ISL54222AIRUEVAL1Z Evaluation Board User’s Manual ® Application Note Description July 24, 2009 AN1450.1 Picture of Evaluation Board (Top View) The ISL54222AIRUEVAL1Z evaluation board is designed to provide a quick and easy method for evaluating the ISL54222A USB Switch IC. The ISL54222A device is a 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 device’s truth-table along with its pinout diagram in the data sheet is the best way to get a quick understanding of how the part works. A picture of the evaluation board is shown in Figure 1. The ISL54222A µTQFN IC is soldered onto the evaluation board. It is located in the center of the board and is designated as U1. The evaluation board contains USB connectors to allow the user to easily interface with the IC to evaluate its functions, features, and performance. For example, with the board properly powered and configured as shown in Figure 2, you can control the logic pins, SE and OE, to switch between the two high-speed USB devices while connected to a single USB host (computer). In a typical application, the ISL54222A dual SPDT device is used to select between two different USB transceiver sections of a media player. Logic control from a µprocessor determines which section to connect to the computer. To change channels, the following sequence would possibly be followed: 1. A signal would be sent to take the OE pin High, to open all switches. The off-isolation of the ISL54222A device would allow the present active channel to properly disconnect from the computer. 2. The SEL pin would be set to select the other USB channel. FIGURE 1. ISL54222AIRUEVAL1Z EVALUATION BOARD Features • Standard USB Connectors • Standard Banana Jacks for Power, Ground, VBUS and Logic Connections • Jumpers to Allow a Device to be Powered Through the Host Controller • Convenient Test Points and Connections for Test Equipment 3. The OE pin would then be taken Low to close the switches to make the connection between the computer and the other USB section of the player. This application note will guide the user through the process of configuring and using the evaluation board to evaluate the ISL54222A device. 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2009. All Rights Reserved All other trademarks mentioned are the property of their respective owners. Application Note 1450 Board Architecture/Layout Basic Layout of Evaluation Board The basic layout of the main board is as follows: (Refer to Figure 1). 1. Power and Ground connections are at the top of the board at banana jacks (J1 and J2). 2. Logic connections, SEL and OE , are at the top of the board at banana jacks (J4 and J3). 3. USB connection to an upstream host controller (Computer) is made at J5, located on the left side of the board. 4. USB connections to downstream USB devices are made at connectors J6 and J7, located on right side of the board. 5. VBUS voltage for the USB devices are made through banana jacks J8 and J9. Optionally, VBUS for the USB devices can be connected to the Host Controller VBUS through jumpers JP4 and JP5. 6. Located in the center of the board is the ISL54222A IC (U1). The eval board has a pin 1 dot, to show how the IC should be oriented onto the evaluation board. The IC pin 1 indicator dot needs to be aligned with the evaluation board pin 1 dot indicator. IC Power Supply A DC power supply connected at banana jacks J1 (VDD) and J2 (GND) provides power to the ISL54222A IC. The IC requires a 1.8VDC to 3.3VDC power supply for proper operation. The power supply should be capable of delivering 100µA of current. VBUS Power Supply A DC power supply connected at banana jacks J8 (VBUSCH1) and J9 (VBUSCH2) provides the VBUS voltage required by the USB devices. The devices require a DC power supply in the range of 4.4V to 5.25V for proper operation. The power supply should be capable of delivering 100µA of current. Logic Control The state of the ISL54222A device is determined by the voltage at the SEL pin and the OE pin. Access to the SEL pin is through the banana jack J4 (SEL), and access to the OE pin is through the banana jack J3 (OE). If SEL is driven Low (to ground) and EN = Low (to ground), the high-speed (HS) Channel 1 switches will be ON. In this state, the USB host controller (computer) connected at J5 will be connected through to the USB device connected at J6 and data will be able to be transmitted between the computer and the device. If SEL is driven High (>1.4V) and EN = Low (to ground), the high-speed (HS) Channel 2 switches will be ON. In this state, the USB host