esl-epfl/CHEEP-boards2This chewing gum board is designed to be an extended-range voltage supply + current measurement circuit, intended for connection to the main board through the male pin headers to both sides.
CurrentSource is an open-source printed circuit board by esl-epfl, from the esl-epfl/CHEEP-boards repository on GitHub. It is a 4-layer board of 15.3 × 45.8 mm with 39 parts on 31 nets, routed with 366 tracks and 40 vias.
It is built around the ADS1219IPW and TLV75801PDBV. Its parts include 12 resistors, 10 capacitors, 6 ICs, 4 connectors and 1 diode.
This chewing gum board is designed to be an extended-range voltage supply + current measurement circuit, intended for connection to the main board through the male pin headers to both sides. It can produce a voltage output from 0 to 5 V approximately, with currents of up to 1 A (@nominal voltage, check datasheet).
This chewing gum board is an adaptation of the CurrentMeasurementSupply chewing gum and as such can be used in a similar way, the main difference being the wider supply voltage range. This Extended Range version, however, supports only a single voltage output ("A").
It is based on the TPS7A9401 IC. The output voltage is defined via a resistor network, with a potentiometer soldered to the board that allows to manually modify the output within this range.
The TPS7A9401 is always ON and will operate when the EN pin is high. Either the external EN input, or the internal supply signal can be used to set the EN pin. This can be selected through the J2 jumper.
Similar to the CurrentMeasurementSupply chewing gum board, this extended range version can also be use to obtain a reading of the output current. All the current measurement circuits are kept unchanged and therefore can be used in the same way by employing shunt resistors + the ADC reading.
Female pin header J3 can be used to connect a through-hole resistor for current measurement. This allows for quicker replacement of the shunt resistor values, as opposed to the SMD alternatives.
The "VLDO" test point next to the SMA connector can also be used to measure the output voltage.
Besides using the potentiometer for trimming, the output voltage can also be adjusted by changing the input to the DAC. For this operation, however, resistors R15 and R16 need to be selected for this by carefully checking the possible voltage range with the datasheet.
Jumper J3 can be used to set potentiometer or DAC trimming.
A macromodel of the TPS7A9401, together with a simplified circuit modeling its behavior in this board has been included. The simulation can be run using TINA-TI. This allows, for example, to change resistors and verify the output voltage of the TPS7A9401, as well as the output current when simulating with a load.
| Qty | Value | Footprint | References |
|---|---|---|---|
| 7 | 0.1u | Capacitor_SMD:C_0603_1608Metric | C1, C2, C5, C6, C7, C8, C10 |
| 2 | 10k | Resistor_SMD:R_0603_1608Metric | R7, R9 |
| 2 | ~ | TestPoint:TestPoint_Loop_D1.80mm_Drill1.0mm_Beaded | TP1, TP2 |
| 1 | .1u | Capacitor_SMD:C_0603_1608Metric | C4 |
| 1 | 10 | Resistor_SMD:R_0805_2012Metric_Pad1.20x1.40mm_HandSolder | R1 |
| 1 | 10 | Resistor_SMD:R_1206_3216Metric_Pad1.30x1.75mm_HandSolder | R12 |
| 1 | 10 | Resistor_SMD:R_2512_6332Metric_Pad1.40x3.35mm_HandSolder | R6 |
| 1 | 10 | Resistor_SMD:R_2010_5025Metric_Pad1.40x2.65mm_HandSolder | R11 |
| 1 | 100k | Resistor_SMD:R_0603_1608Metric | R10 |
| 1 | 10u | Capacitor_SMD:C_0603_1608Metric | C3 |
| 1 | 140k | Resistor_SMD:R_0603_1608Metric | R3 |
| 1 | 1M | Resistor_SMD:R_0402_1005Metric | R5 |
| 1 | 1u | Capacitor_SMD:C_0603_1608Metric | C9 |
| 1 | 20k | Resistor_SMD:R_0603_1608Metric | R8 |
| 1 | 24AA02E-OT | Package_TO_SOT_SMD:SOT-23-5 | U1 |
| 1 | 3.3k | Resistor_SMD:R_0603_1608Metric | R4 |
| 1 | 500K | Potentiometer_THT:Potentiometer_Bourns_3296W_Vertical | RV1 |
| 1 | 75k | Resistor_SMD:R_0603_1608Metric | R2 |
| 1 | ADS1219 | Package_DFN_QFN:Texas_RTE0016D_WQFN-16-1EP_3x3mm_P0.5mm_EP0.8x0.8mm_ThermalVias | U2 |
| 1 | BOARD_CONNECTOR | heep-footprints:chewing-gum-pcb | CG1 |
| 1 | Conn_01x02 | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | J2 |
| 1 | Conn_01x02 | Connector_PinSocket_2.54mm:PinSocket_1x02_P2.54mm_Vertical | J3 |
| 1 | Conn_02x01 | Connector_PinHeader_2.54mm:PinHeader_1x03_P2.54mm_Vertical | J4 |
| 1 | Conn_Coaxial | Connector_Coaxial:SMA_Amphenol_132289_EdgeMount | J1 |
| 1 | INA212AIDCKR | Package_TO_SOT_SMD:SOT-363_SC-70-6 | IC1 |
| 1 | LED | LED_SMD:LED_0603_1608Metric | D1 |
| 1 | LM334M_NOPB | LM334:SOIC127P600X175-8N | IC2 |
| 1 | LOGO | heep-footprints:ESL_3x3 | G*** |
| 1 | LOGO | heep-footprints:EPFL_3x1 | G*** |
| 1 | MCP4726 | Package_TO_SOT_SMD:TSOT-23-6 | U4 |
| 1 | TLV75801PDBV | Package_TO_SOT_SMD:SOT-23-5 | U3 |
It measures 15.3 × 45.8 mm and has 4 copper layers, 1.61 mm thick.
39 parts, built around the ADS1219IPW and TLV75801PDBV. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
From the esl-epfl/CHEEP-boards repository on GitHub, at the commit this page was made from: the board is chewing-gums/CurrentSource/CurrentSource.kicad_pcb and its schematic chewing-gums/CurrentMeasurementSupply/nA_current_shunt_monitor_gum.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Its repository states no licence, so its author keeps all rights: ask esl-epfl before reusing the design.
esl-epfl/CHEEP-boards
This chewing gum board is designed to be an extended-range voltage supply + current measurement circuit, intended for connection to the main board through the male pin headers to both sides.
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