Shunt Mode Audio Click-and-Pop Eliminator

Transcription

1 ; Rev ; 1/8 Shunt Mode udio Click-and-Pop Eliminator General Description The is an audio click-and-pop eliminator for portable multimedia devices. Operating from a 1.7V to 3.6V supply, the connects to the output of the existing system amplifier and provides a low-impedance path to ground during startup and shutdown. The inputs INL and INR accept voltage swings from to 5.5V below. See the Setting the Supply Voltage section for more information. The power-up and powerdown transients are shunted to ground to prevent clicks and pops from becoming audible. The features two low-impedance analog switches controlled by that opens and closes the switches. The switches are open during normal operation and have no impact on the output signal. During startup and shutdown of the amplifier, the can be activated to short the outputs to ground and prevent clicks and pops from pulling current through the headphones. The is available in 6-bump UCSP (1mm x 1.52mm x.6mm) and 6-pin µdfn (2mm x 2mm x.75mm) packages. The is specified over the -4 C to +85 C temperature range. Mobile Phones Smart Phones Mobile Internet Devices Portable Gaming Consoles Portable Media Players Notebook Computers pplications Features Distortion-Free, Click-and-Pop Elimination Less than 1µ Supply Current 1.7V to 3.6V Single-Supply Operation Tiny Packages 6-Bump UCSP (1mm x 1.52mm x.6mm) 6-Pin µdfn (2mm x 2mm x.75mm) +Denotes a lead-free/rohs-compliant package. TOP VIEW (BUMPS ON BOTTOM) Ordering Information PRT TEMP RNGE PIN-PCKGE ERT+ -4 C to +85 C 6 UCSP ELT+ -4 C to +85 C 6 µdfn Pin Configurations INL INR Typical Operating Circuit B SET HEDPHONE MPLIFIER R SERIES R SERIES TOP VIEW 6 UCSP 5 SET 4 INL INR 1.7V TO 3.6V.1μF SET C SET + 1 INL 2 μdfn 3 INR Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at , or visit Maxim s website at

2 BSOLUTE MXIMUM RTINGS,, SET to...-.3v to +6V INL, INR to...( - 6V) to ( +.3V) Continuous Current In/Out of...3m Continuous Current In/Out of...3m Continuous Current In/Out of SET...3m Continuous Current In/Out of INL, INR and...39m Continuous Power Dissipation (T = +7 C) 6-Bump UCSP (derate 3.9mW/ C above +7 C) mW 6-Pin µdfn (derate 4.5mW/ C above +7 C) mW Operating Temperature Range...-4 C to +85 C Junction Temperature C Storage Temperature Range C to +15 C Lead Temperature (soldering, 1s)...+3 C Bump Temperature (soldering) Reflow C Stresses beyond those listed under bsolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICL CHRCTERISTICS ( = 3.V, V =, T = T MIN to T MX, unless otherwise noted. Typical values are at T = +25 C.) (Note 1) PRMETER SYMBOL CONDITIONS MIN TYP MX UNITS Supply Voltage Range Guaranteed by R ON test V Recommended Supply Voltage Range (Note 2) V Supply Current I DD = 5.5V, T = +25 C (Note 3).6 1 µ Input Voltage Range V IN Guaranteed by input leakage current test - 5.5V V Turn-On Time (Figure 1) t ON Measured from = and input voltage settled to 9% of its final value 13 ns C SET = 5pF Turn-Off Time (Figure 1) t OFF C SET = 5pF 1 C SET = 5nF 1 ms Turn-On Time Resistor R SET C SET = 5pF kω = 3.V.3 Switch On-Resistance R ON = 1.7V 2 = 5.5V 1 Ω Click-and-Pop Reduction R SERIES = 3Ω, R LOD = 16Ω 35 db Input Leakage Current I IN T = +25 C V IN = - 5.5V, = 1.7V ±1 V IN =, = 5.5V ±1 Leakage Current I = 5.5V, V = or 5.5V, T = +25 C ±1 µ Input-Voltage High V IH 1.5 V Input-Voltage Low V IL.4 V Note 1: ll devices are 1% production tested at T = +25 C. ll temperature limits are guaranteed by design. Note 2: Operating within the recommended supply voltage range ensures that negative audio signals are not limited by the device. Supply voltages above the recommended supply voltage range may limit the headphone amplifier s maximum output voltage. Note 3: Supply current is measured when switches are off. µ 2

3 ( = 3.V, V =, T = +25 C, unless otherwise noted.) CLICK ND POP (dbv) CLICK ND POP vs. R SERIES INTO SHUTDOWN TESTED WITH THE MX4338 OUT OF SHUTDOWN R SERIES (Ω) toc1 toff (ms) t OFF vs. C SET C SET (nf) Typical Operating Characteristics toc2 RON (Ω) R ON vs. SUPPLY VOLTGE (V) toc3 IDD (μ) SUPPLY CURRENT vs. SUPPLY VOLTGE toc4 CLICK ND POP (dbv) CLICK ND POP vs. TESTED WITH THE MX4338 OUT OF SHUTDOWN INTO SHUTDOWN toc5 SWITCH TURN-OFF/ON TIME toc6 C SET = 5pF 2V/div IN_ 2V/div (V) (V) 2ms/div -2 CROSSTLK vs. FREQUENCY toc7 CROSSTLK (db) FREQUENCY (khz) 3

