TDF8599 NXP Semiconductors, TDF8599 Datasheet - Page 21

• Manufacturer Part Number: TDF8599
• Description: I2C-bus controlled dual channel 43 W/2 W single channel 85 W/1 W class-D power amplifier
• Manufacturer: NXP Semiconductors

www.DataSheet4U.com
NXP Semiconductors
TDF8599_1
Product data sheet
8.6.2.3 AC load detection
8.6.2.4 CLIP detection
AC load detection is only available in I
The default setting for bit IB3[D4] = 0 which disables AC load detection. When AC load
detection is enabled (bit IB3[D4] = 1), the amplifier load current is measured and
compared with a reference level. Pin CLIP is activated when this threshold is reached.
Using this information, AC load detection can be performed using a predetermined input
signal frequency and level. The frequency and signal level should be chosen so that the
load current exceeds the programmed current threshold when the AC coupled load
(tweeter) is present.
CLIP detection gives instantaneous information for clip levels
the output for the clip detection circuitry on both channel 1 and channel 2. Setting either
bit IB1[D5] or bit IB2[D5] defines which channel reports clip information on the CLIP pin.
Fig 20. Recommended start-up sequence with DC load detection enabled
DB1[D4] = 1
DB2[D4] = 1
DB1[D6] = 1
IB1[D0] = 1
IB2[D2] = 1
IB1[D1] = 1
IB2[D1] = 1
IB1[D0] = 1
IB2[D2] = 0
IB1[D1] = 0
IB2[D1] = 0
COUNT = COUNT + 1
WAIT DC load
DC load valid
DB1[D6] = 1
COUNT = 0
I
I
I
2
2
2
C-bus RX
C-bus TX
C-bus TX
startup
enable DC load
disable channel 1
disable channel 2
startup
disable DC load
enable channel 1
enable channel 2
YES
Rev. 01 — 13 November 2008
ch1 openload
ch2 openload
DC load valid
NO
IB1[D0] = 1
IB2[D2] = 1
IB1[D1] = 1
IB2[D1] = 1
IB1[D0] = 1
IB2[D2] = 0
IB1[D1] = 1
IB2[D1] = 1
2
C-bus mode and is controlled using bit IB3[D4].
Class-D power amplifier with load diagnostics
COUNT
I
I
2
2
C-bus TX
C-bus TX
COUNTMAX
startup
enable DC load
disable channel 1
disable channel 2
startup
disable DC load
disable channel 1
disable channel 2
NO
YES
1 %. Pin CLIP is used as
ERROR HANDLING
TDF8599
© NXP B.V. 2008. All rights reserved.
restart
DC load
start amplifier
anyway
001aaj061
21 of 52