The L9935 is a two-phase stepper motor driver
circuit suited to drive bipolar stepper motors. The
device can be controlled by a serial interface
(SPI). All protections required to design a well
protected system (short-circuit, overtemperature,
cross conduction etc.) are integrated.
OUT
OUT
GND
SCK
SDI
SDO
VCC
CSN
GND
201
~
2
A1
3
4
5
6
7
8
EN
9
B1
10
DRIVER
COMMON
LOGIC
DRIVER
LOGIC
OSCILLATOR
DIAGNOSTIC
BIASING
LOGIC
~
19
18
17
16
15
14
13
12
11
D99AT415
GND
SR
OUT
N.C.
V
OSC
C
OUT
SR
GND
A
A2
S
DRV
B2
B
November 1999
1/19
L9935
PIN CONNECTION
GND
OUT
B1
EN
CSN
VCC
SDO
SDI
SCK
OUT
A1
GNDGND
10
9
8
7
6
5
4
3
2
1
D99AT416
11
12
13
14
15
16
17
18
19
20
GND
SR
OUT
C
DRV
OSC
V
S
N.C.
OUT
SR
B
B2
A2
A
PIN FUNCTIONS
o
Pin N
1,10,11,20GNDGround. (All ground pins are internally connected to the frame of thedevice).
2OUT
3SCKClock for serial interface (SPI)
4SDISerial data input
5SDOSerial data output
6VCC5V logic suplly voltage
7CSNChip select (Low active)
8ENEnable (Low active)
9OUT
12SR
13OUT
14C
15OSCOscillator capacitor or external clock
16VSSupply voltage
17NCNot connected
18OUT
19SR
NameDescription
A1
B1
B
B2
DRV
A2
A
Output 1 of full bridge 1
Output 1 of full bridge 2
Cyrrent sense resistor of the chopper regulator for OUT
Output 2 of full bridge 2
Charge pump buffer capacitor
Output of full bridge 1
Current sense resistor of the chopper regulator for OUT
B
A
2/19
L9935
ABSOLUTE MAXIMUM RATINGS
SymbolParameterValueUnit
V
S
V
SPulsed
V
OUT (Ai/Bi)
I
OUT (Ai/Bi)
V
SRA/SRB
V
CC
V
CDRV
V
SCK,VSDI
V
CSN,VEN
V
OSC,VSDO
Note: ESD for allpins, except pins SDO, SRA and SRB, areaccording to MIL883C, tested at 2kV, corresponding to a maximum energy
dissipation of 0.2mJ. SDO, SRA and SRB pins are tested with800V.
THERMAL DATA
SymbolParameterValueUnit
R
th j-case
R
th j-amb
R
th j-amb,FR4
T
S
T
SD
DC Supply Voltage-0.3 to 35V
Pulsed supply voltage T < 400ms-0.3 to 40V
Output Voltagesinternally clamped to V
or GND depending on the
current direction
DC Output Currents
Peak Output Currents (T/tp ≥ 10)
1.2
±
±2.5
Sense Resistor Voltages-0.3 to 6.2V
Logic Supply Voltages-0.3 to 6.2V
Charge Pump BufferVoltage versus V
,
Logic Input Voltages-2 to 8V
S
-0.3 to 10V
Oscillator Voltage Range, Logic Output-0.3 to VCC+0.3V
Typical Thermal Resistance Junction to Case5°C/W
Typical Thermal Resistance Junction to Ambient
2
(6cm
Ground Plane 35µm Thhickness)
Typical Thermal Resistance Junction to Ambient
35°C/W
8°C/W
(soldered on a FR 4 board with through holes for heat transfer
and external heat sink applied)
Storage Temperature-40 to 150°C
Typical Thermal Shut-Down Temperature180°C
1) Parameters are tested at 125°C. Values at 140°C are guaranteed by design and correlation.
2) Currents of combinations LH and LL are sensed at the external resistors. The Current of bit combination HL is sensed internally and
cannot be adjusted by changing the sense resistors.
C1 and C2 should be placed as close to the device as possible. Low ESR of C2 is advantageous. Peak currents through C1 and C2 may
reach 2A. Care should be taken that the resonance of C1, C2 together with supply wire inductances isnot the choppingfrequencyor a multiple
of it.
FUNCTIONAL DESCRIPTION
Basic structure
The L9935 is a dual full bridgedriver for inductive
Table 1.
15 OSC
14
C
DRV
13 OUT
12 SR
11 GND
C
OSC
1nF
C
Driver
100nF
C1
100nF
B2
B
R2 0.33Ω
D99AT417
DRIVER
LOGIC
~
OSCILLATOR
DIAGNOSTIC
BIASING
loads with a choppercurrentregulation.
OutputsA1and A2belongto full bridge A
OutputsB1and B2belongto full bridge B
The polarity of the bridges can be controlled by
bit0 and bit3 (for full bridge A, bit3, for full bridge
B, bit0). Bit5, bit4 (for full bridge A) and bit2, bit1
(for full bridge B) control the currents. Bit3 high
leads to output A1 high. Bit0 high leads to output
B1 high.
Current setting Table 1 using a 0.33W sense resistor.
STEPPER
MOTOR
POWER
SUPPLY
C2
10µF
bit5, bit2bit4, bit1IQX(Typ.)I
H
H
L
L
H
L
H
L
0
60mA
550mA
900mA
RX/max
0%
61%
100%
Remark
inernally sensed
5/19
L9935
Figure 2. Typical average load current dependence on R