4 UCSP BUMP µdfn PIN NME FUNCTION Pin Description 1 1 INL Left-Channel Input. Connect INL in between the output coupling capacitor and the headphone jack. 2 2 Ground 3 3 INR Right-Channel Input. Connect INR in between the output coupling capacitor and the headphone jack. B1 6 ctive-low Enable B2 5 Power Supply B3 4 SET Turn-Off Time Set. Connect an external capacitor in between SET and to set the switch open delay; see the Setting the Turn-Off Time section for more information. Timing Diagram IN_ - 5.5V t OFF t ON R ON.5Ω Figure 1. Turn-On/Off Time 4

5 Detailed Description The is the second-generation click-and-pop eliminator designed to be used with conventional headphone amplifiers. The works by adding a lowimpedance current path from the headphone side of the DC-blocking capacitor to ground. Drive low when turning off the amplifier, and high when enabling the amplifier. short turn-on time allows the switches in the to close before the DC-blocking capacitors have significantly discharged, eliminating clicks and pops at amplifier turn-off. n adjustable turn-off time allows the delay to be set to mask all clicks and pops during amplifier turn-on. Setting the Turn-Off Time The features a SET input that allows the turnoff time to be adjusted from 1ms to 1ms to match the click-and-pop profile of the amplifier startup. The value of an external capacitor sets the switch open delay, as shown in the following equation: t ON (ms) =.2 x C SET (pf) When the headphone amplifier is enabled, the automatically waits the set delay time before opening the analog switches. This allows amplifier turnon click and pop to be eliminated. pplications Information Setting the Supply Voltage The operates from 1.7V to 3.6V supply voltage. The inputs, INL and INR, accept voltage swings from to - 5.5V. The audio signal applied to a headphone is ground biased, meaning that the signal swings just as much negative as positive. Since the input voltage is limited to - 5.5V on the negative side, the voltage on must be set properly to pass the audio signal when the switch is open (Figure 2). voltage-divider can be used to scale down an available supply voltage as shown in Figure 3. The voltagedivider allows the creation of a supply voltage for the that is low enough to allow the negative portion of the audio signal to pass. When using large resistances for the voltage-divider, the supply current affects what resistors to use. Select R 2 between 1kΩ to 1MΩ for a given supply voltage. Use the following equation to calculate the R 1 : where V MP is the supply voltage of the amplifier, and I 2 is the current through R 2. For a signal of ±2V in reference to, the supply can be set from 2V to 3.5V. Selecting Series Resistors series resistor (R SERIES ), as shown in the Typical Operating Circuit, is necessary to achieve optimal clickand-pop reduction. See the Click and Pop vs. R SERIES graph in the Typical Operating Characteristics for details on how much click-and-pop reduction to expect for a given series resistor. Layout Considerations Bypass to with a.1µf capacitor. The.1µF bypass capacitor should be positioned as close as possible to. Minimize trace length from to solid system ground plane to ensure optimum performance. Refer to the Evaluation Kit for a proven PCB layout. IN_ IN_ - 5.5V - 5.5V B Figure 2. Proper Supply Selected for a Given Input Signal. : Supply Voltage with a Large Signal; B: Supply Voltage with a Small Signal ( V V R MP DD) 1 = I2 + IDD 5

6 UCSP pplications Information For the latest application details on UCSP construction, dimensions, tape-carrier information, printed circuit board techniques, bump-pad layout, and recommended reflow temperature profile, as well as the latest information on reliability testing results, refer to pplication Note 1891: Understanding the Basics of the Wafer- Level Chip-Scale Package (WL-CSP) at See Figure 4 for the recommended PCB footprint. HEDPHONE MP R 1 R 2.1μF 45±5μm 25μm Figure 3. Scaling Down the Supply Voltage with a Voltage Divider Figure 4. PCB Footprint Recommendation Diagram PROCESS: BiCMOS Chip Information 6

7 Package Information For the latest package outline information and land patterns, go to PCKGE TYPE PCKGE CODE DOCUMENT NO. 6 UCSP R µdfn L UCSP.EPS 7

8 Package Information (continued) For the latest package outline information and land patterns, go to D E e b N SOLDER MSK COVERGE PIN 1.1x45 6, 8, 1L UDFN.EPS L L1 PIN 1 INDEX RE SMPLE MRKING 7 (N/2-1) x e) 1 LC LC b L L 2 e e 1 EVEN TERMINL ODD TERMINL PCKGE OUTLINE, 6, 8, 1L udfn, 2x2x.8 mm B 1 2 8

9 Package Information (continued) For the latest package outline information and land patterns, go to COMMON DIMENSIONS SYMBOL MIN. NOM. MX D E L L1.1 REF. PCKGE VRITIONS PKG. CODE N e b L BSC.3±.5 L822-1 L BSC.4 BSC.25±.5.2±.3 (N/2-1) x e 1.3 REF. 1.5 REF. 1.6 REF. PCKGE OUTLINE, 6, 8, 1L udfn, 2x2x.8 mm B 2 2 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 12 San Gabriel Drive, Sunnyvale, C Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.