RT3602AE datasheet(23/46 Pages) RICHTEK

23 / 46 page

RT3602AE

DS3602AE-00 August 2017

www.richtek.com

is a registered trademark of Richtek Technology Corporation.

Applications information

The RT3602AE includes three voltage rails : a single phase

synchronous Buck controller, the MAIN VR, a 2/1

multiphase synchronous Buck controller, the auxiliary VR,

and a single phase synchronous Buck controller, the

VCCSA VR, designed to meet Intel IMVP8 compatible

CPUs specification with a serial SVID control interface.

The controller uses an ADC to implement all kinds of

settings to save total pin number for easy use and

increasing PCB space utilization. The RT3602AE is used

in notebooks, desktop computers and servers.

General loop Function

G-NAVPTM Control Mode

The RT3602AE adopts the G-NAVPTM controller, which is

a current mode constant on-time control with DC offset

cancellation. The approach can not only improve DC offset

problem for increasing system accuracy but also provide

fast transient response. When current feedback signal

reaches comp signal, the RT3602AE generates an on-

time width to achieve PWM modulation. Figure 1 shows

the basic G-NAVPTM behavior waveforms in continuous

conduct mode (CCM).

Figure 1 (a). G-NAVPTM Behavior Waveforms in CCM in

Steady State

PWM1

PWM2

PWM3

PWM4

Current feedback signal

Comp signal

Figure 1 (b). G-NAVPTM Behavior Waveforms in CCM in

Load Transient.

PWM1

PWM2

PWM3

PWM4

Current feedback signal

Comp signal

Diode Emulation Mode (DEM)

As well-known, the dominate power loss is switching

related loss during light load, hence VR needs to be

operated in asynchronous mode (or called discontinuous

conduct mode, DCM) to reduce switching related loss

since switching frequency is dependent on loading in the

asynchronous mode. The RT3602AE can operate in diode

emulation mode (DEM) to improve light load efficiency. In

DEM operation, the behavior of low-side MOSFET(s) needs

to work like a diode, that is, the low-side MOSFET(s) will

be turned on when the phase voltage is a negative value,

i.e. the inductor current follows from Source to Drain of

low-side MOSFET(s). And the low-side MOSFET(s) will

be turned off when phase voltage is a positive value, i.e.

reversed current is not allowed. Figure 2 shows the control

behavior in DEM. Figure 3 shows the G-NAVPTM operation

in DEM to illustrate the control behaviors. When the load

decreases, the discharge time of output capacitors

increases during UGATE and LGATE are turned off. Hence,

the switching frequency and switching loss will be reduced

to improve efficiency in light load condition.

RT3602AE датащи(PDF) 23 Page - Richtek Technology Corporation

RT3602AE датащи(HTML) 23 Page - Richtek Technology Corporation

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46

датащи скачать

ссылки URL