ZLED7001 Datasheet

© 2016 Integrated Device Technology, Inc.

7

April 20, 2016

(

)

S

G

IN

f

Q

mA

5

.

0

I

∗

+

≈

IN

IN

INDC

IN

I

V

V

R

−

=

2.3.

Input Voltage Regulator

The value and rating of the RIN input resistor must be selected as needed to drop the application supply voltage

(Vs) to the proper operating voltage for the ZLED7001 specified in section 0 (see equation (2) below). When these

conditions are met, the ZLED7001’s internal input voltage regulator maintains a stable 7.1V (typical) at the VIN pin

to power the ZLED7001. A low-equivalent-series-resistance (ESR) bypass capacitor is required on the VIN pin to

provide a low-impedance path for the GATE pin output driver’s high frequency current.

The VIN pin draws an input current that is the sum of the 0.5mA (typical) required by the internal circuit and the

average current drawn by the GATE driver. The GATE driver current is primarily determined by the GATE charge

(QG) and switching frequency (fs) of the external MOSFET as shown in equation (1).

(1)

Where

fS =

Switching frequency

G

Q = External MOSFET gate charge (refer to the MOSFET data sheet)

The input resistor RIN value is given by equation (2).

(2)

For two typical MOSFET types, the following IIN diagram will result:

Figure 2.1

Input Current