Datasheet

IN-

IN+

OUTA

OUTB

1 PF

LM48310

SINGLE-ENDED

AUDIO INPUT

LM48310

SNAS430D –NOVEMBER 2007–REVISED MAY 2013

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Figure 32. Single-Ended Input Configuration

PCB LAYOUT GUIDELINES

As output power increases, interconnect resistance (PCB traces and wires) between the amplifier, load and

power supply create a voltage drop. The voltage loss due to the traces between the LM48310 and the load

results in lower output power and decreased efficiency. Higher trace resistance between the supply and the

LM48310 has the same effect as a poorly regulated supply, increasing ripple on the supply line, and reducing

peak output power. The effects of residual trace resistance increases as output current increases due to higher

output power, decreased load impedance or both. To maintain the highest output voltage swing and

corresponding peak output power, the PCB traces that connect the output pins to the load and the supply pins to

the power supply should be as wide as possible to minimize trace resistance.

The use of power and ground planes will give the best THD+N performance. In addition to reducing trace

resistance, the use of power planes creates parasitic capacitors that help to filter the power supply line.

The inductive nature of the transducer load can also result in overshoot on one of both edges, clamped by the

parasitic diodes to GND and V

in each case. From an EMI standpoint, this is an aggressive waveform that can

radiate or conduct to other components in the system and cause interference. In is essential to keep the power

and output traces short and well shielded if possible. Use of ground planes beads and micros-strip layout

techniques are all useful in preventing unwanted interference.

As the distance from the LM48310 and the speaker increases, the amount of EMI radiation increases due to the

output wires or traces acting as antennas become more efficient with length. Ferrite chip inductors places close

to the LM48310 outputs may be needed to reduce EMI radiation.

Designator Quantity Description

C1 1 10μF ±10% 16V 500Ω Tantalum Capacitor (B Case) AVX

TPSB106K016R0500

C2, C3 2 1μF ±10% 16V X7R Ceramic Capacitor (603) Panasonic

ECJ-1VB1C105K

C4, C5 2 1μF ±10% 16V X7R Ceramic Capacitor (1206) Panasonic

ECJ-3YB1C105K

C6 1 Not Installed Ceramic Capacitor (603)

R1 1 0Ω ±1% resistor (603)

JP1 — JP2 2 3 Pin Headers

LM48310SDL 1 LM48310SD (10-pin WSON)

Product Folder Links: LM48310