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PN output mode (PN and POL bits)
The PN output mode is available using an external charge pump. When this mode is selected, the two DO1/2 pins
are switched to the P- and N-output pins. The P/N output logic can be reversed by using the POL bit.
An example of the use of an external charge pump is shown below. Configure the circuit depending on your
desired characteristics.
Reference frequency
基準周波数
位相比較器
comparator
プログラマブル
Programmable
カウンタ出力
counter output
Example of use of the external charge pump (when PN= "1")
Note:
Set the POL bit to "0" unless the PN output mode is selected.
Note:
When the PN output mode is selected, the output will be CMOS output and the "H" level will be
the V
pin level outputp.
DB
Built-in LPF amplifier (LPF ON bit)
This amplifier incorporates the N-channel FET transistor for LPF. This transistor withstands 5.5 V and it can
configure the voltage control oscillator (VCO) that can vary the VT within a range of 0 to 5.5 V.
Setting the LPF ON bit to "1" turns the built-in LPF on. Pins DO2 and P9-1 are then switched to the FET gate
input (Tin) and the FET drain pin (Tout) respectively. The DO2 phase comparator output is connected to the FET
gate pin. The LPF can be configured only by connecting an external filter resistor and capacitor.
Reference frequency
基準周波数
プログラマブル
Programmable
カウンタ出力
counter output
内蔵ローパスフィルタアンプアンプの構成 LPF ON="1"設定
Configuration of built-in low-pass filter amplifier (when LPF ON= "1")
Note:
When the built-in LPF is used, the DO2 output mode, resistor setting and the automatic phase
difference switching mode are available.
Note:
The Tout output withstands up to 5.5 V. Do not use voltages exceeding this limit.
Note:
Set the resistance values for R0 and R1 depending on your desired characteristics.
Note:
The filter circuit constants shown above are for reference only. Examine and design actual
circuits according to the system band configuration and your desired characteristics.
Note:
The Tout pin is also used as pin P9-0. When the built-in LPF is used, the P9-0 output data will
be invalid.
V
VDB
DB
～
P
53
Phase
N
54
POL
～
外部チャージポンプ使用回路例 PN="1"設定
V
VDB
DB
V
VDB
DB
Phase
位相比較器
comparator
R0,R1
106
ＤＣ－ＤＣ
DC-DC
コンバータ
converter
VT
VCOの
To vari-cap of VCO
バリキャップへ
（
）
55
Tin
Tout
54
10kΩ
0.01uF
Voltage of DC-DC converter for VT
VT用DC-DCコンバータ電圧
（
）
TC9349AFG
VT
VCOの
To vari-cap of VCO
バリキャップへ
2006-02-24
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