DRV8305_16 Datasheet, PDF (21/59 Pages) Texas Instruments – Three Phase Gate Driver

www.ti.com
DRV8305
SLVSCX2B – AUGUST 2015 – REVISED FEBRUARY 2016
7.3.5 GHx/GLx: Half-Bridge Gate Drivers
The DRV8305 gate driver uses a complimentary push-pull topology for both the high-side and the low-side gate
drivers. Both the high-side (GHx to SHx) and the low-side (GLx to SLx) are implemented as floating gate drivers
in order to tolerate switching transients from the half-bridges. The high-side and low-side gate drivers use a
highly adjustable current control scheme in order to allow the DRV8305 to adjust the V_DS slew rate of the
external MOSFETs without the need for additional components. The scheme also incorporates a mechanism for
detecting issues with the gate drive output to the power MOSFETs during operation. This scheme and its
application benefits are outlined below as well as in application report, SLVA714.
VCPH
INHx
INLx
Level Shifters
GHx
Logic
SHx
VCP_LSD
Level Shifters
GLx
SLx
Figure 9. DRV8305 Gate Driver Architecture
7.3.5.1 IDRIVE: Gate Driver Output Current
The first component of the gate drive architecture implements adjustable current control for the gates of the
external power MOSFETs. This feature allows the gate driver to control the V_DS slew rate of the MOSFETs by
adjusting the gate drive current. This is realized internally to reduce the need for external components inline with
the gates of the MOSFETs. The DRV8305 provides 12 adjustable source and sink current levels for the high-side
(the high sides of all three phases share the same setting) and low-side gate drivers (the low sides of all three
phases share the same settings). The gate drive levels are adjustable through the SPI registers in both the
standby and operating states. This flexibility allows the system designer to tune the performance of the driver for
different operating conditions through software alone.
Copyright © 2015–2016, Texas Instruments Incorporated
Product Folder Links: DRV8305
Submit Documentation Feedback
21