Datasheet
Data Sheet ADP1046A
Rev. 0 | Page 71 of 88
Table 86. Register 0x56—SR2 Rising Edge Setting (SR2 Pin)
Bits Bit Name R/W Description
[7:4] t
11
R/W These bits contain the four LSBs of the 12-bit t
11
time. This value is always used with the eight
bits of Register 0x55, which contains the eight MSBs of the t
11
time. Each LSB corresponds to 5 ns
resolution. The entire switching period is divided into 40 ns time steps. If the t
Rx
and t
Fx
of a PWM
edge occur within the same 40 ns time step, the PWM output is 0 V. If the t
Rx
and t
Fx
occur in
different 40 ns time steps, the PWM output is set to the programmed value. The absolute
maximum pulse width is t
PERIOD
− 5 ns. It is recommended that the SR2 rising edge not be set
between 80 ns and 115 ns when using the SR soft start.
3 Modulate enable R/W 1 = PWM modulation acts on the t
11
edge.
0 = no PWM modulation of the t
11
edge.
2
t
11
sign
R/W
1 = negative sign. Increase of PWM modulation moves t
11
right.
0 = positive sign. Increase of PWM modulation moves t
11
left.
[1:0] Reserved R/W Reserved.
Table 87. Register 0x57—SR2 Falling Edge Timing (SR2 Pin)
Bits Bit Name R/W Description
[7:0] t
12
R/W This register contains the eight MSBs of the 12-bit t
12
time. This value is always used with the top
four bits of Register 0x58, which contains the four LSBs of the t
12
time. Each LSB corresponds to
5 ns resolution. The entire switching period is divided into 40 ns time steps. If the t
Rx
and t
Fx
of a
PWM edge occur within the same 40 ns time step, the PWM output is 0 V. If the t
Rx
and t
Fx
occur
in different 40 ns time steps, the PWM output is set to the programmed value. The absolute
maximum pulse width is t
PERIOD
− 5 ns.
Table 88. Register 0x58—SR2 Falling Edge Setting (SR2 Pin)
Bits Bit Name R/W Description
[7:4] t
12
R/W These bits contain the four LSBs of the 12-bit t
12
time. This value is always used with the eight
bits of Register 0x57, which contains the eight MSBs of the t
12
time. Each LSB corresponds to 5 ns
resolution. The entire switching period is divided into 40 ns time steps. If the t
Rx
and t
Fx
of a PWM
edge occur within the same 40 ns time step, the PWM output is 0 V. If the t
Rx
and t
Fx
occur in
different 40 ns time steps, the PWM output is set to the programmed value. The absolute
maximum pulse width is t
PERIOD
− 5 ns.
3
Modulate enable
R/W
1 = PWM modulation acts on the t
12
edge.
0 = no PWM modulation of the t
12
edge.
2 t
12
sign R/W 1 = negative sign. Increase of PWM modulation moves t
12
right.
0 = positive sign. Increase of PWM modulation moves t
12
left.
[1:0] Reserved R/W Reserved.
Table 89. Register 0x59—OUTAUX Rising Edge Timing (OUTAUX Pin)
Bits Bit Name R/W Description
[7:0]
t
13
R/W
This register contains the eight MSBs of the 12-bit t
13
time. This value is always used with the top
four bits of Register 0x5A, which contains the four LSBs of the t
13
time. Each LSB corresponds to
5 ns resolution. The entire switching period is divided into 40 ns time steps. If the t
Rx
and t
Fx
of a
PWM edge occur within the same 40 ns time step, the PWM output is 0 V. If the t
Rx
and t
Fx
occur
in different 40 ns time steps, the PWM output is set to the programmed value. The absolute
maximum pulse width is t
PERIOD
− 5 ns. Depending on the switching frequency and the OUTAUX
frequency, there is a constant lag/lead time between this edge and the other edges (t
1
to t
12
);
therefore, OUTAUX is not synchronized to the other PWM outputs but can be made synchronous
by adjusting the delay accordingly. If either the OUTAUX switching frequency (Register 0x3F) or
the PWM switching frequency (Register 0x40) is changed after edge adjustment, the synchroniza-
tion between OUTAUX and the PWM edges is no longer maintained. The OUTAUX delay must be
adjusted again to synchronize the edges to the PWM edges for the new set of switching frequencies.