l6571 STMicroelectronics, l6571 Datasheet - Page 4

• Manufacturer Part Number: l6571
• Description: High Voltage Half Bridge Driver With Oscillator
• Manufacturer: STMicroelectronics

L6571A L6571B
ELECTRICAL CHARACTERISTCS (continued)
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 R
The device can be driven in "shut down" condition keeping the C
taken:
1. When C
2. The forced discharge of the oscillator capacitor C
Figure 1.
Figure 2. Waveforms
4/8
Symbol
limit the current discharge with a resistive path imposing R · C
I
DC
f
AVE
out
F
and C
F
Pin
1
6
is to GND the high side driver is off and the low side is on
Duty Cycle, Ratio Between Dead
Time + Conduction Time of High
Side and Low Side Drivers
Average Current from Vs
Oscillation Frequency
F
are the external resistor and capacitor.
Parameter
LVG
V
fault signal
V
CF
S
f
O SC
=
---------------------------------------- -
2 R
T1
F
R
1
C
C
No Load, fs = 60KHz
R
F
F
T
F
T
= 12K; C
C
must not be shorter than 1us: a simple way to do this is to
In2
GNDM
R
Test Condition
F
=
T
----------------------------------------- -
1.3863 R
= 1nF
1
2
3
4
F
F
pin close to GND, but some cares have to be
>1 s (see fig.1)
1
F
C
8
7
6
5
F
Min.
0.45
D96IN434
57
V
SUVP
Typ.
0.5
1.2
60
Max.
0.55
1.5
63
Unit
kHz
mA