FSA2000UMX

FSA2000 Auto-Selecting HS-USB Switch with Cap-Free Headphone Audio Amplifier Description Features Switch Type Switch Mechanism USB Detection The FSA2000 is a low-cost integrated HS-USB and audio switch that incorporates an audio headphone amplifier. This solution eliminates many of the discrete parts currently used in stereo headset applications. It provides stereo headphone drivers designed to operate with a ground-centered output signal. This allows for the removal of large and expensive DC blocking capacitors. The headphone drivers are capable of driving up to 40mWRMS per channel. USB + Headphone Amplifier Auto (USB with VBUS) YES USB 2.0 High Speed & Full-Speed Compliant Class AB 40mWRMS (32Ω) 0dB 0.1% -90dB -95dB 2.7 to 4.3V 3mA 6µA 16- Lead UMLP 1.80 x 2.60 x 0.55mm, 0.40mm pitch FSA2000UMX USB Audio Amplifier Amplifier Output Power Amplifier Gain THD+N SNR PSRR VCC ICC (Audio) ICC(USB) Package Ordering Information Related Resources       FSA2000 Demonstration Board FSA2000 Evaluation Board FDB323 — FSA2000 Demonstration Board User Guide FEB322 — FSA2000 Evaluation Board User Guide AN-8032 — Demonstration Board Quick-Start Guide AN-8031 — Utilizing the FSA2000 MUTE Function to Reduce Audio “Click” and “Pop”  For samples, questions, or board requests; please contact: Analog.Switch@fairchildsemi.com. Applications  MP3 Portable Media Players  Cellular Phones, Smartphones Typical Application Auto Switches to USB when VBUS present USB Data Cable FS / HS USB D+ USB TX D+/ R D- + - 0.1µF R Audio Subsystem 0.1µF L Headphone Amplifiers + - V+ OR V- D-/ L V+ 32Ω 32Ω V- Eliminates large 220µF capacitors Figure 1. Mobile Phone Example © 2009 Fairchild Semiconductor Corporation FSA2000 • Rev. 1.0.0 www.fairchildsemi.com FSA2000 – Auto-Selecting HS-USB Switch with Cap-Free Headphone Audio Amplifier March 2013 Pin # Name Type Description 1 D+ I/O USB D+ port from processor or transceiver 2 D- I/O USB D- port from processor or transceiver 3 R Input Right audio channel input 4 L Input Left audio channel input 5 VCC Audio Supply 6 MUTE Input Control pin intended to be used temporarily to quiet transients on the audio path upon transition of /SHDN. Ground if not being used. 7 /SHDN Input Shutdown Enable (Requires VCC only) 8 GND GND IC ground Supply voltage for audio amplifiers, charge pump, and audio control; not required for USB path 9 D-/L I/O Common USB/Audio Port; USB D- data to connector or left audio channel output 10 D+/R I/O Common USB/Audio Port; USB D+ data to connector or right audio channel output 11 VBUS Input/Supply 12 V+ Node Node for filtering internal positive amplifier rail; suggest 1µF to GND 13 V- Input Negative amplifier rail input; suggest 1µF to GND. Requires connection to CPO. 14 CPO Output 15 CM I/O Charge pump negative flying capacitor pin; connect to CP via storage capacitor, typically 1µF. 16 CP I/O Charge pump positive flying capacitor pin; connect to CM via storage capacitor ,typically 1µF. USB input select pin and USB supply Charge pump output used to drive V-, suggest 2.2 µF to GND for filtering. Pin Configuration D+ CP CM CPO V- 16 15 14 13 Charge Pump & Voltage Regulator 1 12 V+ 3MΩ D- 2 11 R 3 V- Switch V+ + - VBUS 10 D+/R V+ + - L 4 9 V- D-/L Audio / Click & Pop Control 5 6 7 8 VCC MUTE /SHDN GND Figure 2. FSA2000UMX (Top View) © 2009 Fairchild Semiconductor Corporation FSA2000 • Rev. 1.0.0 www.fairchildsemi.com 2 FSA2000 – Auto-Selecting HS-USB Switch with Cap-Free Headphone Audio Amplifier Pin Descriptions Functional Mode Power Down Audio Power Down Transient Suppression Audio Mode USB Mode VBUS LOW LOW LOW LOW HIGH VCC LOW HIGH HIGH HIGH X(1) LOW HIGH HIGH X HIGH LOW X (1) (1) /SHDN X MUTE X X Charge Pump OFF OFF ON ON OFF R/L Amplifiers OFF OFF OFF ON OFF D+/R, D-/L HI-Z HI-Z D+/R, D-/L=0V R/L D+/D- Figure 3 Label A B C D E (1) (1) (1) Notes: 1. The (X) indicates “Don’t Care” state. A B C D C B E VCC Audio Control /SDHN MUTE R L USB Control VBUS D+ D- Audio Mode USB Mode D+/R D-/L Figure 3. Functional Diagram  Audio Power Down –An active-LOW shutdown pin (/SHDN) allows the amplifiers to be placed in low-power (or shutdown) mode to conserve battery power. While the FSA2000 is in shutdown mode, USB data transfers are allowed whenever a USB cable is connected to a host (VBUS is HIGH). The audio amplifiers are enabled and connected to the common port when /SHDN is HIGH and VBUS is LOW.  