AN-581: 单电源应用中的偏置和去耦运算放大器 (Rev. 0)

AN-581: 单电源应用中的偏置和去耦运算放大器 (Rev. 0)
AN-581
ᆌᆩԴऻ
One Technology Way t P.O. B ox 9106 t Norwood, MA 02062-9106 t Tel: 781/329-4700 t Fax: 781/326-8703 t www.analog.com
‫ۉڇ‬ᇸᆌᆩዐ‫ڦ‬ೋዃࢅඁ᳘ሏ໙‫ٷݣ‬ഗ
Kitchin
ፕኁǖCharles
‫ۉڇ‬ᇸ࣏๟ມ‫ۉ‬ᇸǛ
ഛ‫ࢅכ‬຤ฉยԢ‫ڪ‬ᆌᆩዐ‫ۉࠃ׾ۉڦ‬႙ሏ໙‫ٷݣ‬ഗৈᆶᅃ
߲‫ۉ‬ᇸ੗ᆩăऺ໙ऐ‫ڪ‬ഄ໱ᆌᆩ໚඗੗ᆩ঍ୁ‫ۉ‬ᇸࠃ‫ۉ‬Lj
‫ڍ‬ධ඗ኻᆶᅃ߲‫ڇ‬टႠ‫ۉ‬ᇸLjස5 Vई12 V኱ୁ‫ۉ‬ᇸăᅺܸ
ሞํा֡ፕዐLjྫྫႴᄲཚࡗ‫ڇ‬टႠ‫ۉ‬ᇸઠൻ‫ۯ‬ሏ໙‫ٷݣ‬
ഗă‫ۉڇڍ‬ᇸఇ๕ඓํ٪ሞᅃၵփፁǖ߳प਩Ⴔ֑ᆩ‫ྔܮ‬
‫ڦ‬࿮ᇸᇮॲLjܸ൐සࡕኴႜփ‫ړ‬Lj࣏੗ీሰ‫ׯ‬ჹዘ‫ڦ‬փ࿘
ۨ࿚༶ă
ᆯᇀ‫ۉ‬ᇸ‫ۉ‬უ௅߀Վᅃ‫ޚ‬༬Lj‫ݴ‬ፆഗ‫ۉ‬უॽ߀Վӷ‫ޚ‬༬Lj
ᅺܸ‫ۉ‬ୟPSRৈྺ6 dBă঳ࡕLjඪࢆ၄‫پ‬ሏ໙‫ٷݣ‬ഗཚ‫׉‬ਏ
ᆶ‫ۉߛڦ‬ᇸᅞ዆Ⴀీॽփް٪ሞLjܸ޿Ⴀీ੗‫ޗٷ‬३ณٗ
ཚࡗ‫ۉ‬ᇸࠃ‫ۉ‬᳘ࢇ዁ሏ໙‫ٷݣ‬ഗ‫ڦ‬ඪࢆ঍ୁ႑ࡽ(न‫ۉ‬ᇸ
“࿛࿛”ሯำ)ă
0.1 F
RA
100k
‫ۉ‬ፆೋዃ‫׉ڦ‬९࿚༶!
‫ۉڇ‬ᇸᆌᆩ‫ాڦ‬ሞ࿚༶ཚ‫׉‬փ٪ሞᇀມ‫ۉ‬ᇸሏ໙‫ٷݣ‬ഗ‫ۉ‬
ୟኮዐăएԨ࿚༶ሞᇀLjሏ໙‫ٷݣ‬ഗ๟ᅃዖມ‫ۉ‬ᇸഗॲLj
ᅺܸՂႷཚࡗ֑ᆩྔևᇮॲ‫ڦ‬గዖೋዃॽሏ໙‫ٷݣ‬ഗ‫ڦ‬๼
‫ۉ؜‬უೋዃ‫ۉۉࠃڟ‬უᅃӷ‫ڦ‬࿋ዃă‫ܔ‬ᇀߴۨ‫ۉ‬ᇸ‫ۉ‬უLj
ኄዖ‫݆ݛ‬੗ํ၄ፌ‫ٷ‬๼෇ࢅ๼‫ۉ؜‬უӦ‫ޗ‬ă
VS
VS
1 F
*
*
CIN
VS /2
VIN
COUT
VOUT
RB
100k
VS /2
R LOAD
ሞ๼෇႑ࡽटၭ‫ڦ‬గၵ‫گ‬ሺᅮᆌᆩዐLjኻ੗ॽሏ໙‫ٷݣ‬ഗ
‫ڦ‬๼‫ۉ؜‬უۙ዁ߛᇀথ‫ۉں‬უ2 Vई3 V‫ڦ‬຤ೝă‫ܠڍ‬ຕ൧઄
ူ਩ႴՆ௨ඪࢆၥհ၄ၡLjᅺܸႴ๑๼‫ۉ؜‬უೋዃ‫ۉڟ‬ᇸ
‫ۉ‬უ‫ڦ‬ᅃӷ޹ৎă
*
R2
R1
C1
཮1ዐ‫ۉڦ‬ୟቛ๖‫ڦ‬๟ᅃዖ०‫ۉڇڦڇ‬ᇸೋዃ݆ăኄዖཞ
၎঍ୁ᳘ࢇ‫ٷݣ‬ഗ‫ۉ‬ୟཚࡗᅃ߲‫ټ‬ᆶRAࢅRBଇ߲ೋዃ‫ۉ‬ፆ
‫ݴڦ‬ፆഗॽཞ၎ᆅগ‫ۉ‬უೋዃ‫ڟ‬VS/2ăස཮໯๖Lj๼෇႑
ࡽVINሶཚࡗ‫ۉ‬ඹ᳘ࢇ዁ཞ၎๼෇‫܋‬ă
ኄዖ०‫ۉڇ‬ୟ٪ሞᅃၵჹዘ‫ڦ‬ਆ၌Ⴀăഄዐኮᅃ๟Ljሏ໙
‫ٷݣ‬ഗ‫ۉڦ‬ᇸᅞ዆ࠀీबࢭ‫ږ‬඗࿮٪Ljᅺྺ‫ۉ‬ᇸ‫ۉ‬უ݀ิ
‫ڦ‬ඪࢆՎࣅ‫ॽۼ‬኱থ߀Վ‫ݴ‬ፆഗยۨ‫ڦ‬VS/2ೋዃ‫ۉ‬უă‫ۉ‬
ᇸᅞ዆(PSR)๟ሏ໙‫ٷݣ‬ഗᅃၜटഄዘᄲ)ܸྫྫԥࢮ๫*‫ڦ‬
༬Ⴀă
Rev. 0 | Page 1 of 8
* STAR GROUND
BW1 =
BW2 =
BW3 =
*
1
2 π (1/2R A) C IN
1
2 π R1 C1
1
2 π R LOAD C OUT
FOR R A = R B
FOR AC SIGNALS, VOUT = V IN (1 + (R2/R1))
WHERE X C1 << R1
཮1 ٪ሞփ࿘ۨᅺ໎‫ۉڇڦ‬ᇸሏ໙‫ٷݣ‬ഗ‫ۉ‬ୟ
AN-581
