FAH4840-269128 Datasheet, PDF (13/21 Pages) List of Unclassifed Manufacturers – FAH4840 Haptic Driver for Linear Resonant Actuators (LRAs)

Table 10.
Address:
Reset Value:
CTRL_THR
0x07
00000100
Bit #
Name
Type
Function
Threshold for transition region around zero-crossing point. It represents the jitter
width around the zero-crossing point. When accumulative comparator result for
7:0
Z_X_NUM[7:0]
R/W
one level (HIGH or LOW) around the transition edge reaches the threshold, zero-
crossing point is thought to be found.
The threshold is programmed referring to PWM_DIV. To be safe, set the threshold
a bit larger than the real transition region.
Table 11.
Address:
Reset Value:
CALIB_STATUS1
0x08
x0010000
Bit #
Name
Type
Function
7
Reserved
6
CALIB_FAIL
R
After the measurement delay period passes, count period of 3*PWM_DIV. During
this time, if the four zero-crossing points are not found, calibration fails.
5 LAST_LEVEL R Indicate the last level (HIGH or LOW) for detecting next zero-crossing point.
4 CALIB_FIRST R Indicate whether current resonant detection is the first after power on reset or not.
3:0 CALIB_STATE R Resonant detection state machine.
Table 12.
Address:
Reset Value:
CALIB_STATUS2
0x09
00000000
Bit #
7:0
Name
FIRST_TAG[7:0]
Type
Function
R LSB bits of the tag for the first found zero-crossing edge.
Table 13.
Address:
Reset Value:
CALIB_STATUS3
0x0A
00000000
Bit #
7:0
Name
FIRST_TAG[15:8]
Type
Function
R MSB bits of the tag for the first found zero-crossing edge.
Table 14.
Address:
Reset Value:
CALIB_STATUS4
0x0B
00000000
Bit #
7:0
Name
PWM_DIVISOR_A[7:0]
Type
R
Function
LSB bits of the resonant period calculated by the first zero-crossing
point and third point.
© 2013 Fairchild Semiconductor Corporation
FAH4840 • Rev. 1.0.0
13
www.fairchildsemi.com