SPMD250STP STMicroelectronics, SPMD250STP Datasheet - Page 14

• Manufacturer Part Number: SPMD250STP
• Description: MOD STEPPER MOTOR DRV 2.5A BIPO
• Manufacturer: STMicroelectronics
• Series: EASY POWER™r
• Type: Stepper Motor Driverr

Specifications of SPMD250STP

• Motor Type: Stepper, Bipolar
• Number Of Motors: 1
• Voltage - Output: 40V
• Voltage - Logic Supply: 4.5 V ~ 5.5 V
• Current - Output: 2.5A
• Transistor Type: MOSFET
• Termination Style: PC Pin
• Operating Temperature Classification: Industrial
• Operating Supply Voltage (min): 12V
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (max): 40V
• Product: Stepper Motor Controllers / Drivers
• Operating Supply Voltage: 5 V
• Mounting Style: SMD/SMT
• For Use With: 497-10050 - BOARD EVAL SPMD250497-9011 - DEMO SYSTEM BASED ON SPMD250STP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-8416

RESET, ENABLE and HOME signals
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RESET, ENABLE and HOME signals
The RESET is an asynchronous reset input which restores the module to the home position
(state 1 : ABCD = 0101). Reset is active when low.
The HOME output signals this condition and it is intended to be ANDed with the output of a
mechanical home position sensor.
The ENABLE input is used to start up the module after the system initialization. ENABLE is
active when high or unconnected.
Motor current regulation
The two bipolar winding currents are controlled by two internal choppers in a PWM mode to
obtain good speed and torque characteristics.
An internal oscillator supplies pulses at the chopper frequency to both choppers.
When the outputs are enabled, the current through the windings raises until a peak value set
by Ioset and Rsense (see the equivalent block diagram) is reached. At this moment the
outputs are disabled and the current decays until the next oscillator pulse arrives.
The decay time of the current can be selected by the CONTROL input (pin 10). If the
CONTROL input is kept high or open the decay is slow, as shown in
equivalent power stage and the voltages on A and B are shown as well as the current
waveform on winding AB.
When the CONTROL input is forced low, the decay is fast as shown in fig. 13.
The CONTROL input is provided on
If the modules must drive a large motor that does not store much energy in the windings, the
chopper frequency must be decreased: this is easily obtained by connecting an external
capacitor between OSC pin and GND1.
In these conditions a fast decay (CONTROL LOW) would impose a low average current and
the torque could be inadequate. By selecting CONTROL HIGH, the average current is
increased thanks to the slow decay.
When the module is used in the fast-decay mode it is recommended to connect external fast
recovery, low drop diodes between each phase output and the supply return (GND). The
slow-decay should be the preferred operating recirculation mode because of the lower
power dissipation and low noise operations.
Doc ID 14350 Rev 2
SPMD250STP
to allow maximum flexibility in application.
Figure
12, where the
SPMD250STP