߸ሧߞ‫ڦ‬๟Ljሞሏ໙‫ٷݣ‬ഗՂႷၠ޶ሜ༵ࠃড‫ٷ‬๼‫ୁۉ؜‬
‫ۉڦ‬ୟዐLjྫྫࣷ‫؜‬၄փ࿘ۨ၄ၡă‫ۉݥأ‬ᇸঢ়ࡗଆࡻۙ
ব)൐ಖୟยऺ‫*ړڥ‬Lj‫ޏ‬ሶLjࠃ‫ۉۉ‬ᇸฉॽ‫؜‬၄ড‫ٷ‬႑ࡽ
‫ۉ‬უăᆯᇀሏ໙‫ٷݣ‬ഗཞ၎๼෇‫ڦ܋‬एጚ‫ۉ‬უ኱থઠࠃ‫ۉ‬
‫ۉ‬ᇸLjᅺܸኄၵ႑ࡽॽ኱থໃ࣮ሏ໙‫ٷݣ‬ഗLjᆯُᆅ݀
“ഛ‫ذ‬ำ”)‫گ‬ೕसิና‫*ږ‬ईഄ໱ႚ๕‫ڦ‬փ࿘ۨ၄ၡă
৑࠶ཚࡗ৛႐ยऺքਆĂ‫ۉܠ‬ඹ‫ۉ‬ᇸಖୟĂ႓ႚথ‫ࢅں‬ᆇ
ຘ‫ۉ‬ୟӱ“‫ۉ‬ᇸ֫”‫݆ݛڪ‬੗‫ټ‬ઠ‫ۉ‬ୟ࿘ۨႠLj‫ڍ‬ሞยऺዐ
ምᆅ෇ᅃۨ‫ۉڦ‬ᇸᅞ዆၂‫ྺ߸ڥ‬ඹᅟă
ೋዃྪஏᇑ‫ۉ‬ᇸ‫ڦ‬ඁ᳘
ਏ༹‫݆ݛ‬๟‫ۉܔ‬ୟ৊ႜႪ߀Ljස཮2໯๖ăഄዐLjཚࡗ‫ۉ‬
ඹC2ሞ‫ݴ‬უഗ‫؏ڦ‬ཀྵ‫ۅ‬ยዃಖୟLjᆩᅜ‫ت‬૙঍ୁ႑ࡽLj࣬
ްକᅃۨ‫ڦ‬঍ୁPSRႠీă‫ۉ‬ፆRINྺVS/2एጚ‫ۉ‬უ༵ࠃ኱
ୁ࣮ୟLjཞ้ยۨ‫ۉ‬ୟ)঍ୁ*๼෇ፆੇă
VS
VS
1 F
0.1 F
RA
100k
*
*
R IN
100k
VS /2
COUT
+
VOUT
RB
100k
C2
VS /2
R LOAD
*
*
CIN
R2
150k
VIN
R1
C1
BW1 =
BW2 =
BW3 =
BW4 =
1
* STAR GROUND
2 π (1/2R A) C2
*
1
2 π R IN C IN
1
2 π R1 C1
ሞႹ‫ܠ‬ᅙ‫؜‬Ӳ‫ڦ‬ᆌᆩ‫ۉ‬ୟዐLjRAࢅRB֑ᆩᅃ߲100 kΩ/100 kΩ
‫ݴ‬უഗLjC2‫ۉ‬ඹኵྺ0.1 μFईૌຼኵă‫ྪ޿ڍ‬ஏ‫–ڦ‬3 dB‫੻ټ‬
ᆯRAࢅRBत‫ۉ‬ඹC2ࠓ‫ڦׯ‬ժ૴ፇࢇඓۨLj‫ڪ‬ᇀǖ
–3 dB BW =
1
= 30Hz
2 π (50, 000)(0.1 × 10-6Farads)
‫ܔ‬ᇀ30 Hzᅜူ‫ڦ‬ೕ୲Lj޿‫ۉ‬ୟํाฉժ࿮‫ۉ‬ᇸᅞ዆ࠀీLj
ᅺܸධ੗ీ݀ิഛ‫ذ‬ำईഄ໱ႚ๕‫ڦ‬փ࿘ۨ၄ၡă঳ࡕLj
ࠃ‫ۉۉ‬ᇸฉ٪ሞ‫ڦ‬30 Hzᅜူ႑ࡽ੗ᅜൟᅟ࣮‫ڟ‬ሏ໙‫ٷݣ‬ഗ
‫ڦ‬ኟ๼෇ᆅগዐă
ኄ߲࿚༶‫ڦ‬ᅃዖํᆩ঴ਦӸ݆๟ሺे‫ۉ‬ඹC2‫ڦ‬ኵă޿ኵՂ
Ⴗፁࠕ‫ٷ‬Ljܸٗీࠕ‫ݴܔ‬უഗ‫ۉ‬ୟཚ‫ా੻ټټ‬໯ᆶೕ୲ഐ
‫ڟ‬ಖୟ‫ీࠀڦ‬ăᅃཉᆶၳ݆ሶ๟ॽ޿ट‫ۅ‬ยዃྺ–3 dB๼෇
‫ڦ੻ټ‬ๆ‫ݴ‬ኮᅃLjᆯRIN/CINࢅR1/C1ยۨă
Ⴔᄲጀᅪ‫ڦ‬๟Lj኱ୁ‫ۉ‬ୟሺᅮྺ‫ڇ‬࿋ሺᅮă৑࠶සُLjධ
Ⴔ੊୯ሏ໙‫ٷݣ‬ഗ‫ڦ‬๼෇ೋዃ‫ୁۉ‬ăRA/RB‫ݴ‬უഗॽሺे‫ٷ‬
ଉᇑሏ໙‫ٷݣ‬ഗ‫ڦ‬ኟ๼‫܋؜‬၎‫ۉڦ૴ز‬ፆLjഄኵ‫ڪ‬ᇀኄଇ
߲‫ۉ‬ፆࠓ‫ڦׯ‬ժ૴ፇࢇăᄲ๑ሏ໙‫ٷݣ‬ഗ‫ڦ‬๼‫ۉ؜‬უྼ‫׼‬
ሞࠃ‫ۉۉ‬უᅃӷ޹ৎLj৽Ⴔ‫ڪ‬ኵሺे޶๼෇‫ۉڦ܋‬ፆLjᅜ
๑ኄၵ‫ۉ‬ፆ‫“ڟٳ‬ೝ࢚”ă‫ݒୁۉ‬ઍሏ໙‫ٷݣ‬ഗ‫ڦ‬๼෇ೋዃ
‫ୁۉ‬ཚ‫׉‬փ၎‫ڪ‬Lj৊ᅃօे‫ٷ‬କยऺ‫ްڦ‬ሗႠă
ᅺُLjยऺᅃዖॽ๼෇ೋዃ‫ୁۉ‬ဃֶᅜत‫ۉ‬ᇸᅞ዆Ăሺ
ᅮĂ๼෇ࢅ๼‫ۉ؜‬ୟ‫ڪ੻ټ‬ᅺ໎ཥཥభ෇੊୯‫ۉڇڦ‬ᇸሏ
໙‫ٷݣ‬ഗ‫ۉ‬ୟ੗ీ๟ᅃॲटഄްሗ‫ڦ‬๚൧ăփࡗLjཚࡗᅃ
ዖํᆩ႙‫݆ݛ‬ඐ੗‫ٷٷ‬०ࣅยऺࡗ‫ײ‬ă‫ܔ‬ᇀ֑ᆩ15 Vई12 V
‫ۉڇ‬ᇸࠃ‫ࠌڦۉ‬უ‫ݒ‬ઍሏ໙‫ٷݣ‬ഗLjࡤᆶଇ߲100 kΩ‫ۉ‬ፆ‫ڦ‬
