<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE eagle SYSTEM "eagle.dtd">
<eagle version="9.2.0">
<drawing>
<board>
<plain>
<wire x1="1.778" y1="10.668" x2="70.104" y2="10.668" width="0" layer="20"/>
<wire x1="70.104" y1="10.668" x2="70.104" y2="57.15" width="0" layer="20"/>
<wire x1="70.104" y1="57.15" x2="1.778" y2="57.15" width="0" layer="20"/>
<wire x1="1.778" y1="57.15" x2="1.778" y2="10.668" width="0" layer="20"/>
<hole x="68.072" y="55.118" drill="2.286"/>
<hole x="3.81" y="55.118" drill="2.286"/>
<hole x="4.064" y="12.7" drill="2.286"/>
<hole x="68.0266" y="12.7" drill="2.286"/>
</plain>
<libraries>
<library name="samacSys">
<description>&lt;b&gt;https://eagle.componentsearchengine.com&lt;/b&gt;&lt;p&gt;&lt;author&gt;Created by SamacSys&lt;/author&gt;</description>
<packages>
<package name="SOIC127P600X175-14N">
<description>&lt;b&gt;D(R-PDSO-G14)&lt;/b&gt;&lt;br&gt;
</description>
</package>
<package name="SOIC127P600X175-8N">
<description>&lt;b&gt;R-8 (SOIC)&lt;/b&gt;&lt;br&gt;
</description>
</package>
<package name="SM42TX102">
<description>&lt;b&gt;SM-42TX102&lt;/b&gt;&lt;br&gt;
</description>
</package>
</packages>
</library>
<library name="fablab">
<packages>
<package name="C1206FAB">
</package>
<package name="MINI-SMA">
<description>mini-SMA diode</description>
</package>
<package name="SOT23">
<description>&lt;b&gt;SOT 23&lt;/b&gt;</description>
</package>
<package name="R1206FAB">
</package>
<package name="SMB_CONN_J">
</package>
<package name="2X02SMD">
</package>
<package name="USB_MINIB">
</package>
<package name="2X5_1.27MM_SMD">
</package>
</packages>
</library>
<library name="lights">
<packages>
<package name="LED1206FAB">
<description>LED1206 FAB style (smaller pads to allow trace between)</description>
</package>
</packages>
</library>
</libraries>
<attributes>
</attributes>
<variantdefs>
</variantdefs>
<elements>
<element name="C6_FILTER" library="fablab" package="C1206FAB" value="1.6nF">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="C7_FILTER" library="fablab" package="C1206FAB" value="1.6nF">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="D5" library="lights" package="LED1206FAB" value="LEDFAB1206">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="IC1" library="samacSys" package="SOIC127P600X175-14N" value="ATSAMD11C14A-SSNT">
<attribute name="DESCRIPTION" value="ARM Microcontrollers - MCU 14 SOIC,105C, GREEN,1.6-3.6V,48MHz,USB"/>
<attribute name="HEIGHT" value="1.75mm"/>
<attribute name="MANUFACTURER_NAME" value="Microchip"/>
<attribute name="MANUFACTURER_PART_NUMBER" value="ATSAMD11C14A-SSNT"/>
<attribute name="MOUSER_PART_NUMBER" value="556-ATSAMD11C14ASSNT"/>
<attribute name="MOUSER_PRICE-STOCK" value="https://www.mouser.com/Search/Refine.aspx?Keyword=556-ATSAMD11C14ASSNT"/>
<attribute name="NAME"/>
<attribute name="RS_PART_NUMBER" value=""/>
<attribute name="RS_PRICE-STOCK" value=""/>
<attribute name="VALUE"/>
</element>
<element name="3.3V" library="fablab" package="SOT23" value="">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="R2_REF" library="fablab" package="R1206FAB" value="10kΩ">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="R2_FILTER" library="fablab" package="R1206FAB" value="141kΩ">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="R3_REF" library="fablab" package="R1206FAB" value="10kΩ">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="LED_R" library="fablab" package="R1206FAB" value="499Ω">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="U$2" library="fablab" package="SMB_CONN_J" value="SMD_CONN_J_J*"/>
