TD230IDT STMicroelectronics, TD230IDT Datasheet - Page 3

• Manufacturer Part Number: TD230IDT
• Description: MOSFET & Power Driver ICs
• Manufacturer: STMicroelectronics

Specifications of TD230IDT

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

AN1280 - APPLICATION NOTE
To avoid cumulative charging of the protection ca-
pacitors C
conditions, the capacitors C
discharged by another fixed current source IP/N3
which value is a fourth of I
Figure 3 : Fault Time Limitation
Trace 1 represents the C
5+13,4 = 18,4V)
Trace 2 represents the C
The value of the capacitors C
sen in relation with the required protection time as
indicated in equation (iv) :
where t
fore a definitive resettable shutdown of MOS-
FET
Equation (iv) can be translated to :
Note that the positive power supply disjonction
leads to the negative power supply disjonction,
whereas the opposite is not true.
2.3. Step-Up Converter
To ensure proper voltage on the gate of the posi-
tive supply NMOS1 (V
integrates a step-up converter which is to be
boosted with two small low cost external compo-
nents : an inductor L
as shown in figure 4.
1/2
.
C
PROTECT 1/2
C
TRIP1/2
TRIP 1/2
TRIP 1/2
= (I
= t
in case of successive overcurrent
is the time defined by the user be-
PROTECT 1/2
P/N2
BOOST
- I
GS
P/N3
= 13.4V typ), the TD230
TRIP1
P/N2
and a capacitor C
) x t
x 3 A / 1.20V (iv)
TRIP 1/2
BOOST
TRIP 1/2
Voltage.
PROTECT1/2
(1 A).
Voltage (0 to
should be cho-
are constantly
/ VS
PN/3
BOOST
(iv)
,
Figure 4 : Step Up Converter External
The principle of this inductive step-up converter is
to pump charges in the tank capacitor C
lowing the equation (v) :
Figure 5 : Internal Step Up Schematic
Charges are pumped by means of an oscillator
commanded switch, and stored in the C
capacitor through a diode as shown on figure 5.
When
V
ates a ripple voltage with an amplitude of 0.2V.
Note that the min and max values of V(C
comprised between V
ready take the ripple voltage into account.
CC
+
+13.4V typ, the oscillator is stopped. This cre-
V(C
the
Components
BOOST
voltage
) = V
CC+
CC
across
+
+ 13.4V typ (v)
+10V and V
C
BOOST
CC
+
BOOST
BOOST
+15V al-
reaches
BOOST
tank
fol-
3/8
)