Datasheet TLE6280GP
4 2007-07-19
Functional description
General
In the automotive sector there are more and more applications requiring high performance
motor drives, such as electro-hydraulic or electric power steering. In these applications
3-phase motors, synchronous and asynchronous, are used, combining high output perform-
ance, low space requirements and high reliability.
The TLE6280GP is a driver IC dedicated to control the 6 to 12 external Mosfets forming the
converter for high current 3 phase motor drives in the automotive sector. It incorporates fea-
tures like short circuit detection, diagnosis and high output performance and combines it with
typical automotive specific requirements like full functionality even at low battery voltages. Its
3 high-side and 3 low-side output stages are powerful enough to drive Mosfets with 250nC
gate charge with approx. 300ns fall and rise times.
Typical applications are cooling fan, water pump, electro-hydraulic and electric power steer-
ing. The TLE6280GP is designed for a 12V power net.
Use in 24V application is possible as well. Limiting factor could be the power dissipation.
This datasheet describes all functionality of this device. Additional application tips are given
in an application note available on the Internet.
Output stages
The 3 low-side and 3 high-side powerful push-pull output stages are all floating blocks, each
with its own Source pin. This allows the direct connection of the output stage to the Source
of each single Mosfet, allowing a perfect control of each Gate-Source voltage even when
200A are driven in the bridge with rise and fall times clearly below 1µs.
All 6 output stages have the same output power and, due to the use of the bootstrap princi-
ple, they can be switched all up to 30kHz.
Its output stages are powerful enough to drive Mosfets with 250nC gate charge with approx.
300ns fall and rise times, or even to run 12 such Mosfets with fall and rise times of approx.
600ns.
Maximum allowed power dissipation and the need to refresh the bootstrap capacitors with a
minimum refresh pulse limit the divice use for higher frequencies.
Fig. 2 shows the supply structure of TLE6280GP. The bootstrap capacitors are charged by
the charge pump capacitor C
CP
via the CH pin and diodes.
The exact value for this minimum refresh pulse is given by the RC time constant formed by
the impedance between the CH pin and Bxx pin, and the capacitor formed by the external
Mosfet (C
Mosfet
=Q
Gate-total
/ V
GS
). The size of the bootstrap capacitor has to be adapted to the
external Mosfet that the driver IC has to drive. Usually the bootstrap capacitor is about 10-20
times bigger than C
Mosfet
. External components, such as R-C networks, at the Vs Pin have to
be considered, too.
Operation at Vs<12V – integrated charge pump
The TLE6280GP provides a feature tailored to the requirements of 12V automotive applica-
tions. Often the operation of an application has to be assured even at 9V-supply voltage or
lower. Normally bridge driver ICs provide in such conditions clearly less than 9V to the Gate
of the external Mosfet, increasing its RDSon and associated the power dissipation.
The supply structure of the device is shown in fig.2. The TLE 6280GP has a built-in voltage
regulator with charge pump control to generate an internal supply voltage of 13V within a
supply voltage range of 8-40V. Operation below 8V is possible as well and will result in a re-
duced Gate voltage. The charge pump works with an external capacitor C
CP
connected be-
tween the CL and CH pins. It provides more than 13V at the CH pin and guarantees high
supply voltage for the bootstrap capacitors C
Bx
.
