ADSP-BF50x Blackfin Processor Hardware Reference
14-29
PWM Controller
Gate Drive Unit
The Gate Drive Unit is described in the following sections:
•
“High-Frequency Chopping”
•
“PWM Polarity Control” on page 14-30
High-Frequency Chopping
The Gate Drive Unit of the PWM Controller simplifies the design of
isolated gate drive circuits for PWM inverters. If a transformer-coupled
power device gate drive amplifier is used, the active PWM signal must be
chopped at a high frequency. The 10-bit read/write
PWM_GATE
register
allows you to specify this high-frequency chopping mode.
Chopped active PWM signals may be required for high-side drivers only,
for low-side drivers only, or for both high-side and low-side switches.
Therefore, independent control of this mode for both high- and low-side
switches is included with two separate control bits (
CHOPHI
and
CHOPLO
) in
the
PWM_GATE
register.
Typical PWM output signals with high-frequency chopping enabled on
both high- and low-side signals are shown in
Figure 14-8
. Chopping the
high-side PWM outputs (
AH
,
BH
, and
CH
) is enabled by setting the
CHOPHI
bit of the
PWM_GATE
register; chopping the low-side PWM outputs (
AL
,
BL
,
and
CL
) is enabled by setting the
CHOPLO
bit of the
PWMGATE
register. The
high-frequency chopping frequency is controlled by the 8-bit word placed
in bits 0 to 7 (
GDCLK
) of the
PWM_GATE
register. The period of this high-fre-
quency carrier is:
T
chop
4
GDCLK
1
+
t
SCLK
=
Summary of Contents for EZ-KIT Lite ADSP-BF506F
Page 50: ...Contents l ADSP BF50x Blackfin Processor Hardware Reference ...
Page 92: ...Development Tools 1 30 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 110: ...Interface Overview 3 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 236: ...Internal Flash Memory Control Registers 6 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 650: ...Programming Examples 15 56 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 804: ...Programming Examples 17 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1194: ...Programming Examples 24 90 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1256: ...ACM Registers A 50 ADSP BF50x Blackfin Processor Hardware Reference ...
Page 1264: ...Boundary Scan Architecture B 8 ADSP BF50x Blackfin Processor Hardware Reference ...