AN3956 STMICROELECTRONICS | Alldatasheet

Document overview

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  • PDF pages: 14

Technical content

Datasheet sections

  • 1 Operation
  • 1.1 Power supply
  • 1.2 Demonstration board preparation
  • 1.3 Inputs and outputs
  • 1.4 Powering up
  • 1.5 Gain settings
  • 1.6 Single-ended or differential input
  • 1.7 Board schematic and bill of material
  • 2 PCB layout
  • 2.1 Layout views
  • 2.2 Design guidelines for PCB schematic and lay out
  • 2.2.1 Dumping network
  • 2.2.2 Filterless operation
  • 2.2.3 Layout recommendations
  • 3 Revision history

5 W + 5 W dual BTL class-D audio amplifier demonstration board

layout and bill of material. Figure 1. STEVAL-CCA029V1

1 Operation

The TDA7491LP demonstration board specifications are as follows:

  • Power supply voltage range: 5 V to 14V
  • Number of channels: 2 BTL (bridge-tied load) stereo
  • Load impedance: 4 Ω to 8 Ω
  • Gain settings: 20 dB, 26 dB, 30 dB, 32 dB
  • Undervoltage protection (UVP): 4 V

1.1 Power supply

A single power supply is required to feed the TDA7491LP demonstration board via the connector J2 (see Figure 2). Connect the positive voltage of the 15 V/3 A DC power supply to the +Vcc pin and the negative to GND. Note: Voltage range 5 V to 14 V = 3 A current capability

1.2 Demonstration board preparation

  1. Ensure that the power supply is switched OFF . 2. Connect the regulated power supply, adjusted in the device operating range, to the connector J7(Vcc) - J8(GND) (observe the polarity).

1.3 Inputs and outputs

  1. Connect the loads across the connectors J5-J6 (LEFT) and J9-J10 (RIGHT), the specified impedance ranges from 4 to 8 Ω. 2. Connect the analog audio inputs, single-ended, to the L-input and R-input RCA plugs (J1). Refer to Figure 2: Demonstration board connections on page 4.

Figure 2. Demonstration board connections

1.4 Powering up

dedicated switches and jumpers. Figure 3. Standby and mute switches Table 1. Standby and mute settings

1.5 Gain settings

Figure 4. Jumpers J11 and J12

1.6 Single-ended or differential input

CCA029V1 allows only the single-ended connection. Table 2. Configuration of jumpers J11 and J12

1.7 Board schematic and bill of material

Figure 5. STEVAL-CCA029V1 schematic

Table 3. Bill of material

2 PCB layout

2.1 Layout views

Figure 6. Top view of PCB layout Figure 7. Bottom view of PCB layout

Figure 8. Top view of PCB layout - with dimensions

2.2 Design guidelines for PCB schematic and layout

2.2.1 Dumping network

Figure 9. Dumping network (for one channel)

2.2.2 Filterless operation

are used (see Figure 5 and Table 3 for details).

2.2.3 Layout recommendations

The following figures illustrate layout recommendations. inductance caused by the copper supply lines. Figure 10. Capacitors soldered as close as possible to V Solder the snubber networks as close as possible to the IC related pin. the output pins be within 5 mm. Figure 11. Snubber networks soldered as close as possible to relevant IC pin

Signal ground should be directly connected to the negative terminal of the bulk capacitor. Figure 14. Signal ground routing

3 Revision history

Table 4. Document revision history 21-Sep-2012 1 Initial release.