iC-JRX
µP INTERFACE WITH 2×4 24V HIGH-SIDE DRIVERS
Rev A1, Page 22/23
Pulse-width modulation
This function can be activated for any chosen I/O stage
in output mode.
First the duty cycle is determined via the PWM register
in 256 steps within one PWM period. Pulse direction
and the address for the desired driver stage is selected
via control word 5 (PWMPN, PWMADR2..0).
The PWM enable bit can now also be set via control
word 5. With this enable, the current source and any
active flash mode for the selected output are
automatically switched off.
The set duty cycle is activated when a new PWM
period is started.
A PWM signal is set at the selected output, whose
frequency is determined by the clock signal at CLK and
whose duty cycle follows the PWM register.
The following correlations apply:
Fig. 5: PWM signal form
fCLK
4096
1
fPWM
'
;
∆tPWM
'
;
tPWMlo ' (PWMLEN %1) × ∆tPWM
fPWM × 256
fCLK
: Clock frequency CLK
fPWM
: frequency for the PWM signal at IOx
∆tPWM
tPWMlo
: Smallest possible pulse duration ‘lo’ (8 µs with a 2 MHz clock)
: pulse duration ‘lo’ (Iox = OFF with PWMPN = 1)
PWMLEN
: Count pulse duration ‘lo’ stored in register PWM7..0
Selectable Pulse-Pause Ratios
PWM7..0
PWMPN
Output signal
0
1
0
Output stage "ON", Pin Iox = '1'
Output stage "OFF", Pin Iox = '0'
(reset entry)
'00'h
Output pin IOx goes for (PWMLEN + 1) × ∆tPWM to '0', and then for
(255 - PWMLEN) × ∆tPWM to '1'
'01'h .. 'FE'h
'FF'h
1
Output pin IOx goes for (PWMLEN + 1) × ∆tPWM to '1', and then for
(255 - PWMLEN) × ∆tPWM to '0'
0
1
Output stage "OFF", Pin Iox = '0'
Output stage "ON", Pin Iox = '1'
This specification is for a newly developed product. iC-Haus therefore reserves the right to change or update, without notice, any information contained herein,
design and specification; and to discontinue or limit production or distribution of any product versions. Please contact iC-Haus to ascertain the current data.
Copying - even as an excerpt - is only permitted with iC-Haus approval in writing and precise reference to source.
iC-Haus does not warrant the accuracy, completeness or timeliness of the specification on this site and does not assume liability for any errors or omissions in
the materials. The data specified is intended solely for the purpose of product description. No representations or warranties, either express or implied, of
merchantability, fitness for a particular purpose or of any other nature are made hereunder with respect to information/specification or the products to which
information refers and no guarantee with respect to compliance to the intended use is given. In particular, this also applies to the stated possible applications
or areas of applications of the product.
iC-Haus conveys no patent, copyright, mask work right or other trade mark right to this product. iC-Haus assumes no liability for any patent and/or other trade
mark rights of a third party resulting from processing or handling of the product and/or any other use of the product.
ICHAUS [ IC-HAUS GMBH ]
