USERS MANUAL ISL54210EVAL1Z AN1407 Rev 0.00 Evaluation Board January 23, 2009 Description Picture of Evaluation Board (Top View) The ISL54210EVAL1Z evaluation board is designed to provide a quick and easy method for evaluating the ISL54210 USB/Audio Switch IC. The ISL54210 device is an unique IC. To use this evaluation board properly requires a thorough knowledge of the operation of the IC. Refer to the data sheet for an understanding of the functions and features of the device. Studying the devices truth-table along with its pinout diagram is the best way to get a quick understanding of how the part works. A picture of the main evaluation board is shown in Figure 2. The ISL54210 TDFN IC is soldered onto the evaluation board. It is located in the center of the board and is designated as U1. The ISL54210 IC has three modes of operation called Audio mode, USB mode and Mute mode. The evaluation board contains standard Audio and USB connectors to allow the user to easily interface with the IC to evaluate its functions, features, and performance in these modes of operation. For example, when the board is properly powered, a headphone can be plugged into the headphone jack (J7) and a stereo source, such as an MP3 player, can be connected FIGURE 1. ISL54210EVAL1Z EVALUATION BOARD at the RCA connectors J3 (AUDIO LEFT) and J4 (AUDIO RIGHT) to play music through the audio switches of the IC. Board Architecture/Layout See Figure 2. You can then turn-off the audio source, remove the headphones, configure the logic for USB Basic Layout of Evaluation Board operation and then attach a USB cable from a computer to The basic layout of the main board is as follows (refer to the USB connector J1 (USB TO HOST). This will establish a Figure 1): connection from the computer through the USB switches of the IC to the USB device connected at the USB connector J2 The Power and Ground connections are at the top of the board (J10 and J11). (USB TO DEVICE), to send and receive data. The Logic control connections are at the top of the board This application note will guide the user through the process (J12 and J13). of configuring and using the evaluation board to evaluate the ISL54210 device in both the Audio mode and the USB The Audio Source Inputs are at the lower right side of the mode. board (J3 - J6). Audio outputs are at the lower left side of the board (J7, J8, J9). Connector J7 is a standard headphone jack for connecting a 32 headphone. Features The USB connection to an upstream host controller Standard USB Connectors (Computer) is made at connector J1, located on left RCA Audio Input Jacks and Headphone Speaker Jack under-side of the board. USB connection to a downstream USB device is made at connector J2, located on right Convenient Test Points and Connections for Test under-side of the board. Equipment Located in the center of the board is the ISL54210 IC (U1). The evaluation board has a pin 1 dot, to show how the IC should be oriented on to the evaluation board. The IC pin 1 indicator dot needs to be aligned with the evaluation board pin 1 dot indicator. AN1407 Rev 0.00 Page 1 of 7 January 23, 2009ISL54210EVAL1Z JP3 at location 2 to 3. This connects the J13 banana jack to the Power Supply V pin of the part. The DC power supply connected at banana jacks J10 (VDD) and BUS J11 (GND) provides power to the part. The IC requires a 2.7V to Audio Inputs 3.6V DC power supply for proper operation. The power supply The evaluation board has two audio inputs labeled AUDIO should be capable of delivering 100A of current. LEFT (J3 or J5) and AUDIO RIGHT (J4 or J6). Each of these inputs have a BNC connector wired in parallel with an RCA Logic Control jack connector. You can connect an audio source/generator at The state of the ISL54210 device is determined by the voltage either the BNC connector or the RCA connector. at the V pin and the CTRL pin. These logic pins have BUS internal 4M pull-down resistors and can be left floating. In a typical application the left and right outputs of a stereo source, such as an MP3 player, would be connect to the RCA Access to the CTRL pin is through the banana jack J12 jacks J3 and J4, respectfully. (CTRL). Over a signal range of 1V (0.707V ), these switches have Access to the V pin is through banana jack J13 (V ) RMS BUS BUS an extremely low r resistance variation. They can pass when jumper JP3 is in position 2 to 3 and through the USB J1 ON ground referenced audio signals with very low distortion (USB TO HOST) connector V line when the jumper JP3 is BUS (<0.05% THD+N) when delivering 15.6mW into a 32 in position 2 to 1. headphone speaker load. A 3V signal is acceptable but P-P If V is floating (no USB host controller connected at the J1 BUS performance will degrade. connector) and CTRL = High (J12 connected to J10), the part The audio channels are AC coupled with 100F capacitors. will be in the Audio mode. These capacitors remove any DC voltage from the audio If V is floating (no USB host controller connected at the J1 BUS signals and reference them to ground of the device. If the connector) and CTRL = Low or Floating, the part will be in the audio source being connected to the evaluation board already MUTE mode. In MUTE mode all switches are OPEN and the has internal AC coupling capacitors at the output of its drivers, click and pop circuitry on the L and R side of the switch is then the capacitors on the evaluation board should be shorted activated. out (replaced with 0 resistors). This will prevent further attenuation of the low frequency content of the audio signal If V is greater than V by 0.8V (USB computer V line BUS DD BUS due to the increase of the high-pass corner frequency resulting connected at the J1 USB connector), the part will be in the USB from the evaluation board capacitor in series with the audio mode. In a typical application, the V voltage from BUS source capacitor. computer/host controller will be in the range of 4.4V to 5.25V and the V voltage will be in the range of 2.7V to 3.6V. DD Audio Outputs When the computer is not connected at J1, the internal The evaluation board has a standard headphone jack labeled pull-down will pull the V pin low putting the ISL54210 in the HEADPHONE JACK (J7). A 32 stereo headphone should be BUS Audio mode or Mute mode depending on the condition of the plugged into this jack. CTRL pin. The BNC connector J8 (COM-) is in parallel with the audio left When a USB cable from the computer is connected at J1, the line of the headphone jack and the D- line of the J1 (USB To voltage at the V pin will be driven high and the part will HOST) connector. The BNC connector J9 (COM+) is in parallel BUS automatically go into the USB mode. with the audio right line of the headphone jack and the D+ line of the J1 (USB To DEVICE) connector. These BNC connectors When the USB cable is disconnected from the J1 connector, can be used to connect resistive loads and/or test equipment the voltage at the V pin will be pulled low by the pull-down BUS to evaluate the performance of the IC. resistor and return to the Audio mode or Mute mode depending on the condition of the CTRL pin. USB Connections Note: The evaluation board has the option of putting a 4M A B type USB receptacle labeled USB TO HOST (J1) is pull-down resistor from the V pin to ground by putting a located on the left under-side of the board. This receptacle BUS jumper at JP4. However, it is not required for the ISL54210 part should be connected using a standard USB cable to the because the V and CTRL pins have internal 4M pull- up-stream USB host controller, which is usually a PC computer BUS down resistors. These resistors pull the logic pins to ground or hub. When this connection is made, the ISL54210 device when J13, J1, or J12 are floated. will sense the V voltage from the host controller and go BUS into USB mode. The USB switches will be turned ON. Rather than using the V voltage from the computer to BUS control the V logic pin of the part through USB connector An A type USB receptacle labeled USB TO DEVICE (J2) is BUS J1 (USB TO HOST), you can drive the V pin through the located on the right under-side of the board. The USB device BUS banana jack J13 (V ). To control the part through the J13 can be plugged directly into this receptacle or through a BUS banana jack make the following connections: Install jumper standard USB cable. AN1407 Rev 0.00 Page 2 of 7 January 23, 2009