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Analog-to-Digital Converter/Brownout Detector
LH75400/01/10/11 (Preliminary) User’s Guide
23-4
6/25/03
23.1.3 Brownout Detector
The Brownout Detector is an asynchronous comparator that compares a divided version
of the 3.3 V supply and a bandgap-derived reference voltage. If the supply dips below a
Trip point, the Brownout Detector sets a bit in the IS Register. The status bit is wired to the
VIC and can interrupt the processor core. This allows the Host Controller to warn users of
an impending shutdown and may provide the ADC with time to save its state. For Brownout
Detector trip point and hysteresis levels, see Chapter 24.
NOTE: The Brownout Detector indicates a brownout condition on startup until the VDDA pin rises
above the trip point.
Figure 23-2. Bias-and-Control Network Block Diagram
LH754xx-28
11-TO-1
ANALOG
MUX
A/D IN+
B12
PENIRQ
B8
B7
B6
B4
B2
AVDD
AVDD
AVDD
AVDD
AN0/UL/X+
B3
AN1/UR/X-
B5
AN2/LL/Y+
AN6
A3
TSCHWR[6]
A2
TSCHWR[5]
A1
TSCHWR[4]
A0
TSCHWR[3]
AN8
AN9
AN3/LR/Y-
AN4/WIPER
VREF -
B13
PENIRQ
100K
100K
AVDD