ZSSC3122 Datasheet, PDF (34/64 Pages) List of Unclassifed Manufacturers – Low Voltage Capacitive Sensor Signal Conditioner

ZSSC3122
cLite™ Low Voltage Capacitive Sensor Signal Conditioner
Figure 3.10 I²C Measurement Packet Reads
I²C DF – 2 Bytes: Slave returns only capacitance data to the master in 2 bytes
S 6 5 4 3 2 1 0 R A 15 14 13 12 11 10 9 8 A 7 6 5 4 3 2 1 0 N S
Device Slave Address [6:0]
Wait for
Slave ACK
Cap. Data [13:8]
Cap. Data [7:0]
Master ACK
Master ACK
Master NACK
S 6 5 4 3 2 1 0 R A 15 14 13 12 11 10 9 8 A 7 6 5 4 3 2 1 0 A 7 6 5 4 3 2 1 0 N S
Device Slave Address [6:0]
Cap. Data [13:8]
Cap. Data [7:0]
Temp. Data [13:6]
I²C DF – 3 Bytes: Slave returns 2 capacitance data bytes & temperature high byte (T[13:6]) to master
S ^{Start Condition} S ^{Stop Condition}
A ^{Acknowledge (ACK)}
N ^{Not Acknowledge}
(NACK)
2 Slave Address Bit (Example: Bit 2)
2 _{Command or Data Bit (Example: Bit 2)}
R ^Read/Write
(Read = 1)
Status Bit
3.6.4.2. SPI Data Fetch
By default the SPI interface will have data change after the falling edge of SCLK. The master should sample
MISO on the rising (opposite) edge of SCLK. This is configurable via the SPI_Phase bit in EEPROM word
Cust_Config (see Table 5.5 for bit assignments). The SPI protocol can handle high and low polarity of the clock
line without configuration change.
As seen in Figure 3.11 the entire output packet is 4 bytes (32 bits). The high capacitive data byte comes first,
followed by the low byte. Then 14 bits of corrected temperature (T[13:0]) are sent: first the T[13:6] byte and then
the {T[5:0],xx} byte. The last 2 bits of the final byte are undetermined and should be masked off in the application.
If the user only requires the corrected capacitance value, the read can be terminated after the 2^nd byte. If the cor-
rected temperature is also required but only at an 8-bit resolution, the read can be terminated after the 3^rd byte is
read.
Data Sheet
August 16, 2011
© 2011 Zentrum Mikroelektronik Dresden AG — Rev.1.20
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used
without the prior written consent of the copyright owner. The information furnished in this publication is subject to changes
without notice.
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