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参数资料
| 型号： | LMX2353TMX/NOPB |
| 厂商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分类： | PLL合成/DDS/VCOs |
| 英文描述： | PHASE LOCKED LOOP, 2500 MHz, PDSO16 |
| 封装： | LEAD FREE, PLASTIC, TSSOP-16 |
| 文件页数： | 2/16页 |
| 文件大小： | 209K |
| 代理商： | LMX2353TMX/NOPB |
2.0 Programming Description (Continued)
2.3.2.4 Power Down Mode
(PWDN_MODE)
Synchronous Power Down Mode
The PLL loop can be synchronously powered down by setting the PWDN mode bit HIGH (F2_19=1) and then asserting the power
down mode bit (N20 = 1). The power down function is gated by the charge pump. Once the power down program bit is loaded,
the part will go into power down mode upon the completion of a charge pump pulse event.
Asynchronous Power Down Mode
The PLL loop can be asynchronously powered down by setting the PWDN mode bit LOW (F2_19=0) and then asserting the
power down mode bit (N20 = 1). The power down function is NOT gated by the charge pump. Once the power down program bit
is loaded, the part will go into power down mode immediately.
2.3.3 Feedback Divide Ratio
(NB Counter)
NB_CNTR[9:0]
Divide Ratio
N_18
N_17
N_16
N_15
N_14
N_13
N_12
N_11
N_10
N_9
3
000000001
1
4
000000010
0
1023
111111111
1
Note: B-counter divide ratio must be
≥ 3.
NB_CNTR
≥ (NA_CNTR +2).
2.3.4 Swallow Counter Divide Ratio
(NA Counter)
NB_CNTR[4:0]
Divide Ratio
N_8
N_7
N_6
N_5
N_4
0
00000
1
00001
31
11111
Note: Swallow Counter Value: 0 to 31.
NB_CNTR
≥ (NA_CNTR +2).
2.3.5 Fractional Modulus Accumulator
(FRAC_CNTR)
Divide
Ratio
Divide
Ratio
FRAC_CNTR[3:0]
Modulus 15
Modulus 16
N_3
N_2
N_1
N_0
0
0000
1/15
1/16
0001
2/15
2/16
0010
14/15
14/16
1110
N/A
15/16
1111
2.3.6 Pulse Swallow Function
f
VCO = [N+F] x [fOSC/R] where N = (PxB) + A
f
VCO:
Output frequency of external voltage controlled oscillator (VCO)
F:
Fractional ratio (contents of FRAC_CNTR divided by the fractional modulus)
B:
Preset divide ratio of binary 10-bit programmable counter (3 to 1023)
A:
Preset divide ratio of binary 5-bit swallow counter
0 < A < 31 {P=32};
0 < A < 15 {P=16};
A+2 < B
f
OSC:
Output frequency of the external reference frequency oscillator
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相关代理商/技术参数 |
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|---|---|
| LMX2354 | 制造商:NSC 制造商全称:National Semiconductor 功能描述:PLLatinum Fractional N RF/ Integer N IF Dual Low Power Frequency Synthesizer |
| LMX2354SLB | 制造商:NSC 制造商全称:National Semiconductor 功能描述:PLLatinum Fractional N RF/ Integer N IF Dual Low Power Frequency Synthesizer |
| LMX2354SLBX | 制造商:Rochester Electronics LLC 功能描述: 制造商:Texas Instruments 功能描述: |
| LMX2354SLBX/NOPB | 功能描述:IC FREQ SYNTH DUAL 24-LAMCSP RoHS:是 类别:集成电路 (IC) >> 时钟/计时 - 时钟发生器，PLL，频率合成器 系列:PLLatinum™ 标准包装:39 系列:- 类型:* PLL:带旁路 输入:时钟 输出:时钟 电路数:1 比率 - 输入:输出:1:10 差分 - 输入:输出:是/是 频率 - 最大:170MHz 除法器/乘法器:无/无 电源电压:2.375 V ~ 3.465 V 工作温度:0°C ~ 70°C 安装类型:* 封装/外壳:* 供应商设备封装:* 包装:* |
| LMX2354SLDX | 制造商:Rochester Electronics LLC 功能描述:- Bulk 制造商:Texas Instruments 功能描述: |
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