Integrated Circuits Inc.
aIVR Series
VIN=+5V
VOUT=+3.5V
HT7335
C1
R
OSC
=610K
470K
8Ω 1/4W
Speaker
VDD,VDDA
OSC
PB0
PB1
PB2
PB3
RST
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
MCU
VOUT2_
COUT
Rb
Tr
0.1uF
VSS
Note :
PB0 to PB2 set to internal pull-up
Addr[0] to [2] are open drain output drive
5V CPU Control with COUT
7
Nov 06, 2008
APLUS [ APLUS INTERGRATED CIRCUITS ]
