Integrated Circuits Inc.

aP89021/010

Ver 2.2

May 31, 2007

17

CPU Parallel Mode

Fig. 14 5V CPU Control with COUT

Note:

1. C1 is capacitor from 0.1uF to 4.7uF depends on the kind of Vdd source and sound loudness.

2. Rb is base resistor from 120 Ohm to 390 Ohm depends on Vdd value and transistor gain.

3. T is an NPN transistor with beta larger than 150.

4. Reference value for the above components are C = 2.2uF, Rb = 390 Ohm and T = 8050D.

5. Refer to the Oscillator Resistor Table for suitable value of Rosc.

VDD,VPP

VSS

RST

S4

OUT[1..3]

OSC

0.1uF

C1

T

COUT

8Ω 1/4W

Speaker

HT7335

S1

S2

S3

VOUT=+3.5V

Addr[0]

Addr[1]

Addr[2]

Addr[3]

I[0..2]

VIN=+5V

Rin = 860KΩ x (VIN-VOUT) / VIN

Rin

3

Rb