參數(shù)資料
型號(hào): S4402
廠商: Applied Micro Circuits Corp.
英文描述: BiCMOS PLL Clock Generator(能產(chǎn)生6個(gè)時(shí)鐘輸出的BiCMOS鎖相環(huán)時(shí)鐘發(fā)生器)
中文描述: BiCMOS工藝PLL時(shí)鐘發(fā)生器(能產(chǎn)生6個(gè)時(shí)鐘輸出的BiCMOS工藝鎖相環(huán)時(shí)鐘發(fā)生器)
文件頁數(shù): 3/13頁
文件大?。?/td> 154K
代理商: S4402
Applied Micro Circuits Corporation
6195 Lusk Blvd., San Diego, CA 92121 (619) 450-9333
Page 3
Enabling Outputs
The S4402 has two output-enable inputs that con-
trol which outputs toggle. (The S4403 has three
output-enable inputs.) When held LOW, OUTEN0
controls the frequency doubler output X2FOUT
and the half-frequency output HFOUT. OUTEN1
controls the FOUT0–FOUT3 outputs. The third in-
put on the S4403, OUTEN2, controls the duplicate
set of four outputs FOUT0A–FOUT3A. When an
output enable pin is held High, its associated out-
puts are disabled and held in a High state.
Filter
The FILTER output is a tap between the analog out-
put of the phase detector and the VCO input. This pin
allows a simple external filter (Figure 2) to be in-
cluded in the PLL. AMCC recommends the use of the
filter component values shown. This filter was chosen
for its ability to reduce the output jitter and filter out
noise on the REFCLK input. The filter components
should be in surface mounted packages with mini-
mum lead inductance.
Power Supply Considerations
Power for the analog portion of the S4402/S4403
chips must be isolated from the digital power supplies
to minimize noise on the analog power supply pins.
This isolation between the analog and digital power
supplies can be accomplished with a simple external
power supply filter (Figure 3). The analog power
planes are connected to the digital power planes
through single ferrite beads (FB1 and FB2) or induc-
tors capable of handling 25 mA. The recommended
value for the inductors is in the range from 5 to
100
μ
H, and depends upon the frequency spectrum of
the digital power supply noise. The ferrite beads
should exhibit 75
impedance at 10 MHz.
Decoupling capacitors are also very important to mini-
mize noise. The decoupling capacitors must have low
lead inductance to be effective, so ceramic chip ca-
pacitors are recommended. Decoupling capacitors
should be located as close to the power pins as physi-
cally possible. And the decoupling should be placed
on the top surface of the board between the part and
its connections to the power and ground planes.
S4402/S4403
BiCMOS PLL CLOCK GENERATOR
Figure 2. External PLL Filter
Figure 3. External Power Supply Filter
A +5V
0.1μF
1.5k
20
19
S4402
A VCC
FILTER
ANALOG +5V
0.1 μF
DIGITAL +5V
DIGITAL GND
ANALOG GND
FB1
FB2
10 μF
Tantalum
(optional)
Reset
When the RESET pin is pulled low, all the internal
states go to zero one clock cycle (from the VCO or
REFCLK in the test mode) before the outputs go low.
After the chip is reset, the PLL requires a
resynchronization time of
5ms before lock is again
achieved.
Lock Detect
A lock detect function is provided by the LOCK out-
put. When REFCLK and FBCLK are within 2–4 ns of
each other, the PLL is in lock, and the LOCK output
goes High.
Test Capabilities
The TSTEN input puts the S4402/S4403 into a test
mode and allows users to bypass the VCO and pro-
vide their own clock through the REFCLK input.
When TSTEN is High, the VCO is turned off and the
REFCLK signal drives the divider/phase adjust cir-
cuitry, directly sequencing the outputs. The TSTEN
and REFCLK inputs join the divider circuitry after the
initial divide-by-two stage. Therefore, REFCLK is di-
vided by two in the divide-by-four mode and divided
by four in the divide-by-eight mode.
相關(guān)PDF資料
PDF描述
S4403 BiCMOS PLL Clock Generator(能產(chǎn)生6個(gè)時(shí)鐘輸出的BiCMOS鎖相環(huán)時(shí)鐘發(fā)生器)
S4405 BiCMOS PECL Clock Generator(能產(chǎn)生6個(gè)時(shí)鐘輸出的BiCMOS時(shí)鐘發(fā)生器)
S4406 12-Output BiCMOS PLL Clock Generator(能產(chǎn)生12個(gè)時(shí)鐘輸出的BiCMOS鎖相環(huán)時(shí)鐘發(fā)生器)
S4503 BiCMOS Clock Synthesizer(帶可編程時(shí)鐘輸出的BiCMOS時(shí)鐘合成器)
S4505 RAMBUS COMPATIBLE CLOCK GENERATORS
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
S-440-2C 制造商:PennEngineering (PEM) 功能描述:
S4403B66 制造商:AMCC 功能描述:*
S4404-01 制造商:HAMAMATSU 制造商全稱:Hamamatsu Corporation 功能描述:High sensitivity phototransistor
S-4406-AB 制造商:Molex 功能描述:
S-4406-DB 制造商:Molex 功能描述: