TSM111 STMicroelectronics, TSM111 Datasheet - Page 14

• Manufacturer Part Number: TSM111
• Description: 3.3, 5, 12V triple over voltage and over current protection
• Manufacturer: STMicroelectronics

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
100k
R5, knowing that the threshold voltage of the input
comparator is 1.4V. Therefore, R5 should be low-
er than 38.8k .
R5 = 1k
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
where Vth is 2V and Ic is 20 A.
C3=2.2 F => 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 20k
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.
14/17
is to be taken into account in the choice of
is a good value.
serial pull down resistor is inte-
eq6
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
R10
R11
U1
U2
R1
R2
R3
R4
R5
R6
R7
R8
R9
D1
D5
D6
C1
C2
C3
C4
C5
C6
C7
IC
IC
R 1/4W
R 1/2W
R 1W
R 1/4W
R 1/2W
R 1W
R 1/4W
R 1/2W
R 1W
R 1/4W
R 1/4W
R 1/4W
Z 1/4W
D 1/4W
D 1/4W
C Electro
C Plastic
C Electro
C Plastic
C Plastic
C Plastic
C Electro
R 1/4W
R 1/4W
R 1/4W
R 1/4W
R 1/4W
Type
depends on opto used
10k
be fine tuned
depends on opto used
10k
be fine tuned
10NF comp. network to
be fine tuned
10NF comp. network to
be fine tuned
TSM111
1N4148
1N4148
2.5m
2.5m
6.5m
100nF
100nF
78L05
10m
10m
65m
13m
Value
33K
47K
47K
4.7 F
2.2 F
10 F
5m
5m
1K
15V
comp. network to
comp. network to
Comment
DIP20
TO92
10A
20A
10A
20A
10A
5A
5A
1A
5A