Technical information

STA518

12/21

DocID010708 Rev 6

4

Technical information

The STA518 is a high-efficiency dual-channel H-Bridge that is able to deliver 50 W per

channel (@ THD = 10% RL = 8 , VCC = 29 V) of audio output power.

The STA518 converts both DDX and binary-controlled PWM signals into audio power at the

load. It includes a logic interface, integrated bridge drivers, high-efficiency MOSFET outputs

and thermal and short-circuit protection circuitry.

In DDX mode, two logic level signals per channel are used to control high-speed MOSFET

switches to connect the speaker load to the input supply or to ground in a bridge

configuration, according to the damped ternary modulation operation.

In binary mode operation, both full-bridge and half-bridge modes are supported. The

STA518 includes overcurrent and thermal protection as well as an undervoltage lockout with

automatic recovery. A thermal warning status is also provided.

Figure 6. STA518 block diagram full-bridge DDX® or binary modes

Figure 7. STA518 block diagram binary half-bridge mode

4.1

Logic interface and decode

The STA518 power outputs are controlled using one or two logic level timing signals. In

order to provide a proper logic interface, the Vbias input must operate at the same voltage as

the DDX control logic supply.

Protection circuitry:

The STA518 includes protection circuitry for overcurrent and thermal overload conditions. A

thermal warning pin (pin 28) is activated low (open-drain MOSFET) when the IC

Logic I/F

and Decode

Left

H-Bridge

Protection

Circuitry

INL 1:2

INR 1:2

PWRDN

OUTPL

FAULT

VL

TRI-STATE

OUTNL

OUTPR

OUTNR

TWARN

Regulators

Right

H-Bridge

Logic I/F

and Decode

LeftA

-Bridge

Protection

Circuitry

INL 1:2

INR 1:2

PWRDN

OUTPL

FAULT

VL

TRI-STATE

OUTNL

OUTPR

OUTNR

TWARN

Regulators

RightA

-Bridge

LeftB

-Bridge

RightB

-Bridge