A6984 datasheet(21/47 Pages) STMICROELECTRONICS

部件名	A6984

功能描述	36 V, 400 mA automotive synchronous step-down switching regulator

PDF	47 Pages

Scroll/Zoom	100%

制造商	STMICROELECTRONICS [STMicroelectronics]

网页	http://www.st.com

标志

21 / 47 page

DocID030396 Rev 1

21/47

A6984

Device description

Figure 14. Virtual ESR network

The CDC capacitor decouples the feedback DC path through the RCOT so the output voltage

is adjusted accordingly with Section 4.1 on page 13.

Basically the network RCOT, CCOT generates a voltage signal proportional to the inductor

current ripple and superimposed with the real partitioned output voltage that increases the

SNR at the input of the PWM comparator. As a consequence the PWM converter

commutation is clean, removing the duty cycle dithering.

For the purpose of the signal generated by the RCOT and CCOT the output capacitor

represents a virtual ground so the equivalent small signal circuit of the output of the virtual

ESR network is shown in Figure 15.

Figure 15. Virtual ESR equivalent circuit

A6984 数据表(PDF) 21 Page - STMicroelectronics