SI57X-EVB Datasheet, PDF (3/34 Pages) Silicon Laboratories – Si57X/598/599 ANY FREQUENCY I2C PROGRAMMABLE XO/VCXO EVALUATION BOARD

Si57x-EVB
1. Functional Description
The Si57x-EVB is the evaluation board assembly for the Si57x/598/599 any frequency I²C programmable XO/
VCO. This evaluation board assembly provides access to all signals for programming and operating the device.
The Si57x-EVB assembly motherboard and daughterboard schematics, bills of material, and PCB layouts are
appended as sections 5, 6 and 7, respectively. Reference designators below refer to the Si57x-EVB motherboard
unless otherwise noted. The Si57x-EVB is oriented with the daughterboard at the bottom in the directions below.
1.1. Motherboard-Daughterboard Connection
The Si57x-EVB motherboard connects to the Si57x daughterboard at connectors J13-J14. Each of these is a 2x20
pin, impedance controlled connector. The connectors are keyed so there is only one proper way to install the
board. Orient the boards on installation so that the silkscreen triangle on the daughterboard matches the silkscreen
on the motherboard.
1.2. Power Supply
The Si57x-EVB is pre-configured to accept 5 V from the USB connector at J15. To change the board's 5 V power
supply from the USB connection to the terminal block at J18, make these changes:
 Remove R7.
 Populate R8.
Note: If both R7 and R8 are installed, do not simultaneously connect to both the USB connector at J15 and to a separate 5 V
supply at J18. Otherwise, power supply contention may occur.
Typical supply current draw for the Si57x-EVB assembly (motherboard + daughterboard) is approximately 230 mA.
See the device data sheet for device power consumption specifications.
The evaluation daughter board are designed to operate at any of the following nominal voltages: 1.8, 2.5, or 3.3 V.
The Si57x-EVB has an on-board voltage regulator which supplies any of these voltages. The Si57x-EVB voltage
regulator is controlled via jumpers. By default, a jumper is installed, selecting 3.3 V for the Si57x/598/599.
Alternatively, VREG may be set to 1.8 or 2.5 V per Table 1.
Table 1. VREG Jumpers
Voltage
J6 Jumper Installation
Selection (Assuming S/W Control Unavailable)
3.3
Connect pin 1 “3.3 V” to center pin 2
2.5
Connect pin 3 “2.5 V” to center pin 2
1.8
No jumper
Rev. 0.2
3