SI4123-EVB Silicon Laboratories Inc, SI4123-EVB Datasheet - Page 2

• Manufacturer Part Number: SI4123-EVB
• Description: BOARD EVALUATION FOR SI4123
• Manufacturer: Silicon Laboratories Inc
• Type: Synthesizerr

Specifications of SI4123-EVB

• Contents: Board and CD-ROM
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: SI4123
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Si4133/33G-EVB
Functional Description
The evaluation board accommodates the synthesizer by
providing clock circuitry, a PC interface, and other
support circuitry necessary for operation.
Synthesizer
The heart of the evaluation board is the Silicon
Laboratories
includes the synthesizer integrated circuit (IC), external
tuning components, output matching, and power supply
decoupling circuitry.
For devices requiring an external inductor to establish
the center frequency for the RF1 and RF2 synthesizers,
the inductor is implemented with a printed trace. The IF
synthesizer inductor is set by an 0402-size chip
inductor. The inductors are set for the nominal center
frequencies shown in Table 1.
Outputs of the synthesizers are ac-coupled and
matched to a 50
are provided for easy connection to measurement
equipment or to target systems. Output JRF1 is
multiplexed between the RF1 and RF2 synthesizers and
is toggled through the evaluation software. See the
synthesizer data sheet for more detail. The second
output, JIF1, is connected to the IF synthesizer output.
Clock Circuitry
The reference frequency for the synthesizer is
generated on-board by a temperature-compensated,
voltage-tuned, crystal oscillator. The circuit is flexible to
allow evaluation with an external reference source or
with different frequency oscillators in varying packages.
Header JP6 selects the reference frequency source to
the frequency synthesizer IC. Either the on-board
oscillator or the external SMA input, J8, can be
selected.
The tuning control of the oscillator, Vc, is fixed at
2
frequency
Si4133G-X2
Si4113G-X5
Si4133W
Si4133G
Si4114G
Device
Si4133
Si4135
Si4136
load impedance. SMA connectors
synthesizer.
Table 1. Center Frequencies
This
Frequency (MHz)
Preliminary Rev. 0.5
section
RF1 Center
1600
1600
1600
1540
1920
2360
1750
2400
Both the multiplexed RF output and the IF output can be
active simultaneously. Synthesizers are independently
enabled using the radio buttons in the evaluation
software.
The synthesizer IC is supplied by three different power
supplies. VDDR supplies the analog circuitry for the
RF1 and RF2 synthesizers. VDDI supplies the analog
circuitry for the IF synthesizer, and VDDD supplies the
digital prescaler, serial interface, and reference input
circuitry. Each of these supplies is bypassed to ground
with a 22 nF capacitor close to the body of the IC.
PC Interface
The frequency synthesizer IC uses a serial interface for
programming. The three primary signals are serial data
(SDATA), serial clock (SCLK), and serial enable
(SENB). These are all mapped to data pins of the PC’s
parallel port. Data is read back from the IC using the
BUSY input of the parallel port and SCLK.
One additional signal, GPO, is a multipurpose signal
used to control the synthesizer’s hardware power-down
enable (PWDNB) and/or to trigger external test
equipment. The intended use is for power-up and
channel-to-channel settling time measurements. See
the "Evaluation Software" section for more detail.
(Vsupply/2) by R19 and R20. C14 provides filtering for
noise reduction on the tuning input. Test points JP9 and
JP10 allow easy connection to the tuning voltage for
external frequency trimming or reference modulation.
Power Supplies
The evaluation board requires a 5 V supply at JP11 to
power the digital interface to the PC. The synthesizer’s
supply voltage can be taken from the on-board 3 V
regulator or a user-supplied voltage at JP11 depending
on the jumper setting at JP4.
Frequency (MHz)
RF2 Center
1200
1200
1200
1365
1780
1200
2100
967
Frequency (MHz)
170.76, 420.76
IF Center
1080
550
550
N/A
N/A
760
550