CAP1188 Datasheet, PDF (72/79 Pages) Microchip Technology – 8 Channel Capacitive Touch Sensor with 8 LED Drivers

CAP1188
APPENDIX A: DEVICE DELTA
A.1 Delta from CAP1088 to CAP1188
1. Updated circuitry to improve power supply rejection.
2. Updated LED driver duty cycle decode values to have more distribution at lower values - closer to a logarithmic
curve. See Table 6-60, "LED Duty Cycle Decode".
3. Updated bug that breathe periods were not correct above 2.6s. This includes rise / fall time decodes above 1.5s.
4. Added filtering on RESET pin to prevent errant resets.
5. Updated controls so that the RESET pin assertion places the device into the lowest power state available and
causes an interrupt when released. See Section 5.2, "RESET Pin".
6. Added 1 bit to the LED Off Delay register (see Section 6.38, "LED Off Delay Register") to extend times from 2s
to 5s in 0.5s intervals.
7. Breathe behavior modified. A breathe off delay control was added to the LED Off Delay Register (see Section
6.38, "LED Off Delay Register") so the LEDs can be configured to remain inactive between breathes.
8. Added controls for the LED transition effects when linking LEDs to capacitive sensor inputs. See Section 6.29,
"Linked LED Transition Control Register".
9. Added controls to “mirror” the LED duty cycle outputs so that when polarity changes, the LED brightness levels
look right. These bits are automatically set when polarity is set. Added control to break this auto-set behavior.
See Section 6.30, "LED Mirror Control Register".
10. Added Multiple Touch Pattern detection circuitry. See Section 6.15, "Multiple Touch Pattern Configuration Regis-
ter".
11. Added General Status register to flag Multiple touches, Multiple Touch Pattern issues and general touch detec-
tions. See Section 6.2, "Status Registers".
12. Added bits 6 and 5 to the Recalibration Configuration register (2Fh - see Section 6.17, "Recalibration Configura-
tion Register"). These bits control whether the accumulation of intermediate data and the consecutive negative
delta counts counter are cleared when the noise status bit is set.
13. Added Configuration 2 register for LED linking controls, noise detection controls, and control to interrupt on press
but not on release. Added control to change alert pin polarity. See Section 6.6, "Configuration Registers".
14. Updated Deep Sleep behavior so that device does not clear DSLEEP bit on received communications but will
wake to communicate.
15. Changed PWM frequency for LED drivers. The PWM frequency was derived from the programmed breathe
period and duty cycle settings and it ranged from ~4Hz to ~8000 Hz. The PWM frequency has been updated to
be a fixed value of ~2000Hz.
16. Register delta:
Table A.1 Register Delta From CAP1088 to CAP1188
Address
Register Delta
Delta
Default
00h
Changed - Main Status /
added bits 7-6 to control gain
00h
Page 32
Control
02h
New - General Status new register to store MTP, MULT, LED,
00h
Page 33
RESET, and general TOUCH bits
44h
New - Configuration 2 new register to control alert polarity, LED
40h
Page 37
touch linking behavior, LED output behav-
ior, and noise detection, and interrupt on
release
24h
Changed - Averaging
updated register bits - moved
39h
Page 40
Control
SAMP_AVG[2:0] bits and added SAMP_-
TIME bit 1. Default changed
2Bh
New - Multiple Touch
new register for Multiple Touch Pattern
80h
Page 44
Pattern Configuration configuration - enable and threshold set-
tings
DS00001620C-page 72
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