E-L6569 Datasheet, PDF (4/13 Pages) STMicroelectronics – HIGH VOLTAGE HALF BRIDGE DRIVER WITH OSCILLATOR

L6569 L6569A
ELECTRICAL CHARACTERISTCS (continued)
Symbol Pin
Parameter
Test Condition
V_RFON 2 RF High Level Output Voltage
I_RF = 1mA
V_{RF OFF}
RF Low Level Output Voltage
I_RF = -1mA
V_CFU
3 CF Upper Threshold
V_CFL
CF Lower Threshold
t_d
Internal Dead Time
DC
Duty Cycle, Ratio Between Dead
Time + Conduction Time of High
Side and Low Side Drivers
R_ON
On resistance of Boostrap
LDMOS
V_BC
Boostrap Voltage before UVLO V_S = 8.2
I_AVE
1 Average Current from Vs
No Load, fs = 60KHz
f_out
6 Oscillation Frequency
R_T = 12K; C_T = 1nF
Min. Typ. Max. Unit
V_S -0.05
50
V_S -0.2 V
200 mV
7.7
8
8.2
V
3.80
4
4.3
V
0.85 1.25 1.65
µs
0.45 0.5 0.55
120
Ω
2.5
3.6
V
1.2
1.5
mA
57
60
63
kHz
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:
f_OSC
=
-------------------¹---------------------
2 ⋅ R_F ⋅ C_F ⋅ In2
=
--------------------¹---------------------
1.3863 ⋅ R_F ⋅ C_F
Where R_F and C_F are the external resistor and capacitor.
The device can be driven in "shut down" condition keeping the C_F pin close to GND, but some cares have to be
taken:
1. When C_F is to GND the high side driver is off and the low side is on
2. The forced discharge of the oscillator capacitor C_F must not be shorter than 1us: a simple way to do this is to
limit the current discharge with a resistive path imposing R · C_F >1µs (see fig.1)
Figure 1.
1
8
2
7
R
RF
fault signal
3
6
CF
4
5
GNDM
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