PD同步整流芯片ZCC6908HV替代MP6908

ZCC6908HV

Fast Turn-off Intelligent Rectifier

DESCRIPTION

The

ZCC6908HV

is

a

Low-Drop

Diode

Emulator

IC

that,

combined

with

an

external

switch,

replaces

Schottky

diodes

in

high- efficiency

Flyback

converters.

The

chip

regulates

the

forward

drop

of

an

external

Synchronous

Rectifier

(SR)

MOSFET

to

about 40mV and switches it off as soon as the voltage becomes negative. ZCC6908HV

can generate its own supply voltage for battery charging applications with low output

voltage

or

high

side

rectification

applications.

A

programmable

ringing

detection

circuitry

prevents

ZCC6908HV

false

turn-on

during

DCM

and

Quasi-Resonant

operations.

ZCC6908HV is available in space saving TSOT23-6 packages.

FEATURES

●

Operates in a wide output voltage range down to 0V

●

Self-supplying for operation with low output voltage

rectification without an auxiliary winding

●

Works with 12V Standard and 5V Logic Level SR MOSFETS

●

Compatible with Energy Star, 1W Standby Requirements

●

<30ns Fast Turn-off and Turn-on Delay

●

<100uA Quiescent Current

●

Supports DCM, Quasi-Resonant and CCM Operations

●

Supports both High-side and Low-side Rectification

●

Power Savings of Up to 1.5W in a Typical Notebook Adapter

●

TSOT23-6 Package Available

APPLICATIONS

●

Industrial Power Systems

●

Distributed Power Systems

●

Battery Powered Systems

●

Flyback Converters

TYPICAL APPLICATION

ZCC6908HV

Fast Turn-off Intelligent Rectifier

PACKAGE REFERENCE

ABSOLUTE MAXIMUM RATINGS

V

DD

to V

SS

........................ .................................................. .

–

0.3V to +14V

V

G

to V

SS

........................ .................................................. .

–

0.3V to +14V

V

D

to Vss

........................ .......................................... .... .....

–

1V to + 200V

HVC to V

SS

...... .................................................. ........... .... ..

–

1V to + 80V

SLEW to VSS ........... .................................................. ........

–

0.3V to +6.5V

Continuous Power Dissipation (TA = +25°

C)

Junction Temperature .................. ..................................... 150°

C

Lead Temperature (Solder) ............................................... 260°

C

Storage Temperature ...................................... ..................

–

55°

C to +150°

C

Recommended Operation Conditions

VDD to VSS ................. .................................................. ..... 3.6 to 13V

Maximum Junction Temp. (TJ) ........................................... +125°

C

Thermal Resistance

θ

JA

θ

JC

TSOT23-6 .............................. ............................................ 220 ....110 °

C /W

ZCC6908HV

Fast Turn-off Intelligent Rectifier

ELECTRICAL CHARACTERISTICS

VDD=5V. TJ=-40°

C~125°

C, Min & Max are guaranteed by characterization, typical is tested

under 25°

C, unless otherwise specified.

Parameter

VDD UVLO Rising

V

DD

UVLO Hysteresis

VDD

Maximum

Charging

Current

VDD Regulation Voltage

Symbol

Conditions

Min

0.1

Typ

4

0.2

Max

0.35

Units

V

V

SUPPLY MANAGEMENT SECTION

IVDD

VDD=7V,HVC=40V

VDD=4V, VD=30V

VD=12V,HVC=12V

HVC=3V, VD=12V

VDD=9V,

C

LOAD

=2.2nF,

60

30

9.5

5.2

mA

V

2.9

mA

Operating Current

ICC

F

SW

=100kHz

VDD=5V,

C

LOAD

=2.2nF,

F

SW

=100kHz

1.72

100

130

100

uA

uA

Quiescent Current

Shutdown Current

V

SS

–< /p>

V

D

Forward

Regulation Voltage

Turn-On Threshold (V

DS

)

Turn Off

Threshold (VSS-VD)

Turn-On Delay

Turn-Off Delay

Turn On Blanking Time

Threshold

Turn

On

Slew

Rate

Iq(VDD)

VDD=5V

ISD(VDD)

VDD=UVLO-0.05V

CONTROL CIRCUITRY SECTION

Vfwd

VLL-DS

CLOAD = 2.2nF

CLOAD = 2.2nF

CLOAD = 2.2nF

40

-86

mV

mV

2

3

TDon

TDoff

TB-ON

0

30

30

1.97

mV

ns

ns

us

V

Turn

Off

Blanking

V

DS

VB-OFF

Rslew=100kohm,

Vds from 2.5V step

down.

Detection Timer

GATE DRIVER SECTION

VG (Low)

VG (High)

Maximum Source Current

Maximum Sink Current

VG-L

VG-H

60

ns

ILOAD=10mA

100mA

ILOAD=10mA

100mA

or

or

0.02

VDD

0.1

V

V

0.5

3

A

A

ZCC6908HV

Fast Turn-off Intelligent Rectifier

1

Ω

Pull Down Impedance

Same as VG(Low)

PIN FUNCTIONS

Pin #

Name

Description

HV Linear Regulator Input

Ground, also used as FET source sense reference for VD

Programming for turn on signal slew rate detection. To prevent SR

SLEW

controller false turn on by ringing below turn on threshold at VD in

DCM and QR modes, any signal slower than pre-set slew rate is

not going to turn on VG

Linear Regulator Output, supply ZCC6908HV

Gate drive output

FET drain voltage sense

1

2

3

HVC

VSS

4

5

6

VDD

VG

VD

BLOCK DIAGRAM

Figure 1

—

Functional Block Diagram

OPERATION

The ZCC6908HV supports operation in DCM and Quasi-Resonant Flyback converters

as well as in CCM mode. The control circuitry controls the gate in forward mode and

will turn the gate off when SR MOSFET current drops to zero.

Start-up and VDD Generation