WM8960 datasheet(16/92 Pages) WOLFSON

部品番号	WM8960

部品情報	Stereo CODEC with 1W Stereo Class D Speaker Drivers and Headphone Drivers for Portable Audio Applications

PDF	92 Pages

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メーカー	WOLFSON [Wolfson Microelectronics plc]

ホームページ	http://www.wolfsonmicro.com

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16 / 92 page

WM8960

Production Data

PD, August 2013, Rev 4.2

INTERNAL POWER ON RESET CIRCUIT

Figure 5 Internal Power on Reset Circuit Schematic

The WM8960 includes an internal Power-On-Reset Circuit, as shown in Figure 5, which is used to

reset the digital logic into a default state after power up. The POR circuit is powered from AVDD and

monitors DCVDD. It asserts PORB low if AVDD or DCVDD is below a minimum threshold.

Figure 6 Typical Power up Sequence where AVDD is Powered before DCVDD

Figure 6 shows a typical power-up sequence where AVDD comes up first. When AVDD goes above

the minimum threshold, Vpora, there is enough voltage for the circuit to guarantee PORB is asserted

low and the chip is held in reset. In this condition, all writes to the control interface are ignored. Now

AVDD is at full supply level. Next DCVDD rises to Vpord_on and PORB is released high and all registers

are in their default state and writes to the control interface may take place.

On power down, where AVDD falls first, PORB is asserted low whenever AVDD drops below the

minimum threshold Vpora_off.

WM8960 データシート(PDF) 16 Page - Wolfson Microelectronics plc