Overview
The FSA221L10X, produced by Fairchild Semiconductor, is a Double-Pole, Double Throw (DPDT) multiplexer designed to combine low-distortion audio and USB2.0 High-Speed (HS) switch paths. This component enables the sharing of the D+/D- lines of a USB connector with stereo audio CODEC outputs, making it ideal for portable devices such as cell phones, PDAs, digital cameras, and notebooks. The FSA221L10X features automatic Vbus detection and power-off protection to minimize current consumption when Vbus is not present, enhancing its suitability for ultra-portable applications.
Key Specifications
| Parameter | Typical Value | Unit | Conditions |
|---|---|---|---|
| On Resistance (HS-USB) | 4Ω | - | - |
| On Capacitance (HS-USB) | 4.5pF | - | - |
| On Resistance (Audio) | 3Ω | - | - |
| -3db Bandwidth | > 720MHz | - | - |
| Supply Voltage (VAUDIO / VBUS) | -0.5 to 6.0V | V | - |
| Switch I/O Voltage (D+, D-, D+/R, D-/L Pins) | VBUS -7.0 to VBUS +0.3V | V | - |
| Control Input Voltage (ASel) | -0.5 to 6.0V | V | - |
| Turn-On Time (VAUDIO↑ to Output) | 10μs | - | VBUS=0V, VD+/R, D-/L=1.0V, RL=50Ω, CL=50pF |
| Turn-Off Time (VBUS↑ to Output) | 10μs | - | VAUDIO=3.0V, VD+/R, D-/L=1.0V, RL=50Ω, CL=50pF |
Key Features
- Combines low-distortion audio and USB2.0 High-Speed switch paths.
- Automatic Vbus detection for switch path selection.
- Power-off protection on common D+/R, D-/L ports to minimize current consumption.
- Handles negative audio signals down to -2V, eliminating the need for large coupling capacitors.
- Low power consumption.
- ASel pin for software-controlled switching between USB and audio modes.
- High bandwidth (> 720MHz) and low on-resistance (4Ω for HS-USB, 3Ω for audio).
Applications
- Cell phones, PDAs, digital cameras, and notebooks.
- LCD monitors, TVs, and set-top boxes.
- Portable media players and other consumer electronics.
- Devices requiring shared USB and audio connectors.
Q & A
- What is the primary function of the FSA221L10X?
The FSA221L10X is a DPDT multiplexer that combines low-distortion audio and USB2.0 High-Speed switch paths, allowing audio and USB data to share a common connector port.
- What is the typical on-resistance for the HS-USB path?
The typical on-resistance for the HS-USB path is 4Ω.
- How does the FSA221L10X handle negative audio signals?
The FSA221L10X can handle negative audio signals down to -2V, eliminating the need for large coupling capacitors.
- What is the purpose of the ASel pin?
The ASel pin allows for software-controlled switching between the USB and audio modes, especially useful when Vbus is not guaranteed to be removed.
- What are the typical turn-on and turn-off times for the FSA221L10X?
The typical turn-on and turn-off times are both 10μs under specified conditions.
- What are the common applications for the FSA221L10X?
Common applications include cell phones, PDAs, digital cameras, notebooks, LCD monitors, TVs, and set-top boxes.
- How does the FSA221L10X minimize power consumption?
The FSA221L10X includes power-off protection on common D+/R, D-/L ports to minimize current consumption when Vbus is not present.
- What is the bandwidth of the FSA221L10X?
The bandwidth is greater than 720MHz.
- What are the package options for the FSA221?
The FSA221 is available in 10-Lead MicroPak™, 10-Lead MSOP, and 10-Lead Quad Ultrathin MLP packages.
- What is the supply voltage range for VAUDIO and VBUS?
The supply voltage range is from -0.5V to 6.0V for both VAUDIO and VBUS.
