DS4420 Datasheet, PDF (6/10 Pages) Maxim Integrated Products – I2C Programmable-Gain Amplifier for Audio Applications

I²C Programmable-Gain Amplifier
for Audio Applications
Pin Description
PIN
NAME
FUNCTION
1
A2
2
A1
Address Select Inputs—Determine I²C Slave Address. Device address is 1010A₂A₁A₀.
3
A0
4
SCL
I²C Serial Clock—Input for I²C Clock
5
SDA
I²C Serial Data—Input/Output for I²C Data
6
V_CC
Digital Power-Supply Terminal
7
GND
Ground
8
IN+
Differential Audio Input Signal
9
IN-
10
N.C.
No Connection
11
AGND Analog Ground (Must be Connected to GND)
12
OUT-
Differential Audio Output Signal
13
OUT+
14
AV_CC
Analog Power Supply (Must be Connected to V_CC)
EP
EP
Exposed Paddle. Connect to GND and AGND.
Detailed Description
The key features of the DS4420 are illustrated in the
Block Diagram.
Controlling the DS4420
The DS4420 is controlled through the I²C serial inter-
face. Gain, mute, and standby settings all reside in one
control register located at memory address F8h (see
Figure 1). Writes to other memory addresses are invalid.
Programmable Gain
The gain is adjustable from -35dB to +25dB in 3dB
increments. The gain is determined by the five LSBs of
the control register as shown in Figure 1. Gain settings
greater than 14h are invalid.
Mute Mode
The DS4420 is placed in mute mode by setting the mute
bit located in the control register (see Figure 1). When in
this mode, the output of the amplifier is muted and is
independent of the gain setting. The input-to-output
attenuation is specified in the Electrical Characteristics
table as A_MUTE.
Standby Mode
Standby mode is entered by setting the standby control
bit (see Figure 1). Setting the standby control bit mutes
the output of the amplifier and places the DS4420 into a
A0 A1 A2 VCC
Block Diagram
AV_CC
SDA
I²C INTERFACE
SCL
3dB
GAIN
DS4420
STEPS
IN+
-35dB
TO +25dB
IN-
GAIN
OUT+
OUT-
GND
AGND
low-current (I_STBY) consumption state. Unlike mute
mode, however, standby mode is intended for use when
no input signal is present. While in standby mode, the
DS4420 maintains input and output common-mode bias
voltages. The device produces no audible clicks or
pops when entering or exiting the standby state. The
time required for the output to become active when
exiting standby mode is specified as t_PU.
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