NJM2673E3 [NJRC]
Stepper Motor Controller, 1A, PDSO24, 0.300 INCH, SOP-24;
| 型号： | NJM2673E3 |
| 厂家： | 
NEW JAPAN RADIO |
| 描述： | Stepper Motor Controller, 1A, PDSO24, 0.300 INCH, SOP-24 电动机控制 光电二极管 |
| 文件： | 总12页 (文件大小：310K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
NJM2673
STEPPER MOTOR DRIVER
■ GENERAL DESCRIPTION
■ PACKAGE OUTLINE
The NJM2673 is a stepper motor driver, which consists of a
LS-TTL compartible logic input stage, off time control circuits and
a pair of high power H-bridges and protection diodes.
The output current is up to 1000mA.
The NJM2673 with small number of external components
conforms a complete control and drive unit for stepper motor
systems.
NJM2673E3
( SOP24 )
.
■ FEATURES
• Switched mode bipolar constant current drive
• Wide voltage range 4 to 45V
• Wide range of current control 5 to 1000mA
• Half- step and full-step operation
• Thermal overload protection
• Package
SOP24 JEDEC 300mil (batwing)
■ PIN CONNECTION
24
23
22
T2
VCC
T1
1
VR2
VR1
PHASE2
4
PHASE1
I11
I12
I02
21
20
19
18
GND
GND
MB2
C2
GND
GND
I01
NJM
2673E3
7
8
17
MB1
C1
16
15
10
E2
E1
MA2
MA1
11
12
14
13
VMM
Figure1. Pin configuration
- 1 -
NJM2673
■ BLOCK DIAGRAM
T1
VCC
C1
E1
PHASE1
I11
I01
MA1
MB1
Current
Select
Logic
VR1
VMM1
VMM2
TSD
PHASE 2
MB2
MA2
I 02
Current
Select
Logic
I12
VR2
GND
C2
T2
E2
Figure 2. Block Diagram
- 2 -
NJM2673
■ PIN DESCRIPTION
SOP Symbol Description
1
2
VCC
T1
Logic voltage supply normally +5V.
Clock Oscillator, channel 1. Timing pin connect a 56kΩ resistance and a 820pF in
parallel between T and ground.
3
4
5
VR1
Reference voltage, channel 1. Controls the threshold voltage for the comparator and
hence the output current.
Controls the direction of the motor current of MA1 and MB1 outputs. Motor current flows
from MA1 to MB1 when Phase1 is HIGH.
Logic input, channel 1. It controls, together with the I01 input, the current level in the
output stage.
PHASE1
I11
6,7,18,19 GND
Ground and negative supply. These pins are used for heat sinking. Make sure that all
ground pins are soldered onto a suitable large copper ground plane for efficient heat
sinking.
8
I01
Logic input, channel 1. It controls, together with the I11 input, the current level in the
output stage.
9
MB1
C1
E1
Motor output B, channel 2. Motor current flows from MA1to MB1 when Phase1 is high.
Comparator input, channel 1. This input senses the instantaneous voltage across the
sensing resistor, filtered through a RC network.
Common emitter, channel 1. Connect the Sense resistor between this pin and ground.
Motor supply voltage, 4 to 40V.
10
11
Motor output A, channel 1. Motor current flows from MA1to MB1 when Phase1 is high.
Motor output A, channel 2. Motor current flows from MA2to MB2 when Phase2 is high.
Common emitter, channel 2. Connect the Sense resistor between this pin and ground.
Comparator input, channel 2. This input senses the instantaneous voltage across the
sensing resistor, filtered through a RC network.
Motor output B, channel 2. Motor current flows from MA2to MB2 when Phase2 is high.
Logic input, channel 2. It controls, together with the I12 input, the current level in the
output stage.
Logic input, channel 2. It controls, together with the I02 input, the current level in the
output stage.
Controls the direction of the motor current of MA2 and MB2 outputs. Motor current flows
from MA2 to MB2 when Phase2 is HIGH.
12
13
VMM
MA1
14
15
16
17
20
21
22
23
24
MA2
E2
C2
MB2
I02
Reference voltage, channel 2. Controls the threshold voltage for the comparator and
hence the output current.
Clock Oscillator, channel 2. Timing pin connect a 56kΩ resistance and a 820pF in
parallel between T and ground.