‫ݴ‬ፆഗन੗๑‫ۉ‬ᇸࠀࡼᇑ๼෇ೋዃ‫ୁۉ‬ဃֶ‫ࢇڟٳ‬૙ೝ
࢚ă‫ܔ‬ᇀ5 V‫ۉ‬ᇸLjሶ੗๑ᆩড‫گ‬ኵ‫ۉڦ‬ፆLjස42 kΩ‫ۉ‬ፆă
ፌࢫLjᆶၵᆌᆩႴ߾ፕᇀႎ‫ڦ‬3.3 VՔጚኮူă‫ܔ‬ᇀ3.3 Vᆌ
ᆩLjခՂඓԍሏ໙‫ٷݣ‬ഗྺ“ࡆ‫”ࡆڟ‬ഗॲLj࣏Ⴔཚࡗೋዃ
๑ഄ৑ଉথৎዐ࿋‫ۉ‬უǗೋዃ‫ۉ‬ፆ‫ڦ‬ኵ੗৊ᅃօইྺ27 kΩ
ፑᆸă
1
2 π R LOAD C OUT
FOR R A = R B AND BW1 = 1/10TH BW2,
BW3, AND BW4
FOR AC SIGNALS, V OUT = V IN (1 + (R2/R1))
WHERE X C1 <<R1
TO MINIMIZE INPUT BIAS CURRENT ERRORS,
R2 SHOULD EQUAL R IN + (1/2 R A)
཮2 ঢ়ඁ᳘‫ۉڇڦ‬ᇸሏ໙‫ٷݣ‬ഗೋዃ‫ۉ‬ୟ
Rev. 0 | Page 2 of 8
AN-581
ጀᅪLj‫ݒୁۉ‬ઍሏ໙‫ٷݣ‬ഗཚ‫׉‬ยऺᆩᇀߛೕᆌᆩLjR2ࢅ
ሗො‫ۉ‬ୟ‫ۉ‬ඹႚ‫گڦׯ‬ཚ୳հഗీट‫ںٷ‬३ณ‫ۉ‬ୟ‫ڦ‬3 dB‫ټ‬
੻ăᅺُLj‫ݒୁۉ‬ઍሏ໙‫ٷݣ‬ഗྫྫႴᄲ๑ᆩ‫ۉ‬ፆኵट‫گ‬
‫ۉڦ‬ፆR2ă‫ܔ‬ᇀኍ‫ܔ‬๫ೕे໏ᆌᆩ‫ڦ‬AD811ኮૌ‫ڦ‬ሏ໙‫ݣ‬
‫ٷ‬ഗLjැR2๑ᆩ1k౹ఛ‫ۉ‬ፆLjሶ੗ํ၄ፌॅႠీăᅺُLj
ኄૌᆌᆩႴሞRA/RB‫ݴ‬უഗዐ๑ᆩ‫ۉ‬ፆኵ‫ۉڦܠڥگ‬ፆLjᅜ
ॽ๼෇ೋዃ‫ୁۉ‬ဃֶ३዁ፌ‫گ‬ă
+VS
+VS
0.1 F
RA
100k
*
*
VOUT
๑ᆩ၄‫پ‬FET๼෇ሏ໙‫ٷݣ‬ഗܸ‫ݥ‬ມटഗॲ੗‫ޗٷ‬३ณ๼
෇ೋዃ‫ୁۉ‬ဃֶLj‫ۉ‬ୟՂႷ߾ፕᇀट੻‫ڦ‬࿒‫أ้ྷݔ܈‬
ྔăࢫᅃዖ൧઄ူLj‫ܔ‬ሏ໙‫ٷݣ‬ഗ๼෇‫ۉڦ܋‬ፆ৊ႜೝ࢚
‫ت‬૙ධփ฿ྺᅃዖ௽዇‫ڦ‬ᇨ‫ٯݞ‬แă
RB
100k
VS /2
R LOAD
*
*
՗Iଚ‫؜‬କ཮2໯๖‫ۉ‬ୟ‫ۆڦ‬႙ᇮॲኵLjഄዐԈઔຕዖփཞ
ሺᅮࢅ3 dB‫੻ټ‬ă
C1
R1
(kΩ)
C1*
(μF)
C2 COUT
(μF) (μF)
RLOAD
(kΩ)
10
20
10
101
10
10
50
20
0.3
0.3
0.1
0.2
16.5
7.87
16.5
1.5
1.5
3
0.3
6.8
3
3
0.6
2
100
100
100
100
10
10
50
20
0.2
0.2
0.05
0.1
* STAR GROUND
VIN
BW1 =
CIN*
(μF)
R2
50k
R1
՗I ཮2໯๖‫ۉ‬ୟ‫ۆڦ‬႙ᇮॲኵLjഄዐRA = RB = 100 kΩLjRIN
= 100 kΩLjR2 = 150 kΩ
๼‫؜‬
‫੻ټ‬
(Hz)
C OUT
VS /2
C2
๼෇
‫੻ټ‬
ሺᅮ (Hz)
1 F
BW2 =
BW3 =
1
2 π (1/2 R A) C2
1
2 π R1 C1
1
2 π R LOAD C OUT
FOR R A = R B AND X C2 <<X C1
FOR AC SIGNALS, V OUT = V IN (R2/R1)
WHERE X C1 <<R1
*‫ۉ‬ඹኵᅙᅈ਍ူᅃፌߛࠅኵፕป෇‫ت‬૙ăᆯᇀCIN/RINट‫ࢅۅ‬C1/R1ट
TO MINIMIZE INPUT BIAS CURRENT ERRORS,
R2 SHOULD EQUAL 1/2 R A.
