TSM101C STMICROELECTRONICS [STMicroelectronics], TSM101C Datasheet - Page 7

• Manufacturer Part Number: TSM101C
• Description: VOLTAGE AND CURRENT CONTROLLER
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

The current regulation is effective when the voltage
drop across R5 is equal to the voltage on pin 5 of
the TSM101 (assuming that the internal current
source is disabled).
For medium currents (<1A), a voltage drop across
R5 of 200mV = Vr5 is a good value, R5 can be
realized with standard low cost 0.5W resistors in
parallel.
R2 and R3 can be chosen using the following
formula :
CHARGE CONTROL
If the pin 2 is left open, the charge current is nominal
at # 700mA.
If pin 2 is connected to ground, the internal current
source is enabled, the current measurement is
off-setted by a voltage equal to :
This can be used to lower the charging current or
eventually to stop the charge, if V
Figure 3 : SMPS Using the TSM101
R5
parallel)
R2
V
r4
= I
R3
V
I
o
ch
r5
x R4 with Io = 1.4mA
x
, R5 = 0.285
V
ref
V
r5
V
r5
(four 1.2
r4
> V
r5
resistor in
In our example, the current offset is equal to 700 -
200mA = 500mA, representing a voltage offset
V
The following values are used on the application
board :
4 - SCHEMATIC DIAGRAM
Figure 2 represents a schematic of the output
circuit of a ”classical” SMPS using a TL431 for
voltage regulation. This circuit is modified to use
the TSM101 and the final circuit is represented in
figure 3.
r4
R5 = 4 *1.2 0.5W in parallel
R4 = 100
R2 = 1.2k
R3 = 220
R9 = short circuit
R1 = 10k
C2 = 100nF
C5 = 100nF
C1 = output capacitor of the SMPS
C4 = 10 F
= 140mV across R4.
TSM101/A
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