TSM111
When the system has latched (either after over-
current or overvoltage condition), the system
needs to be reset via the Remote input. The C2
capacitor determines two different timings to the
Fault output :
C2=100nF => Trem1(ON to OFF)=8ms
C2=100nF => Trem2(OFF to ON)=24ms
R5 is a pull down resistor on the remote pin of
TSM111. Note that an integrated pull up resistor of
100kΩ is to be taken into account in the choice of
R5, knowing that the threshold voltage of the input
comparator is 1.4V. Therefore, R5 should be low-
er than 38.8kΩ.
R5 = 1kΩ is a good value.
The evaluation board integrates the possibility to
make the Remote signal either manual, or elec-
tronic thanks to the ORing diodes D5 and D6 (and
the pull down resistor R5), and the Push Button
(SW1). These diodes can of course be replaced
by straps according to the evaluation require-
ments (manual or electronic).
The Tpor delay time allows the PG output (Power
Good) to rise to high level when the 5V power line
internal supervision circuitry has stayed above the
undervoltage 4.3V threshold for more than Tpor
time following the approximated equation 6 :
C3 x Vth = Ic x Tpor
eq6
where Vth is 2V and Ic is 20µA.
C3=2.2µF => Tpor=300ms
When the 5V power line passes under the 4.3V
undervoltage threshold, the Power Good signal
(PG) falls immediately to low level.
The Power Good output can also be triggered by
the Vdet input of the board. This input should be
connected to a power line representative of the
AC mains power situation. As an example, an ad-
ditional winding on the auxiliary power supply offer
an early warning of power down from the mains
power point of view. The UV threshold is internally
fixed to Vdet=1.26V. Therefore, it is necessary to
add a zener diode D1.
D1=15Vzener => Vdet=16.26V
Note that a 20kΩ serial pull down resistor is inte-
grated. Therefore, only a low power zener is need-
ed.
The Fault output needs a pull up resistor R6.
The Power Good output needs a pull up resistor
R11. Both signals are pulled up to the 5Vstandby
power supply which can be generated from the
evaluation board thanks to a 78L05 5V regulator.
This regulator needs a C6 bypass capacitor.
The C7 bypass capacitor smoothens the VCC pin
of TSM111.
The Adj (Adjust) pin should be connected to
ground. Adjust allows to tune a new overvoltage
protection value (ex 2.7V instead of 3.3V).
Example of component lists
Table 1 gives an example of component list
Name
Type
Value Comment
U1 IC
U2 IC
R 1/4W
R1 R 1/2W
R 1W
R 1/4W
R2 R 1/2W
R 1W
R 1/4W
R3 R 1/2W
R 1W
R4 R 1/4W
R5 R 1/4W
R6 R 1/4W
R7 R 1/4W
R8 R 1/4W
R9 R 1/4W
R10 R 1/4W
R11 R 1/4W
D1 Z 1/4W
D5 D 1/4W
D6 D 1/4W
C1 C Electro
C2 C Plastic
C3 C Electro
C4 C Plastic
C5 C Plastic
C6 C Plastic
C7 C Electro
TSM111 DIP20
78L05
TO92
10mΩ
5A
5mΩ
10A
2.5mΩ
20A
10mΩ
5A
5mΩ
10A
2.5mΩ
20A
65mΩ
1A
13mΩ
5A
6.5mΩ
10A
33KΩ
1KΩ
47KΩ
depends on opto used
10kΩ comp. network to
be fine tuned
depends on opto used
10kΩ comp. network to
be fine tuned
47KΩ
15V
1N4148
1N4148
4.7µF
100nF
2.2µF
10NF comp. network to
be fine tuned
10NF comp. network to
be fine tuned
100nF
10µF
14/17