UPD784915B Datasheet, PDF (43/86 Pages) NEC – 16-BIT SINGLE-CHIP MICROCONTROLLERS

µPD784915B, 784916B
(2) DPG comparator, DFG amplifier, and DPFG separation circuit
The DPG comparator converts the drum PG (DPG) signal that indicates the phase information of the drum motor
into a logic signal.
The DFG amplifier amplifies the drum FG (DFG) signal that indicates the speed information of the drum motor.
The DPFG separation circuit (ternary separation circuit) separates a drum PFG (DPFG) signal having speed and
phase information into a DFG and DPG signals.
Figure 3-20. Block Diagram of DPG Comparator, DFG Amplifier, and DPFG Separation Circuit
Drum PG signal
Drum FG signal or
drum PFG signal
VREF
AMPM0.0
DPGIN
AMPC.2
DPG
comparator
AMPM0.2
AMPC.2
1
1
0
0
VREF
AMPC.2
AMPM0.0
+
DFGIN
-
AMPM0.2
DFG amplifier
01
AMPC.2
DPFG separation circuit
(ternary separation circuit)
AMPM0.2
AMPM0.2
AMPC.2
1
1
0
0
DPG signal
(to timer unit)
DFG signal
(to timer unit)
43