NJM3773D2 NJR, NJM3773D2 Datasheet - Page 3

• Manufacturer Part Number: NJM3773D2
• Description: IC STEPPER MOTOR DVR DUAL 22-DIP
• Manufacturer: NJR
• Type: Stepper Motor Controller/Driverr

Specifications of NJM3773D2

• Applications: Stepper Motor Driver, 2 Phase
• Number Of Outputs: 1
• Current - Output: 750mA
• Voltage - Load: 10 V ~ 40 V
• Voltage - Supply: 4.75 V ~ 5.25 V
• Operating Temperature: -20°C ~ 125°C
• Mounting Type: Through Hole
• Package / Case: 22-DIP (0.400", 10.16mm)
• Product: Stepper Motor Controllers / Drivers
• Operating Supply Voltage: 7 V
• Supply Current: 70 mA
• Mounting Style: Through Hole
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Each channel of the NJM3773 consists of the following sections: an output H-bridge with four transistors and four
recirculation diodes, capable of driving up to 750 mA continuous current to the motor winding, a logic section that
controls the output transistors, an S-R flip-flop, and a comparator. The clock-oscillator is common to both channels.
peak current through the winding via a current-sensing resistor R
winding. As the current increases, a voltage develops across the sensing resistor, which is fed back to the com-
parator. At the predetermined level, defined by the voltage at the reference input V
flop, which turns off the upper output transistor. The turn-off function of the two channels works independently of
each other. The current decreases until the clock oscillator triggers the flip-flops of both channels simultaneously,
which turns on the output transistors again, and the cycle is repeated.
NJM3773 includes a digital filter. The clock oscillator provides a blanking pulse which is used for digital filtering of
the voltage transient across the current sensing resistor during turn-on.
Constant current control is achieved by switching the output current to the windings. This is done by sensing the
To prevent erroneous switching due to switching transients at turn-on, the
The current paths during constant current switching and phase shift are shown in figure 3.
FUNCTIONAL DESCRIPTION
Figure 3. Output stage with current paths
during turn-on, turn-off and phase shift.
Motor Current
3
1
Fast Current Decay
Slow Current Decay
1
2
2
V
R
MM
S
S
, effectively connected in series with the motor
3
Time
R
, the comparator resets the flip-
NJM3773