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AK1547 Datasheet, PDF (16/37 Pages) Asahi Kasei Microsystems – 4GHz Low Noise Integer-N Frequency Synthesizer | |||
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[AK1547]
5ï¼Reference counter
The reference input can be set with a dividing number in the range of 1 to 16383 using {R [13:0]}, which is a 14-bit
address of {D[13:0]} in <Address0>. 0 cannot be set as a dividing number.
6ï¼Prescaler
The dual modulus prescaler (P/P + 1) and the swallow counter are used to provide a large dividing ratio.
The prescaler is set by {PRE[1:0]}, which is a 2-bit latch of {D[21:20]} in <Address2>.
{PRE[1:0]}=â00Binâ, P=8, Dual modulus prescaler 8/9
{PRE[1:0]}=â01Binâ, P=16, Dual modulus prescaler 16/17
{PRE[1:0]}=â10Binâ, P=32, Dual modulus prescaler 32/33
{PRE[1:0]}=â11Binâ, P=64, Dual modulus prescaler 64/65
The Maximum Allowable Prescalor Output Frequency is 125MHz. âPâ must be set as âRF Input Frequency/Pâ¦
125MHzâ.
7ï¼Power-down and Power-save mode
It is possible to operate in the power-down or power-save mode if necessary by using the external control pin.
Power On
Follow the power-up sequence.
Normal Operation
[PDN]
âLowâ
âHighâ
âHighâ
âHighâ
Table 7 Power-down and Power-save mode
<Address2>
{PD2} {PD1}
Function
X
X Power Down
X
0 Normal Operation
0
1 Asynchronous Power Down
1
1 Synchronous Power Down
X : Donât care (â0â is recommended)
MS1464-E-00
16
2012/9
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