APW7058 Ver la hoja de datos (PDF) - Anpec Electronics

Número de pieza

componentes Descripción

Fabricante

APW7058

Synchronous Buck PWM and Linear Controllers

Anpec Electronics 

APW7058

Functional Pin Description

12VCC (Pin 1)

FB2 (Pin 7)

Connect this pin to 12V supply voltage. It provides

bias voltage for the high-side MOSFET driver and the

linear controller. The voltage at this pin is monitored

for Power-On-Reset purposes.

UGATE (Pin 2)

Connect this pin to the gate of the high-side MOSFET.

This pin provides gate drive for the MOSFET.

GND (Pin 3)

Signal and power ground for the IC. Putting vias to

ground planet directly and close to GND pins mini-

mizes noises.

Connect this pin to the output (VOUT2) of the linear

regulator via a proper sized resistor divider. The volt-

age at this pin is regulated to 0.8V and the VOUT2 is

determined using the following formula :

VOUT2=0.8V

x

(1+

R7

R8

)

where R7 is the resistor connected from VOUT2 to FB2,

and R8 is the resistor connected from FB2 to GND.

This pin is also monitored for under-voltage events.

Pulling and holding FB2 above 1.28V shuts down both

regulators. Releasing FB2 initiates soft-start on both

regulators.

FB (Pin 8)

LGATE (Pin 4)

Connect this pin to the gate of the low-side MOSFET.

This pin provides gate drive for the MOSFET.

5VCC (Pin 5)

Connect this pin to a 5V supply voltage via a RC filter

(2.2Ω and 1µF are recommended). This pin pro-

vides the bias for the control circuitry and the low-

side MOSFET driver. The voltage at this pin is moni-

tored for Power-On-Reset purposes.

This pin is the inverting input of the internal error

amplifier. Connect this pin to the output (VOUT1) of

the Buck converter via a proper sized resistor divider

to provide feedback loop of the Buck converter. The

VOUT1 is determined using the following formula :

VOUT1=0.8V

x

(1+

R1

R2

)

where R1 is the resistor connected from VOUT1 to FB,

and R2 is the resistor connected from FB to GND.

This pin is also monitored for under-voltage events.

DRIVE2 (Pin 6)

Connect this pin to the gate of an external N-Channel

MOSFET transistor. This pin provides the gate volt-

age for the linear regulator pass transistor. It also

provides a means of compensating the linear control-

ler for applications where the user needs to optimize

the regulator transient response.

Copyright  ANPEC Electronics Corp.

6

Rev. A.3 - Mar., 2005

www.anpec.com.tw

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