltage is still selectable at three steps. In "disabled" mode (DIN has been low for 2ms typically) all functional blocks are switched off to achieve the quiescent current less than. See more information in the chapter Detailed Description. APPLICATIONS Wrist Watches Alarm Clocks Handheld GPS devices PDAs Portable Device with Sound Feature ()

2 BLOCK & APPLICATION DIAGRAM CP CN CP2 CN2 VIN (3V) Oscillator MHz x/2x/3x Charge Pump VOUT EN EN2 Control Logic Short Circuit Protection DIN VO PIEZO SOUNDER 9k Pull Down Resistor VO2 GND Figure : Charge Pump + Single End Piezo Driver (max 9Vpp) CP CN CP2 CN2 VIN (3V) Oscillator MHz x/2x/3x Charge Pump VOUT EN EN2 Control Logic Short Circuit Protection DIN 9k Pull Down Resistor VO VO2 PIEZO SOUNDER GND Figure 2: Charge Pump + Differential Piezo Driver (max 8Vpp) Table Charge Pump boosting mode selection DIN EN EN2 Charge Pump - - OFF OFF x Mode (VIN) 2x Mode (2xVIN) 3x Mode (3xVIN) Note: Pulsed signal at digital input DIN is taken as if pulse low time is less than 2 ms typically! 2 ()

3 ABSOLUTE MAXIMUM RATINGS Parameter Symbol Conditions Min Max Unit Supply Voltage VIN Charge pump in x or 2x mode. Charge pump in 3x mode. Outputs and Flying VOUT, Capacitors Pins Voltages CP, CP2, CN, CN2, VO, VO2 Voltage Range for Input DIN, Pins EN, EN2 VOUT Short-Circuit Duration V V -.3 VIN +.3 V t SC Note Indefinite Storage Temperature ESD Rating Human Body Model (HBM) ±2 kv Note: Stresses beyond the values listed may cause a permanent damage to the device. The device may not operate under these conditions, but it will not be destroyed. Note : Short Circuit current internally limited. o C RECOMMENDED OPERATING CONDITIONS All voltages with respect to ground. Parameter Symbol Conditions Min Typ Max Unit Operating Junction Temperature T J C Operating Ambient Temperature T A C Operating Supply Voltage V IN V 3 ()

4 ELECTRICAL CHARACTERISTICS T A = -4 C to +85 C, typical values at T A = 27 C, V IN = 3. V, C = nf, C 2 = nf, C OUT = nf, C IN = nf, C piezo = 5 nf, digital input DIN=4kHz; unless otherwise specified Parameter Symbol Conditions Min Typ Max Unit Output Voltage VOUT VOUT pin voltage towards ground at VDD = 3 V (load 3 ma) x Mode 2x Mode 3x Mode Current Consumption I CC Charge Pump (no load): x Mode 2x Mode 3x Mode Single ended application (C piezo = 5nF; f=4khz): x Mode 2x Mode 3x Mode Differential application (C piezo = 5 nf; f=4khz): x Mode 2x Mode 3x Mode Signal Frequency F AUDIO khz Shutdown Current I SD DIN = V, Note Internal Switching Frequency (Charge Pump) F OSC.6.8 MHz VOUT Turn-ON Time t ON x Mode µs (From DIN signal HIGH to 9% VOUT steady state) 2x Mode 3x Mode Shut Down delay t OFF Time before device shutdown after ms DIN signal goes to LOW Short Circuit Current Limit I SC From VIN pin 3 5 ma Control Input Threshold Control Input Current V IH V IL I IH I IL EN, EN2, DIN pins.6 V DIN = 3V, (9kΩ pull down) V DIN = V V DIN = 3V V EN,EN2 = 3V, (9kΩ pull down) V EN,EN2 = V V DIN = V, Note 2 V EN,EN2 = 3V V EN,EN2 = V Note : DIN has been low at least 5 ms. Note 2: EN and EN2 pins are at high-z state while V DIN =V. I IH I IL I IH I IL V ma ma V V 4 ()

5 PIN DESCRIPTION Pin Description Symbol Type X-coordinate Y-coordinate Control signal input for setting charge pump mode EN DI Control signal input for setting charge pump mode EN2 DI 5 89 Enable signal + Digital signal input DIN DI Flying capacitor negative terminal CN I/O Supply ground GND G Digital audio signal output VO2 DO Digital audio signal output VO DO Flying capacitor negative terminal CN2 I/O Flying capacitor positive terminal CP I/O Charge pump output VOUT AO Flying capacitor positive terminal CP2 I/O 62 4 Power supply VIN P G = Ground, P = Power, D = Digital, A = Analog, I = Input, O = Output. Note: Because the substrate of the die is internally connected to GND, the die has to be connected to GND or left floating. Please make sure that GND is the first pad to be bonded. Pick-and-place and all component assembly are recommended to be performed in ESD protected area. Note: Pad coordinates are measured from the left bottom corner of the chip to the center of the pads. The coordinates may vary depending on sawing width and location, however, distances between pads are accurate. IC OUTLINES VIN CP2 VOUT EN EN2 DIN CP CN2 VO 2 µm VO2 MAS624 CN GND 3 µm DIE size =.3 x.2 mm; PAD size = 8 x 8 µm 5 ()

