Integrated Circuits Inc.
VIN=+5V
aIVR341N
VOUT=+3.5V
Rp=1ohm
C1, 0.1uF
8 1/4W
Speaker
HT7335
C2, 0.1uF
VDD
4.7K
R
OSC
220K
VDDA
OSC
PB0
PB1
PB2
PB3
RSTB
0.1uF
Addr[0]
Addr[1]
Addr[2]
IO0
Note for COUT speaker drive:
1. C1 and C2 must be connected as close to the VDD/VDDA and VSS/VSSA pins as possible.
2. Rb is base resistor from 120 Ohm to 390 Ohm depends on value of VDD and transistor gain.
3. Tr is an NPN transistor with beta larger than 150, e.g. 8050D.
4. Rosc = 220K Ohm with Vdd=3.0V can support sampling rate up to 14KHz.
MCU
VOUT2_
COUT
Rb
Tr
VSS, VSSA
Note :
PB0 to PB2 set to internal pull-up
Addr[0] to [2] are open drain output drive
5V CPU Control with COUT
8
SEP 15, 2011
APLUS [ APLUS INTERGRATED CIRCUITS ]
