SM6453AB_02 Datasheet, PDF (15/19 Pages) Nippon Precision Circuits Inc – 3-wire Serial Data Volume Control for Headphone Amplifier IC

SM6453AB
Power-down Function (PDN)
The power-down function is selected when PDN goes LOW. This reduces the power consumption, while
LOUT and ROUT become high impedance. A pull-down resistor connected to PDN is recommended.
Mute Function
Mute function (MUTEN)
The mute function is selected when MUTEN goes LOW. At initial startup, it is recommended that a delay of
2.5 seconds (typ) occur before MUTEN goes HIGH to prevent pop-noise output on LOUT and ROUT that can
occur when muting is released and after power-down is released (see mute release timing in figures 4 and 5).
Note that when muting using the MUTEN pin, outputs LOUT and ROUT do not become high impedance. A
pull-down resistor connected to MUTEN is recommended.
RSTN
Reset
PDN
MUTEN
MDT
LOUT/ROUT High Impedance
Current consumption Power Down
MUTE
2.5 [sec]
Medium Impedance
MUTE ON
High Impedance
(Power ON)
MUTE OFF
Low Impedance
MUTE OFF
Figure 4. Initial startup recommended mute release timing example 1
RSTN
Reset
PDN
MUTEN
MDT
LOUT/ROUT High Impedance
Current consumption Power Down
MUTE
2.5 [sec]
MUTE OFF
Medium Impedance
Low Impedance
(Power ON)
MUTE ON
MUTE OFF
Figure 5. Initial startup recommended mute release timing example 2
Mute function (Microcontroller Data)
Mute is ON when Microcontroller Data D0 to D7 = LOW. Output impedance is HIGH when Microcontroller
Data D0 to D7 = LOW, Mute function.
Beep Signal Input/Output (BEEPI, BEEPLO, BEEPRO)
The beep signal is a constant-current output signal on BEEPLO and BEEPRO in response to an input signal on
BBEPI. The beep signal input/output circuit should be used when MUTEN is HIGH, when muting using the
attenuation data bits D0 to D7, and during power-down.
NIPPON PRECISION CIRCUITS INC.—15