LV8760TGEVB_TEST_PROCEDURE.PDF - 135 KB

Test Procedure for the LV8760TGEVB Evaluation Board
For DC Motor Control
CURRENT PROBE
AMPLIFIER
Osclloscope
PROBE
INPUT
OUTPUT
CHANNEL
1
2
3
4
Power supply 1
A
V
DC Motor
-
+
Power supply 2
Power supply 3
A
V
V
A
-
+
+
Function generator
Multimeter
VOUT
Hz
CHANNEL
1
-
+
2
Table1: Required Equipment
Equipment
Power supply1
Power supply2
Power supply3
Function generator
Multimeter
Oscilloscope
Current probe
LV8760T Evaluation Board
DC Motor
1/8/2014
1
Efficiency
10V-1A
5V-0.5A
40V-5A
200kHz
4 channel
40V-3A
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Test Procedure:
1. Connect the test setup as shown above.
2. Set it according to the following specifications.
Supply Voltage
•
•
•
VM (9 to 35V): Motor Power Supply
VREF (0 to VCC-1.8V): Current Limit Control Reference Voltage
VCC (3 to 5.5V): Control Power Supply
Toggle Switch State
•
•
•
Upper Side: High (VCC)
Middle: Open, enable to external logic input
Lower Side: Low (GND)
Operations Guide
1.
2.
3.
4.
Initial Condition Setting: Set “Open or Low” all switches.
Motor Connection: Connect the Motor between OUTA and OUTB.
Power Supply: Supply DC voltage to VM, VCC and VREF.
Ready for Operation from Standby State: Turn “High” the PS pin toggle
switch.
5. Motor Operation: Set IN1, and IN2 pin according to the purpose.
(See LV8760T‘s logic table).
Setting for External Component Value
1. Current limit value
At VREF
= 1.5V
(I)limit = VREF [V]/5/R1 [ohm]
= 1.5 [V] / 5 / 0.22 [ohm]
= 1.36 [A]
2. Current limit regeneration time and short-circuit detection time
Tscp ≈ C5 [pF]× Vthscp[V]/Iscp[µA]
= 100[pF] × 1[V]/5[µA]
= 20[µs]
3. Check VREG5 and VG pin voltage at multimeter.
4. Check the IN1 or IN2 pin voltage at scope CH1, OUTA pin voltage at scope CH2,
OUTB pin voltage at scope CH3, and the output current waveform at scope CH4.
Table2: Desired Results
INPUT
OUTPUT
VM=24V
VREF=1.5V REG5=4.5V to 5.5V
VCC=5V
VG=28V to 29.8V
PS=High
1/8/2014
2
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Figure.1 Forward↔Output off
IN2=Low
Figure 2. Forward↔Brake
IN1=High
200ms/div
1/8/2014
200ms/div
IN1
5V/div
IN2
5V/div
OUTA
10V/div
OUTA
10V/div
OUTB
10V/div
OUTB
10V/div
Motor
current
0.5A/div
Motor
current
0.5A/div
3
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