SPMD150STP STMicroelectronics, SPMD150STP Datasheet - Page 15

• Manufacturer Part Number: SPMD150STP
• Description: MOD STEPPER MOTOR DRV 1.5A BIPO
• Manufacturer: STMicroelectronics
• Type: Motor / Motion Controllers & Driversr

Specifications of SPMD150STP

• Motor Type: Stepper, Bipolar
• Number Of Motors: 1
• Current - Output: 1.5A
• Transistor Type: MOSFET
• Termination Style: PC Pin
• Product: Stepper Motor Controllers / Drivers
• Operating Supply Voltage: 50 V
• Supply Current: 1.5 A
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-10065

SPMD150STP
4.4
Figure 14. VREFx from internal source
Decay modes
The CONTROL input is used to select the behavior of the bridge during the off time. When
the CONTROL pin is low, the fast decay mode is selected and both transistors in the bridge
are switched off during the off time.
When the CONTROL pin is high, the slow decay mode is selected and only the low side
transistor of the bridge is switched off during the off time.
Figure 15
time, both of the power MOSFETs are switched off and the current recirculates through the
two opposite free wheeling diodes. The current decays with a high di/dt, since the voltage
across the coil is essentially the power supply voltage. After the dead time, the lower power
MOSFET in parallel with the conducting diode is turned on in synchronous rectification
mode. In applications where the motor current is low it is possible that the current can decay
completely to zero during the off time. At this point if both of the power MOS were operating
in the synchronous rectification mode it would then be possible for the current to build in the
opposite direction. To prevent this only the lower power MOS is operated in synchronous
rectification mode. This operation is called quasi-synchronous rectification mode. When the
mono-stable circuit times out, the power FETs are turned on again after some delay set by
the dead time to prevent cross conduction.
shows the operation of the bridge in the fast decay mode. At the start of the off
Doc ID 17160 Rev 1
Function description and application information
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