SPC08A

8.2. Current Mode DAC Speaker Driver

VDD

RB1

8050

RB1: 10K ~ 50K

RB2: 820 ~ 1.5K

C1: 0.1

µ F ~ 1µ F

RB2

AUD

VDD

C1

RB1

8050

AUD

VDD

C1

RB1

8050

AUD

C2

VDD

C1

RB1

8050

AUD

C2

Enable

RB2

RB2

VDD

RB1

8050

AUD

RE1

1N4148

Power

LM386

AUDP

RB1

20K

10

0.01

µ F

Figure 6

Figure 5

Figure 2

Figure 3

Figure 4

Figure 1

6

5

7

4

3

2

C1

C1: 0.1

µ F ~ 1µ F

RB1: 680 ~ 1.5K

32

Ω ~ 64Ω

4Ω ~ 8Ω

RB1: 2K~10K; C1: 1

µ F~10µ F

RB2: ~1K;

C2: ~0.1

µ F

4Ω ~ 64Ω

4Ω ~ 64Ω

RB1: 2K~10K; C1: 1

µ F~10µ F

RB2: ~1K;

C2: ~0.1

µ F

4Ω ~ 8Ω

0.1

µ F

220

µ F

RB1: ~ 360

Ω (Vol)

RB2: ~ 4.7

Ω

Figure 1: The simplest CKT uses a low impedance speaker. It has high operation current, but has lowest cost.

Figure 2: It is the same as Figure 1 but a high impedance speaker is used.

Figure 3: The CKT contains a low pass filter. It is capable of providing higher speech quality, but it takes higher operation current.

Figure 4: Improved version of Figure 3. The standby current can be controlled by the enable pin.

Figure 5: The current mirror mode. It is able to control the volume. In addition, it has more stable and lower operation current than Figure 1-3.

Figure 6: High quality, low operation current CKT, but more expensive.

© Sunplus Technology Co., Ltd.

Proprietary & Confidential

11

SEP. 19, 2001

Version: 1.7