<element name="U$5" library="fablab" package="2X02SMD" value="CONN_02X2-PINHEAD-SMD"/>
<element name="C1" library="fablab" package="C1206FAB" value="1uF">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="IC4" library="samacSys" package="SOIC127P600X175-14N" value="TLV2374ID">
<attribute name="DESCRIPTION" value="TLV2374IDG4, Quad Operational Amplifier 3MHz R-R 3 to 15V, 14-Pin SOIC"/>
<attribute name="HEIGHT" value="1.75mm"/>
<attribute name="MANUFACTURER_NAME" value="Texas Instruments"/>
<attribute name="MANUFACTURER_PART_NUMBER" value="TLV2374ID"/>
<attribute name="MOUSER_PART_NUMBER" value="595-TLV2374ID"/>
<attribute name="MOUSER_PRICE-STOCK" value="https://www.mouser.com/Search/Refine.aspx?Keyword=595-TLV2374ID"/>
<attribute name="RS_PART_NUMBER" value="6612072P"/>
<attribute name="RS_PRICE-STOCK" value="http://uk.rs-online.com/web/p/products/6612072P"/>
<attribute name="VALUE"/>
</element>
<element name="R1_REF" library="fablab" package="R1206FAB" value="4.99k">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="R3_FILTER" library="fablab" package="R1206FAB" value="67kΩ">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="R1_2NDSTAGE" library="fablab" package="R1206FAB" value="110kΩ">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="R1_SCALER" library="fablab" package="R1206FAB" value="19.4kΩ">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="R2_SCALER" library="fablab" package="R1206FAB" value="10kΩ">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="D6" library="fablab" package="MINI-SMA" value="DIODE_SCHOTTKY_CDBM1100-G">
<attribute name="NAME"/>
</element>
<element name="D7" library="fablab" package="MINI-SMA" value="DIODE_SCHOTTKY_CDBM1100-G">
<attribute name="NAME"/>
</element>
<element name="D8" library="fablab" package="MINI-SMA" value="DIODE_SCHOTTKY_CDBM1100-G">
<attribute name="NAME"/>
</element>
<element name="D9" library="fablab" package="MINI-SMA" value="DIODE_SCHOTTKY_CDBM1100-G">
<attribute name="NAME"/>
</element>
<element name="X2" library="fablab" package="USB_MINIB" value="CONN_USB_MINIB">
<attribute name="NAME"/>
</element>
<element name="C5_BYPASS" library="fablab" package="C1206FAB" value="0.1uF">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="BRIDGE1" library="fablab" package="R1206FAB" value="0kΩ">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="BRIDGE2" library="fablab" package="R1206FAB" value="0kΩ">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="J1" library="fablab" package="2X5_1.27MM_SMD" value="">
<attribute name="NAME"/>
<attribute name="PACKAGE" value="2x5_1.27MM_SMD"/>
<attribute name="VALUE"/>
</element>
<element name="BRIDGE6" library="fablab" package="R1206FAB" value="0kΩ">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="BRIDGE7" library="fablab" package="R1206FAB" value="0kΩ">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="IC2" library="samacSys" package="SOIC127P600X175-8N" value="AD8221ARZ">
<attribute name="DESCRIPTION" value="AD8221ARZ, Instrumention Amplifier, 0.06mV Offset, 130dB CMRR, 8-Pin SOIC"/>
<attribute name="HEIGHT" value="1.75mm"/>
<attribute name="MANUFACTURER_NAME" value="Analog Devices"/>
<attribute name="MANUFACTURER_PART_NUMBER" value="AD8221ARZ"/>
<attribute name="MOUSER_PART_NUMBER" value="584-AD8221ARZ"/>
<attribute name="MOUSER_PRICE-STOCK" value="https://www.mouser.com/Search/Refine.aspx?Keyword=584-AD8221ARZ"/>
<attribute name="NAME"/>
