XE8806A SEMTECH [Semtech Corporation], XE8806A Datasheet - Page 134

• Manufacturer Part Number: XE8806A
• Description: Ultra Low-Power Low-Voltage
• Manufacturer: SEMTECH [Semtech Corporation]

18.5 VLD operation
The VLD is controlled by VldRange, VldTune and VldEn. VldRange selects the voltage range to be detected,
while VldTune is used to fine-tune this voltage level in 8 steps. VldEn is used to enable (disable) the VLD with a
1(0) value respectively. Disabled, the block will dissipate no power.
Note 1: absolute precision of the threshold voltage is ±10%.
Note 2: this timing is respected in case the internal RC or crystal oscillators are selected. Refer to the clock block
documentation in case the external clock is used.
To start the voltage level detection, the user sets bit VldEn. The measurement is started.After 2ms, the bit VldValid
is set to indicate that the measurement results are valid. From that time on, as long as the VLD is enabled, a
maskable interrupt request is sent if the voltage level falls below the threshold. One can also poll the VLD and
monitor the actual measurement result by reading the VldResult bit of the RegVldStat. This result is only valid as
long as the VldValid bit is ‘1’.
© Semtech 2006
symbol
T
Vth
T
EOM
PW
Minimum pulse width
Threshold voltage
description
measurement
duration of
detected
Table 18-5: Voltage level detector operation
min
18-3
Note 1
1.53
1.44
1.36
1.29
1.22
1.16
1.11
1.06
3.06
2.88
2.72
2.57
2.44
2.33
2.22
2.13
typ
875
2.0
1350
max
2.5
unit
ms
us
V
XE8806A/XE8807A
VldRange
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
trimming values:
comments
Note 2
Note 2
VldTune
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000
001
010
011
100
101
110
111
000
001
010
011
100
101
110
111