Transient Suppression – The FSA2000 audio amplifier has a soft turn-on feature that suppresses click and pop on the audio path when the path is selected. In addition to the soft turn-on feature of the amplifier, the MUTE pin mutes the audio path when asserted HIGH. The mute functionality also has an internal pull-down that disables mute if the MUTE pin is floated. The MUTE pin allows control of the mute functionality by the application. Please refer to application note AN-8031, describing the recommended timing and control of MUTE for optimal performance. © 2009 Fairchild Semiconductor Corporation FSA2000 • Rev. 1.0.0 www.fairchildsemi.com 3 FSA2000 – Auto-Selecting HS-USB Switch with Cap-Free Headphone Audio Amplifier Functional Diagram 1µF D+ 2.2µF 1µF CP CM CPO V- 16 15 14 13 Charge Pump & Voltage Regulator 1 12 V+ 1µF HS USB TX D- 2 11 R Audio Subsystem 3 V- ZIN 0.1µF Switch V+ + - Ci VBUS 10 D+/R V+ + - Ci L 4 0.1µF 0.1µF D-/L USB Port Audio / Click & Pop Control 2.7 – 4.3V 1µF 9 V- ZIN 5 6 7 8 VCC MUTE /SHDN GND Figure 4. Micro-USB Application Application Guidelines  Device Placement – Minimize to USB port & USB TX.  PIN 1, 2, 9, 10 – Minimize and match trace lengths for USB compliance. device as possible for DC-blocking and setting lowfrequency response of audio amplifier. The input capacitors combine with the input impedance of the amplifiers to form a high-pass filter. Equation 1 can be used to calculate the -3dB cut-off frequency of the highpass filter for the given input capacitor value and the FSA2000 input impedance. 1 2  ZINCi 17.7 Hz  1 2 (90k)(0.1F )  It is desirable to be below the 20Hz audio range. Users have flexibility to adjust capacitor for audio  PIN 5 – Use standard decoupling devices, 0.1µF & 1µF capacitors; as close to the device as possible.  PIN 3, 4 – Suggest 0.1µFcapacitor as close to the f3 dB  performance in the system design. Equation 2 shows the cut-off frequency of the recommended guidelines. (1) (2)  PIN 8 – Minimize ground trace length between headphone connector and device; minimize ground path resistance.  PIN 12 – Suggested 0.1µFcapacitor to GND for filtering; as close to the device as possible.  PIN13, 14 – Use low-ESR (equivalent series resistance) ceramic capacitors for lowest charge pump impedance, which provides maximum output power of the audio amplifiers. Recommended to place the components as close as possible to the device.  PIN15, 16 - The charge pump has been optimized for lowESR ceramic capacitors for the flying capacitor between CP and CM, along with the output capacitors on V+, CPO, and V-. Optimized values for these capacitors are in Figure 4. © 2009 Fairchild Semiconductor Corporation FSA2000 • Rev. 1.0.0 www.fairchildsemi.com 4 FSA2000 – Auto-Selecting HS-USB Switch with Cap-Free Headphone Audio Amplifier Functional Description USB Compliance over the behavior of the amplifier during startup and power down. The MUTE pin forces the audio outputs into a known and controlled state so that any transients of the amplifier are not propagated to the headphones as clicks and pops. Figure 6 shows the correct timing of the MUTE pin in relation to the /SHDN pin for optimal click and pop performance. Figure 6. Power-Up and Power-Down Timing Figure 5. High-Speed USB 2.0 Eye Compliance (5.5V) Transient Suppression A common issue with headphone amplifiers is audible noises through the headset when the amplifier is powering up or down. Sharp transients often occur on the audio outputs during this transition that cause audible “click and pop.” The FSA2000 prevents these transients during power-up by muting the outputs until the internal charge pumps are stable. This ensures that any transients caused by the charge pump are not propagated to the outputs. In cases where the application needs a longer startup time for mute, the FSA2000 has a MUTE pin that allows application control Table 1. Recommended MUTE Timing Parameter Description Suggested Timing TMUTEPU_SETUP MUTE setup time to /SHDN rising edge >500ns TMUTEPU_HOLD MUTE hold time to /SHDN rising edge ~500ns TMUTEPD_SETUP MUTE setup time to /SHDN falling edge >500ns TMUTEPD_HOLD MUTE hold time to /SHDN falling edge ~500ns © 2009 Fairchild Semiconductor Corporation FSA2000 • Rev. 1.0.0 www.fairchildsemi.com 5 FSA2000 – Auto-Selecting HS-USB Switch with Cap-Free Headphone Audio Amplifier Detailed Description Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The absolute maximum ratings are stress ratings only. Symbol Parameter VCC Supply Voltage VBUS Min. Max. Audio Mode -0.3 +4.5 USB Mode -0.3 +6.0 Unit V Supply Voltage -0.3 +6.0 V VCNTRL Control Pin Voltage - /SHDN, MUTE -0.3 +6.0 V VSWUSB USB I/O VBUS – 6.0 VBUS + 0.3 V VSWAUDIO Audio I/O VCC – 6.0 VCC + 0.3 V Switch I/O Current (Continuous) 30 mA Peak Switch I/O Current (Pulsed, 1ms Duration,