<attribute name="RS_PART_NUMBER" value="6977237P"/>
<attribute name="RS_PRICE-STOCK" value="http://uk.rs-online.com/web/p/products/6977237P"/>
<attribute name="VALUE"/>
</element>
<element name="R1" library="samacSys" package="SM42TX102" value="SM-42TX102">
<attribute name="DESCRIPTION" value="TRIMMER 1K OHM 0.25W SMD"/>
<attribute name="HEIGHT" value="5mm"/>
<attribute name="MANUFACTURER_NAME" value="Copal Electronics"/>
<attribute name="MANUFACTURER_PART_NUMBER" value="SM-42TX102"/>
<attribute name="MOUSER_PART_NUMBER" value=""/>
<attribute name="MOUSER_PRICE-STOCK" value=""/>
<attribute name="NAME"/>
<attribute name="RS_PART_NUMBER" value=""/>
<attribute name="RS_PRICE-STOCK" value=""/>
<attribute name="VALUE"/>
</element>
<element name="R2" library="samacSys" package="SM42TX102" value="SM-42TX102">
<attribute name="DESCRIPTION" value="TRIMMER 1K OHM 0.25W SMD"/>
<attribute name="HEIGHT" value="5mm"/>
<attribute name="MANUFACTURER_NAME" value="Copal Electronics"/>
<attribute name="MANUFACTURER_PART_NUMBER" value="SM-42TX102"/>
<attribute name="MOUSER_PART_NUMBER" value=""/>
<attribute name="MOUSER_PRICE-STOCK" value=""/>
<attribute name="NAME"/>
<attribute name="RS_PART_NUMBER" value=""/>
<attribute name="RS_PRICE-STOCK" value=""/>
<attribute name="VALUE"/>
</element>
<element name="U$1" library="fablab" package="2X02SMD" value="CONN_02X2-PINHEAD-SMD"/>
<element name="BRIDGE3" library="fablab" package="R1206FAB" value="0khΩ">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="C2" library="fablab" package="C1206FAB" value="1uF">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
<element name="FERRITE" library="fablab" package="R1206FAB" value="0kΩ">
<attribute name="NAME"/>
<attribute name="VALUE"/>
</element>
</elements>
<signals>
<signal name="GND">
<contactref element="D5" pad="2"/>
<contactref element="IC1" pad="11"/>
<contactref element="U$5" pad="3"/>
<contactref element="U$5" pad="4"/>
<contactref element="R2_REF" pad="2"/>
<contactref element="IC4" pad="11"/>
<contactref element="R1_SCALER" pad="2"/>
<contactref element="D9" pad="ANODE"/>
<contactref element="D7" pad="ANODE"/>
<contactref element="X2" pad="GND"/>
<contactref element="C5_BYPASS" pad="1"/>
<contactref element="U$2" pad="P$3"/>
<contactref element="U$2" pad="P$1"/>
<contactref element="J1" pad="3"/>
<contactref element="J1" pad="5"/>
<contactref element="J1" pad="9"/>
<contactref element="J1" pad="7"/>
<contactref element="BRIDGE7" pad="1"/>
<contactref element="3.3V" pad="3"/>
<contactref element="BRIDGE7" pad="2"/>
<contactref element="IC2" pad="5"/>
<contactref element="BRIDGE3" pad="1"/>
<contactref element="C1" pad="1"/>
<contactref element="BRIDGE3" pad="2"/>
<contactref element="C2" pad="1"/>
<contactref element="X2" pad="SHIELD@1"/>
<contactref element="X2" pad="SHIELD@4"/>
<contactref element="X2" pad="SHIELD@2"/>
<contactref element="X2" pad="SHIELD@3"/>
</signal>
<signal name="REF">
<contactref element="R2_FILTER" pad="1"/>
<contactref element="R1_REF" pad="1"/>
<contactref element="IC4" pad="7"/>
<contactref element="IC2" pad="6"/>
<contactref element="R2" pad="1"/>
</signal>
<signal name="VCC">
<contactref element="D6" pad="KATHODE"/>
<contactref element="D8" pad="KATHODE"/>
<contactref element="U$5" pad="1"/>
<contactref element="U$5" pad="2"/>
<contactref element="IC4" pad="4"/>
<contactref element="R3_REF" pad="1"/>
<contactref element="LED_R" pad="1"/>
<contactref element="X2" pad="VBUS"/>
<contactref element="C5_BYPASS" pad="2"/>
