EVAL6235PD Datasheet, PDF (8/10 Pages) STMicroelectronics – TACHO output for speed loop

Using the EVAL6235PD
2
Using the EVAL6235PD
EVAL6235PD
The EVAL6235PD demonstration board can be used in combination with the
EVALPRACTISPIN interface board and practiSPIN software, or it can run in stand-alone
mode.
The 5 V for logic inputs and reference voltage is obtained from R1 and D2. For supply
voltages higher than 20 V, R1 must be replaced with a higher value resistor. The jumpers
JP1 and JP2 allow disconnecting the internal Zener diode network, in case the 5 V is
provided through pin 11 of CN4 (for example, an external microcontroller board can provide
5 V to the demonstration board).
The CN2 connector can also be used to provide an external 5 V voltage to the board, and
CN2, or pin 1 of CN4, can be used to provide a 5 V voltage to external circuits. In this case,
only a small current can be drawn from the board, depending on the supply voltage and R1
value.
2.1
Connection to the EVALPRACTISPIN interface board
The EVAL6235PD board connects to the EVALPRACTISPIN board through the 34-pole
CN4 connector.
Device evaluation can be performed by running the dedicated practiSPIN software. For
more details, please refer to application note AN1794 “PractiSPIN evaluation system
configuration and set up guide”, available at www.st.com.
2.2
Running the EVAL6235PD in stand-alone mode
When running the demonstration board in stand-alone mode, the four switches (S1) allow
the user to perform the following:
– enable the device
– set the motor direction
– brake the motor
– choose to run in torque or speed mode
R17 and R22 set the reference voltage provided to the VREF pin of the L6235 (in torque
mode) or to the error amplifier, U2 (in speed mode). R20 and C11 make up a low-pass filter
to provide an external reference voltage by a PWM output of a microcontroller. R10 and C8
are used to set the off-time, and R11 and C9 set the duration of the TACHO output pulses.
For more details on the L6235PD IC, refer to the L6235 datasheet and application note
AN1625, both available on www.st.com.
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Doc ID 022128 Rev 1