WM8983GEFL/V Wolfson Microelectronics, WM8983GEFL/V Datasheet - Page 22

• Manufacturer Part Number: WM8983GEFL/V
• Description: Audio CODECs Mbl Multimedia CODEC w/ 1W Speaker Driver
• Manufacturer: Wolfson Microelectronics

Specifications of WM8983GEFL/V

• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: QFN-32
• Minimum Operating Temperature: - 25 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

WM8983
INTERNAL POWER ON RESET CIRCUIT
Figure 11 Typical Power up Sequence where AVDD1 is Powered before DCVDD
w
Figure 10 Internal Power on Reset Circuit Schematic
The WM8983 includes an internal Power-On-Reset Circuit, as shown in Figure 10, which is used
reset the digital logic into a default state after power up. The POR circuit is powered from AVDD1
and monitors DCVDD. It asserts PORB low if AVDD1 or DCVDD is below a minimum threshold.
Figure 11 shows a typical power-up sequence where AVDD1 comes up first. When AVDD1 goes
above the minimum threshold, V
asserted low and the chip is held in reset. In this condition, all writes to the control interface are
ignored. Now AVDD1 is at full supply level. Next DCVDD rises to V
and all registers are in their default state and writes to the control interface may take place.
On power down, where AVDD1 falls first, PORB is asserted low whenever AVDD1 drops below the
minimum threshold V
pora_off
.
pora
, there is enough voltage for the circuit to guarantee PORB is
pord_on
and PORB is released high
PD, Rev 4.3, May 2010
Production Data
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