Detailed Hardware Description
5.2
Low-Side Current Shunt Sense
The Motor Drive Booster Pack has low side current shunt sense for each half-bridge (phases A, B, and C).
The current sense setup takes advantage of the dual shunt current amplifiers (phases A and B) of
DRV8301 and an external TI OPA2374 CMOS operation amplifier (phase C). The configuration for the
low-side sense resistor is shown in
. The amplifier senses voltage across a 0.01-
Ω
sense resistor
through differential connections. The current measurement is scaled for ±16.5 A. This requirement and the
calculations are described in the InstaSPIN™ FOC
in Chapter 5.
Figure 7. Current Sense Configuration
The configuration for the external OPA2374 (phase C current sense), shown in
, is set to closely
mirror the internal amplifiers of the DRV8301. The gain is set to 10 with a reference voltage of
approximately 1.65 V.
7
SLVU974 – October 2013
BOOSTXL-DRV8301 Hardware User's Guide
Copyright © 2013, Texas Instruments Incorporated
