The DRV201EVM is an evaluation board to assist in evaluating the DRV201 IC as a voice coil motor
(VCM) driver for camera auto focus.
The device is an advanced voice coil motor driver for camera auto focus. It has an integrated D/A
converter for setting the VCM current. VCM current is controlled with a fixed frequency PWM controller or
a linear mode driver. Current generation can be selected via I2C register. Device has integrated sense
resistor for current regulation and the current can be controlled through I2C.
When changing the current in the VCM the lens ringing is compensated with an advanced ringing
compensation function. Ringing compensation reduces the needed time for auto focus significantly. The
device has also VCM short and open protection functions.
The following related documents are available for download through the Texas Instruments web site at
http://www.ti.com.
1. DRV201 Voice Coil Motor Driver for Camera Auto Focus (SLVSB25)
2. USB Interface Adapter Evaluation Module (SLLU093)
The DRV201EVM is an evaluation board to assist in evaluating the DRV201 IC as a voice coil motor
(VCM) driver for camera autofocus.
The device is an advanced voice coil motor driver for camera Auto focus. It has integrated D/A converter
for setting the VCM current. VCM current is controlled with a fixed frequency PWM controller or a linear
mode driver. Current generation can be selected via I2C register. Device has integrated sense resistor for
current regulation and the current can be controlled through I2C.
When changing the current in the VCM the lens ringing is compensated with an advanced ringing
compensation function. Ringing compensation reduces the needed time for auto focus significantly. The
device has also VCM short and open protection functions.
1.2Applications
•Camera auto focus
•Camera Iris control
1.3Features
•Configurable for linear or PWM mode VCM current generation
•High efficiency PWM current control for VCM
•Advanced ringing compensation
•Integrated 10-bit D/A converter for VCM current control
•Protection
– Open and short-circuit detection on VCM pins
– Undervoltage lockout (UVLO)
– Thermal shutdown
– Open and short circuit protection on VCM output
– Internal current limit for VCM driver
•Host (PC): a Windows™ personal computer (PC) – used to configure and monitor the DRV201EVM.
The GUI operates on the host. For the GUI to execute properly, the host needs to have the correct
LabView™ RunTime version. If the host doesn’t have the correct RunTime version it will be prompted
during GUI installation. More information in GUI installation section.
•USB-to-I2C adapter: DRV201EVM uses the I2C interface for communication with the host. The TI-
supplied USB-to-I2C adapter shown in Figure 3. USB-to-GPIO adapter does the appropriate conversion
so the host can use the USB interface for communication. USB-to-I2C adapter has a 3.3-V supply rail
which is used to supply the EVM so no external power supply is needed.
•DRV201EVM: EVM board that houses the DRV201 and peripheral components.
The DRV201EVM allows evaluation of the DRV201 IC as a voice coil motor (VCM) driver for camera
autofocus. DRV201EVM has separate connections for Isource and Isink pins that can be used to connect
to any VCM actuator or VCM in a camera module. If VCM actuator is not available there are on board
mounted inductor and resistor available to model VCM.
The DRV201EVM can be configured and monitored through a Windows GUI application running on a PC.
The GUI communicates with the DRV201EVM through the USB Interface Adapter (included with EVM kit),
which acts as an I2C master for the board.
The DRV201EVM provides the following functionality:
•Programming of the DRV201 device.
•R_VCM and L_VCM are meant as a model of a typical VCM actuator electrical parameters.
•Driving either external VCM connected to I
resistor (see jumper setting).
•Standard 400-kHz I2C communication via I2C connector to USB adapter for connection to a PC.
•Board can be supplied through the 3.3 V from the USB adapter or from an external power source (see
jumper setting).
SOURCE
and I
Hardware Overview
headers or using on board inductor and
SINK
Figure 4. Connecting the ribbon cable to DRV201EVM pin one is marked on the EVM and with the red
The DRV201EVM has connectors for power and I2C communications. J1 provides a possibility to power
EVM from an external power supply (between 2.5 V and 4.8 V). USB adapter interface adapter has a 3.3V power output that can be used to power the board so there is no need for external power source.
P1 header provides the I2C communication interface to the DRV201EVM. The USB Interface Adapter
includes a ribbon cable that can be connected to P1. The adapter is connected to a Windows-based PC.
3.2Jumpers
The DRV201EVM operation can be configured using jumpers:
•Board power from external supply or USB interface adapter
•Driving on board inductor and resistor or external VCM actuator
See Table 1 for descriptions and default settings for the jumpers on the DRV201EVM.
NUMBERFUNCTIONDEFAULT SETTING
JP1 andJP2I
WARNING
When using external power DRV201EVM, it should be noted that
the recommended supply range for DRV201 is from 2.5 V to 4.8 V.
Table 1. DRV201EVM Jumpers
P23.3 V from the USB interface adapter and pins 2-3 if external
Board power supply selection. Connect to pins 1-2 when using
power supply is used.
R_VCM and L_VCM are connected between DRV201 pins
and I
SOURCE
can be connected between I
. If jumpers are not connected, VCM actuator
SINK
SOURCE
and I
SINK
.
Pins 1-2 (power from USB
interface adapter)
JP1 and JP2 jumpers
www.ti.com
connected
3.3Test Points
The DRV201EVM provides test points that can be used for evaluation. Important voltages can be
monitored with a meter through the use of the test points.
3.4EVM Operation
The DRV201EVM operates from either a USB interface adapter (through P1) or an external power supply
(through J1). Jumper P2 can be used to select the power source as described in Section 3.2. Use the
following steps to set up the DRV201EVM.
1. Connect the USB interface adapter to the DRV201EVM P1 connector using the ribbon cable provided.
2. Plug the appropriate end of the USB cable into the adapter and the other end into your PC.
NOTE: If using an external power supply, connect jumper’s pins 2-3 and use J1 to connect the