‫تۅ‬ᇀཞᅃೕ୲൐ଇኁ਩ࣷᆖၚ๼෇‫੻ټ‬LjᅺُLj߳‫ۉ‬ඹԲഄ໱൧
཮3 ঢ়ඁ᳘‫ۉڇڦ‬ᇸ‫ݒ‬၎‫ٷݣ‬ഗ‫ۉ‬ୟ
઄ူ‫ڇڦ‬टRC-᳘ࢇ๼෇‫√ٷ‬2ă჋ስC2ኼሞ༵ࠃ၎‫ړ‬ᇀ๼෇‫੻ټ‬1/10
‫ڦ‬ገችೕ୲ă
՗II ଚ‫؜‬କኍ‫ܔ‬ຕዖփཞሺᅮࢅ3 dB‫ۆڦ੻ټ‬႙ᇮॲኵă
཮3໯๖‫ۉ‬ୟᇑ཮2ૌຼLjኻփࡗ๟‫ݒ‬၎‫ٷݣ‬ഗ‫ۉ‬ୟܸᅙă
՗II ཮3໯๖‫ۉ‬ୟ‫ۆڦ‬႙ᇮॲኵLjഄዐR2 = 50 kΩ൐RA = RB =
100 kΩ
ሺᅮ
๼෇
‫੻ټ‬
(Hz)
๼‫؜‬
‫੻ټ‬
(Hz)
R1
(kΩ)
C1*
(μF)
C2*
(μF)
COUT
(μF)
RLOAD
(kΩ)
10
20
10
100
10
10
50
20
10
10
50
20
2
1
2
1
8.2
20
2
8.2
0.5
0.5
0.1
0.3
0.2
0.2
0.05
0.1
100
100
100
100
*‫ۉ‬ඹኵᅙᅈ਍ူᅃፌߛࠅኵፕป෇‫ت‬૙ăᆯᇀC1/R1ट‫ࢅۅ‬C2/RA/RB
ट‫تۅ‬ᇀཞᅃೕ୲൐ଇኁ਩ࣷᆖၚ๼෇‫੻ټ‬LjᅺُLj߳‫ۉ‬ඹԲഄ໱
൧઄ူ‫ڇڦ‬टRC-᳘ࢇ๼෇‫√ٷ‬2ă
Rev. 0 | Page 3 of 8
AN-581
ഋభܾट࠶ೋዃ
৑࠶‫ݴ‬ፆഗೋዃरຍ‫ׯ‬Ԩড‫گ‬൐ీ๑ሏ໙‫ٷݣ‬ഗ‫ڦ‬๼‫ۉ؜‬
უ๔ዕԍ‫ྺ׼‬VS/2Lj‫ڍ‬ኄૌሏ໙‫ٷݣ‬ഗ‫ࠌڦ‬ఇᅞ዆Ⴀీඐ
ྜඇൽਦᇀRA/RBत‫ۉ‬ඹC2ႚ‫ڦׯ‬RC้क़‫׉‬ຕă֑ᆩᅃ߲
ీ༵ࠃ዁ณ10Ԡᇀ๼෇RC᳘ࢇྪஏ)R1/C1ࢅRIN/CIN*RC้क़
‫׉‬ຕ‫ڦ‬C2ኵᆶዺᇀඓԍइ‫ࢇڥ‬૙‫ࠌڦ‬ఇᅞ዆ԲăැRAࢅRB
਩ྺ100 kΩ‫ۉ‬ፆLjኻᄲ‫ۉ‬ୟ‫੻ټ‬փ๟໿‫گ‬LjC2‫ํڦ‬ाኵ੗ԍ
‫׼‬ሞटၭ຤ೝă‫ۉڇྺڍ‬ᇸᆌᆩ༵ࠃ໯ႴVS/2ೋዃ‫ڦ‬ଷᅃ
ዖ‫݆ݛ‬๟๑ᆩഋభܾट࠶࿘უഗă཮4໯๖नྺኄᄣ‫ڦ‬ᅃ
ዖยऺăഄዐLj‫ୁۉ‬ཚࡗ‫ۉ‬ፆRZୁၠ޿ഋభܾट࠶ă‫ۉ‬ඹ
CN੗ӻዺ‫ݞ‬ኹഋభܾट࠶ׂิ‫ڦ‬ඪࢆሯำઍ෇ሏ໙‫ٷݣ‬
ഗă‫گ‬ሯำ‫ۉ‬ୟ੗ీႴᄲ๑ᆩ‫ٷ‬ᇀ10 μFՔۨኵ‫ڦ‬CNă
VS
0.1 F
1 F
*
*
CIN
VZ
VIN
VZ
R IN
100k
IZ
VZ
ᆌ჋ስ߾ፕ‫ۉ‬უথৎVS/2‫ڦ‬ഋభܾट࠶ă໯჋‫ۉ‬ፆRZႴၠ
ഋభܾट࠶༵ࠃፁࠕߛ‫ୁۉڦ‬Lj๑ഄ߾ፕᇀ࿘ۨ‫ۉۨܮڦ‬
უኮူժ๑ഄ๼‫؜‬ሯำྼ‫׼‬ᇀড‫گ‬຤ೝăই‫݀ࢅ)ࡼࠀگ‬ඤ
ଉ*Ăჽ‫׊‬ഋభܾट࠶‫ڦ‬๱ంᄺ‫׉ݥ‬ዘᄲăᆯᇀሏ໙‫ٷݣ‬ഗ
