st2024c Sitronix Technology Corporation, st2024c Datasheet - Page 36

• Manufacturer Part Number: st2024c
• Description: 24k 8-bit Single Chip Microcontroller
• Manufacturer: Sitronix Technology Corporation

14.3.2 Two-Pin Two Ended mode (Accurate to 8 bits)
Two-Pin Two Ended mode is designed for use with a single
transistor amplifier. It requires two pins that PB0 and PB1.
When the DAC value is positive, PB1 goes high with a duty
cycle proportional to the output value, while PB0 stays high.
When the DAC value is negative, PB0 goes low with a duty
cycle proportional to the output value, while PB1 stays low.
This mode offers a resolution of 8 bits.
Ver 2.2
PB0
PB0
PB1
PB1
High
High
High
High
Low
Low
Low
Low
Where X=0 to -128
Where X=0 to 127
FIGURE 14-19: Two-Pin Two Ended mode Application Circuit
FIGURE 14-18:
|X|
DAC = X
DAC = X
X
128+X
128-X
ST2024C
PSGOB
PSGO
Two-Pin Two Ended PWM DAC Wave-form
32
2.8K
2.5K
DAC = -48
DAC = 32
48
96
36/54
80
vdd
Figure 13-17 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, PB1 goes high for X segments while PB0
stays high. For a negative output value x=0 to -127, PB0
goes low for |X| segments while PB1 stays low.
8050
SPK
DAC = 96
DAC = 0
96
4.7uf
32
DAC = 127
DAC = -128
127
ST2024C
1
1/31/08