NJM3772FM2-TE3 NJR, NJM3772FM2-TE3 Datasheet - Page 8

• Manufacturer Part Number: NJM3772FM2-TE3
• Description: Motor / Motion / Ignition Controllers & Drivers Dual Stepper Motor Driver
• Manufacturer: NJR
• Type: Stepper Motor Controller/Driverr

Specifications of NJM3772FM2-TE3

• Product: Stepper Motor Controllers / Drivers
• Operating Supply Voltage: 10 V to 45 V
• Supply Current: 60 mA to 75 mA
• Mounting Style: SMD/SMT
• Package / Case: PLCC-28
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Motor selection
The NJM3772 is designed for two-phase bipolar stepper motors, i.e., motors that have only one winding per
phase.
imposes certain restrictions on motor selection. Unstable chopping can occur if the chopping duty cycle exceeds
approximately 50%. See figure 5 for definitions. To avoid this, it is necessary to choose a motor with a low winding
resistance and inductance, i.e. windings with a few turns.
needs to be considered. Typical motors to be used together with the NJM3772 have a voltage rating of 1 to 6 V,
while the supply voltage usually ranges from 12 to 40 V.
give the same torque capability at low speed, a reduced number of turns in the winding must be compensated by a
higher current. A compromise has to be made.
supply voltage as possible, without exceeding the maximum recommended 40 V. Check that the chopping duty
cycle does not exceed 50% at maximum current.
Phase inputs.
the opposite direction. A time delay prevents cross conduction in the H-bridge when changing the Phase input.
Heat sinking.
Soldering the batwing ground leads onto a copper ground plane of 20 cm
ness 35 m, permits the circuit to operate with 750 mA output current, both channels driving, at ambient tempera-
tures up to 70 C. Consult figures 8, 9, 10 and 11 in order to determine the necessary copper ground plane area for
heat sinking at higher current levels.
Thermal shutdown.
The circuit is equipped with a thermal shutdown function that turns the output off at chip temperatures above
160 C. Normal operation is resumed when the temperature has decreased.
Operating temperature.
The max recommended operating temperature is 125 C. This gives an estimated lifelength of about 5 years at
continuous drive, A change of 10 would increase/decrease the lifelength of the circuit about 5 years.
A logic HIGH on a Phase input gives a current flowing from pin M
The chopping principle of the NJM3772 is based on a constant frequency and a varying duty cycle. This scheme
It is not possible to use a motor that is rated for the same voltage as the actual supply voltage. Only rated current
Low inductance, especially in combination with a high supply voltage, enables high stepping rates. However, to
Choose a motor with the lowest possible winding resistance that still gives the required torque, and use as high
Figure 8. Typical thermal resistance vs. PC Board copper area and suggested layout
80
70
60
50
40
30
20
Thermal resistance [ C/W]
PLCC package
DIP package
5
PCB copper foil area [cm ]
10
15
20
25
2
30
35
A
into pin M
28-pin PLCC
22-pin
2
DIP
(approx. 1.8" x 1.8"), copper foil thick-
B
. A logic LOW gives a current flow in
NJM3772