Si5338-EVB Si5330/34/35/38 EVALUATION BOARD USERS GUIDE Description EVB Features The Si5338-EVB is used for evaluating the Si5330/34/ Fully powered from a single USB port. 35/38 family of any-frequency, any-output clock Onboard 25 MHz XTAL allows standalone generators and clock buffers. asynchronous operation on the Si5334/35/38. GUI programmable V supply allows device to DD operate from 3.3, 2.5, or 1.8 V. GUI programmable V supplies allow each of the DDO four outputs to have its own supply voltage selectable from 3.3, 2.5, 1.8, or 1.5 V GUI-controlled voltage, current, and power measurements of V and all four V supplies. DD DDO Voltage supply jumpers allow easy access for use of external supplies or current measurements. Input signal jumpers allow external control of pin functions such as output enable, phase inc/dec, frequency inc/dec, and I2C LSB. Rev. 1.5 3/20 Copyright 2020 by Silicon Labs Si5338-EVBSi5338-EVB 1. Functional Block Diagram 2 A functional block diagram of the EVB is shown in Figure 1. The MCU performs the USB to I C conversion, controls the voltage regulators, monitors the INTR pin, and controls the four status LEDS. It also provides control of the eight input pins when the INx CTRL jumpers are populated. There are five programmable voltage regulators (VDD, VDDO0, VDDO1, VDDO2, VDDO3), which supply power to the Si533x device. VDD and VDDO jumpers 2 allow the option of powering the device from external supplies, or as a convenient point for measuring current. I C 2 2 jumpers allow disconnection of the Si533x device from the I C bus to allow external control from another I C master. For the Si5334, Si5335, and Si5338 devices, the EVB is shipped with an onboard 25 MHz XTAL to allow stand-alone asynchronous operation. For Si5335 emulation, synchronization to an external reference is done via IN1 and IN2. Removal of the XTAL and addition of two 0 ohm resistors is required. IN3, IN4, IN5, and IN6 are not available as external clock inputs for Si5335. To VReg I2C VReg To VReg Bus I2C VReg VReg VDD Bus Jumpers XTAL VDDO Jumpers VDD * IN1 VDDO0 0 * IN2 CLK0A term* 0 term * CLK0B IN3 term * term* VDDO1 IN4 CLK1A term* term* CLK1B IN5 Si5338 IN6 VDDO2 CLK2A IN7/SCL term * term* CLK2B IN8/SDA I2C Jumpers VDDO3 CLK3A term* term * CLK3B INTR INx CTRL Jumpers * indicates unpopulated components Status MCU LEDs USB Connector Reset Switch Figure 1. EVB Functional Block Diagram 2 Rev. 1.5 I2C Bus