DRV411_15 Datasheet, PDF (16/34 Pages) Texas Instruments – Sensor Signal Conditioning IC for Closed-Loop Magnetic Current Sensors

DRV411
SBOS693B – AUGUST 2013 – REVISED DECEMBER 2013
www.ti.com
Table 1. Gain Setting and Compensation Frequency
MODE
Gain_1
Gain_2
Gain_3
External gain and compensation
(op-amp mode)
GSEL1
0
0
1
1
GSEL2
0
1
0
1
DESCRIPTION
G = 250 V/V. Compensation frequency set to 3.8 kHz.
G = 250 V/V. Compensation frequency set to 7.2 kHz.
G = 1000 V/V. Compensation frequency set to 3.8 kHz.
Current spinning and front-end chopping are turned off. Constant voltage
excitation is enabled. Gain and compensation set by using external
resistors and capacitors, such as in discrete designs.
3.0
2.9
2.8
ICOMP1
2.7
GSEL [0,0]
Step û I_PRIM = 10 A
Core Inductance 50 mH
2.6
2.5
2.4
2.3
ICOMP2
2.2
2.1
Time (100 µs/div)
C033
Figure 49. Settling of ICOMP1 and ICOMP2
(Mode Gain_1)
3.0
2.9
2.8
ICOMP1
2.7
GSEL [0,1]
Step û I_PRIM = 10 A
Core Inductance 50 mH
2.6
2.5
2.4
2.3
ICOMP2
2.2
2.1
Time (100 µs/div)
C033
Figure 50. Settling of ICOMP1 and ICOMP2
(Mode Gain_2)
3.0
GSEL [1,0]
2.9
Step û I_PRIM = 10 A
2.8
ICOMP1
Core Inductance 50 mH
2.7
2.6
2.5
2.4
2.3
ICOMP2
2.2
2.1
Time (100 µs/div)
C033
Figure 51. Settling of ICOMP1 and ICOMP2
(Mode Gain_3)
Along with symmetrical InSb Hall elements, the DRV411 can also be connected to symmetrical GaAs Hall
elements. The advantage of GaAs Hall elements is that they provide an extended temperature range to +125°C.
See the following section, External Gain and Compensation (Op-amp Mode) for more details. This type of Hall
element has a lower sensitivity than InSb-type sensors. In order to compensate for this difference, TI
recommends using gain setting mode Gain_3 with GaAs sensors. If the sensitivity is too low and the loop gain is
insufficient, the loop can become unstable. In op-amp mode, gain can be set with external components.
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