GPCH4256B

© Generalplus Technology Inc.

Proprietary & Confidential

16

JAN. 19, 2009

Version: 1.0

8.3. Current Mode DAC Speaker Driver

VDD

RB1

8050

32

Ω ~ 64 Ω

RB1: 10K ~ 50K

RB2: 820 ~ 1.5K

C1: 0.1

μ F ~ 1μ F

RB2

DACOL

VDD

C1

RB1

8050

4

Ω ~ 8 Ω

C1: 0.1

μ F ~ 1μ F

RB1: 680 ~ 1.5K

DACOL

VDD

C1

RB1

8050

4

Ω ~64 Ω

DACOL

C2

VDD

C1

RB1

8050

4

Ω ~8 Ω

DACOL

C2

Enable

RB2

RB2

RB1: 2K~10K C1: 1

μ F~10 μ F

RB2: ~ 1K

VDD

RB1

8050

4

Ω ~64 Ω

RB1: ~ 360

Ω (Vol)

RE1: ~ 4.7

Ω

DACOL

RE1

1N4148

Figure 5

Figure 2

Figure 3

Figure 4

Figure 1

C1

RB1: 2K~10K C1: 1

μ F~10 μ F

RB2: ~ 1K

C2: ~ 0.1

μ F

C2: ~ 0.1

μ F

Figure 1

: The simplest CKT uses with low impedance speaker. It has high operation current, but the cost is the cheapest.

Figure 2

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

Figure 3

: The CKT has low pass filter. It can provide higher speech quality, but it always takes high operation current.

Figure 4

: Improved version of Figure 3. The standby current can be controlled by 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.