|TAS5704||20-W Stereo Digital Audio Power Amplifier With Feedback|
|TAS5704 Datasheet PDF : 34 Pages |
SLOS563 – MARCH 2008
PROTECTION MECHANISMS IN THE TAS5704
• SCP (short-circuit protection) protects against shorts across the load, to GND, and to PVCC.
• OTP turns off the device if Tjunction (typical) > 150°C.
• UVP turns off the device if PVCC (typical) < 8.4 V
• OVP turns off the device if PVCC (typical) > 27.5 V
A short-circuit condition can be detected also by an external controller. The VALID pin goes low in the event of a
short circuit. The VALID pin can be monitored by an external µC. The TAS5704 initiates a back-end error
sequence by itself to recover from the error, which involves settling VALID low for 300 ms and then retrying to
check whether the short-circuit condition still exists.
RECOVERY FROM ERROR
• OTP turns on the device back when Tdie(typical) < 135°C.
• UVP turns on the device if PVCC (typical) is > 8.5 V.
• OVP turns on the device if PVCC (typical) is < 27.2 V.
• SCP (short-circuit protection) turns on the device if the short-circuit is removed. See the Back-End Error
section for the sequence.
SINGLE-ENDED OUTPUT CAPACITOR, CO
In single-ended (SE) applications, the dc blocking capacitor forms a high-pass filter with the speaker impedance.
The frequency response rolls of with decreasing frequency at a rate of 20 dB/decade. The cutoff frequency is
fc = 1/2πCOZL
Table 4 shows some common component values and the associated cutoff frequencies:
SPEAKER IMPEDANCE (Ω)
Table 4. Common Filter Responses
fc = 60 Hz (–3 dB)
CSE – DC BLOCKING CAPACITOR (µF)
fc = 40 Hz (–3 dB)
fc = 20 Hz (–3 dB)
OUTPUT FILTER AND FREQUENCY RESPONSE
For the best frequency response, a flat-passband output filter (second-order Butterworth) may be used. The
output filter components consist of the series inductor and capacitor to ground at the output pins. There are
several possible configurations, depending on the speaker impedance and whether the output configuration is
single-ended (SE) or bridge-tied load (BTL). Table 5 lists the recommended values for the filter components. It is
important to use a high-quality capacitor in this application. A rating of at least X7R is required.
Single Ended (SE)
Bridge Tied Load (BTL)
Table 5. Recommended Filter Output Components
SPEAKER IMPEDANCE (Ω)
FILTER INDUCTOR (µH)
FILTER CAPACITOR (nF)
Copyright © 2008, Texas Instruments Incorporated
Product Folder Link(s): TAS5704
Submit Documentation Feedback
|Direct download click here|
|Share Link :|
|All Rights Reserved © datasheetbank.com 2014 - 2019 [ 개인정보 보호정책 ] [ 요청 데이타시트 ][ 제휴문의 ]|