TLE7242-2G Datasheet, PDF (24/50 Pages) Infineon Technologies AG – 4 Channel Fixed Frequency Constant Current Control IC

TLE7242-2G
Functional Description and Electrical Characteristics
5.4
Output Driver
The OUTx pins of the device are connected to the gates of the external MOSFET transistors. The OUTx pin driver
circuits charge and discharge the MOSFET gate capacitance with a constant current source and sink. The supply
for the current source is the V5D pin. Internal resistors to ground are included on the OUTx pins so that the external
MOSFET is held in the off state when power is not applied to the device.
An external resistor is typically placed between the OUTx pin and the gate of the external MOSFET in order to set
the MOSFET turn-on and turn-off times. The value of the resistor must be chosen such that the turn-on and turn-
off times of the MOSFET are no longer than 1/(Fpwm*32).
Electrical Characteristics:
V5D = 4.75V to 5.25V, Vbat = 5.5V to 42V, T_j = -40 °C to +150 °C, all voltages with respect to ground, positive
current flowing into pin (unless otherwise specified)
Pos. Parameter
5.4.1 Passive Gate Pull Down
Resistance
5.4.2
5.4.3
OUTx source current
OUTx sink current
Symbol
R_PD
Limit Values
Min. Typ. Max.
50
–
200
I_{O_SRC}
-15
–
-30
I_{O_SNK}
15
–
30
Unit
kΩ
mA
mA
Conditions
Internal pull down
resistor present at
each OUTx pin
V_OUT = V5D-2V
V_OUT = 2V
5.5
Current Control
Electrical Characteristics:
V5D = 4.75V to 5.25V, Vbat = 5.5V to 42V, T_j = -40 °C to +150 °C, all voltages with respect to ground, positive
current flowing into pin (unless otherwise specified)
Pos. Parameter
5.5.1
5.5.2
Offset Error
Output from Average block in
Figure 3.
1 count = 320/Rsense * 2^-14 mA
Gain Error
Symbol
Limit Values
Min. Typ. Max.
0
–
240
-2% –
2%
Unit Conditions
counts Autozero
disabled.Vpos-
Vneg=0mV
Vpos, Vneg ≤ 30V
%
Autozero
Enabled.Vpos-
Vneg=300mV
Vpos, Vneg ≤ 30V
Data Sheet
24
Rev. 1.0, 2008-07-09