DA7202

10 W Mono Class-D Amplifier for 2S Battery Devices

Company confidential

Datasheet

Revision 3a

20-Aug-2015

CFR0011-120-00 Rev 5

10 of 25

© 2015 Dialog Semiconductor

8

Functional description

The DA7202 is a powerful, high efficiency, low EMI Class-D speaker driver that can drive a maximum

of 10 W into 4 Ω loads directly from a 2S lithium ion battery pack.

The device provides audio noise and RF noise suppression. It also has short circuit protection, as

well as protection against over-heating.

The DA7202 is available in a 9-bump WL-CSP package with 0.5 mm pitch that enables low cost PCB

technology which is ideal for portable applications that require small footprints.

8.1

Pop and click suppression

DA7202 includes noise suppression circuitry that reduces audible pops and clicks at the speaker

output when enabling or disabling the device.

8.2

Short circuit/over-current protection

The DA7202 is protected by a short circuit/over current detector. If a short circuit is detected,

regardless of the frequency of the signal, the device is disabled immediately. After 8 ms, the

short-circuit status is checked. If the short condition has been resolved, the chip will be re-enabled. If

the short condition still persists, the DA7202 remains disabled. The short-circuit status is checked

every 8 ms until the short condition has been resolved. The chip will then be re-enabled.

Note that the disabling of the chip, and its later re-enabling, are both performed without using the

noise suppression circuitry. Audible artefacts may be present in the output signal.

Note also that whenever the DA7202 has been powered down, the power stage is placed in a high

impedance (high-Z) state to minimise power consumption.

8.3

Thermal performance and thermal protection

8.3.1

Thermal shutdown

DA7202 is provided with a thermal protection feature that automatically disables the power stage and

the LDO if the junction temperature reaches 150°C.

When a thermal shutdown is performed, the chip is disabled, leaving only the temperature sensor

block active. The process of disabling the chip is performed using the noise suppression circuitry, so

no audible artefacts will be present on the output signal during the disabling process. The time taken

for a noise free shutdown is illustrated in Figure 16.

If thermal shutdown is activated, the chip is not re-enabled until the temperature has dropped to

100°C. Once the temperature has reached 100°C, the DA7202 restarts with an automatic soft start.

The process of re enabling the chip is performed using the noise suppression circuitry, so no audible

artefacts will be present on the output signal during start-up process. The time taken for a noise free

start-up is illustrated in Figure 15.

Note that whenever the DA7202 has been powered down, the power stage is placed in a high

impedance (high-Z) state to minimise power consumption.

8.3.2

Maximum power dissipation

Given the Junction-to-Ambient thermal impedance (72°C/W), the Power Dissipation versus Output

equation:

Up to an ambient temperature of 85°C, DA7202 can dissipate 0.56 W of heat before reaching 125°C.

Note that if the DA7202 is operated continuously at, or close to, its maximum output power, there is a

risk of overheating and thermal shutdown unless steps are taken to dissipate this excess heat.