<contactref element="C1" pad="2"/>
<contactref element="BRIDGE6" pad="1"/>
<contactref element="BRIDGE6" pad="2"/>
<contactref element="3.3V" pad="2"/>
<contactref element="IC2" pad="8"/>
<contactref element="FERRITE" pad="2"/>
</signal>
<signal name="N$7">
<contactref element="LED_R" pad="2"/>
<contactref element="D5" pad="1"/>
</signal>
<signal name="OUT_TO_FILTER">
<contactref element="C6_FILTER" pad="1"/>
<contactref element="IC2" pad="7"/>
</signal>
<signal name="FEEDBACK_FILTER">
<contactref element="C6_FILTER" pad="2"/>
<contactref element="C7_FILTER" pad="1"/>
<contactref element="R3_FILTER" pad="1"/>
</signal>
<signal name="R2_TO_GND">
<contactref element="C7_FILTER" pad="2"/>
<contactref element="IC4" pad="3"/>
<contactref element="R2_FILTER" pad="2"/>
</signal>
<signal name="RST">
<contactref element="IC1" pad="6"/>
<contactref element="J1" pad="10"/>
</signal>
<signal name="CLK">
<contactref element="IC1" pad="7"/>
<contactref element="J1" pad="4"/>
</signal>
<signal name="DIO">
<contactref element="IC1" pad="8"/>
<contactref element="J1" pad="2"/>
</signal>
<signal name="D+">
<contactref element="IC1" pad="10"/>
<contactref element="X2" pad="D+"/>
</signal>
<signal name="D-">
<contactref element="IC1" pad="9"/>
<contactref element="X2" pad="D-"/>
</signal>
<signal name="OUT_DIVIDER">
<contactref element="IC4" pad="5"/>
<contactref element="R2_REF" pad="1"/>
<contactref element="R3_REF" pad="2"/>
</signal>
<signal name="FEEDBACK_REF">
<contactref element="IC4" pad="6"/>
<contactref element="R1_REF" pad="2"/>
</signal>
<signal name="VCC_3V">
<contactref element="IC1" pad="12"/>
<contactref element="J1" pad="1"/>
<contactref element="3.3V" pad="1"/>
</signal>
<signal name="2ND_STAGE_FEEDBACCK">
<contactref element="IC4" pad="13"/>
<contactref element="R1_2NDSTAGE" pad="1"/>
<contactref element="R2" pad="2"/>
</signal>
<signal name="OUT_TO_2NDSTAGE">
<contactref element="IC4" pad="12"/>
<contactref element="IC4" pad="1"/>
<contactref element="R3_FILTER" pad="2"/>
<contactref element="IC4" pad="2"/>
</signal>
<signal name="OUT_DIVIDER1">
<contactref element="R1_SCALER" pad="1"/>
<contactref element="R2_SCALER" pad="2"/>
<contactref element="IC4" pad="10"/>
</signal>
<signal name="BRIDGE">
<contactref element="BRIDGE1" pad="1"/>
<contactref element="BRIDGE2" pad="2"/>
</signal>
<signal name="PIEZO_IN-">
<contactref element="D7" pad="KATHODE"/>
<contactref element="D6" pad="ANODE"/>
<contactref element="IC2" pad="1"/>
<contactref element="U$1" pad="3"/>
</signal>
<signal name="OUT_TO_SCALER">
<contactref element="IC4" pad="14"/>
<contactref element="R1_2NDSTAGE" pad="2"/>
<contactref element="R2_SCALER" pad="1"/>
</signal>
<signal name="PIEZO_IN+">
<contactref element="D9" pad="KATHODE"/>
<contactref element="D8" pad="ANODE"/>
<contactref element="IC2" pad="4"/>
<contactref element="U$1" pad="1"/>
</signal>
<signal name="OUT_TO_MC">
<contactref element="BRIDGE2" pad="1"/>
<contactref element="IC1" pad="1"/>
<contactref element="U$2" pad="P$2"/>
</signal>
<signal name="N$1">
<contactref element="IC4" pad="8"/>
<contactref element="IC4" pad="9"/>
<contactref element="BRIDGE1" pad="2"/>
</signal>
<signal name="N$2">
<contactref element="R1" pad="2"/>
<contactref element="IC2" pad="3"/>
</signal>
<signal name="N$3">
<contactref element="IC2" pad="2"/>
<contactref element="R1" pad="1"/>
</signal>
<signal name="N$4">
<contactref element="C2" pad="2"/>
<contactref element="FERRITE" pad="1"/>
</signal>
</signals>
</board>
</drawing>
</eagle>
