CLRC663 Datasheet, PDF (85/132 Pages) NXP Semiconductors – Contactless reader IC

NXP Semiconductors
CLRC663
Contactless reader IC
Table 128. DrvMode bits
Bit
Symbol
Description
7
Tx2Inv
Inverts transmitter 2 at TX2 pin
6
Tx1Inv
Inverts transmitter 1 at TX1 pin
5
RFU
4
-
RFU
3
TxEn
If set to 1 both transmitter pins are enabled
2 to 0
TxClkMode
Transmitter clock settings (see 8.6.2. Table 27). Codes 011b and
0b110 are not supported. This register defines, if the output is
operated in open drain, push-pull, at high impedance or pulled to a fix
high or low level.
9.8.2 TxAmp
With the set_cw_amplitude register output power can be traded off against power supply
rejection. Spending more headroom leads to better power supply rejection ration and
better accuracy of the modulation degree.
With CwMax set, the voltage of TX1 will be pulled to the maximum possible. This register
overrides the settings made by set_cw_amplitude.
Table 129. TxAmp register (address 29h)
Bit
7
6
5
4
Symbol
set_cw_amplitude
-
Access
r/w
rights
RFU
3
2
1
0
set_residual_carrier
r/w
Table 130. TxAmp bits
Bit
Symbol
7 to 6 set_cw_amplitude
5
4 to 0
RFU
set_residual_ carrier
Description
Allows to reduce the output amplitude of the transmitter by a fix
value.
Four different preset values that are subtracted from TVDD can
be selected:
0: TVDD -100 mV
1: TVDD -250 mV
2: TVDD -500 mV
3: T_VDD -1000 mV
-
Set the residual carrier percentage. refer to Section 8.6.2
9.8.3 TxCon
Table 131. TxCon register (address 2Ah)
Bit
7
6
5
Symbol
OvershootT2
Access
r/w
rights
4
3
2
1
0
CwMax
TxInv
TxSel
r/w
r/w
r/w
CLRC663
Product data sheet
COMPANY PUBLIC
All information provided in this document is subject to legal disclaimers.
Rev. 3.3 — 3 April 2012
171133
© NXP B.V. 2012. All rights reserved.
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