Maxim Integrated MAXQ7667 - Manual (Page 280)

16.5.2 Digital I/O Supply (DVDDIO) Monitor
The DVDDIO monitor detects a brownout condition on the +5V digital I/O supply. The DVDDIO supply monitor can be independently
activated by setting to 1 the VIBE bit in the APE register. A brownout is detected when the DVDDIO supply voltage falls below the pro-
grammed DVDDIO brownout detection threshold (see Figure 16-8). When using the internal voltage regulators, the DVDDIO brownout
interrupt provides the earliest warning of a loss of power event. If enabled, a DVDDIO brownout interrupt can be generated. When using
the internal voltage regulators, the DVDDIO brownout interrupt provides the earliest warning of a loss of power event. A DVDDIO
brownout interrupt is generated only if the interrupt enable bit (VIBIE) in the AIE register is set. Also, global interrupt mask bits IM5 (in
the IMR register) and IGE (in the IC register) must be enabled.
16.5.3 Analog Supply Voltage (AVDD) Monitor
The AVDD monitor detects a brownout condition on the +3.3V analog I/O supply. The AVDD supply monitor can be independently acti-
vated by setting the VABE bit in the APE register. A brownout is detected when the AVDD supply voltage falls in the programmed AVDD
brownout detection threshold (Figure 16-9). An AVDD brownout interrupt is generated only if the interrupt enable bit (VABIE) in the AIE
register is set. Also, global interrupt mask bits IM5 (in the IMR register) and IGE (in the IC register) must be enabled.
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MAXQ7667 User’s Guide
Figure 16-9. AVDD Brownout Interrupt Threshold Detection
NOMINAL AVDD
(+3.3V)
AVDD
BROWNOUT
INTERRUPT
AVDD INTERRUPT
THRESHOLD
(3.0V TO 3.15V)
AVLVL
Figure 16-8. DVDDIO Brownout Interrupt Threshold Detection
NOMINAL DVDDIO
(+5.0V)
DVDDIO
BROWNOUT
INTERRUPT
VIOLVL
DVDDIO INTERRUPT
THRESHOLD
(4.5V TO 4.75V)