I12
PHASE2
VR2
T2
■ ABSOLUTE MAXIMUM RETINGS
(Ta=25°C)
- 3 -
NJM2673
PARAMETER
SYMBOL
MIN.
MAX.
UNIT
Voltage
Logic Supply
Motor Supply
Logic Input Voltage
Comparator Input Voltage
Reference Input Voltage
Current
VCC
VMM
VI
VC
VC
0
0
-0.3
-0.3
-0.3
7
45
VCC
VCC
VCC
V
V
V
V
V
Motor Output Current
Logic Input Current
Analog Input Current
Temperature
IM
II
IA
-1000
-10
-10
+1000
mA
mA
mA
-
-
Operating Temperature
Storage Temperature
Topr
Tstg
-40
-55
85
150
°C
°C
■ RECOMMENDED OPERATING CONDITIONS
PARAMETER
Logic Supply
SYMBOL
VCC
MIN.
4.75
TYP.
MAX.
5.25
UNIT
V
5.00
Motor Supply
VMM
IM
Tj
tr
4
-800
-20
-
-
-
-
-
-
40
800
+125
2
V
mA
°C
Motor Output Current
Operating Junction Temperature
Rise time Logic Inputs
Fall Time Logic Inputs
µS
µS
tf
-
2
- 4 -
NJM2673
■ ERECTRICAL CHARACTERISTICS (T=+25°C, VCC=5V,VMM=40V,CT=820pF,RT=56kΩ)
j
PARAMETER
SYMBOL
CONDITION
MIN.
TYP.
MAX.
UNIT
General
ICC
td
-
-
-
-
60
-
mA
µS
°C
Supply Current
Turn Off
0.9
170
dVc/dt≥50mV/µs
TSD
-
Thermal Shutdown Temperature
Logic Input
VIH
VIL
IIH
2.0
-
-
-
-
-
0.8
20
-
H Level Input Voltage
L Level Input Voltage
H Level Input Current
L Level Input Current
Input Resistance
Input Resistance
V
V
-
-
VI=2.4V
VI=0.4V
µA
µA
IIL
-250
RR
-
8.8
-
kΩ
Analog Input
Threshold Voltgae
VCH
VCM
VCL
VR=5.0V,I0=I1=L
VR=5.0V,I0=H,I1=L
VR=5.0V,I0=L,I1=H
405
284
134
450
315
150
495
347
163
mV
mV
mV
µA
Input Current
IC
-20
-
-
Motor Output
IM=500mA
IM=800mA
IM=500mA
IM=800mA
IM=500mA
IM=800mA
IM=500mA
IM=800mA
I0=I1=H
-
-
-
-
-
-
-
-
-
1.1
1.3
1.1
1.3
1.0
1.2
1.1
1.3
-
1.4
1.7
1.4
1.7
1.3
1.6
1.4
1.7
100
V
V
V
V
V
V
V
V
µA
Lower Transistor Saturation Voltage
Upper Transistor Saturation Voltage
Lower Diode Forward Voltage Drop
Upper Diode Forward Voltage Drop
VOL
VOU
VfL
VfU
IIL
Output Leak Current
Monostable
toff
-
31
-
µs
Cut Off Time
■ THERMAL CHARACTERISTICS
PARAMETER
SYMBOL
RthJ-GND
CONDITION
MIN.
TYP.
13
MAX.
UNIT
°C
°C
-
-
-
-
Thermal Resistance
RthJ-A Note2
42
Notes
1. All voltages are with respect to ground. Currents are positive into, negative out of specified terminal.
2. All ground pins soldered onto 20cm2 PCB copper area with free air condition, TA=25°C.
- 5 -
NJM2673
■ TYPICAL APPLICATION CIRCUIT
Rs
1ohm
C
820pF
C
R
C
1kohm
E2
GND
C2
TSD
R
S
Q
T2
LOGIC
MB2
MA2
R
T
C
T
56kohm
820pF
VR2
I
02
I
12
PHASE2
PHASE1
MOTOR
VMM
NJM2673
I
11
I
01
VR1
VCC
VCC
MA1
MB1
LOGIC
S
R
Q
T1
TSD
C1
GND
E1
VREF VCC
VMM
C
T
820pF
R
T
56kohm
R
C
1kohm
C
C
Rs
1ohm
820pF
Figure 3.Application Circuit
■ TYPICAL APPLICATION CIRCUIT
- 6 -
NJM2673
■ FUNCTIONAL DESCRIPTION
The NJM2673 is intended to drive a bipolar constant current through one winding of a 2-phase stepper motor.
