E-L9935 STMicroelectronics, E-L9935 Datasheet - Page 17
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E-L9935
Manufacturer Part Number
E-L9935
Description
IC STEPPER MOTOR DVR 2PH 20PWRSO
Manufacturer
STMicroelectronics
Type
2 Phase Stepper Motor Driverr
Datasheet
1.L9935.pdf
(29 pages)
Specifications of E-L9935
Applications
Stepper Motor Driver, 2 Phase
Number Of Outputs
1
Current - Output
±1.2A
Voltage - Supply
8 V ~ 24 V
Operating Temperature
-40°C ~ 150°C
Mounting Type
Surface Mount
Package / Case
PowerSO-20 Exposed Bottom Pad
Product
Stepper Motor Controllers / Drivers
Operating Supply Voltage
14.4 V
Supply Current
4.5 mA
Mounting Style
SMD/SMT
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Voltage - Load
-
Lead Free Status / Rohs Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
L9935
5.6
5.7
5.8
5.9
5.10
Short from an output to ground
The current through the short will be detected by the protection of the source transistor. The
source transistor will turn off exceeding a current of typically 1.8 A. Minimum overload
detection current is 1.2 A. To obtain proper current regulation (by the sink transistors and not
by source transistor shut down) the maximum current of the PWM regulator should be set to
a maximum value of 1.1 A.
Diagnosis of a short to ground
Detecting an overload will set an overcurrent error (Error2 = LOW) (bit6). To reset the error
flag a new byte must be written into the interface. (Reset of the error flag takes place at the
rising slope of CSN).
Shorted load
With a shorted load both, the sink- and the source protection or the PWM alone will
respond. In either case there will be no flyback pulse.
Diagnosis of a shorted load
Shorting the load two events may take place:
Open load
An open load will not lead to any flyback pulses. Error detection will take advantage of the
flyback pulse. Missing the flyback pulse after reversing the polarity of a motor winding bit7
will become LOW.
Open load will not be tested in the low current mode (current bits HL) to avoid the risk of
instable diagnosis at low flyback currents. Open load immediately after reset or power down
may on random be detected in the low current mode too. This diagnosis however will not
persist longer than 8 changes of polarity.
We strongly suggest to test open load at a high current mode (combination LL).
While circuit clock speed passes the stepper motor resonant points during
acceleration/deceleration phase, it can happen that flyback energy is temporarily insufficient
for a proper open load detection. Under specific circumstances, pending on motor and load
characteristics, this could lead to sporadic faulty open load error messages despite proper
system operation. The recommended solution is an appropriate software filter approach.
A detailed description is available in the application note AN2378 on
–
–
overload (of the high side transistor) while low side transistor overcurrent is
detected will set the following combinations:
bit6 = LOW
bit7 = HIGH
overload is marginal. So the low side driver may turn off before overload is
detected. This leads to the combination bit6 = HIGH and bit7 = LOW.
Doc ID 5198 Rev 9
Functional description
www.st.com.
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