DRV3204E-Q1 Datasheet, PDF (22/39 Pages) Texas Instruments – Three-Phase Brushless Motor Driver

DRV3204E-Q1
SLVSCB5A – OCTOBER 2013 – REVISED JANUARY 2013
www.ti.com
Motor-Current Sense
Description:
The operational amplifier operates with an external resistor network for higher flexibility to adjust the current
measurement to application requirements. The first-stage amplifier is operating with the external resistor and the
output voltage up to VB at ALFB. The gain of amplifier is adjustable by external resistors from ×10 to ×30. The
second-stage amplifier is buffer to MCU at ALV. Current sense has comparator for motor overcurrent (OVAD).
ADTH is the overcurrent threshold level and set value by SPI. Figure 15 shows the curve of detection level.
ALFB is divided by 2 and compare this value with ADTH. In the recommended application, zero-point adjustment
is required as large error offset in initial condition.
OVAD
VCC
+
-
1/2ALFB
CLAMP
ADTH
CLAMP
VCC
+
-
ALV
VB
-
+
ALFB
R22
ALP
ALM
C1
R11
Battery
Rshunt
Imotor
VCC
R21
+
AREF
R12
M
-
DC
C2
CLAMP
*R11, R12, R21, R22 z 0.1%
*VGain
X10: R11 = R12 = 3 k , R21 = R22 = 30 k
X20: R11 = R12 = 1.5 k , R21 = R22 = 30 k
X30: R11 = R12 = 1 k , R21 = R22 = 30 k
*C1 = 0~10 pF
*C2 = 10 nF
*AREF: 0.5/1.0/1.5/2.0/2.5 V (SPI)
*ADTH: 2.0/2.5/3.0/3.5/4.0 V (SPI)
*ALV = VGain * (Rshunt * Imotor) + AREF
*OVADth = (2 * ADTH - AREF) / (Rshunt * VGain)
Figure 15. Motor Current-Sense Block Diagram
22
Submit Documentation Feedback
Product Folder Links: DRV3204E-Q1
Copyright © 2013, Texas Instruments Incorporated