M54679FP Renesas Electronics Corporation., M54679FP Datasheet - Page 6

• Manufacturer Part Number: M54679FP
• Description: 2-phase Stepper Motor Driver
• Manufacturer: Renesas Electronics Corporation.

M54679FP
Function Explanation
1. Ph inputs make a decision the output function.
Ph*A
L
H
L
H
* : 1 or 2
2. Output current and terminal of output current setting.
I0
L
H
L
H
3. Equivalent circuit of Vref terminal.
The equivalent circuit of Vref terminal is shown in right circuit.
As Vref terminal needs typical 500 A input current, consider this value when Vref voltage is set.
4. Current sensing comparators.
The current sensing comparators compare the voltage (VRs) of current sensing resistor and threshold voltage (V
this comparators, then if VRs > V
Rev.1.0, Sep.19.2003, page 6 of 12
The outputs shut off under Ph*A and Ph*B High condition at the same time.
I1
L
L
H
H
Ph*B
L
L
H
H
CH
, the comparators output change and shut off the output.
Output current ratio
100%
70%
30%
0%
18k
2k
Vref
3.5k
Out*A
OFF
H
L
OFF
0.68k
Current sensing comparators
threshold voltage (Vref=5V)
500mV
350mV
155mV
I1
I0
Out*B
OFF
L
H
OFF
CH
) of