Silicon Labs Si590 Crystal Oscillator Addresses Lower Frequency, Cost-Sensitive Applications
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The Si590/591/595 XO/VCXOs expand Silicon Labs’ portfolio of high performance DSPLL-based crystal oscillators to address lower frequency, more price-sensitive applications that do not require guaranteed sub 1 ps rms jitter performance. These low jitter oscillators leverage proven 3rd generation DSPLL technology to dramatically simplify the XO/VCXO manufacturing flow. The DSPLL generates any frequency from 10 MHz to 525 MHz from a common, low frequency fundamental mode crystal. The output frequency is set by trimming the DSPLL using digital control with better than 1ppb resolution while providing unrivaled any-rate frequency flexibility and jitter performance. In addition, the Si590/591/595 supports a wide range of ordering options, including output format (CMOS, LVPECL, LVDS and CML) and supply voltage (3.3V, 2.5V and 1.8V). The Si59x is available in an industry-standard 5 x7 mm footprint and supports an operating temperature range of -40 to +85o C operation. The Si590/591 XOs can be used to establish reference clocks that are stable within ±30ppm ±50ppm or ±100ppm across all conditions.
The Si595 single frequency VCXO includes an ADC that digitizes a control voltage. The digital output of the ADC tunes the output frequency to implement a VCXO. Since the VCXO is controlled digitally, it offers extremely linear control voltage gain (Kv). To provide additional design flexibility and drop-in compatibility with existing designs, the Si595 supports five Kv options (45, 95, 125, 185 and 380 ppm/V). Selectable Kv options allow PLL designers to optimize phase noise and absolute pull range for a given application.
Simplified Manufacturing Flow
The Si59x product family uses Silicon Labs’ advanced DSPLL technology to greatly simplify the XO/VCXO manufacturing process. All devices leverage a common, easy to manufacture low frequency fundamental mode crystal as the frequency reference. Any-rate frequency synthesis is performed by the low jitter DSPLL IC, eliminating the need for custom frequency crystals or expensive 3rd overtone crystals required by traditional XO/VCXO solutions. This simplification shortens the lead time for XO/VCXOs from 8-14 weeks to 2 weeks (samples) / 4 weeks (production orders).
Features
- 1ps max jitter (0.5ps typical)
- 10 MHz to 525 MHz output frequency range
- LVPECL, CMOS, LVDS, CML output formats
- 3.3V, 2.5V or 1.8V supply voltage
- ±30, ±50, ±100ppm total stability (Si590/591)
- Multiple Kv options (Si595)
- -40C to 85 oC operating temperature range
- Industry-standard 5mm x 7mm package