controller (computer) connected at J5 will be connected through to the USB device connected at J7 and data will be able to be transmitted between the computer and the device. If OE = High (>1.4V), all switches will be OFF. Neither device will be connected through to the host controller. In a typical application, the ISL54222A dual SPDT device is used to select between two different USB transceiver sections of a media player. Logic control from a µprocessor determines which section to connect to the computer. To change channels, the following sequence would possibly be followed: 1. A signal would be sent to take the OE pin High, to open all switches. The off-isolation of the ISL54222A device would allow the present active channel to properly disconnect from the computer. 2. The SEL pin would then be set to select the other USB channel. 3. The OE pin would then be taken Low to close the switches to make the connection between the computer and the other USB section of the player. USB Connections The VBUS voltage can be provided from the USB host controller (computer) by installing a jumper at either JP4 or JP5. A “B” type USB receptacle labeled “USB TO HOST” (J5) is located on the left side of the board. This receptacle should be connected using a standard USB cable to the upstream USB host controller, which is usually a PC computer or hub. When this connection is made, the ISL54222A device will connect the computer through to the USB device determined by the voltage at the SEL logic control pin. With a jumper at JP4, the VBUS voltage from the J5 “B” type USB receptacle gets routed to the J6 USB connector. With this jumper installed, no DC supply should be connected at the J8 (VBUSCH1) banana jack. An “A” type USB receptacle labeled “USB TO DEVICE 1” (J6) is located on the right side of the board. The USB device can be plugged directly into this receptacle or through a standard USB cable. With a jumper at JP5, the VBUS voltage from J5 “B” type USB receptacle gets routed to the J7 USB connector. With this jumper installed, no DC supply should be connected at the J9 (VBUSCH2) banana jack. An “A” type USB receptacle labeled “USB TO DEVICE 2” (J7) is located on the right side of the board. The USB device can be plugged directly into this receptacle or through a standard USB cable. The J8 banana jack is connected to the VBUS pin of the J6 “A” type USB receptacle. The J9 banana jack is connected to the VBUS pin of the J7 “A” type USB receptacle. 2 AN1450.1 July 24, 2009 Application Note 1450 The USB switches are bi-directional, which allows the host (computer) and downstream USB device to both send and receive data. High-Speed Switches The four HSx switches (HSD1-, HSD1+, HSD2-, HSD2+) are bi-directional switches that can pass rail-to-rail signals. When powered with a 1.8V supply, these switches have a nominal rON of 5.7Ω over the signal range of 0V to 400mV with a rON flatness of 0.60Ω. The rON matching between the HSDx- and HSDx+ switches over this signal range is only 0.072Ω ensuring minimal impact by the switches to USB high speed signal transitions. As the signal level increases, the rON switch resistance increases. At signal level of 1.8V the switch resistance is nominally 12Ω. The HSx switches were specifically designed to pass USB 2.0 high-speed (480Mbps) differential signals typically in the range of 0V to 400mV. They have low capacitance and high bandwidth to pass the USB high-speed signals with minimum edge and phase distortion to meet USB 2.0 high speed signal quality specifications. The HSx switches can also pass USB full-speed signals (12Mbps) with minimal distortion and meet all the USB requirements for USB 2.0 full-speed signaling. The maximum normal operating signal range for the HSx switches is from 0V to 3.3V. The signal voltage should not be allow to exceed the 3.3V or go below ground by more than -0.3V for normal operation. 