DRV401-Q1 Datasheet, PDF (25/39 Pages) Texas Instruments – DRV401-Q1 Sensor Signal Conditioning Device for Closed-Loop Magnetic Current Sensor

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DRV401-Q1
SBOS814 – DECEMBER 2016
Application Information (continued)
8.1.2 Basic Connection
The circuit shown in Figure 42 offers an example of a fully-connected current sensor system.
I_P
Probe
Core
Probe Coil
S1
S2
IS2
Current Sensor Module
R₃
R₄ C₄
C₃
+5 V
Primary Winding
Main Core
Compensation Coil
K₁
K₂
I_COMP
R₂
R₁
+5 V
D₁
D₂
IS1 IS2
PWM PWM
GAIN
(PWM is in
phase with IS1)
CCdiag
+5 V V_DD1
Probe Coil
C₂
Driver and
V_SW
Comparator
GND1
Integrator
H-Bridge
Driver
I_COMP1 I_COMP2 IA_IN2
IA_IN1
V_SW
Bandgap
Reference
Amp
V=4
+5 V
R₆
OVER-RANGE
R₅
V_OUT
REF_IN
2.5 V
REF_OUT
DEMAG
10 MHz
Logic: Timing, Error Detection, and Demagnetize
DRV401-Q1
Oscillator Reset
Power Valid
+5 V
R₇ ERROR
+5 V
V_DD2
C₄
GND2
Copyright © 2016, Texas Instruments Incorporated
Figure 42. Basic Connection Circuit
The connection example in Figure 42 illustrates the few external components required for optimal performance.
Each component is described in the following list:
• I_P is the primary current to be measured; K₁ and K₂ connect to the compensation coil. S1 and S2 connect to
the magnetic field probe. The dots indicate the winding direction on the sensor main core.
• R₁ and R₂ form the shunt resistor R_SHUNT. This resistance is split into two to allow for adjustments to the
required R_SHUNT value. The accuracy and temperature stability of these resistors are part of the final system
performance.
• R₃ and R₄, together with C₃ and C₄, form a network that reduces the remaining probe oscillator ripple in the
output signal. The component values depend on the sensor type and are tailored for best results. This
network is not required for normal operation.
Copyright © 2016, Texas Instruments Incorporated
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