6 DETAILED DESCRIPTION MAS624 first pulse skipping voltage [V] time [ms] VO DIN Figure 3: Enabling output VO The piezo driver is enabled at the second rising edge of the pulse at DIN, thus the signal is transferred to the piezo output VO. An output VO2 is enabled at the same time, but it is optional to take it in use. Control logic is switching the charge pump on at first rising signal of digital input DIN pin. If only one continuous pulse is fed to the input DIN, the output VO is not enabled. This make it possible to control e.g. a white LED or other device through pin VOUT while charge pump is enabled, without enabling the piezo output VO. MAS624 first pulse skipping & power down delay 8 6 voltage [V] 4 2 DIN VO time [sec] Figure 4: Disabling VO2 Figure 4 is drawn in the case of VO2. The switch-off signal will be generated after the signal at DIN has been low at mostly for 5 ms. In the figure 4 the switch-off delay is about 25 ms. Again when new pulses are fed into DIN, the charge pump and piezo driver will be enabled. 6 ()

7 DEVICE OUTLINE CONFIGURATION QFN 3x3 2ld GAv YWW Top Marking Information: 234 = Product Number Av = Version Number G = Lead Free, RoHS Compliant Package YWW = Year Week Pin nr. Pin Name Pin nr. Pin Name Pin nr. Pin Name Pin nr. Pin Name EN 4 CN 7 VO VOUT 2 EN2 5 GND 8 CN2 CP2 3 DIN 6 VO2 9 CP 2 VIN 4 7 ()

8 E2 E2/2 A A3 A E/2 DA624.4 PACKAGE (QFN 3X3x.75 2ld) OUTLINE D D/2 TOP VIEW PIN MARK AREA SIDE VIEW SEATING PLANE DETAIL A OPTIONAL PIN # IDENTIFICATION PAD (connected to GND) b D2 D2/2 SHAPE OF PIN # IDENTIFICATION IS OPTIONAL L e Terminal Tip Package Center Line X or Y BOTTOM VIEW DETAIL A EXPOSED PAD (connected to GND) Symbol Min Nom Max Unit PACKAGE DIMENSIONS A mm A..2.5 mm A mm b mm D mm D2 (Exposed.pad) mm E mm E2 (Exposed.pad) mm e.5 BSC mm L mm Dimensions do not include mold or interlead flash, protrusions or gate burrs. 3 Components on Each Reel Reel Material: Conductive, Plastic Antistatic or Static Dissipative Carrier Tape Material: Conductive Cover Tape Material: Static Dissipative 8 ()

9 SOLDERING INFORMATION For Lead-Free / Green QFN 3mm x 3mm x.75mm Resistance to Soldering Heat According to RSH test IEC /2 Maximum Temperature 26 C Maximum Number of Reflow Cycles 3 Reflow profile Thermal profile parameters stated in IPC/JEDEC J-STD-2 should not be exceeded. Lead Finish µm, Matte Tin EMBOSSED TAPE SPECIFICATIONS P2 PO P D X T E W F B R.25 typ A User Direction of Feed X K Orientation on tape Dimension Min/Max Unit Ao 3.3 ±. mm Bo 3.3 ±. mm Do.5 +./-. mm E.75 mm F 5.5 ±.5 mm Ko. ±. mm Po 4. mm P 8. ±. mm P2 2. ±.5 mm T.3 ±.5 mm W 2. ±.3 mm All dimensions in millimeters 9 ()

10 REEL SPECIFICATIONS W 2 A D Tape Slot for Tape Start C N B W Carrier Tape Cover Tape End Start Trailer Components Leader Dimension Min Max Unit A 33 mm B.5 mm C mm D 2.2 mm N mm W (measured at hub) mm W 2 (measured at hub) 8.4 mm Trailer 6 mm Leader 39, of which minimum 6 mm of empty carrier tape sealed with cover tape mm ()

11 ORDERING INFORMATION Product Code Product Package Comments MAS624AHP6 MAS624ATC Piezo Driver with Multi-Mode Charge Pump Piezo Driver with Multi-Mode Charge Pump QFN 3x3x.75 2ld, Pb Free, Tape and Reel RoHS Compliant 3 pcs / r EWS Tested wafers 4 µm Die size.3 x.2 mm The formation of product code An example for MAS624AHP6: MAS624 A HP 6 Product name Design version Product Version Package: HP = QFN 3 x 3 x.75 (Pb free, RoHS compliant) Delivery format: 6 = T&R 8 = Loose components LOCAL DISTRIBUTOR MICRO ANALOG SYSTEMS OY CONTACTS Micro Analog Systems Oy Kamreerintie 2, P.O.Box 5 FIN-277 Espoo, FINLAND Tel Telefax NOTICE Micro Analog Systems Oy reserves the right to make changes to the products contained in this data sheet in order to improve the design or performance and to supply the best possible products. Micro Analog Systems Oy assumes no responsibility for the use of any circuits shown in this data sheet, conveys no license under any patent or other rights unless otherwise specified in this data sheet, and makes no claim that the circuits are free from patent infringement. Applications for any devices shown in this data sheet are for illustration only and Micro Analog Systems Oy makes no claim or warranty that such applications will be suitable for the use specified without further testing or modification. ()