Sharp Aquos LC-37D90U, Руководство по обслуживанию

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LC-37D90U
5 – 21
2.2. VH+-1Y (ASSY: IC2303)
STEREO DIGITAL AUDIO AMPLIFIER
• Block Diagram [VH+-1Y (ASSY: IC2303)]
• Pin Function [VH+-1Y (ASSY: IC2303)]
Pin No. Pin Name I/O Pin Function
2,3 DCAP2,
DCAP1 Charge pump switching pins. DCAP1 (pin 3) is a free running 300kHz square wave between
VDDA and DGND (12Vpp nominal). DCAP2 (pin 2) is level shifted 10 volts above DCAP1 (pin 3)
with the same amplitude (12Vpp nominal), frequency, and phase as DCAP1.
4,9 V5D, V5A --- Digital 5VDC, Analog 5VDC.
5,8,17 AGND1,
AGND2,
AGND3 --- Analog Ground.
6 REF --- Internal reference voltage; approximately 1.0 VDC.
7 OVERLOADB A logic low output indicates the input signal has overloaded the amplifier.
10,14 OAOUT1,
OAOUT2 O Input stage output pins.
11,15 INV1,
INV2 Single-ended inputs. Inputs are a “virtual” ground of an inverting opamp with approximately
2.4VDC bias.
12 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. This pin should
be tied to GND if not used.
16 BIASCAP Input stage bias voltage (approximately 2.4VDC).
18 SLEEP When set to logic high, device goes into low power mode. If not used, this pin should be
grounded.
19 FAULT A logic high output indicates thermal overload, or an output is shorted to ground, or another out-
put.
20,35 PGND2,
PGND1 --- Power Grounds (high current).
22 DGND --- Digital Ground. Connect to AGND locally (near the TA2024).
24,27,
31,28
OUTP2 & OUTM2,
OUTP1 & OUTM1 O Bridged output pairs.
25,26,
29,30
VDD2,VDD2,
VDD1,VDD1 Supply pins for high current H-bridges, nominally 12VDC.
13,21,23,
32,34
NC --- Not connected. Not bonded internally.
33 VDDA --- Analog 12VDC.
36 CPUMP Charge pump output (nominally 10V above VDDA).
1 5VGEN Regulated 5VDC source used to supply power to the input section (pins 4 and 9).