參數(shù)資料
型號(hào)： LMX2331
廠商： National Semiconductor Corporation
英文描述： PLLatinum⑩ Low Power Dual Frequency Synthesizer for RF Personal Communications
中文描述： PLLatinum⑩低功耗雙頻率合成射頻個(gè)人通信
文件頁(yè)數(shù)： 15/21頁(yè)
文件大?。?/td> 496K
代理商： LMX2331
Functional Description
(Continued)
TABLE 3. The F
o
LD (Pin 10) Output Truth Table
RF R[19]
(RF LD)
0
0
1
1
X
X
X
X
0
0
1
1
IF R[19]
(IF LD)
0
1
0
1
0
0
1
1
0
1
0
1
RF R[20]
(RF F
o
)
0
0
0
0
0
1
0
1
1
1
1
1
IF R[20]
(IF F
o
)
0
0
0
0
1
0
1
0
1
1
1
1
F
o
Output State
Disabled (Note 12)
IF Lock Detect (Note 13)
RF Lock Detect (Note 13)
RF/IF Lock Detect (Note 13)
IF Reference Divider Output
RF Reference Divider Output
IF Programmable Divider Output
RF Programmable Divider Output
Fastlock (Note 14)
IF Counter Reset (Note 15)
RF Counter Reset (Note 15)
IF and RF Counter Reset (Note 15)
X = don’t care condition
Note 12:
When the F
o
LD output is disabled, it is actively pulled to a low logic state.
Note 13:
Lock detect output provided to indicate when the VCO frequency is in “l(fā)ock.” When the loop is locked and a lock detect mode is selected, the pins output
is HIGH, with narrow pulses LOW. In the RF/IF lock detect mode a locked condition is indicated when RF and IF are both locked.
Note 14:
The Fastlock mode utilizes the F
LD output pin to switch a second loop filter damping resistor to ground during fastlock operation. Activation of Fastlock
occurs whenever the RF loop’s lcpo magnitude bit
#
17 is selected HIGH (while the
#
19 and
#
20 mode bits are set for Fastlock).
Note 15:
The IF Counter Reset mode resets IF PLL’s R and N counters and brings IF charge pump output to a TRI-STATE condition. The RF Counter Reset mode
resets RF PLL’s R and N counters and brings RF charge pump output to a TRI-STATE condition. The IF and RF Counter Reset mode resets all counters and brings
both charge pump outputs to a TRI-STATE condition. Upon removal of the Reset bits then N counter resumes counting in “close” alignment with the R counter. (The
maximum error is one prescaler cycle.)
POWERDOWN OPERATION
Synchronous and asynchronous powerdown modes are
both available by MICROWIRE selection. Synchronously
powerdown occurs if the respective loop’s R18 bit (Do
TRI-STATE) is LOW when its N20 bit (Pwdn) becomes HI.
Asynchronous powerdown occurs if the loop’s R18 bit is HI
when its N20 bit becomes HI.
In the synchronous powerdown mode, the powerdown func-
tion is gated by the charge pump to prevent unwanted fre-
quency jumps. Once the powerdown program bit N20 is
loaded, the part will go into powerdown mode when the
charge pump reaches a TRI-STATE condition.
In the asynchronous powerdown mode, the device powers
down immediately after the LE pin latches in a HI condition
on the powerdown bit N20.
Activation of either the IF or RF PLL powerdown conditions
in either synchronous or asynchronous modes forces the re-
spective loop’s R and N dividers to their load state condition
and debiasing of its respective f
input to a high impedance
state. The oscillator circuitry function does not become dis-
abled until both IF and RF powerdown bits are activated. The
MICROWIRE control register remains active and capable of
loading and latching data during all of the powerdown
modes.
The device returns to an actively powered up condition in ei-
ther synchronous or asynchronous modes immediately upon
LE latching LOW data into bit N20.
Powerdown Mode Select Table
R18
0
1
N20
0
0
Powerdown Status
PLL Active
PLL Active
(Charge Pump Output TRI-STATE)
Synchronous Powerdown Initiated
Asynchronous Powerdown Initiated
0
1
1
1
www.national.com
15
相關(guān)PDF資料
PDF描述
LMX2331LTM PLLatinum⑩ Low Power Dual Frequency Synthesizer for RF Personal Communications
LMX2331LSLB PLLatinum⑩ Low Power Dual Frequency Synthesizer for RF Personal Communications
LMX2335UTMX PLLatinum Ultra Low Power Dual Frequency Synthesizer for RF Personal Communications
LMX2335USLBX PLLatinum Ultra Low Power Dual Frequency Synthesizer for RF Personal Communications
LMX2335UTM PLLatinum Ultra Low Power Dual Frequency Synthesizer for RF Personal Communications
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LMX2331 WAF 制造商:Texas Instruments 功能描述:
LMX2331A 制造商:NSC 制造商全稱(chēng):National Semiconductor 功能描述:PLLatinum⑩ Dual Frequency Synthesizer for RF Personal Communications
LMX2331ATM 制造商:Texas Instruments 功能描述:
LMX2331ATMX 功能描述:IC FREQ SYNTH DUAL 20-TSSOP RoHS:否 類(lèi)別:集成電路 (IC) >> 時(shí)鐘/計(jì)時(shí) - 時(shí)鐘發(fā)生器，PLL，頻率合成器 系列:PLLatinum™ 標(biāo)準(zhǔn)包裝:39 系列:- 類(lèi)型:* PLL:帶旁路 輸入:時(shí)鐘 輸出:時(shí)鐘 電路數(shù):1 比率 - 輸入:輸出:1:10 差分 - 輸入:輸出:是/是 頻率 - 最大:170MHz 除法器/乘法器:無(wú)/無(wú) 電源電壓:2.375 V ~ 3.465 V 工作溫度:0°C ~ 70°C 安裝類(lèi)型:* 封裝/外殼:* 供應(yīng)商設(shè)備封裝:* 包裝:*
LMX2331L 制造商:未知廠家 制造商全稱(chēng):未知廠家 功能描述:
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