l6706 STMicroelectronics, l6706 Datasheet - Page 32

• Manufacturer Part Number: l6706
• Description: Vr11.1 Single Phase Controller With Integrated Driver
• Manufacturer: STMicroelectronics

Soft-start
32/47
Figure 14. SSOSC connection
where T
connected between SSOSC and SSEND (through a signal diode) in kΩ.
Figure 15. Soft-start time (T
Use the following relationship to select the maximum LTB switching frequency:
where F
T
SS
[
SS
LIMIT
μs
is the time spent to reach the programmed voltage V
]
=
has to be higher than the F
200 μs
to SSEND Logic
[
R
V
SSOSC
Pull-Up
]
R
+
FLIMIT
(1.2V)
⎧
⎪
⎪
⎨
⎪
⎪
⎩
R
---------------------------------- -
R
---------------------------------- -
[
kΩ
SSOSC
SSOSC
40 10
40 10
[
Doc ID 15698 Rev 1
R
kΩ
]
SS
Pull-Up
⋅
⋅
=
) when using R
]
(1k)
[
[
T
SS_END
–
–
kΩ
kΩ
=
3
3
D2
-------------------------------- -
F
]
]
[
2.11 10
LIMIT
μs
⋅
⋅
SW
---------------------------------------------- -
1.24 V
---------------------------------------------- -
1.24 V
] 40 10
⋅
⋅
Soft Start time and FLIMIT
selected in indipendent way.
[
switching frequency.
kHz
–
–
D
1.24
1.24
⋅
4
DIODE
DIODE
]
SSOSC
⋅
–
3
1.24 V
---------------------------------------------- -
R
⋅
SSOSC
R
[ ]
[ ]
1.24 V
---------------------------------------------- -
b
V
V
(10k)
, diode versus SSEND
–
R
⋅
⋅
1.24
SSOSC
FLIMIT
----------------- -
V
–
CE
1
V
BOOT
1.24
+
SS
BJT
DIODE
----------------- -
V
Q
SS
V
BOOT
[ ]
SS
V
and R
[ ]
V
Soft Start time depends
on selected FLIMIT.
R
if V
if V
FLIM_SS
SSOSC
(
(
SS
SS
>
<
the resistor
V
V
BOOT
BOOT
L6706
)
)