|
|
實物圖：
0.png (391.56 KB, 下載次數(shù): 156)
下載附件
2016-6-19 14:55 上傳
大多數(shù)系統(tǒng)中，需要在性能與低功耗之間進行權(quán)衡。本電路設(shè)計的重點是考察部分權(quán)衡因素，同時在16位、100 kSPS數(shù)據(jù)采集系統(tǒng)中實現(xiàn)低功耗（8 mW，典型值）和高性能。
本電路使用 AD7988-1低功耗(350 μA) PulSAR®模數(shù)轉(zhuǎn)換器(ADC)，該器件直接從 ADA4841-1 高性能、低電壓、低功耗運算放大器驅(qū)動。選擇該放大器是因為它具有極佳的動態(tài)性能，可采用單電源電壓供電且提供軌到軌輸出。此外，輸入共模電壓范圍包括負供電軌。
AD7988-1 ADC需要2.4 V至5.1 V間的外部基準(zhǔn)電壓。本應(yīng)用中，選擇的基準(zhǔn)電壓是 ADR4525 精密2.5 V基準(zhǔn)電壓源。
電路原理圖：
0.png (41.62 KB, 下載次數(shù): 148)
下載附件
2016-6-19 14:51 上傳
本電路的核心是 AD7988-1 16位、100 kSPS逐次逼近型ADC，采用VDD單電源供電。它內(nèi)置一個低功耗、高速、16位采樣ADC和一個多功能串行端口接口(SPI)。在CNV上升沿，該器件對IN+與IN-之間的模擬輸入電壓差進行采樣，范圍從0 V至REF。基準(zhǔn)電壓(REF)由外部提供，并且可以獨立于電源電壓(VDD)。
在為本電路筆記執(zhí)行的實驗中， AD7988-1 評估板與系統(tǒng)演示平臺（SDP， EVAL-SDP-CB1Z）接口，ADC SPI兼容串行接口則連接到DSP SPORT接口。ADC SPI接口能夠?qū)讉�ADC以菊花鏈形式連結(jié)到單三線式總線上。采用獨立VIO電源引腳時，它與1.8 V、2.5 V、3 V或5 V邏輯兼容。
AD7988-1 采用10引腳MSOP或10引腳QFN (LFCSP)封裝。為方便起見，該電路板采用MSOP封裝。
ADC輸入從 ADA4841-1單位增益穩(wěn)定、低噪聲和低失真、軌到軌輸出放大器進行緩沖和驅(qū)動，該器件通常在1.1 mA的靜態(tài)電流下工作。此放大器提供2.1 nV/√Hz的低寬帶電壓噪聲和1.4 pA/√Hz的電流噪聲，100 kHz時具有極佳的−105 dBc無雜散動態(tài)范圍(SFDR)。為了在更低頻率下保持低噪聲環(huán)境，10 Hz時放大器具有7 nV/√Hz和13 pA/√Hz的低1/f噪聲。
使 ADA4841-1非常適合單電源應(yīng)用的主要特性是，它在該應(yīng)用中可以采用單供電軌供電，同時將可負供電軌接地。放大器輸出擺幅可以達到地電平的50 mV范圍內(nèi)，這是本應(yīng)用可接受的值。請注意，輸入共模電壓范圍從負供電軌擴展至正供電軌的1 V范圍內(nèi)。為容納目標(biāo)信號范圍（0 V至2.5 V），必須提供1 V裕量；因此本電路中使用4 V供電軌。
ADA4841-1 采用6引腳SOT-23或8引腳SOIC封裝。
本應(yīng)用中使用的2.5 V基準(zhǔn)電壓源是 ADR4525 ，屬于 ADR45xx 基準(zhǔn)電壓源系列，可以提供高精度、低功耗、低噪聲，且具有±0.01%初始精度、極佳的溫度穩(wěn)定性和低輸出噪聲。 ADR4525 的低熱致輸出電壓遲滯和低長期輸出電壓漂移提高了系統(tǒng)性能。700 μA的最大工作電流和500 mV的低壓差（最大值）使該器件最適合便攜式設(shè)備。
用于本電路中的三個產(chǎn)品的額定工作溫度范圍均為−40°C至+125°C全工業(yè)溫度范圍。
BOM表：
| C1 | CAP | 0.1uF | ±10% | C0603 | Yes | Top | 50V X7R Ceramic Capacitor | Murata | GRM188R71H104KA93D | FEC 8820023 | | C2 | CAP | 0.1uF | ±10% | C0603 | Yes | Top | 50V X7R Ceramic Capacitor | Murata | GRM188R71H104KA93D | FEC 8820023 | | C3 | CAP | 10nF | ±10% | C0603 | Yes | Top | 50V X7R Ceramic Capacitor | Murata | GRM188R71H103KA01D | FEC 1118178 | | C4 | CAP | 0.1uF | ±10% | C0603 | Yes | Top | 50V X7R Ceramic Capacitor | Murata | GRM188R71H104KA93D | FEC 8820023 | | C5 | CAP | 0.1uF | ±10% | C0603 | Yes | Top | 50V X7R Ceramic Capacitor | Murata | GRM188R71H104KA93D | FEC 8820023 | | C6 | CAP | 1uF | ±10% | C0805 | Yes | Top | CAPACITOR, 0805, 1UF, 50V, X7R | MURATA | GRM21BR71H105KA12L | FEC 1735541 | | C7 | CAP | 0.1uF | ±10% | C0603 | Yes | Top | 50V X7R Ceramic Capacitor | MURATA | GRM188R71H104KA93D | FEC 8820023 | | C8 | CAP | 1uF | ±10% | C0805 | Yes | Top | CAPACITOR, 0805, 1UF, 50V, X7R | MURATA | GRM21BR71H105KA12L | FEC 1735541 | | C9 | CAP+ | 10uF | ±10% | RTAJ_B | Yes | Top | 20V Tantalum Capacitor | AVX | TAJB106K020RNJ | FEC 197427 | | C10 | CAP+ | 10uF | ±10% | RTAJ_B | Yes | Top | 20V Tantalum Capacitor | AVX | TAJB106K020RNJ | FEC 197427 | | C11 | CAP+ | 10uF | ±10% | RTAJ_B | Yes | Top | 20V Tantalum Capacitor | AVX | TAJB106K020RNJ | FEC 197427 | | C12 | CAP+ | 10uF | ±10% | RTAJ_B | Yes | Top | 20V Tantalum Capacitor | AVX | TAJB106K020RNJ | FEC 197427 | | C13 | CAP | 2.7nF | ±5% | C0603 | Yes | Top | CAPACITOR CERAMIC, 2700PF, 50V, C0G/NP0, 0603 | TDK | C1608C0G1H272J | FEC 1844178 | | C14 | CAP | 10pF | ±5% | C0603 | Yes | Top | CAP CERAMIC 10PF, 100V, C0G, 0603 | AVX | 06031A100JAT2A | FEC 1273324 | | C15 | CAP | 0.1uF | ±10% | C0603 | Yes | Top | 50V X7R Ceramic Capacitor | Murata | GRM188R71H104KA93D | FEC 8820023 | | C16 | CAP | 0.1uF | ±10% | C0603 | Yes | Top | 50V X7R Ceramic Capacitor | Murata | GRM188R71H104KA93D | FEC 8820023 | | C17 | CAP | 0.1uF | ±10% | C0603 | Yes | Top | 50V X7R Ceramic Capacitor | Murata | GRM188R71H104KA93D | FEC 8820023 | | C18 | CAP | 1uF | ±10% | C0805 | Yes | Top | CAPACITOR, 0805, 1UF, 50V, X7R | MURATA | GRM21BR71H105KA12L | FEC 1735541 | | C19 | CAP+ | 10uF | ±10% | RTAJ_B | Yes | Top | 20V Tantalum Capacitor | AVX | TAJB106K020RNJ | FEC 197427 | | C20 | CAP | 0.1uF | ±10% | C0603 | Yes | Top | 50V X7R Ceramic Capacitor | Murata | GRM188R71H104KA93D | FEC 8820023 | | C21 | CAP | 0.1uF | ±10% | C0603 | Yes | Top | 50V X7R Ceramic Capacitor | Murata | GRM188R71H104KA93D | FEC 8820023 | | C22 | CAP | 0.1uF | ±10% | C0603 | Yes | Top | 50V X7R Ceramic Capacitor | Murata | GRM188R71H104KA93D | FEC 8820023 | | C23 | CAP | 0.1uF | ±10% | C0603 | Yes | Top | 50V X7R Ceramic Capacitor | Murata | GRM188R71H104KA93D | FEC 8820023 | | C24 | CAP | 0.1uF | ±10% | C0603 | Yes | Top | 50V X7R Ceramic Capacitor | Murata | GRM188R71H104KA93D | FEC 8820023 | | C25 | CAP+ | 22uF | ±10% | RTAJ_B | Yes | Top | 20V Tantalum Capacitor | AVX | TAJB226K020RNJ | FEC 1135057 | | C26 | CAP | DNI |
