X1G005421020400愛普生溫補(bǔ)晶振TCXO溫度補(bǔ)償方式石英晶體振蕩器的應(yīng)用
移動通信機(jī)電路框圖及其TCXO外觀由于TCXO具有較高的頻率穩(wěn)定度,而且體積小,在小電流下能夠快速啟動,其應(yīng)用領(lǐng)域重點擴(kuò)展到移動通信系統(tǒng).
為移動通信機(jī)射頻(RF)電路框圖.愛普生晶振TCXO作為基準(zhǔn)振蕩器為發(fā)送信道提供頻率基準(zhǔn),同時作為接收通道的第一級本機(jī)振蕩器;另一只TCXO作為第2級本機(jī)振蕩器,將其振蕩信號輸入到第2變頻器.移動電話要求的頻率穩(wěn)定度為0.1~2.5ppm(-30~+75℃),但出于成本上的考慮,通常選用的規(guī)格為1.5~2.5ppm.移動電話用12~20MHz的TCXO代表性產(chǎn)品之一是VC-TCXO-201C1,采用直接補(bǔ)償方式.X1G005421020400愛普生溫補(bǔ)晶振,TCXO溫度石英晶體振蕩器
TCXO的溫度補(bǔ)償方式對石英晶體振子頻率溫度漂移的補(bǔ)償方法主要有直接補(bǔ)償和間接補(bǔ)償兩種類型:
愛普生晶振編碼
型號
頻率
長x寬x高
輸出波
電源電壓
頻率偏差
TCXO
工作溫度
X1G005421002900
TG2520SMN
19.200000MHz
2.50x2.00x0.80mm
Clippedsinewave
3.135to3.465V
+/-2.0ppm
TCXO
40to+85°C
X1G005421003000
TG2520SMN
12.000000MHz
2.50x2.00x0.80mm
Clippedsinewave
3.135to3.465V
+/-2.0ppm
TCXO
30to+85°C
X1G005421003700
TG2520SMN
16.384000MHz
2.50x2.00x0.80mm
Clippedsinewave
1.700to1.900V
+/-1.5ppm
TCXO
40to+85°C
X1G005421003800
TG2520SMN
16.384000MHz
2.50x2.00x0.80mm
Clippedsinewave
2.260to3.465V
+/-1.5ppm
TCXO
40to+85°C
X1G005421020100
TG2520SMN
16.368000MHz
2.50x2.00x0.80mm
Clippedsinewave
1.700to1.900V
+/-1.5ppm
TCXO
-40to+85°C
X1G005421020200
TG2520SMN
16.369000MHz
2.50x2.00x0.80mm
Clippedsinewave
1.700to1.900V
+/-1.5ppm
TCXO
-40to+85°C
X1G005421020300
TG2520SMN
19.200000MHz
2.50x2.00x0.80mm
Clippedsinewave
1.700to1.900V
+/-1.5ppm
TCXO
-40to+85°C
X1G005421020400
TG2520SMN
26.000000MHz
2.50x2.00x0.80mm
Clippedsinewave
1.700to1.900V
+/-1.5ppm
TCXO
-40to+85°C
X1G005421020500
TG2520SMN
32.000000MHz
2.50x2.00x0.80mm
Clippedsinewave
1.700to1.900V
+/-1.5ppm
TCXO
-40to+85°C
X1G005421020600
TG2520SMN
38.400000MHz
2.50x2.00x0.80mm
Clippedsinewave
1.700to1.900V
+/-1.5ppm
TCXO
-40to+85°C
X1G005421020700
TG2520SMN
40.000000MHz
2.50x2.00x0.80mm
Clippedsinewave
1.700to1.900V
+/-1.5ppm
TCXO
-40to+85°C
X1G005421020800
TG2520SMN
16.000000MHz
2.50x2.00x0.80mm
Clippedsinewave
1.700to1.900V
+/-1.5ppm
TCXO
-40to+85°C
X1G005421021100
TG2520SMN
20.000000MHz
2.50x2.00x0.80mm
Clippedsinewave
