非接触式数字音量控制电路图(digital volume control circuit)
DS1669是maxim公司生产的非易失性数字电位器DS1669（50kΩ）构成的轻触式按钮调节电位器,DS1669主要由64位等步距抽头可变电阻、641多路选择器、控制电路和EEPROM等组成，工作电压为4.5～8V，使用比较灵活。下图是一采用MAX芯片DS1669的数字音量控制器电路图，按S1，S2分别是音量调大，调小按钮。电源采用正负电源效果会更好。
This digital volume control has no pot to wear out and introduces almost no noise in the circuit. Instead, the volume is controlled by pressing UP and DOWN buttons. This simple circuit would be a great touch to any home audio project.
Schematic
器件清单
Part
Total Qty.
Description
C1
1
0.1uf Ceramic Disc Capacitor
U1
1
DS1669 Digital Pot IC (See Notes)
S1, S2
2
Momentary Push Button Switch
MISC
1
Board, Wire, Socket For U1
Notes:
1. U1 is available from Dallas Semiconductor.
2. S1 turns the volume up, S2 turns it down.
3. The input signal should not fall below -0.2 volts.
4. Using a dual polariity power supply (+-5V works fine) will cure most clipping problems. You will have to check the data sheet for the correct pins to connect your voltages. 