Current Measurement Box Rev03#
Overview#
Rev03 is the latest revision of the current measurement box. The schematic is built around four identical measurement channels. Each channel uses a Sensitec CAS50xxSRA or CAS50xxKRA current sensor and a THS4521 fully differential amplifier stage.
Changes from Rev02#
Input and output terminals changed to Wuerth REDCUBE press-fit terminals for M3 ring shoes.
Input supply range in the schematic is extended to 7 V to 65 V.
The power supply now generates an intermediate 6.5 V rail and a clean 5.10 V VCC+ rail.
Differential output filtering is populated with 5.6 nF differential capacitance and 470 pF common-mode capacitors.
Interface#
Inputs:
Supply voltage VIN: 7 V to 65 V via Samtec IPL1-102-02-L-D-K.
Alternative VIN connector footprint: TSW-102-07-F-S.
Sensor current path per channel through REDCUBE press-fit terminals for M3 ring shoes, rated for 130 A.
Initially, the external-thread Wuerth 7461094 terminal was used.
Due to production issues during press-fit assembly, it was changed to the internal-thread Wuerth 7461093 terminal.
Outputs:
4 fully differential voltage outputs via RJ45.
Fig. 297 Rev03 with internal-thread REDCUBE terminals 7461093.#
Functionality and Specifications#
Parameter |
Description |
|---|---|
VIN |
7 V to 65 V |
Intermediate supply |
6.5 V generated by TPSM365R6 buck converter |
VCC+ Supply |
5.10 V generated by TPS7A4700 LDO |
Reference / output common-mode |
2.5 V generated by REF35250QDBVR |
Number of channels |
4 |
Current sensor |
Sensitec CAS50xxSRA/CAS50xxKRA |
Amplifier |
THS4521 fully differential amplifier, gain = 2 |
Input current connection |
REDCUBE press-fit terminals |
Output connector |
RJ45 for fully differential output pairs |
Output filter |
R13/R15 = 49.9 Ohm, C18 = 5.6 nF, C16/C20 = 470 pF |
Filter cutoff |
273 kHz |
Supported Sensors#
Rev03 supports all current transducers listed in Supported Sensors, including CAS5075KRA-KH.
Schematic#
Known Issues#
No known issues are documented yet.