This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS7A84A: Cout at low current

Part Number: TPS7A84A

Hi Team, 

If Iout is below 2A, then can the Cout be similar with TPS7A83/A, that is, decrease Cout from 47uf to 22uf? If not, what's the reason for that? Thanks. 

BRs

Given 

  • Hi Given,

    The Minimum output capacitance for TPS7A84A is 47uF to optimize output performance. 

    In section 8.1.1.7 Input and Output Capacitor Requirements, it explains that the system is designed to operate with 22uF capacitance or greater. The capacitor value on the capacitor typically gets de-rated by a large percentage which is why the data sheet recommends to use at least a 47uF capacitor with a minimum impedance in the 100-kHz to 1-MHz band. 

    Even with a 47uF capacitor, the datasheet also recommends to use smaller capacitors in parallel to ensure that a 22uF capacitance is achieved. 

    By not using a minimum 22uF capacitance on the output, the performance on the datasheet cannot be guaranteed - specifically in the high frequency range [ refer to datasheet section 8.1.3.1 Power-Supply Rejection Ratio (PSRR), 8.1.3.2 Output Voltage Noise, and 8.1.3.3 Optimizing Noise and PSRR ].

    Best,

    Juliette