| C0603 | Yes | Top | n/a | n/a | n/a | Do Not Place | | C27 | CAP | DNI |
| C0603 | Yes | Top | n/a | n/a | n/a | Do Not Place | | C28 | CAP | DNI |
| C0603 | Yes | Top | n/a | n/a | n/a | Do Not Place | | C29 | CAP | DNI |
| C0603 | Yes | Top | n/a | n/a | n/a | Do Not Place | | C30 | CAP | DNI |
| C0603 | Yes | Top | n/a | n/a | n/a | Do Not Place | | C31 | CAP | DNI | ±5% | C0603 | Yes | Top | CAPACITOR CERAMIC, TBD, 50V, C0G/NP0, 0603 | TDK | C1608C0G1H272J | Do Not Place | | C32 | CAP | DNI | ±5% | C0603 | Yes | Top | CAPACITOR CERAMIC, TBD, 50V, C0G/NP0, 0603 | TDK | C1608C0G1H272J | Do Not Place | | C33 | CAP | DNI | ±5% | C0603 | Yes | Top | CAPACITOR CERAMIC, TBD, 50V, C0G/NP0, 0603 | TDK | C1608C0G1H272J | Do Not Place | | C34 | CAP | DNI | ±5% | C0603 | Yes | Top | CAPACITOR CERAMIC, TBD, 50V, C0G/NP0, 0603 | TDK | C1608C0G1H272J | Do Not Place | | C35 | CAP | DNI | ±5% | C0603 | Yes | Top | CAPACITOR CERAMIC, TBD, 50V, C0G/NP0, 0603 | TDK | C1608C0G1H272J | Do Not Place | | C36 | CAP | DNI | ±5% | C0603 | Yes | Top | CAPACITOR CERAMIC, TBD, 50V, C0G/NP0, 0603 | TDK | C1608C0G1H272J | Do Not Place | | C37 | CAP | DNI | ±5% | C0603 | Yes | Top | CAPACITOR CERAMIC, TBD, 50V, C0G/NP0, 0603 | TDK | C1608C0G1H272J | Do Not Place | | C38 | CAP | DNI | ±5% | C0603 | Yes | Top | CAPACITOR CERAMIC, TBD, 50V, C0G/NP0, 0603 | TDK | C1608C0G1H272J | Do Not Place | | C39 | CAP | DNI | ±5% | C0603 | Yes | Top | CAPACITOR CERAMIC, TBD, 50V, C0G/NP0, 0603 | TDK | C1608C0G1H272J | Do Not Place | | C40 | CAP | DNI | ±5% | C0603 | Yes | Top | CAPACITOR CERAMIC, TBD, 50V, C0G/NP0, 0603 | TDK | C1608C0G1H272J | Do Not Place | | C41 | CAP | DNI | ±5% | C0603 | Yes | Top | CAPACITOR CERAMIC, TBD, 50V, C0G/NP0, 0603 | TDK | C1608C0G1H272J | Do Not Place | | C42 | CAP | 10nF | ±10% | C0603 | Yes | Top | 50V X7R Ceramic Capacitor | Murata | GRM188R71H103KA01D | FEC 1118178 | | C43 | CAP | 150pF | ±5% | C0805 | Yes | Top | CAPACITOR, 0805, 150pF, 50V, COG/NPO | MULTICOMP | MCAA000332 | FEC 1759205 | | C44 | CAP | DNI | ±10% | C0805 | Yes | Top | CAPACITOR, 0805, 1UF, 50V, X7R | MURATA | GRM21BR71H105KA12L | Do Not Place | | C45 | CAP | 10nF | ±10% | C0603 | Yes | Top | 50V X7R Ceramic Capacitor | Murata | GRM188R71H103KA01D | FEC 1118178 | | C46 | CAP | 10nF | ±10% | C0603 | Yes | Top | 50V X7R Ceramic Capacitor | Murata | GRM188R71H103KA01D | FEC 1118178 | | C47 | CAP+ | 10uF | ±10% | RTAJ_B | Yes | Top | 20V Tantalum Capacitor | AVX | TAJB106K020R | FEC 197427 | | C48 | CAP | 1uF | ±10% | C0805 | Yes | Top | CAPACITOR, 0805, 1UF, 50V, X7R | MURATA | GRM21BR71H105KA12L | FEC 1735541 | | J1 | CON\POWER4 |
|
| CON\POWER4 | No | Top | TERMINAL BLOCK, PCB, 4WAY | LUMBERG | KRM 04 | FEC 1177877 | | J2 | SDP-STANDARD-CONN |
|
| CON-120/FX8-120S-SV_W/S | No | Top | 120-way connector, 0.6mm pitch | Hirose | FX8-120S-SV(21) | FEC 1324660 | | J3 | SMB_JACK_RIGHT_ANGLED | N/A | N/A | SMB_JACK_RIGHT_ANGLED | No | Top | CONN SMB JACK R/A PC MNT GOLD | EMERSON | 131-3701-301 | Digikey J472-ND | | J4 | SMB_JACK_RIGHT_ANGLED | N/A | N/A | SMB_JACK_RIGHT_ANGLED | No | Top | CONN SMB JACK R/A PC MNT GOLD | EMERSON | 131-3701-301 | Digikey J472-ND | | R1 | RES | DNI | 1% | R0603 | Yes | Top | RESISTOR, 0603 TBD | MULTICOMP | MC 0.063W 0603 1% TBD | Do Not Place | | R2 | RES | 49r9 | 0.01 | R0805 | Yes | Top | RESISTOR, 0805, 49R9, 0.1%, 0.125W | PANASONIC | ERA6AEB49R9V | FEC 1810372 | | R3 | RES | 0r | 0.01 | R0603 | Yes | Top | SMD Resistor | Multicomp | MC 0.063W 0603 0R | FEC 9331662 | | R4 | RES | 49r9 | 0.01 | R0805 | Yes | Top | RESISTOR, 0805, 49R9, 0.1%, 0.125W | PANASONIC | ERA6AEB49R9V | FEC 1810372 | | R5 | RES | 10k | 0.01 | R0805 | Yes | Top | THICK FILM CHIP RESISTOR | VISHAY DRALORIC | CRCW080510K0FKEAHP | FEC 1738972 | | R6 | RES | 10k | 0.01 | R0805 | Yes | Top | THICK FILM CHIP RESISTOR | VISHAY DRALORIC | CRCW080510K0FKEAHP | FEC 1738972 | | R7 | RES | DNI | 1% | R0603 | Yes | Top | RESISTOR, 0603 TBD | Multicomp | MC 0.063W 0603 1% TBD | Do Not Place | | R8 | RES | 22R | 0.01 | R0805 | Yes | Top | RESISTOR, 22R 1% 0805 | Vishay Draloric | CRCW080522ROFKEAHP | FEC 1738936 | | R9 | RES | 0r | 0.01 | R0603 | Yes | Top | SMD Resistor | Multicomp | MC 0.063W 0603 0R | FEC 9331662 | | R10 | RES | 0r | 0.01 | R0603 | Yes | Top | SMD Resistor | Multicomp | MC 0.063W 0603 0R | FEC 9331662 | | R11 | RES | DNI | 1% | R0603 | Yes | Top | SMD Resistor | Multicomp | MC 0.063W 0603 0R | Do Not Place | | R12 | RES | 60k4 | 0.01 | R0603 | Yes | Top | RESISTOR, 0603 60K4 | MULTICOMP | MC 0.063W 0603 1% 60K4 | FEC 1170965 | | R13 | RES | 294k | 0.01 | R0603 | Yes | Top | RESISTOR, 0603 294K | MULTICOMP | MC 0.063W 0603 1% 294K | FEC 1171030 | | R14 | RES | 100K | 0.01 | R0603 | Yes | Top | SMD Resistor | Multicomp | MC 0.063W 0603 1% 100K | FEC 9330402 | | R15 | RES | 100K | 0.01 | R0603 | Yes | Top | SMD Resistor | Multicomp | MC 0.063W 0603 1% 100K | FEC 9330402 | | R16 | RES | 0r | 0.01 | R0603 | Yes | Top | SMD Resistor | Multicomp | MC 0.063W 0603 0R | FEC 9331662 | | R17 | RES | 0r | 0.01 | R0603 | Yes | Top | SMD Resistor | Multicomp | MC 0.063W 0603 0R | FEC 9331662 | | R18 | RES | 0r | 0.01 | R0603 | Yes | Top | SMD Resistor | Multicomp | MC 0.063W 0603 0R | FEC 9331662 | | R19 | RES | DNI |
|
| Yes | Top |
|
|
| Do Not Place | | R20 | RES | DNI |
|
| Yes | Top |
|
|
| Do Not Place | | R21 | RES | DNI |
|
| Yes | Top |
|
|
| Do Not Place | | R22 | RES | 10k | 0.01 | R0805 | Yes | Top | THICK FILM CHIP RESISTOR | VISHAY DRALORIC | CRCW080510K0FKEAHP | FEC 1738972 | | R23 | RES | 10k | 0.01 | R0805 | Yes | Top | THICK FILM CHIP RESISTOR | VISHAY DRALORIC | CRCW080510K0FKEAHP | FEC 1738972 | | R24 | RES | 82K | 0.01 | 603 | Yes | Top | RESISTOR, 0603 82K,0.063W,1% | MULTICOMP | MC 0.063W 0603 1% 82K | FEC 9331573 | | R25 | RES | DNI |
|
| Yes | Top |
|
|
| Do Not Place | | R26 | RES | DNI | 1% | R0603 | Yes | Top | RESISTOR, 0603 TBD | MULTICOMP | MC 0.063W 0603 1% TBD | Do Not Place | | R27 | RES | DNI | 1% | R0603 | Yes | Top | RESISTOR, 0603 TBD | MULTICOMP | MC 0.063W 0603 1% TBD | Do Not Place | | R28 | RES | DNI | 1% | R0603 | Yes | Top | RESISTOR, 0603 TBD | MULTICOMP | MC 0.063W 0603 1% TBD | Do Not Place | | R29 | RES | DNI | 1% | R0603 | Yes | Top | RESISTOR, 0603 TBD | MULTICOMP | MC 0.063W 0603 1% TBD | Do Not Place | | R30 | RES0603 | 330k | 5% | R0603 | Yes | Top | RESISTOR, 0603 330K | MULTICOMP | MC 0.063W 