Current control is achieved through switched-mode regulation, see figure 4 and 5.
Three different current levels and zero current can be selected by the input logic.
The circuit contains the following functional blocks:
● Input logic
● Current sense
● Single-pulse generator
● Output stage
Input logic
Phase input
The phase input determines the direction of the current in the motor winding. High input forces the current from terminal
MA to MB and low input from terminal MB to MA. A Schmitt trigger provides noise immunity and a delay circuit eliminates
the risk of cross conduction in the output stage during a phase shift.
Half- and full-step operation is possible.
Current level selection.
The status of I0 and I1 inputs determines the current level in the motor winding. Three fixed current levels can be
selected according to the table below.
Motor current
High level
Medium level
Low level
I0
L
H
L
I1
L
L
H
H
100%
60%
20%
0%
Zero current
H
Rs
Motor Current
Figure 4. Motor current (IM ),
Vertical : 200 mA/div,
Horizontal: 1 ms/div,
Fast Current Decay
Slow Current Decay
Time
expanded part 100 µs/div.
Figure 5. Output stage with current
pathsfor fast and slow current
decay.
- 7 -
NJM2673
The specific values of the different current levels are determined by the reference voltage VR together with the value of
the sensing resistor RS.
The peak motor current can be calculated as follows:
im = (VR • 0.080) / RS [A], at 100% level
im = (VR • 0.050) / RS [A], at 60% level
im = (VR • 0.016) / RS [A], at 20% level
The motor current can also be continuously varied by modulating the voltage reference input.
Current sensor
The current sensor contains a reference voltage divider and three comparators for measuring each of the selectable
current levels. The motor current is sensed as a voltage drop across the current sensing resistor, RS, and compared with
one of the voltage references from the divider. When the two voltages are equal, the comparator triggers the single-pulse
generator. Only one comparator at a time is activated by the input logic.
Single-pulse generator
The pulse generator is a monostable multivibrator triggered on the positive edge of the comparator output. The
multivibrator output is high during the pulse time, toff , which is determined by the timing components RT and CT.
The single pulse switches off the power feed to the motor winding, causing the winding to decrease during toff.
If a new trigger signal should occur during toff, it is ignored.
Output stage
The output stage contains four transistors and four diodes, connected in an H-bridge. Note that the upper recirculation
diodes are connected to the circuit externally. The two sinking transistors are used to switch the power supplied to the
motor winding, thus driving a constant current through the winding. See figures 4 and 5.
Overload protection
The circuit is equipped with a thermal shut-down function, which will limit the junction temperature. The output current
will be reduced if the maximum permissible junction temperature is exceeded. It should be noted, however, that it is not
short circuit protected.
Operation
When a voltage VMM is applied across the motor winding, the current rise follows the equation:
im = (VMM / R) • (1 - e-(R • t ) / L
)
R = Winding resistance
L = Winding inductance
t = time
(see figure 5, arrow 1)
The motor current appears across the external sensing resistor, RS, as an analog voltage. This voltage is fed through a
low-pass filter, RCCC, to the voltage comparator input (pin 10 and pin 16 ). At the moment the sensed voltage rises above
the comparator threshold voltage, the monostable is triggered and its output turns off the conducting sink transistor. The
polarity across the motor winding reverses and the current is forced to circulate through the appropriate upper protection
diode back through the source transistor (see figure 5 , arrow 2).
After the monostable has timed out, the current has decayed and the analog voltage across the sensing resistor is
below the comparator threshold level. The sinking transistor then turns on and the motor current starts to increase again,
The cycle is repeated until the current is turned off via the logic inputs. When both I1 and I0 are high, all four transistors in
the output H-bridge are turned off, which means that inductive current recirculates through two opposite free-wheeling
diodes (see figure 5, arrow 3). this method of turning off the current results in a faster current decay than if only one
transistor was turned off and will therefore improve speed performance in half-stepping mode.
- 8 -
NJM2673
■ PRINCIPAL OPERATING SEQUENCE
- 9 -
NJM2673
■ APPLICATIONS INFORMATION
Motor selection
Some stepper motors are not designed for continuous operation at maximum current. As the circuit drives a constant
current through the motor, its temperature can increase, both at low- and high-speed operation.
