Datasheet

DS4420
I
2
C Programmable-Gain Amplifier
for Audio Applications
_____________________________________________________________________ 7
Slave Address Byte and Address Pins
The slave address byte consists of a 7-bit slave
address plus a R/W bit (see Figure 2). The DS4420’s
slave address is determined by the state of the A0, A1,
and A2 address pins. These pins allow up to eight
DS4420s to reside on the same I
2
C bus. Address pins
connected to GND result in a ‘0’ in the corresponding
bit position in the slave address. Conversely, address
pins connected to V
CC
result in a ‘1’ in the correspond-
ing bit positions. For example, the DS4420’s slave
address byte is A0h when A0, A1, and A2 pins are
grounded. I
2
C communication is described in detail in
the
I
2
C Serial Interface Description section.
Figure 1. Control Register Description
Control Register (F8h)
Power-Up Default: 1000 0000 b
F8h Standby x Mute Gain Setting[4:0]
bit 7 bit 4 bit 3 bit 2 bit 1 bit 0
bit 7
Standby: Places the DS4420 in standby mode.
0 = Normal operation.
1 = Places the DS4420 in standby mode. (Power-up default.)
bit 6 Don’t care.
bit 5
Mute: Mutes the amplifier output, regardless of the current gain setting.
0 = Normal operation. (Power-up default.)
1 = Mutes the amplifier output.
bit 4:0 Gain Setting: Five-bit gain setting. The power-up default is setting 00h.
GAIN
SETTING
(hex)
GAIN
(dB)
GAIN
SETTING
(hex)
GAIN
(dB)
00h -35 0Bh -2
01h -32 0Ch +1
02h -29 0Dh +4
03h -26 0Eh +7
04h -23 0Fh +10
05h -20 10h +13
06h -17 11h +16
07h -14 12h +19
08h -11 13h +22
09h -8 14h +25
0Ah -5 15h to 1Fh Illegal
*THE SLAVE ADDRESS IS DETERMINED BY ADDRESS PINS A0, A1, AND A2.
1
MSB
SLAVE
ADDRESS*
LSB
010
A2
A1 A0
R/W
READ/WRITE
BIT
Figure 2. DS4420 Slave Address Byte