Integrated Circuits Inc.
aIVR1004/2104/4208
VIN=+5V
VOUT=+3.5
HT7335
C1
R
OSC
=610K
4.7K
8Ω 1/4W
Speaker
VDD,VDD
OSC
PB0
PB1
PB2
PB3
RSTB
Addr[0
Addr[1
Addr[2
IO0
Note:
1. C1 is capacitor from 0.1uF to 2.2uF depends on the kind of Vdd source and sound loudness.
E.g. If COUT is used, C1 can be 0.1uF. However, if PWM direct drive speaker is used, C1
should be at least 2.2uF
2. Rb is base resistor from 120 Ohm to 390 Ohm depends on Vdd value and transistor gain.
3. Tr is an NPN transistor with beta larger than 150, e.g. 8050D.
4. Rosc = 610K Ohm with Vdd=3.0V and support sampling rate up to 14KHz
5. For sampling rate higher than 14KHz, smaller value of Rosc should be used.
MCU
VOUT2
_
Rb
Tr
0.1uF
VS
Note :
PB0 to PB2 set to internal pull-up
Addr[0] to [2] are open drain output
5V CPU Control with COUT
7
Oct 12, 2009
APLUS [ APLUS INTERGRATED CIRCUITS ]