‫ڦ‬๼෇‫ํୁۉ‬ाฉྺଭLjᅺُ჋ስ‫ڦࡼࠀگ‬ഋభܾट࠶փ
฿ྺᅃ߲ࡻӸ݆ă໚඗ፌॅ჋ስ๟250 mW႙ࡽLj‫׉ྺ߸ڍ‬
९‫ڦ‬500 mW႙ࡽᄺ๟੗ᅜথ๴‫ڦ‬ă૙ၙഋభ‫ୁۉ‬ᅺ዆ሰฆ
ܸᅴLj‫ܔڍ‬ᇀኄዖᆌᆩઠຫLjኻᄲIZ‫ت‬ᇀ5 mA)250 mWഋభ
ܾट࠶*ᇑ5 μA)500 mWഋభܾट࠶*ኮक़Ljन๟ᅃዖփ‫ڦٱ‬
ችዔӸ݆ă
ሞഋభܾट࠶‫߾ڦ‬ፕ‫ྷݔ‬ኮాLj཮4໯๖‫ۉ‬ୟएԨฉ࣬ް
କሏ໙‫ٷݣ‬ഗ‫ۉڦ‬ᇸᅞ዆Ⴀీă‫ڍ‬ኄዖ঳ࡕժ‫ݥ‬ுᆶ‫پ‬
ॏǖُ้Ljሏ໙‫ٷݣ‬ഗ‫ڦ‬๼‫ۉ؜‬უ۠ेሞഋభܾट࠶‫ۉڦ‬
უฉLjܸփ๟VS/2ăසࡕ‫ۉ‬ᇸ‫ۉ‬უူইLj‫ٷ‬႑ࡽ้੗ీࣷ
݀ิ‫׬ܔݥ‬၌‫ޗ‬ăُྔLjُ้‫ۉ‬ୟ‫ٷ߸ࡼࠀڦ‬ăፌࢫLjධ
Ⴔ੊୯๼෇ೋዃ‫ୁۉ‬ă‫ۉ‬ፆRINࢅR2ᆌথৎཞᅃ‫ۉ‬ፆኵLjᅜ
‫ݞ‬ኹ๼෇ೋዃ‫ڞୁۉ‬ዂ‫ڦٷ‬฿ۙ‫ۉ‬უဃֶă
཮5๟֑ᆩཞᅃഋభೋዃ݆‫ݒڦ‬၎‫ٷݣ‬ഗ‫ۉ‬ୟă
COUT
VOUT
VZ
VS
R LOAD
RZ
+ C
N
*
10 F
R2
100k
R1
C1
* STAR GROUND
*
SELECT R Z TO PROVIDE THE DESIRED
ZENER OPERATING CURRENT, I Z. SEE TEXT.
RZ =
+VS – V ZENER
BW1 =
BW2 =
BW3 =
IZ
1
2 π R IN C IN
1
2 π R1 C1
1
2π R LOAD C OUT
FOR AC SIGNALS, VOUT = V IN (1 + (R2/R1))
WHERE X C1 <<R1
TO MINIMIZE INPUT BIAS CURRENT ERRORS,
R2 SHOULD EQUAL R IN.
཮4 ֑ᆩഋభܾट࠶ೋዃ݆‫ڦ‬ཞ၎‫ۉڇ‬ᇸ‫ٷݣ‬ഗ
Rev. 0 | Page 4 of 8
AN-581
՗III੗ᇑ‫ۉ‬ୟ4ࢅ‫ۉ‬ୟ5ದࢇ๑ᆩLjᅜՍྺగၵ‫׉‬९ഋభܾ
ट࠶ᆌᆩ༵ࠃํᆩ‫ڦ‬RZ‫ۉ‬ፆኵăጀᅪLjྺ๑‫ۉ‬ୟሯำই዁
ፌ‫گ‬Ljᆌ֖੊ഋభׂ೗ຕ਍๮֩Lj჋ስፌॅഋభ‫ୁۉ‬ă
VS
0.1 F
*
R IN
100k
IZ
1 F
՗III ದࢇ཮4ࢅ཮5๑ᆩ‫ॺڦ‬ᅱRZኵतఊྂஆઙഋభܾट࠶
ׂ೗႙ࡽ
*
VZ
VS
COUT
RZ
VZ
VOUT
VZ
+
ZENER
C2
10 F
R LOAD
*
*
R2
100k
VIN
C1
R1
*STAR GROUND
SELECT R Z TO PROVIDE THE DESIRED
ZENER OPERATING CURRENT, IZ. SEE TEXT.
