Onkyo TX-L55 Service Manual page 37

IC BLOCK DIAGRAMS AND DESCRIPTIONS
TC2100(Audio Signal Processor)
Pin Connection
Pin Descriptions
Pin Function
1 BIASCAP
2, 6 FBKGND2,
FBKGND1
3
4, 7 FBKOUT2,
FBKOUT1
5
8
9, 12
10, 11 Y1B, Y2B
13 NC
14, 16 OCD2, OCD1
15
17 VNNSENSE
18 OVRLDB
19 VPPSENSE
20 AGND
21
22, 27 OAOUT1, OAOUT2
23, 28 INV1, INV2
24
25, 26 BBM1, BBM0
BIASCAP
FBKGND2
DCM P
FBKOUT2
VPW R
FBKGND1
FBKOUT1
HM UTE
Y1
Y1B
Y2B
Y2
NC
OCD2
Bandgap reference times two (typically 2.5VDC). Used to set the
common mode voltage for the input op amps. This pin is not capable of
driving external circuitry.
Ground Kelvin feedback (Channels 1 & 2)
DCMP Internal mode selection. This pin must be grounded for proper device
operation.
Switching feedback (Channels 1 & 2)
VPWR Test pin. Must be left floating.
HMUTE Logic output. A logic high indicates both amplifiers are muted, due to the
mute pin state, or a "fault".
Y1, Y2 Non-inverted switching modulator outputs.
Inverted switching modulator outputs.
No connect
Over Current Detect pins.
REF Internal bandgap reference voltage; approximately 1.2 VDC.
Negative supply voltage sense input. This pin is used for both over and
under voltage sensing for the VNN supply.
A logic low output indicates the input signal has overloaded the amplifier.
Positive supply voltage sense input. This pin is used for both over and
under voltage sensing for the VPP supply.
Analog Ground.
V5 5 Volt power supply input.
Input stage output pins.
Single-ended inputs. Inputs are a "virtual" ground of an inverting opamp
with approximately 2.4VDC bias.
MUTE When set to logic high, both amplifiers are muted and in idle mode.
When low (grounded), both amplifiers are fully operational. If left floating,
the device stays in the mute mode. Ground if not used.
Break-before-make timing control to prevent shoot-through in the output
MOSFETs.
28-pin SOIC
(Top View)
28
1
INV2
27
2
OAOUT2
26
3
BBM 0
25
4
BBM 1
24
5
M UTE
23
6
INV1
22
7
OAOUT1
21
8
V5
20
9
AGND
19
10
VPPSENSE
18
11
OVRLDB
17
12
VNNSENSE
16
13
OCD1
15
14
REF
Description
TX-L55/LR552