STW81102ATR STMicroelectronics, STW81102ATR Datasheet - Page 19

• Manufacturer Part Number: STW81102ATR
• Description: IC SYNTHESIZER MULTI RF 28VFQFPN
• Manufacturer: STMicroelectronics
• Type: Frequency Synthesizerr

Specifications of STW81102ATR

• Pll: Yes
• Input: Clock, Crystal
• Output: Clock, Crystal
• Number Of Circuits: 1
• Ratio - Input:output: 3:2
• Differential - Input:output: No/No
• Frequency - Max: 4.65GHz
• 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: 4.65GHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

STW81102
5
5.1
5.2
5.3
Circuit description
Reference input stage
The reference input stage is shown in
F
Figure 15. Reference frequency input buffer
Reference divider
The 10-bit programmable reference counter allows division of the input reference frequency
to produce the input clock to the PFD. The division ratio is programmed through the digital
interface.
Prescaler
The dual-modulus prescaler P/P+1 takes the CML clock from the VCO buffer and divides it
down to a manageable frequency for the CMOS A and B counters. The modulus P is
programmable and can be set to 16 or 19. The prescaler is based on a synchronous 4/5
core whose division ratio depends on the state of the modulus input.
ref
F
ref
input while the inverter used as the frequency reference buffer is AC coupled.
VDD
Figure 15
. The resistor network feeds a DC bias at the
INV
Power Down
Circuit description
BUF
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