LM49153TMEVAL National Semiconductor, LM49153TMEVAL Datasheet - Page 20

• Manufacturer Part Number: LM49153TMEVAL
• Description: EVAL BOARD LM49153
• Manufacturer: National Semiconductor
• Series: Boomer®r

Specifications of LM49153TMEVAL

• Amplifier Type: Class D
• Output Type: 1-Channel (Mono) with Stereo Headphones
• Max Output Power X Channels @ Load: 145mW x 2 @ 16 Ohm
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Board Type: Fully Populated
• Utilized Ic / Part: LM49153
• Lead Free Status / Rohs Status: Lead free by exemption / RoHS compliant by exemption

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ALC HEADROOM
When either voltage limiter or no clip is enabled, it is still pos-
sible to drive LM49153 into clipping by overdriving the input
volume stage of the signal path beyond its output dynamic
range. In this case, clipping occurs at the input volume stage,
and although ALC is active, the gain reduction will have no
effect on the output clipping. The maximum input that can
safely pass through the input volume stage can be calculated
by following formula:
FIGURE 7. Voltage Limiter Function
FIGURE 6. Clip Control Levels
V
f
DD
IN
= 1kHz, LS_GAIN = 0
= 3.3V, R
(1)
20
L
= 8Ω+30μH
So in the case of 0 dB volume gain, audio input has to be less
than V
When voltage limiter is enabled, ALC can reach its max at-
tenuation for lower voltage limit levels as shown in the Figure
8. Typically, after the ALC started working, with 6dB of audio
input change ALC is well within its regulation. Voltage limiter
Input headroom can be increased by switching to the
LS_GAIN to 18dB in the Gain Control Register (see
8).
DD
for both voltage limiter or No clip settings.
30121078
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