Datasheet

R
OV1
= 15.8 k:
R
OV2
= 499 k:
=
V
OFFTURN
=
-
R
OV1
k8.15 :
V
OFFTURN-
(
)
RR1.24V
OV2OV1
+x
0.5x
( )
k499k8.151.24V :+:x 0.5
x
V= 39.8
:== k15.7
-
-
0.62VV
OFFTURN
x R1.24V
OV2
=R
OV1
:x k4991.24V
- 0.62V40V
2
9.98VA20k499A20RV
OVHYSO
=
x:
=
x
=
P
P
===
A
20
10V
R
OV2
P
:k500
V
HYSO
A20
P
k:501R
2UV
=
k:12R
1UV
=
R
UV1
(
)
RR1.24V
UV2UV1
+x
V
ONTURN
=
-
= V10.1=
( )
k150k211.24V :+:x
k21 :
V
ONTURN-
:== k2.21
-
-
1.24VV
ONTURN
x R1.24V
UV2
=R
UV1
:x k1501.24V
-1.24V10V
3VA20k150A20RV
2UVHYS
=
x:
=
x
=
PP
===
A
20
3V
R
UV2
P
:k150
V
HYS
A20
P
LM3424
SNVS603B –AUGUST 2009–REVISED OCTOBER 2009 www.ti.com
13. INPUT UVLO
Solve for R
UV2
:
(149)
The closest standard resistor is 150 kΩ therefore V
HYS
is:
(150)
Solve for R
UV1
:
(151)
The closest standard resistor is 21 kΩ making V
TURN-ON
:
(152)
The chosen components from step 13 are:
(153)
14. OUTPUT OVLO
Solve for R
OV2
:
(154)
The closest standard resistor is 499 kΩ therefore V
HYSO
is:
(155)
Solve for R
OV1
:
(156)
The closest standard resistor is 15.8 kΩ making V
TURN-OFF
:
(157)
The chosen components from step 14 are:
(158)
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