0603 5% 330K | FEC 9332057 | | R31 | RES | 0r | 0.01 | R0603 | Yes | Top | SMD Resistor | MULTICOMP | MC 0.063W 0603 0R | FEC 9331662 | | R32 | RES | DNI | 1% | R0603 | Yes | Top | RESISTOR, 0603 TBD | MULTICOMP | MC 0.063W 0603 1% TBD | Do Not Place | | R33 | RES | 0r | 0.01 | R0603 | Yes | Top | SMD Resistor | MULTICOMP | MC 0.063W 0603 0R | FEC 9331662 | | SL1 | JUMPER2\0603_BRIDGE |
|
| 0603-3PIN_BRIDGE | Yes | Top | 2-Way Shorting Option - Use 0r 0603 Resistor in Position "B" | Multicomp | MC 0.063W 0603 0r | FEC 933-1662 | | U1 | NC7S08 |
|
| SOT23-5 | Yes | Top | Single AND Gate | Fairchild | NC7SZ085M | FEC 1013807 | | U2 | 24LC32A-I/MS |
|
| MSO8 | Yes | Top | 32K I2C Serial EEPROM, MSOP8 | Microchip | 24LC32A-I/MS | FEC 1331330 | | U3 | NC7S08 |
|
| SOT23-5 | Yes | Top | Single AND Gate | Fairchild | NC7SZ085M | FEC 1013807 | | U4 | NC7S08 |
|
| SOT23-5 | Yes | Top | Single AND Gate | Fairchild | NC7SZ085M | FEC 1013807 | | U5 | NC7S04 |
|
| SOT23-5 | Yes | Top | Single INV | Fairchild | NC7SZ04 | FEC 1013809 | | U6 | ADR4525BRZ |
|
| SO8NB | Yes | Top |
| Analog Devices | ADR4525BRZ | ADR4525BRZ | | U7 | AD8032ARMZ |
|
| MSO8 | Yes | Top | 2.7 V, 800 μA, 80 MHz Rail-to-Rail I/O Dual Amplifier | Analog Devices | AD8032ARMZ | AD8032ARMZ | | U8 |
|
|
|
| Yes | Top |
|
|
| Do Not Place | | U9 | DNI (solder short needed between pads 1 and 8) |
|
|
| Yes | Top |
|
|
| DNI (solder short needed between pads 1 and 8) | | U10 | AD7988-1BRMZ |
|
| MSO10 | Yes | Top | 16-Bit, 1 MSPS PulSAR® ADC in MSOP | Analog Devices | AD7988-1BRMZ | AD7988-1BRMZ | | U11 |
|
|
|
| Yes | Top |
|
|
| Do Not Place | | U12 | ADA4841-1YRZ-R7 |
|
| SO8NB | Yes | Top | Low Noise, High Speed Amplifier for 16-Bit Systems | Analog Devices | ADA4841-1YRZ-R7 | ADA4841-1YRZ-R7 | | Screw1 |
| ** |
|
|
|
| SCREW, CHEESE, NYLON, M3X10, PK100 | ALLTHREAD | 119030010 | FEC 7070597 | | Screw2 |
| ** |
|
|
|
| SCREW, CHEESE, NYLON, M3X10, PK100 | ALLTHREAD | 119030010 | FEC 7070597 | | Nut1 |
| ** |
|
|
|
| NUT/WASHER, NYLON, M3, PK100 | DURATOOL | 1140030 | FEC 7061857 | | Nut2 |
| ** |
|
|
|
| NUT/WASHER, NYLON, M3, PK100 | DURATOOL | 1140030 | FEC 7061857 |
全部資料（壓縮包）下載：
|
|
QQ好友和群
QQ空間
騰訊微博
騰訊朋友
收藏
淘帖
頂
踩
