Hitachi 17LD4220, Service Manual

Page: 17 / 51

13
17” TFT TV Service Manual 21/09/2004
11.9. TPA3003D2
11.9.1. General Description
The TPA3003D2 is a 3-W (per channel) efficient, Class-D audio amplifier for driving bridged-tied stereo
speakers. The TPA3003D2 can drive stereo speakers as low as 8
Ω
. The high efficiency of the TPA3003D2
eliminates the need for external heatsinks when playing music. Stereo speaker volume is controlled with a dc
voltage applied to the volume control terminal offering a range of gain from –40 dB to 36 dB.
11.9.2. Features
•
3-W/Ch Into an 8-
Ω
Load From 12-V Supply
• Efficient, Class-D Operation Eliminates Heatsinks and Reduces Power Supply Requirements
• 32-Step DC Volume Control From
−
40 dB to 36 dB
•
Third Generation Modulation Techniques
−
Replaces Large LC Filter With Small Low-Cost Ferrite Bead Filter
•
Thermal and Short-Circuit Protection
11.9.3. Pinning
TERMINAL
NAME NO.
I/O DESCRIPTION
AGND 9, 10, 26
−
Analog ground for digital/analog cells in core
AVCC 33
−
High-voltage analog power supply (8.5 V to 14 V)
AVDD 29
O 5-V Regulated output
AV
DD
REF 7
O 5-V Reference output—provided for connection to adjacent VREF terminal.
BSLN 13 I/O Bootstrap I/O for left channel, negative high-side FET
BSLP 24 I/O Bootstrap I/O for left channel, positive high-side FET
BSRN 48 I/O Bootstrap I/O for right channel, negative high-side FET
BSRP 37 I/O Bootstrap I/O for right channel, positive high-side FET
COSC 28 I/O I/O for charge/discharging currents onto capacitor for ramp generator triangle wave biased at V2P5
FADE 30 I Input for controlling volume ramp rate when cycling SD or during power-up. A logic low on this pin
places the amplifier in fade mode. A logic high on this pin allows a quick transition to the desired
volume setting.
LINN 6 I Negative differential audio input for left channel
LINP 5 I Positive differential audio input for left channel
LOUTN 16, 17 O Class-D 1/2-H-bridge negative output for left channel
LOUTP 20, 21 O Class-D 1/2-H-bridge positive output for left channel
MUTE 34 I A logic high on this pin disables the outputs. A low on this pin enables the outputs.
NC 31, 32, 35
−
Not internally connected
PGNDL 18, 19
−
Power ground for left channel H-bridge
PGNDR 42, 43
−
Power ground for right channel H-bridge
PVCCL 14, 15
−
Power supply for left channel H-bridge (tied to pins 22 and 23 internally), not connected to PVCCR or
AV
CC
.
PVCCL 22, 23
−
Power supply for left channel H-bridge (tied to pins 14 and 15 internally), not connected to PVCCR or
AV
CC
.
PVCCR 38,39
−
Power supply for right channel H-bridge (tied to pins 46 and 47 internally), not connected to PVCCL
or AV
CC
.
PVCCR 46, 47
−
Power supply for right channel H-bridge (tied to pins 38 and 39 internally), not connected to PVCCL
or AV
CC
.
REFGND 12
−
Ground for gain control circuitry. Connect to AGND. If using a DAC to control the volume, connect the
DAC ground to this terminal.
RINP 3 I Positive differential audio input for right channel
RINN 2 I Negative differential audio input for right channel
ROSC 27 I/O
Current setting resistor for ramp generator. Nominally equal to 1/8*V
CC
ROUTN 44, 45 O Class-D 1/2-H-bridge negative output for right channel
ROUTP 40, 41 O Class-D 1/2-H-bridge positive output for right channel
SD 1 I
Shutdown signal for IC (low = shutdown, high = operational). TTL logic levels with compliance to V
CC
.
VCLAMPL 25
−
Internally generated voltage supply for left channel bootstrap capacitors.
VCLAMPR 36
−
Internally generated voltage supply for right channel bootstrap capacitors.