L6569 datasheet(4/13 Pages) STMICROELECTRONICS

4 / 13 page

L6569 L6569A

4/13

OSCILLATOR FREQUENCY

The frequency of the internal oscillator can be programmed using external resistor and capacitor.

The nominal oscillator frequency can be calculated using the following equation:

Where RF and CF are the external resistor and capacitor.

The device can be driven in "shut down" condition keeping the CF pin close to GND, but some cares have to be

taken:

1. When CF is to GND the high side driver is off and the low side is on

2. The forced discharge of the oscillator capacitor CF must not be shorter than 1us: a simple way to do this is to

limit the current discharge with a resistive path imposing R · CF >1µs (see fig.1)

Figure 1.

VRFON

RF High Level Output Voltage

IRF = 1mA

VS -0.05

VS -0.2

VRF OFF

RF Low Level Output Voltage

IRF = -1mA

200

VCFU

CF Upper Threshold

7.7

8.2

VCFL

CF Lower Threshold

3.80

4.3

Internal Dead Time

0.85

1.25

1.65

µs

Duty Cycle, Ratio Between Dead

Time + Conduction Time of High

Side and Low Side Drivers

0.45

0.5

0.55

RON

On resistance of Boostrap

LDMOS

120

Ω

VBC

Boostrap Voltage before UVLO

VS = 8.2

2.5

3.6

IAVE

Average Current from Vs

No Load, fs = 60KHz

1.2

1.5

fout

Oscillation Frequency

RT = 12K; CT = 1nF

kHz

Symbol

Parameter

Test Condition

Min.

Typ.

Max.

Unit

OSC

In2

⋅⋅

⋅

-----------------------------------------

1.3863 R

⋅⋅

------------------------------------------

GNDM

fault signal

ELECTRICAL CHARACTERISTCS (continued)

L6569 数据表(PDF) 4 Page - STMicroelectronics

L6569 数据表(HTML) 4 Page - STMicroelectronics

Html Pages

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

数据表下载