3 However, in the event that the USB 5.25V VBUS voltage gets shorted to one or both of the D-/D+ pins, the ISL54222A has special fault protection circuitry to prevent damage to the ISL54222A part. The fault circuitry allows the signal pins (D-, D+, HS1D-, HS1D+, HS2D-, HS2D+) to be driven up to 5.5V while the VDD supply voltage is in the range of 0V to 3.3V. In this condition, the part draws < 300µA of current and causes no stress to the IC. In addition, when VDD is at 0V, (ground) all switches are OFF, and the fault voltage is isolated from the other side of the switch. When VDD is in the range of 1.8V to 3.3V, the fault voltage will pass through to the output of an active switch channel. TABLE 1. BOARD COMPONENT DEFINITIONS DESIGNATOR DESCRIPTION U1 ISL54222AIRUZ IC J5 “B” type USB Receptacle J6, J7 “A” type USB Receptacle J1 VDD Positive Connection J2 VDD Negative Connection J4 SEL Logic Control J3 OE Logic Control J8 VBUS Voltage for Highspeed Device 1 J9 VBUS Voltage for Highspeed Device 2 JP1, JP2, JP3 D-/D+ Differential Probe Connection JP4, JP5 Host Controller VBUS Jumper AN1450.1 July 24, 2009 Application Note 1450 DC POWER SUPPLY +1.8V + - DC POWER SUPPLY +5V + - LOGIC CONTROL COMPUTER J4 OE GND VDD SEL USB PORT J1 J2 VBUSCH1 J3 J8 JP4 USB TO DEVICE 1 USB TO HOST U1 USB HIGH-SPEED DEVICE 1 J6 J5 JP1 JP2 JP5 USB TO DEVICE 2 J7 USB HIGH-SPEED DEVICE 2 JP3 VBUSCH2 J9 ISL54222AEVAL1Z EVALUATION BOARD NOTE: DISCONNECT THE +5V POWER SUPPLY CONNECTED TO J8 AND J9 WHEN POWERING THROUGH HOST CONTROLLER BUS. FIGURE 2. BASIC EVALUATION TEST SETUP BLOCK DIAGRAM Using The Board (Refer to Figure 2) 4. Remove jumpers JP4 and JP5. Lab Equipment 5. Drive the OE control pin HIGH to open all switches of the ISL54222A IC. The equipment, external supplies and signal sources needed to operate the board are listed in the following: 6. Connect USB cable from host (PC computer) to the USB “B” type receptacle, J5 (USB TO HOST). 1. +1.8V to +3.3V DC Power Supply High-Speed Channel 1 Operation 2. +5V DC Power Supply 1. Apply a logic LOW to the SEL pin. 3. Two High-Speed USB device (i.e. USB memory stick, MP3 Player, etc.) 2. Apply a logic LOW to the OE pin. 4. Computer with 2.0 High-Speed USB port 5. Standard USB Cable 6. Logic Controller Initial Board Setup Procedure 1. Attach the main evaluation board to a DC power supply at J1 (VDD) and J2 (GND). Positive terminal at J1 and negative terminal at J2. The supply should be capable of delivering 1.8V to 3.3V and 100µA of current. Set the supply voltage to 1.8V. 2. Connect a DC power supply at J8 (VBUSHCH1) and J9 (VBUSCH2). Positive terminal at J8 and J9 and negative terminal at J2 (GND). The supply should be capable of delivering 5V and 100mA of current. Set the supply voltage to 5V. This supply will provide 5V at the VBUS pin of the USB “A” type connectors, J6 and J7. 3. You should now be able to send and receive data between the computer and the USB device 1 connected at J6. 4. To disconnect the USB device 1 from the computer take the OE pin HIGH. High-Speed Channel 2 Operation 1. Apply a logic HIGH to the SEL pin. 2. Apply a logic LOW to the OE pin. 3. You should now be able to send and receive data between the computer and USB device 2 connected at J7. Test Points The board has various test points for ease of connecting probes to make measurements. The test points available are described in Table 2. 3. Connect one high-speed USB device at USB connector J6 and the other high-speed USB device at USB connector J7. These connectors are located on the right side of the evaluation board. 4 AN1450.1 July 24, 2009 Application Note 1450 You can observe the D- and D+ USB signal of the High-Speed Channel 1 on an oscilloscope or other test equipment by connecting a differential probe at JP2. TABLE 2. TEST POINT DESCRIPTIONS DESIGNATOR DESCRIPTION You can observe the D- and D+ USB signal of the High-Speed Channel 2 on an oscilloscope or other test equipment by connecting a differential probe at JP3. TP1 VDD test point TP2 Ground Test Point TP3 OE Test Point TP5 SEL Test Point TP6 VBUS from Pin 1 of Connector J5 Test Point JP1 D-/D+ Differential Probe Connection - COM Side of Switch JP2 D-/D+ Differential Probe Connection - Device 1Side of Switch JP3 D-/D+ Differential Probe Connection - Device 2Side of Switch You can observe the D- and D+ USB signal at the COM side of the switch on an oscilloscope or other test equipment by connecting a differential probe at JP1. ISL54222AIRUEVAL1Z Board Schematic 1 2 JP2 4 C4 1 3 A U1 1 1 2 2 A 2 4JP3 C5 3 3 4 4 5 5 1 3 2 JP1 4 1 J8 VBUSCH1 J9 VBUSCH2 4 MOUNT A 2 JP5 1 1 A 1 JP42 1 1 2 6 USB 897-30-004-90-000 4 3 USB TO J5 HOST A 32 C3 0.1UF 5 MOUNT A A TP6 1 A 1 3 DIFFPROBE 5 MOUNT 1 2 3 USB 4 TO 6 DEVICE2 MOUNT J7 A DUSB_ARA42_T11A 1 24 3 UTQFN10 7 7 6 6 5 MOUNT 1 USB 2 TO 3 DEVICE1 4 6 MOUNT J6 A DUSB_ARA42_T11A 1 24 3 10 10 9 9 8 8 A 0.1UF 0 1 TP2 0.1UF 1 TP1 R2 C1 10UF C2 0.1UF TP3 1 1 1 OE J3 GND J2 1 0 1 VDD J1 R1 SEL J4 TP5 Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that the Application Note or Technical Brief is current before proceeding. For information regarding Intersil Corporation and its products, see www.intersil.com 5 AN1450.1 July 24, 2009