RZ =
+VS – VZENER
BW1 =
BW2 =
BW3 =
IZ
1
‫ۉ‬ᇸ
‫ۉ‬უ
(V)
ഋభ
‫ۉ‬უ
(V)
ഋభׂ
೗႙ࡽ
ഋభ
‫ୁۉ‬
(IZ)
RZኵ
(Ω)
+15
+15
+12
+12
+9
+9
+5
+5
7.5
7.5
6.2
6.2
4.3
4.3
2.4
2.7
1N4100
1N4693
1N4627
1N4691
1N4623
1N4687
1N4617
1N4682
500 μA
5 mA
500 μA
5 mA
500 μA
5 mA
500 μA
5 mA
15K
1.5K
11.5K
1.15K
9.31K
931
5.23
464
՗IVࢅ՗V‫ݴ‬՚ྺ཮4ࢅ཮5ଚ‫؜‬କኍ‫ܔ‬ຕዖփཞ‫ۉ‬ୟሺᅮ
ࢅ‫ํڦ੻ټ‬ᆩᇮॲኵă
2 π R1 C1
1
2 π R IN C2
1
՗IV ཮4໯๖‫ۉ‬ୟ‫ۆڦ‬႙ᇮॲኵLjഄዐRIN = R2 = 100 kΩ൐CN
= 0.1 μFăٗ՗IIIዐ჋ስRZ
2 π R LOAD C OUT
ሺᅮ
๼෇
‫੻ټ‬
(Hz)
๼‫؜‬
‫੻ټ‬
(Hz)
CIN*
(μF)
R1
(kΩ)
C1*
(μF)
COUT
(μF)
RLOAD
(kΩ)
10
20
10
101
10
10
50
20
10
10
50
20
0.3
0.3
0.1
0.2
11.0
5.23
11.0
1.0
2
4.7
0.47
15
0.2
0.2
0.05
0.1
100
100
100
100
FOR AC SIGNALS, V OUT = V IN (R2/R1)
WHERE X C1 <<R1
TO MINIMIZE INPUT BIAS CURRENT ERRORS,
R2 SHOULD EQUAL R IN.
཮5 ֑ᆩഋభܾट࠶ೋዃ‫ݒڦ‬၎‫ۉڇ‬ᇸ‫ٷݣ‬ഗ
*‫ۉ‬ඹኵᅙᅈ਍ူᅃፌߛࠅኵፕป෇‫ت‬૙ăᆯᇀCIN/RINट‫ࢅۅ‬C1/R1ट
‫تۅ‬ᇀཞᅃೕ୲൐ଇኁ਩ࣷᆖၚ๼෇‫੻ټ‬LjᅺُLj߳‫ۉ‬ඹԲഄ໱൧
઄ူ‫ڇڦ‬टRC - ᳘ࢇ๼෇‫√ٷ‬2ă
՗V ཮5໯๖‫ۉ‬ୟ‫ۆڦ‬႙ᇮॲኵLjഄዐRIN = R2 = 100 kΩăٗ
՗IIIዐ჋ስRZ
ሺᅮ
๼෇
‫੻ټ‬
(Hz)
๼‫؜‬
‫੻ټ‬
(Hz)
R1
(kΩ)
C1*
(μF)
C2*
(μF)
COUT
(μF)
RLOAD
(kΩ)
10
20
10
100
10
10
50
20
10
10
50
20
10
5
10
1
2.7
4.7
0.5
12
0.2
0.2
0.05
0.1
0.2
0.2
0.05
0.1
100
100
100
100
*‫ۉ‬ඹኵᅙᅈ਍ူᅃፌߛࠅኵፕป෇‫ت‬૙ăᆯᇀC1/R1ट‫ࢅۅ‬C2/RINट
‫تۅ‬ᇀཞᅃೕ୲൐ଇኁ਩ࣷᆖၚ๼෇‫੻ټ‬LjᅺُLj߳‫ۉ‬ඹԲഄ໱൧
઄ူ‫ڇڦ‬टRC-᳘ࢇ๼෇‫√ٷ‬2ă
Rev. 0 | Page 5 of 8
AN-581
ཚࡗ၍Ⴀ࿘უഗ‫ܔ‬ሏ໙‫ٷݣ‬ഗ৊ႜೋዃ‫ت‬૙!
एᇀႎ‫ڦ‬3.3 VՔጚ‫ڦ‬ሏ໙‫ٷݣ‬ഗ‫ۉ‬ୟႴ๑ᆩ1.65 V‫ڦ‬ೋዃ‫ۉ‬
უă‫׉‬९ഋభܾट࠶‫ڦ‬ፌ‫ۉگ‬უኻీྺ2.4 Văइ‫ڥ‬ኄᅃೋ
ዃ‫ۉ‬უፌ०‫݆ݛڦڇ‬๟๑ᆩ၍Ⴀ࿘უഗLjසADM663Aई
ADM666AഗॲLjස཮6໯๖ă
VS
VIN
ADM663A
ADM666A
GND
110k
* STAR GROUND
+VS
0.1 F
1 F
VS
SENSE
VOUT (2)
0.1 F
RA
220k
1 F
*
*
+
REF
RA
VSET
1.3V TO 16V
ADJUSTABLE
