TSM101ACDT Datasheet, PDF (10/13 Pages) STMicroelectronics – VOLTAGE AND CURRENT CONTROLLER

EVALUATION BOARD -TECHNICAL NOTE
TSM101 integrates in the same 8 pin DIP or SO
package
• one 1.24V precision voltage reference
• two operationnal amplifiers
• two diodes which impose a NOR function on the
outputs of the operationnal amplifiers
• one current source which can be activated/ in-
hibited thanks to an external pin.
An immediate way to take advantage of the high
integration and reliability of TSM101 is to use it as
a voltage and current controller on power supplies
secondary. The application note AN896 describes
precisely how to use TSM101 in an SMPS battery
charger.
The TSM101 Evaluation Board is adaptable to any
power supply or battery charger (SMPS or linear)
as a voltage and current controller with minimal
constraints from the user.
HOW TO USE THE TSM101 EVALUATION
BOARD ?
The generic Electrical Schematic is shown on fig-
ure 1. It represents an incomplete SMPS power
supply where the primary side is simplified.
Figure 1
The “IN+”and “IN-” power inputs of the evalua-
tion board should be connected directly to the
power lines of the power supply secondary.
The “Vcc” input of the evaluation board should
be connected to the auxiliary supply line.
In the case of an SMPS power supply, the “Reg”
output of the evaluation board should be connect-
ed to the Optocoupler input to regulate the PWM
block in the primary side. In the case of a linear
power supply, the “Reg” output should be con-
nected to the base of the darlington to regulate the
power output.
A diode might be needed on the output of the eval-
uation board in the case of a battery charger appli-
cation to avoid the discharge of the battery when
the charger is not connected.
COMPONENTS CALCULATIONS
The voltage control is given by the choice of the
resistor bridge R6/R7 (and the trimmer P1) due to
equation 1 :
• Vref = R6/(R6+R7)xVout
eq1
where Vref = 1.24V
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