LV8498CTGEVK_TEST_PROCEDURE - 321 KB

Test Procedure for the LV8498CTGEVK Evaluation Kit
For AF-VCM control
CURRENT PROBE
AMPLIFIER
Oscilloscope
PROBE
INPUT
OUTPUT
CHANNEL
1
2
3
4
Lens unit
Power supply
A
V
-
+
ANALOG
POWER
USB
READY
AUX
PC
Figure 1. Setup for AF-VCM control
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Table1: Required Equipment
Equipment
Power supply
Oscilloscope
Current probe
LV8099CT Evaluation Board
USB adapter
Cable for USB adapter
USB cable
Lens unit
Efficiency
5V-0.5A
4 channel
LV8498CTGEVB
USBADAPTORGEVK
LV8483CSCBLGEVK
Type mini-B
5V-200mA
Allowable Operating Ratings
Power supply voltage (VCC): 2.2 to 5.0V
Coil resistance of VCM:
RAF +RTTL < VCC / IOUT
(RAF: Coil resistance of VCM, RTTL: combination of Output ON resistor and sense resistor,
IOUT: Output current)
In case of VCC=2.8V
RAF < VCC / IAF- RTTL
< 2.8V/ 120mA- 3 Ω
< 20.3 Ω
Test Procedure
・ Connect AF-VCM with OUT and VCC.
・ Connect a power supply with VCC pin.
Connect GND line with GND pin.
・ If you use the master device we provided, connect USB adapter with the evaluation board.
2
If you have the original master device, connect I C lines with SDA and SCL pin.
Check if pull-up resistors have been connected to the lines. If not, mount R1 and R2 on the
evaluation board.
・ The USB adapter we provided has built-in resistors. Therefore, you do not need to mount any
resistor.
・ Check the ENA pin is not OPEN. And supply power.
After powered, if the ENA pin is pull-down, input High signal to the pin.
If the pin is pull-up, transfer zero-code to all data.
・ If you use the master device we provided, refer to manual below.
2
If you have the original master device, refer to “Description of Operation” from P. and make I C
program.
・ Check the drive signals and output current waveforms in the scope if they are similar to the charts.
(1) Window setup details
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1)
2)
3)
6)
5)
4)
1) Connection status of I2C transmission board
2
“CONNECTED” = I C transmission board is connected with PC properly via USB cable.
2
“DISCONNECTED” = I C transmission board is not connected with PC.
2) Chip enable setup
Select L (standby) or H (active).
3) Output setup
Select a setting value from the pulldown menu.
4) I2C data display
2
Displays I C data based on the setting value of 3).
5) Data transfer button
After all the parameter setups are completed, click this button.
6) Slave address display
The slave address transferred from this software is fixed to “0110011” from LV8498CT that
cannot be modified.
(2) Function setup
To startup the IC, select H in the “ENABLE”.
As soon as H is selected, ENABLE signal is output.
To set to standby, select L.
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From “Output” pulldown menu, select an output current value between 0mA and 150mA.
When 0mA is selected, the drive circuit is set to standby mode.
Select “Step current” from 8 values.
When OFF is selected, current slope function does not operate.
As a result, current value changes rapidly to the selected output current.
If you select other than OFF for “Step current”, select “Step time” from the pulldown menu.
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When current-carrying AF is
increased.
When current-carrying AF is
decreased.
Current setting code
IST
IST
TST
TST
“Step current” : IST shown in the above chart
“Step time”
: TST shown in the above chart
To drive VCM, set “OFF”(=0) for “Power_down”.
Also by setting “Power_down”=“ON”(=1), standby mode is set forcibly regardless of the setting value of
“Output”.
In this case, current decreases according to the setting value of “Current slope setting”.
2
To change or transfer setting values besides ENABLE, click SEND button to output I C signal.
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4ch: IOUT
(50mA/DIV)
3ch: VOUT
(2V/DIV)
1ch: VSDA
(5V/DIV)
2ch: VSCL
(5V/DIV)
Waveform when it drives from 0 code to Full code
Waveform when it drives from Full code to 0 code
4ch: IOUT
(50mA/DIV)
3ch: VOUT
(2V/DIV)
1ch: VSDA
(5V/DIV)
2ch: VSCL
(5V/DIV)
Waveform when it drives from code 256 to code 511
256
Waveform when it drives from code 511 to code
*) Time range of all waveforms are 5 mSec/DIV.
*) Current slope setting of all waveforms are
Step time: 0.032 mSec
Step current: 0.0978 mA
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