Datasheet
Table Of Contents
- 1 Block diagram
- 2 Electrical data
- 3 Electrical characteristics
- 4 Pin connection
- 5 Functional description
- 5.1 Power supply and standby
- 5.2 Microstepping sequencer
- Table 7. Step mode selection through MODEx inputs
- Figure 4. MODEx, STCK and DIR timing diagram
- Table 8. Target reference and current direction according to sequencer value (full-step mode)
- Table 9. Target reference and current direction according to sequencer value (not full-step mode)
- Table 10. Example
- 5.3 PWM current control
- 5.4 Overcurrent and short-circuit protections
- 5.5 Thermal shutdown
- 5.6 ESD protection strategy
- 6 Typical applications
- 7 Layout recommendations
- 8 Package information
- 9 Ordering information
- 10 Revision history
Functional description STSPIN820
12/29 DocID031065 Rev 2
5 Functional description
The STSPIN820 is a stepper motor driver integrating a microstepping sequencer (up to
1/256
th
step), two PWM current controllers and a power stage composed by two fully-
protected full-bridges.
5.1 Power supply and standby
The device is supplied through the VS pins, the two pins must be at the same voltage.
At power-up the power stage is disabled and the FAULT pin is forced low until the VS
voltage rises above the V
Sth(ON)
threshold.
If the V
S
falls below the V
Sth(ON)
- V
Sth(HYST)
value the power stage is immediately disabled
and the FAULT pins are forced low.
Figure 3. UVLO protection management
The device provides a low consumption mode which is set forcing the STBY\RESET input
below the V
STBYL
threshold.
When the device is in standby status the power stage is disabled (outputs are in high
impedance) and the supply to the integrated control circuitry is strongly reduced. When the
device exits the standby status, all of the control circuitry is reset at power-up condition.
74
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108&3
TUBHF
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*OUFSOBM0%
SFMFBTFE
*OUFSOBM0%
SFMFBTFE
0VUQVUTTUBUF
BDDPSEJOHUP
JOQVUTUBUVT
0VUQVUTTUBUF
BDDPSEJOHUP
JOQVUTUBUVT
".