NJM3774FM2# NJR, NJM3774FM2# Datasheet - Page 3

• Manufacturer Part Number: NJM3774FM2#
• Description: IC STEPPER MOTOR DVR DUAL 28PLCC
• Manufacturer: NJR

Specifications of NJM3774FM2#

• Applications: Stepper Motor Driver, 2 Phase
• Number Of Outputs: 1
• Current - Output: 1A
• Voltage - Load: 10 V ~ 40 V
• Voltage - Supply: 4.75 V ~ 5.25 V
• Operating Temperature: -20°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 28-PLCC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: NJM#3774FM2; NJM#3774FM2

Each channel of the NJM3774 consists of the following sections: an output H-bridge with four transistors, capable
of driving up to 1000mA 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 resistor, R
turn-on period. As the current increases, a voltage develops across the resistor, and is fed back to the comparator.
At the predetermined level defined by the voltage at the reference input V
turning off the output transistors. The current decreases until the clock oscillator triggers the flip-flop, turning on the
output transistors, and the cycle is repeated.
diodes are connected to the circuit externally.
Constant current control is achieved by switching the output current to the windings. This is done by sensing the
The current paths during turn-on, turn-off and phase shift are shown in figure 3. Note that the upper recirculation
FUNCTIONAL DESCRIPTION
Figure 3. Output stage with current paths
during turn-on, turn-off and phase shift.
Motor Current
3
External recirculation diodes
Fast Current Decay
Slow Current Decay
1
1
S
, effectively connected in series with the motor winding during the
V
R
2
MM
S
2
3
R
, the comparator resets the flip-flop,
Time
NJM3774