OUTPUT
C1
VIN
RB
*
R1
*
VS /2
0.1 F
*
VOUT
VS /2
VS /2
VS /2
COUT
C2
0.1 F
0.1 F
R LOAD
*
*
R2
1 F
RB
220k
*
*
* STAR GROUND
–VS
཮6 ֑ᆩ၍Ⴀ࿘უഗ‫ڦ‬ሏ໙‫ٷݣ‬ഗ‫ۉڇ‬ᇸೋዃ‫ۉ‬ୟ
཮7 ᆩሏ໙‫ٷݣ‬ഗྺ‫ۉࠃ׾ۉ‬኱ୁ᳘ࢇᆌᆩ༵ࠃ“Ⴕెথ‫”ں‬
໚඗ഋభܾट࠶ཚ‫׉‬๟‫ׯ‬Ԩፌ‫ڦگ‬࿘უഗૌ႙Lj‫ڍ‬၍Ⴀ࿘
უഗ‫ڦ‬࿒‫܈‬೏ᅎԲഋభܾट࠶‫گ‬Ljሯำ߸ณă
჋ስ‫ۉ‬ፆRAࢅRBᅜ༵ࠃ໯ႴVS/2एጚ‫ۉ‬უLj൩֖ለAD663A
ຕ਍๮֩ă
኱ୁ᳘ࢇ‫ۉۉࠃ׾ۉ‬ୟ
മ௬࿢்ኻ༪ஃକ঍ୁ᳘ࢇሏ໙‫ٷݣ‬ഗ‫ۉ‬ୟă৑࠶ሞ๑ᆩፁ
ࠕ‫ڦٷ‬๼෇ࢅ๼‫؜‬᳘ࢇ‫ۉ‬ඹ‫ڦ‬൧઄ူLj঍ୁ᳘ࢇ‫ۉ‬ୟ੗߾ፕ
ᇀ1 Hzᅜူೕ୲Lj‫ڍ‬ᆶၵᆌᆩᄲ൱ఁ‫ޙ‬ഄํ‫ڦ‬኱ୁၚᆌă
‫ۉࠃ׾ۉ‬ᆌᆩሎႹ๑ᆩ“Ⴕెথ‫ۉ”ں‬ୟLjස཮7໯๖ăኄዖ
‫݆ݛ‬੗ٗ‫ࠃ༵׾ۉڇ‬ມ‫ۉ‬ᇸ‫ۉ‬უLjԈઔኟ޶থ‫ۉں‬უăሏ
໙‫ٷݣ‬ഗᆩᇀ࣐؋VS/2‫ݴ‬უഗ‫ڦ‬๼‫؜‬ăැ֑ᆩ‫گ‬უ‫)׾ۉ‬ස
3.3 V*Ljሏ໙‫ٷݣ‬ഗᆌྺ“ࡆ‫”ࡆڟ‬ഗॲժీሞ޿‫ۉ‬ᇸ‫ۉ‬უူ
ᆶၳ߾ፕăཞ้Ljሏ໙‫ٷݣ‬ഗ࣏Ⴔ༵ࠃፁࠕ‫ڦٷ‬๼‫ۉ؜‬
ୁLjᅜՍൻ‫޶ۯ‬ሜ‫ۉ‬ୟă‫ۉ‬ඹC2‫ܔ‬ᇀ‫ݴ‬უഗഐ‫ڟ‬ಖୟࠀ
ీLjፁᅜ‫ݞ‬ኹඪࢆ‫ۉ‬ፆሯำઍ෇ሏ໙‫ٷݣ‬ഗă޿‫ۉ‬ඹ࿮Ⴔ
༵ࠃ‫ۉ‬ᇸᅞ዆ࠀీLjᅺྺ޶ሜ‫ୁۉ‬኱থ‫ںڟ‬Lj঳ࡕLjඪࢆ
႑ࡽ‫׾ۉٗୁۉ‬ଇ‫܋‬਩‫؜ୁڪ‬ă
ሯำ࿚༶
ᆶၵሏ໙‫ٷݣ‬ഗᆌᆩႴ๑ᆩ‫گ‬ሯำ‫ٷݣ‬ഗLjܸ‫گ‬ሯำ‫ٷݣ‬
ഗ‫ۉ‬ୟሶᄲ൱႑ࡽཚ‫ڢ‬ਏᆶ‫ۉگ‬ፆኵăሀࡪს)‫ۉ‬ፆ*ሯำ
‫ڪ‬ᇀ4 nVᇑ‫ۉ‬ፆኵ)‫ڇ‬࿋ǖkΩ*ೝ‫ߵݛ‬ኮओă৑࠶ᅃ߲1 kΩ‫ۉ‬
ፆ‫ڦ‬ሀࡪსሯำৈྺ4 nV/√HZLj‫ڍ‬20 kΩ‫ۉ‬ፆሶྺ18 nV/
√HZLj100 kΩ‫ۉ‬ፆ߸๟ߛ‫ٳ‬40 nV/√HZăन๑ཚࡗ‫ۉ‬ඹ(C2)
ॽRA/RB‫ݴ‬ፆഗಖୟ‫ںڟ‬Ljኄၵ‫ۉ‬ፆᄺࣷ‫ܔ‬੗ᆩᇀሏ໙‫ٷݣ‬
ഗ‫ݒ‬ઍ‫ۉ‬ፆ‫ڦ‬ፌၭኵႚ‫ׯ‬၌዆Ǘ޿ኵሁ‫ٷ‬Ljሀࡪსሯำሁ
‫ٷ‬ăᅺُLj‫گ‬ሯำᆌᆩ໯ᆩሏ໙‫ٷݣ‬ഗ‫ڦ‬ೋዃ‫ۉ‬ፆኵႴᇺ
ၭᇀُ‫ڦۨࡀت‬100 kΩă‫ݴڍ‬ፆഗ‫ۉ‬ፆኵሁ‫گ‬Lj‫ۉ‬ᇸ‫৽ୁۉ‬
ሁߛLj‫׾ۉ‬๱ంሁ‫܌‬ă
႞ሏ‫ڦ‬๟Ljഋభܾट࠶ೋዃ݆੗ሞփᆩ‫ۉٷ‬ፆ‫ڦ‬൧઄ူ༵
ࠃVS/2ăኻᄲ‫ܔ‬ഋభܾट࠶৊ႜಖୟ୳հLj๑ഄሯำփ৊
෇‫ۉ‬ୟLjሯำࢅ‫ۉ‬ᇸ‫ୁۉ‬਩੗ྼ‫׼‬ᇀ‫گ‬࿋ă၍Ⴀ࿘უഗ๟
߸ࡻ‫ڦ‬჋ስLjᅺྺഄሯำࢅ๼‫؜‬ፆੇ‫ۼ‬ट‫گ‬ă
჋ስ‫ۉ‬ፆRAࢅRBᅜ༵ࠃ໯ႴVS/2एጚ‫ۉ‬უLj൩֖ለAD663A
ຕ਍๮֩ă
Rev. 0 | Page 6 of 8
AN-581
‫ۉ‬ୟਸഔ้क़࿚༶
๼෇Đᇧଉđ੊୯
ፌࢫႴ੊୯‫ڦ‬ᅃ߲࿚༶๟‫ۉ‬ୟਸഔ้क़ăਸഔ้क़ৎຼ‫ڪ‬
ᇀ໯ᆩፌ‫୳੻ټگ‬հഗ‫ڦ‬RC้क़‫׉‬ຕă
ᆶၵጆᄽሏ໙‫ٷݣ‬ഗยऺᆩᇀ‫گ‬უᆌᆩăැኄၵഗॲ֑ᆩ
‫گ‬უ‫ۉڇ‬ᇸ)ස5 Vई3.3 V*ࠃ‫ۉ‬Ljሶ੗ᆅ෇๼෇ᇧଉ၌዆ă
සࡕ‫ٷݣ‬ഗ๼෇पྺ‫׬ܔݥ‬၌዆Lj৽੗ీ‫؜‬၄ኄዖ൧઄ă
ُ‫ت‬໯๖‫ۉ‬ୟඇևᄲ൱RA/RBĂC2‫ݴ‬უഗྪஏ‫้ڦ‬क़‫׉‬ຕ
Բ๼෇ई๼‫ۉ؜‬ୟ‫้ڦ‬क़‫׉‬ຕ‫ٷ‬10Ԡăኄ๟ྺକ०ࣅ‫ۉ‬ୟ
