XE8805 SEMTECH [Semtech Corporation], XE8805 Datasheet - Page 121

• Manufacturer Part Number: XE8805
• Description: Data Acquisition MCU
• Manufacturer: SEMTECH [Semtech Corporation]

17.1 Features
17.2 Overview
The Vmult block generates a voltage (called “Vmult”) that is higher or equal to the supply voltage. This output
voltage is used in the acquisition chain.
The voltage multiplier should be on (bit ENABLE in RegVmultCfg0) when using the acquisition chain or analog
properties of the Port B while VBAT is below 3V. If the multiplier is enabled, the external capacitor on the pin
VMULT is mandatory.
The source clock of Vmult is selected by FIN[1:0] in RegVmultCfg0. It is strongly recommended to use the same
settings as in the ADC.
17.3 Control register
There is only one register in the Vmult. Table 177-1 describes the bits in the register.
Pos.
2
1-0
Table 177-1. RegVmultCfg0
17.4 External component
When the multiplier is enabled, a capacitor has to be connected to the VMULT pin. If the multiplier is disabled, the
pin may remain floating.
Capacitor on VMULT
© Semtech 2006
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RegVmultCfg0
Enable
Fin
Generates a voltage that is higher or equal to the supply voltage.
Can be easily enabled or disabled
rw
rw
rw
0
Reset
0
resetsystem
resetsystem
Function
enable of the vmult
‘1’ : enabled
‘0’ : disabled
system clock division factor
‘00’ : 1/2,
‘01’ : 1/4,
‘10’ : 1/16,
‘11’ : 1/64
17-2
Min.
1.0
Max.
3.0
nF
Note
XE8805/05A
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