SBOS820A September 2019 – June 2020 TMCS1100
The TMCS1100 only requires a power supply (VS) on the low-voltage isolated side, which powers the analog circuitry independent of the isolated current input. VS determines the full-scale output range of the analog output VOUT, and can be supplied with any voltage between 3 V and 5.5 V. To filter noise in the power-supply path, place a low-ESR decoupling capacitor of 0.1 uF between VS and GND pins as close as possible to the supply and ground pins of the device. To compensate for noisy or high-impedance power supplies, add more decoupling capacitance.
The TMCS1100 power supply VS can be sequenced independently of current flowing through the input. However, there is a typical 25ms delay between VS reaching the recommended operating voltage and the analog output being valid. Within this delay VOUT transfers from a high impedance state to the active drive state, during which time the output voltage could transition between GND and VS. If this behavior must be avoided, a stable supply voltage to VS should be provided for longer than 25ms prior to applying input current.