Some stepper motors have such high core losses that they are not suited for switched-mode operation.
Interference
As the circuit operates with switched-mode current regulation, interference-generation problems can arise in some
applications. A good measure is then to decouple the circuit with a 0.1 µF ceramic capacitor, located near the package
across the power line VMM and ground.
Also make sure that the VRef input is sufficiently decoupled. An electrolytic capacitor should be used in the +5V rail,
close to the circuit.
The ground leads between RS, CC and circuit GND should be kept as short as possible. This applies also to the leads
connecting RS and RC to pin 10 and pin 11, pin 15 and pin 16 respectively.
In order to minimize electromagnetic interference, it is recommended to route MA and MB leads in parallel on the printed
circuit board directly to the terminal connector. The motor wires should be twisted in pairs, each phase separately, when
installing the motor system.
Unused inputs
Unused inputs should be connected to proper voltage levels in order to obtain the highest possible noise immunity.
Ramping
A stepper motor is a synchronous motor and does not change its speed due to load variations. This means that the
torque of the motor must be large enough to match the combined inertia of the motor and load for all operation modes. At
speed changes, the requires torque increases by the square, and the required power by the cube of the speed change.
Ramping, i.e., controlled acceleration or deceleration must then be considered to avoid motor pullout.
VCC , VMM
The supply voltages, VCC and VMM, can be turned on or off in any order. Normal dv/dt values are assumed.
Before a driver circuit board is removed from its system, all supply voltages must be turned off to avoid destructive
transients being generated by the motor.
Switching frequency
The motor inductance, together with the pulse time, toff, determines the switching frequency of the current regulator. The
choice of motor may then require other values on the RT, CT components than those recommended in figure 3, to obtain
a switching frequency above the audible range. Switching frequencies above 40 kHz are not recommended because the
current regulation can be affected.
Analog control
As the current levels can be continuously controlled by modulating the VR input, limited microstepping can be achieved.
Sensor resistor
The RS resistor should be of a noninductive type power resistor. A 1.0 ohm resistor, tolerance ≤ 1%, is a good choice for
415 mA max motor current at VR = 5V.
The peak motor current, im , can be calculated by using the formula:
im=(VR • 0.080) / RS [A], at 100% level
- 10 -
NJM2673
■ TYPICAL CHARACTERISTICS
VCC VS. ICC
@NJM2673 I0=I1=LOW
VCC VS. ICC
@NJM2673 I0=I1=HIGH
80
70
60
50
40
30
20
10
0
80
70
60
50
40
30
20
10
0
0
1
2
3
4
5
6
7
8
0
1
2
3
4
5
6
7
8
VCC[V]
VCC[V]
COMP input Voltage VS. COMP input Current
@NJM2673 VCC=VR=5V I0=I1=LOW
COMP input Voltage VS. COMP input Current
@NJM2673 VCC=VR=5V I0=LOW I1=HIGH
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
0
100
200
300
400
500
0
100
200
300
400
500
Vc[mV]
Vc[mV]
COMP input Voltage VS. COMP input Current
@NJM2673 VCC=VR=5V I0=HIGH I1=LOW
Phase input Voltage VS. Phase input Current
@NJM2673 VCC=VR=5V
160
140
120
100
80
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
60
40
20
0
0
100
200
300
Vc[mV]
400
500
0.0
1.0
2.0
3.0
4.0
Vin[V]
- 11 -
NJM2673
■ TYPICAL CHARACTERISTICS
Power Dissipation vs Motor Current
NJM2673(1ch Drive)VCC=5V, VMM=40V, ta=25°C
6.0
5.0
4.0
3.0
2.0
1.0
0.0
0
200
400
600
800
1000
1200
IM[mA]
Power Dissipation vs Motor Current
NJM2673(2ch Drive)VCC=5V, VMM=40V, ta=25°C
6.0
5.0
4.0
3.0
2.0
1.0
0.0
0
200
400
600
800
1000
1200
IM[mA]
[CAUTION]
The specifications on this databook are only
given for information , without any guarantee
as regards either mistakes or omissions. The
application circuits in this databook are
described only to show representative usages
of the product and not intended for the
guarantee or permission of any right including
the industrial rights.
- 12 -
相关型号：
©2020 ICPDF网 联系我们和版权申明