‫ڦ‬ยऺ)ᅺྺፌ‫ܠ‬ᆶෙ߲փཞ‫ڦ‬RCट‫ۅ‬ยۨ๼෇‫*੻ټ‬ăُ
ྔLj‫้׊‬क़‫׉‬ຕᆶዺᇀ‫ݞ‬ኹೋዃྪஏሞሏ໙‫ٷݣ‬ഗ‫ڦ‬๼෇
ࢅ๼‫ྪ؜‬ஏኮമ“ਸഔ”Lj঳ࡕLjሏ໙‫ٷݣ‬ഗ‫ڦ‬๼‫؜‬ደॷٗ
ଭ‫ޚ‬༬ื዁VS/2Ljܸփ๟‫ۉٳڟ‬ᇸ‫ڦ‬ฉࡆăُ՗༵ࠃ‫ڦ‬๟
3 dBገችೕ୲‫ڦ‬ኵLjྺR1/C1ࢅRLOAD/COUT‫ڦ‬ๆ‫ݴ‬ኮᅃă૩
සǖሞ཮2ዐLjැ‫ۉ‬ୟ‫ྺ੻ټ‬10 HzĂሺᅮྺ10Lj՗Iॺᅱ‫ڦ‬
C2ኵྺ3 μFLj3 dB‫ྺ੻ټ‬1 Hză
5ྤ౹ఛ)RAࢅRB‫ڦ‬ժ૴ፇࢇ*‫ױ‬ᅜ3ྲ݆ઙLj‫ڪ‬ᇀ0.15௱‫ڦ‬
RC้क़‫׉‬ຕăᅺُLjሏ໙‫ٷݣ‬ഗ‫ڦ‬๼‫ٷ)؜‬ሀ*Ⴔᄲ0.15௱
ᅜ‫ڟٳ‬VS/2ă๼෇ࢅ๼‫؜‬RCྪஏ‫ڦ‬؊‫้ۉ‬क़ᄲ੺10Ԡă
ሞ‫ۉ‬ୟ–3 dB‫گ‬ೕ‫੻ټ‬ट‫ڦگ‬గၵᆌᆩዐLj‫ۉ‬ୟਸഔ้क़੗
ీट‫׊‬ăኄዖ൧઄ူLjഋభೋዃ݆੗ీ๟߸ࡻ‫ڦ‬჋ስă
૩සǖߵ਍ยऺLjAD8061ሏ໙‫ٷݣ‬ഗ‫ڦ‬๼෇ࠌఇ‫ۉ‬უ‫ྷݔ‬
੗ၠူჽฦ዁“থ‫)”ں‬ई‫ۉ‬ᇸ޶ࡆ*‫ۉ‬უă‫ڍ‬ഄ๼෇‫ۉ‬უኻ
ీሞኟ‫ۉ‬ᇸ‫ۉ‬უ1.8 V‫ۯޝాྷݔڦ‬Lj֍փࣷ‫ڞ‬ዂ኱ୁဃֶ
ࢅ၌዆ഗॲ‫੻ټ‬ăᅺُLjසࡕُ‫ٷݣ‬ഗᅜ5V‫ۉڇ‬ᇸࠃ‫ۉ‬൐
ഄኟ๼෇ೋዃྺVS/2 (2.5 V)Ljሶ๼෇‫ۉ‬უ੗ሞ޶‫ۉ‬ᇸ2.5 V
‫)ۯޝాྷݔڦ‬੗‫گ‬዁ଭ‫ޚ‬༬*ă‫ڍ‬ሞփ݀ิ၌‫ڦޗ‬൧઄
ူLjኟၠኻీ‫ۯޝ‬1 Vă
Ⴔᄲጀᅪ‫ڦ‬๟Ljසࡕ‫ٷݣ‬ഗ߾ፕሺᅮྺ2.5ई߸ߛLjሶփ٪
ሞኄ߲࿚༶Ljᅺྺሞ‫ڟٳ‬๼෇प၌ኵኮമॽ‫ڟٳ‬ፌ‫ٷ‬๼‫؜‬
Ӧ‫(ޗ‬±2.5 V)ă‫ڍ‬๟Ljසࡕ‫ٷݣ‬ഗ߾ፕሺᅮড‫گ‬Ljሶኟ๼෇
ೋዃႴ‫گ‬ᇀVS/2Ljᅜኧ‫׬ܔ׼‬๼෇प၌዆ă‫ܔ‬ᇀAD8061Lj
සࡕኟ๼෇ೋዃྺ1.5 VLjሶ੗ኧ‫׼‬3 V‫ރރ‬๼෇Ӧ‫ܸޗ‬փሰ
‫ׯ‬၌‫ޗ‬ăැᄲඓۨፌॅ‫ۉڇ‬ᇸೋዃ‫ۉ‬უLj൩֖੊၎ᆌׂ೗
‫ڦ‬ຕ਍๮֩ă
՗VI ኍ‫ܔ‬ႎ႙ยऺ‫ླྀڦ‬४ࡆ‫ࡆڟ‬ሏ໙‫ٷݣ‬ഗ
Type
Single
Dual
AD8031
AD8061
AD8051
AD8063
AD8032
AD8062
AD8052
AD823
High Output
AD8591
AD8531
AD8592
AD8532
AD8594
AD8534
JFET Input
AD820
AD822
AD824
Auto Zero
AD8551
AD8552
AD8554
Digital Trim
AD8601
AD8602
AD8604
Low Noise
OP184
OP162
AD8605
AD8628
OP284
OP262
AD8606
OP484
OP462
AD8608
Low Power
OP196
AD8541
OP296
AD8542
OP496
AD8544
Precision
OP777
OP727
OP747
High Speed
Rev. 0 | Page 7 of 8
Quad
AD8054
P R IN TE D IN U . S . A .
©2007 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
E 0 2 4 9 3 – 0 – 1 0 /0 2 ( 0 )
Rev. 0 | Page 8 of 8
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement