TS2508A_12 Datasheet, PDF (3/8 Pages) Taiwan Semiconductor Company, Ltd – 3A / 330KHz PWM Buck Converter

Application Circuit
Typical Circuit
TS2508A
3A / 330KHz PWM Buck Converter
L1 recommend value (V_IN=12V, I_OUT=3A )
V_OUT
1.8V
2.5V
3.3V
L1 Value 18uH
22uH
27uH
5V
33uH
Function Descriptions
PWM Control
The TS2508A consists of DC/DC converters that employ a pulse-width modulation (PWM) system. In converters of
the TS2508A, the pulse width varies in a range from 0 to 100%, according to the load current. The ripple voltage
produced by the switching can easily be removed through a filter because the switching frequency remains
constant. Therefore, these converters provide a low-ripple power over broad ranges of input voltage and load
current.
RDS(ON) Current Limiting
The current limit threshold is setting by the external resistor (R3) connecting from V_CC supply to OCSET pin. The
internal 110uA sink current crossing the resistor sets the voltage at pin of OCSET. When the PWM voltage is less
than the voltage at OCSET, an over-current condition is triggered. Please refer to the formula for setting the
minimum current limit value:
(Normally, The I_SW(MAX) setting more than I_OUT 1.2A)
Example: I_SW=(0.11mA * 2k + 0.08) / 70mΩ = 4.3A – (V_IN=12V)
I_SW=(0.11mA * 3.3k + 0.08) / 1000mΩ = 4.4A – (V_IN=5V)
3/8
Version: C12