1.700to1.900V
+/-1.5ppm
TCXO
-40to+85°C
X1G005421021200
TG2520SMN
24.000000MHz
2.50x2.00x0.80mm
Clippedsinewave
1.700to1.900V
+/-1.5ppm
TCXO
-40to+85°C
X1G005421021300
TG2520SMN
25.000000MHz
2.50x2.00x0.80mm
Clippedsinewave
1.700to1.900V
+/-1.5ppm
TCXO
-40to+85°C
X1G005421021400
TG2520SMN
27.000000MHz
2.50x2.00x0.80mm
Clippedsinewave
1.700to1.900V
+/-1.5ppm
TCXO
-40to+85°C
X1G005421021500
TG2520SMN
30.000000MHz
2.50x2.00x0.80mm
Clippedsinewave
1.700to1.900V
+/-1.5ppm
TCXO
-40to+85°C
X1G005421021600
TG2520SMN
48.000000MHz
2.50x2.00x0.80mm
Clippedsinewave
1.700to1.900V
+/-1.5ppm
TCXO
-40to+85°C
X1G005421022000
TG2520SMN
52.000000MHz
2.50x2.00x0.80mm
Clippedsinewave
1.700to1.900V
+/-1.5ppm
TCXO
-40to+85°C
X1G005421022100
TG2520SMN
27.600000MHz
2.50x2.00x0.80mm
Clippedsinewave
1.700to1.900V
+/-1.5ppm
TCXO
-40to+85°C
X1G005421022200
TG2520SMN
50.000000MHz
2.50x2.00x0.80mm
Clippedsinewave
1.700to1.900V
+/-1.5ppm
TCXO
-40to+85°C
X1G005421030100
TG2520SMN
16.368000MHz
2.50x2.00x0.80mm
Clippedsinewave
2.660to3.465V
+/-1.5ppm
TCXO
-40to+85°C
X1G005421030200
TG2520SMN
16.369000MHz
2.50x2.00x0.80mm
Clippedsinewave
2.660to3.465V
+/-1.5ppm
TCXO
-40to+85°C
X1G005421030300
TG2520SMN
19.200000MHz
2.50x2.00x0.80mm
Clippedsinewave
2.660to3.465V
+/-1.5ppm
TCXO
-40to+85°C
間接補(bǔ)償型又分模擬式和數(shù)字式兩種類型.模擬式間接溫度補(bǔ)償是利用熱敏電阻等溫度傳感元件組成溫度-電壓變換電路,并將該電壓施加到一支與晶體振子相串接的變?nèi)荻O管上,通過晶體振子串聯(lián)電容量的變化,日產(chǎn)晶振對晶體振子的非線性頻率漂移進(jìn)行補(bǔ)償.該補(bǔ)償方式能實現(xiàn)±0.5ppm的高精度,但在3V以下的低電壓情況下受到限制.
數(shù)字化間接溫度補(bǔ)償是在模擬式補(bǔ)償電路中的溫度—電壓變換電路之后再加一級模/數(shù)(A/D)變換器,將模擬量轉(zhuǎn)換成數(shù)字量.該法可實現(xiàn)自動溫度補(bǔ)償,使溫補(bǔ)晶振晶體振蕩器頻率穩(wěn)定度非常高,但具體的補(bǔ)償電路比較復(fù)雜,成本也較高,只適用于基地站和廣播電臺等要求高精度化的情況.
X1G005421020400愛普生溫補(bǔ)晶振,TCXO溫度石英晶體振蕩器
直接補(bǔ)償型TCXO是由熱敏電阻和阻容元件組成的溫度補(bǔ)償電路,在振蕩器中與石英晶體振子串聯(lián)而成的.在溫度變化時,熱敏電阻的阻值和晶體等效串聯(lián)電容容值相應(yīng)變化,從而抵消或削減振蕩頻率的溫度漂移.日本進(jìn)口晶振該補(bǔ)償方式電路簡單,成本較低,節(jié)省印制電路板(PCB)尺寸和空間,適用于小型和低壓小電石英晶振流場合.但當(dāng)要求晶體振蕩器精度小于±1pmm時,直接補(bǔ)償方式并不適宜.
X1G005421020400愛普生溫補(bǔ)晶振,TCXO溫度石英晶體振蕩器