Datasheet

MAX9742
Single-/Dual-Supply, Stereo 16W,
Class D Amplifier with Differential Inputs
12 ______________________________________________________________________________________12 ______________________________________________________________________________________
Pin Description
PIN NAME FUNCTION
1, 6, 18,
27, 28, 36
N.C. No Connection. Not internally connected.
2, 3 OUTL Left Speaker Output
4 SUB Device Substrate. Connect SUB to V
SS
.
5 BOOTL Left-Channel Bootstrap Capacitor Terminal. Connect a 0.1µF capacitor between BOOTL and OUTL.
7 INL+ Left-Channel Positive Input
8 INL-
Left-Channel Negative Input. Connect an external feedback capacitor between INL- and FBL. See the
Feedback Capacitor (C
FB_
) section.
9 FBL
Left-Channel Feedback Capacitor Terminal. Connect an external feedback capacitor between FBL and
INL-. See the Feedback Capacitor (C
FB_
) section.
10 REGM
-5V Internal Regulator Output. Regulator output voltage is with respect to MID. Bypass REGM with a 1µF
capacitor to signal ground plane (SGND). See the Supply Bypassing/Layout section.
11 MID
Midsupply Bias Voltage Input. The MID input biases the internal preamplifiers to the average value of the
V
DD
and V
SS
supply inputs. For dual-supply operation, connect to the signal ground plane (SGND). For
single-supply operation, apply a voltage to MID equal to 0.5 x V
DD
through an external resistive voltage-
divider and decoupling network (see the Setting V
MID
section). See the Typical Application
Circuits/Functional Diagrams and Supply Bypassing/Layout sections.
12 REGP
5V Internal Regulator Output. Regulator output voltage is with respect to MID. Bypass REGP with a 1µF
capacitor to the signal ground plane (SGND). See the Supply Bypassing/Layout section.
13 REFCUR
Reference Current Resistor Terminal. Connect an external resistor from REFCUR to REGP to set the
switching frequency and output short-circuit current-limit value. Use resistor values greater than or equal
to 58kΩ and less than or equal to 75kΩ. See the Setting the Switching Frequency and Output Current
Limit (R
REF
) section.
14 SFT
Soft-Start Capacitor Terminal/Mute Input. Connect a 0.22µF capacitor between SFT and PGND to utilize
the soft-start power-up sequence. Drive SFT low to mute the outputs.
15 LGND
Logic Ground. Connect LGND to signal ground (SGND) and power ground (PGND) planes. See the
Supply Bypassing/Layout section.
16 LV
DD
Internal 5V Logic Supply. Bypass LV
DD
to LGND with a 0.1µF capacitor.
17 SHDN
Active-Low Shutdown Input. Drive SHDN high for normal operation. Drive SHDN low to place the device
into shutdown mode.
19 FBR
Right-Channel Feedback Capacitor Terminal. Connect an external feedback capacitor between FBR and
INR-. See the Feedback Capacitor (C
FB_
) section.
20 INR-
Right-Channel Negative Input. Connect an external feedback capacitor between INR- and FBR. See the
Feedback Capacitor (C
FB_
) section.
21 INR+ Right-Channel Positive Input
22 NSENSE
Negative Supply Sense Input. NSENSE is internally connected to V
SS
. Connect a 1µF bypass capacitor
between NSENSE and REGLS.
23 REGLS
7V Internal Regulator Output. REGLS output voltage is with respect to V
SS
. Bypass REGLS with a 1µF
capacitor to NSENSE.