st2064b Sitronix Technology Corporation, st2064b Datasheet - Page 34

• Manufacturer Part Number: st2064b
• Description: 8 Bit Microcontroller With 64k Bytes Rom
• Manufacturer: Sitronix Technology Corporation

PSG0
PSG1
14.3.3 Two-Pin Push Pull Mode (8-bit Accuracy)
Two-Pin Push Pull mode is designed for buzzer. It requires
two pin that PSGO and PSGOB. When the DAC value is 0,
both pins are low. When the DAC value is positive, PSGO
goes high with a duty cycle proportional to the output
value, while PSGOB stays low. When the DAC value is
negative, PSGOB goes high with a duty cycle proportional
to the output value, while PSGO stays low. This mode
offers a resolution of 8 bits.
Ver. 3.0
PSGOB
PSGOB
PSGO
PSGO
High
High
High
High
Low
Low
Low
Low
Where X=0 to -128
Where X=0 to 127
|X|
X
DAC = X
DAC = X
FIGURE 14-8 Two-Pin Push Pull Mode Application Circuit
128+X
128-X
FIGURE 14-7 Two-Pin Push Pull Mode Wave Form
ST2064B
PSGOB
PSGO
32
DAC = -48
48
DAC = 32
96
80
34/57
Figure 13-7 shows examples of DAC output waveforms with
different output values. Each pulse of the DAC is divided
into 128 segments per sample period. For a positive output
value x=0 to 127, PSGO goes high for X segments while
PSGOB stays low. For a negative output value x=0 to -127,
PSGOB goes high for |X| segments while PSGO stays low.
DAC = 96
DAC = 0
96
Buzzer
32
DAC = 127
DAC = -128
127
1
ST2064B
5/8/09