STW81101AT STMicroelectronics, STW81101AT Datasheet - Page 23

• Manufacturer Part Number: STW81101AT
• Description: IC SYNTHESIZER MULTI RF 28VFQFPN
• Manufacturer: STMicroelectronics
• Type: Frequency Synthesizer (RF)r

Specifications of STW81101AT

• Pll: Yes
• Input: Clock, Crystal
• Output: Clock, Crystal
• Number Of Circuits: 1
• Ratio - Input:output: 3:2
• Differential - Input:output: No/No
• Frequency - Max: 4.4GHz
• Divider/multiplier: Yes/No
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-VFQFN, 28-VFQFPN
• Frequency-max: 4.4GHz
• Number Of Elements: 1
• Pll Input Freq (min): 10MHz
• Pll Input Freq (max): 200MHz
• Operating Supply Voltage (typ): 3.3V
• Operating Temp Range: -40C to 85C
• Package Type: VFQFPN
• Operating Supply Voltage (min): 3V
• Operating Supply Voltage (max): 3.6V
• Operating Temperature Classification: Industrial
• Pin Count: 28
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

STW81101
5.8
5.8.1
5.8.2
Voltage controlled oscillators
VCO selection
The STW81101 integrates two low-noise VCOs to cover a wide band from:
●
●
●
VCO A frequency range is 3300 MHz to 3900 MHz.
VCO B frequency range 3800 MHz to 4400 MHz.
VCO frequency calibration
Both VCOs can operate on 32 frequency ranges that are selected by adding or subtracting
capacitors from the resonator. These frequency ranges are intended to cover the wide band
of operation and compensate for process variation on the VCO center frequency.
The range is automatically selected when the SERCAL bit is set to 1. The charge pump is
inhibited, and the ICP and VCTRL pins are at VDD/2 volts. The ranges are then tested with
this VCO input voltage to select the one nearest to the desired output frequency
(F
After this selection, the SERCAL bit is automatically reset to 0 and the charge pump is once
again enabled.To enable a fast settle, the PLL needs only to perform fine adjustment around
VDD/2 on the loop filter to reach F
Figure 19. VCO sub-bands frequency characteristics
OUT
3300 MHz to 4400 MHz (direct output)
1650 MHz to 2200 MHz (selecting divider by 2)
825 MHz to 1100 MHz (selecting divider by 4)
= N*F
ref
/R).
OUT
.
Circuit description
23/53