NCP5422ADR2 datasheet(9/16 Pages) ONSEMI

Part #	NCP5422ADR2

Description	Dual Out?뭥f?뭁hase Synchronous Buck Controller with Current Limit

Download	16 Pages

Scroll/Zoom	100%

Manufacturer	ONSEMI [ON Semiconductor]

Direct Link	http://www.onsemi.com

Logo

9 / 16 page

NCP5422A, NCP5423

http://onsemi.com

9

Figure 6. Hiccup Overcurrent Protection

Output Enable

On/Off control of the regulator outputs can be

implemented by pulling the COMP pins low. The COMP

pins must be driven below the 0.425 V PWM comparator

offset voltage in order to disable the switching of the GATE

drivers.

DESIGN GUIDELINES

Definition of the design specifications

The output voltage tolerance can be affected by any or all

of the following reasons:

1. buck regulator output voltage setpoint accuracy;

2. output voltage change due to discharging or charging

of the bulk decoupling capacitors during a load

current transient;

3. output voltage change due to the ESR and ESL of the

bulk and high frequency decoupling capacitors,

circuit traces, and vias;

4. output voltage ripple and noise.

Budgeting the tolerance is left up to the designer who must

take into account all of the above effects and provide an

output voltage that will meet the specified tolerance at the

load.

The designer must also ensure that the regulator

component temperatures are kept within the manufacturer’s

specified ratings at full load and maximum ambient

temperature.

Selecting Feedback Divider Resistors

VOUT

R1

R2

VFB

Figure 7. Selecting Feedback Divider Resistors

Selection of Feedback Divider Resistors

Feedback divider resistors R1 and R2 are selected based

on a design trade−off between efficiency and output voltage

accuracy. Both error amplifiers are referenced to 1.0 V, and

resistors R1 and R2 are connected from each channel’s

output voltage to the inverting pin (VFB1(2)) of each error

amplifier. To set the channel output voltage, first choose a

value for R1, and then R2 can be sized as follows:

R1

Vout

1.0

* 1

R2

+

The output voltage error due to the bias current of the error

amplifier and the parallel combination of R1 and R2 can now

be estimated:

Error

+ 1.6 · 10−6 · R1 · R2

R1

) R2

Reducing the size of R1 and R2 will reduce the output

voltage error, but increase the power dissipation.

Calculating Duty Cycle

The duty cycle of a buck converter (including parasitic

losses) is given by the formula:

Duty Cycle

+ D +

VOUT ) VLFET ) VL

VIN ) VLFET * VHFET

where:

VOUT = buck regulator output voltage;

VHFET = high side FET voltage drop due to RDS(ON);

VL = output inductor voltage drop due to inductor wire

DC resistance;

VIN = buck regulator input voltage;

VLFET = low side FET voltage drop due to RDS(ON).

Similar Part No. - NCP5422ADR2

Manufacturer	Part #	Datasheet	Description
ON Semiconductor	NCP5422ADR2	126Kb / 18P	Dual Out-of-Phase Synchronous Buck Controller with Current Limit November, 2003 ??Rev. 4

More results

Similar Description - NCP5422ADR2

Manufacturer	Part #	Datasheet	Description
ON Semiconductor	CS5422	369Kb / 17P	Dual Out?뭥f?뭁hase Synchronous Buck Controller with Current Limit July, 2006 ??Rev. 7
	CS5421	298Kb / 14P	Dual Out?뭥f?뭁hase Synchronous Buck Controller with Remote Sense July, 2006 ??Rev. 10
	NCP5422A	126Kb / 18P	Dual Out-of-Phase Synchronous Buck Controller with Current Limit November, 2003 ??Rev. 4
	ADP3430	373Kb / 26P	2??to 3?뭁hase Synchronous Buck Controller July, 2009 ??Rev. 2
	NCP5424	131Kb / 20P	Dual Synchronous Buck Controller with Input Current Sharing June, 2003 - Rev. 3
	NCP5424	137Kb / 18P	Dual Synchronous Buck Controller with Input Current Sharing March, 2005 ??Rev. 4
Microsemi Corporation	NX2119	499Kb / 16P	SYNCHRONOUS PWM CONTROLLER WITH CURRENT LIMIT PROTECTION
ON Semiconductor	NCP5306	872Kb / 24P	Three?뭁hase VRM 9.0 Buck Controller July, 2006 ??Rev. 3
	CS5307	880Kb / 24P	Four?뭁hase VRM 9.0 Buck Controller July, 2006 ??Rev. 9
	CS5323	328Kb / 16P	Three?뭁hase Buck Controller with 5?묪it DAC July, 2006 ??Rev. 7

More results

NCP5422ADR2 Datasheet(PDF) 9 Page - ON Semiconductor

NCP5422ADR2 Datasheet(HTML) 9 Page - ON Semiconductor

Similar Part No. - NCP5422ADR2

Similar Description - NCP5422ADR2

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Datasheet Download

Link URL