MP400FCU



MP400FC

P r o d u c t I n n o v a t i o n F r o m

smps operation

The MP400FC is designed to operate off of a standard voltage rail. Typical

values include 12V, 24V, or 48V. The addition of the on-board SMPS elimi-

nates the need to design or purchase a high voltage power supply. The only

inputs required by the SMPS are the V

tor, and boost voltage set resistor (RSET).

The SMPS output can be adjusted between a minimum of 50V to a maximum

of 350V. The voltage boost adjustment is independent of V

the boost level is made through a resistor from the RSET pin to ground. The

resistor value is:

Rset = (3.16E6 • (351-Vboost)) / (Vboost-1.25) / (4.42E3-(715 • (351-Vboost))

/ (Vboost-1.25))

Where Vboost = desired SMPS voltage.

Example:

1) Desired Vboost = 160V

2) Rset = 1K (1074 by equation)

If RSET is open, Vboost will be 50V. If RSET is shorted to ground Vboost will be limited to 350V.

smps output capacitor

An external SMPS output filter capacitor is required for proper operation. ESR considerations prevail in the choice

of the output filter capacitor. Select the highest value capacitor that meets the following ESR requirement. The

minimum value for C

ESR = dVo/I

LPK

Where,

dVo

= the maximum acceptable output ripple voltage

I

LPK

= Peak inductor current = (1/L)•Vin•ton

L

= 10E-6 if the internal inductor is used.

Vin

= Input voltage of the application.

ton

= sqrt(2•Io•L•((Vo+0.6-Vin)/(Fsw•Vin2)))

Vboost = The boost supply voltage of the application.

Io

= The maximum continuous output current for the application.

Fsw

= 100KHz switching frequency of the MP400FC boost supply.

smps input capacitor

An external input capacitor is required. This capacitor should be at least 100uF.