TLE7183QU

Description and Electrical Characteristics

Data Sheet

12

Rev. 1.1, 2016-01-28

5.1.2

Operation at Vs<12V - Integrated Charge Pumps

In 12V automotive applications, correct operation has to be assured also at lower supply voltages, even at 9V. At

low supply voltages conventional bridge drivers provide clearly less than 9V to the gate of an external MOSFET.

dissipation.

The two charge pumps circuitries of TLE7183QU address this problem enabling operation even at lower supply

voltages. Their operational capability does not depend on a specific pulse pattern of the MOSFETs overcoming

duty cycle limitations which are inherent to drivers that use the bootstrap principle instead. Therefore TLE7183QU

supports the complete duty cycle range from 0 to 100%. This simplifies the usabilty in all applications and

especially when used with block wise commutation. The charge pumps are only deactivated if the device is set to

sleep mode using INH.

The first charge pump supplies the low side MOSFETs and the corresponding output stages with sufficient voltage

to assure 10V gate-source voltage even if Vs<10V. In addition it also supplies most of the internal circuitries,

including the second charge pump.

The second charge pump supplies the high side MOSFETs and the corresponding output stages. It is pumped on

the voltage of Vs.

Each charge pump circuitry requires external pump (CPx) and buffer (CBx) capacitors. The output of the first

charge pump is CB1 which is referenced to GND. The output of the second charge pump is CB2 which is

referenced to VDH. VDH and Vs are usually in the same voltage range. The driver is not designed to have

significant higher voltages at VDH compared to Vs. This would lead to reduced supply voltages for the high side

output stages.

The outputs of both charge pumps are regulated. The first charge pump doubles the supply voltage for Vs<8V.

For 8V<Vs<15V, its output is regulated to a typical voltage of 15V. For Vs>15V, its output increases linearly but

does not exceed 25V.

IHx before the charge pumps have ramped up to their final values unless the output stages have been switched

off by setting one of the ENAx pins to low.

The size of the charge pump capacitors (pump capacitors CPx as well as buffer capacitors CBx) can be varied

between 1 µF and 4.7 µF. Yet, larger capacitor values result in higher charge pump voltages and less voltage

ripple on the charge pump buffer capacistors CBx (which supply the internal circuits as well as the external

MOSFETs, pls. see above). Besides the capacitance values the ESR of the buffer capacitors CBx determines the

voltage ripple as well. It is recommended to use buffer capacitors CBx that have small ESR.

Please see also Chapter 5.1.3 for capacitor selection.

5.1.3

Sleep Mode

If the INH pin is set to low, the driver will be set to sleep mode. The INH pin switches off the complete supply

structure of the device and finally leads to an undervoltage shut down of the complete driver. Enabling the device

with the INH pin means to switch on the supply structure. The device will run through power on reset during wake

up. It is recommended to perform a reset using ENAx after wake up to remove possible ERRx signals. Reset is

performed by keeping one or more ENAx pins low until the charge pump voltages have ramped up.

Enabling and disabling with the INH pin is not very fast. Please consider using the ENAx pins to speed things up.

If the TLE7183QU is in sleep mode or if the supply voltage Vs is not available, then the driver IC is not supplied,

the charge pumps are inactive and the charge pump capacitors are discharged. Pin CB2 (+ terminal of buffer

capacitor 2) will decay to GND. If the battery voltage is still applied to VDH (- terminal of buffer capacitor 2) the

buffer capacitor 2 will slowly be charged to battery voltage with reversed polarity compared to the one during

regular operation. Hence, it is important to use a buffer capacitor 2 (CB2) that can withstand both, +25 V in regular

negative voltage across CB2 will be clamped to -31 V (CB2 referenced to VDH).