Cirrus Logic CDB35L00-X4 - Manual (Page 3)

DS913DB2 3
CDB35L00-X4
1. SYSTEM OVERVIEW
The CDB35L00-X4 demonstration board is an practical means for evaluating the CS35L00 2.7 W Hybrid Class-D
amplifier with low idle current consumption. A differential mono analog input signal interface is provided for each
device. Optional input gain and output filtering component placeholders are provided for easy modification to custom
tune the CS35L00 for the user’s specific system requirements.
1.1 CS35L00 Hybrid Class-D Amplifier
The CS35L00 Hybrid Class-D amplifier is a 2.7 W mono, full-bridge, closed-loop, audio amplifier available
in a 10-pin, 3 mm x 3 mm, DFN package. A complete description of the CS35L00 is included in the CS35L00
product data sheet.
1.2 Power Supply
A single +2.5 to +5.5 VDC power supply is required to power the CDB35L00-X4. The supply must be capa-
ble of delivering sufficient current for the intended power output. The supply provides power to each of the
four CS35L00 amplifiers. The power supply connection to the board is provided by the header J1. The pos-
itive terminal is labeled VBATT. The ground terminal is labeled GND.
1.3 Operational Modes
The CS35L00 device has 4 different operational modes. Each of the 4 operational modes requires different
board configuration as described in
Section 1.3.1 and Section 1.3.1.1 . The operational modes of the
CS35L00 are listed below. More information on the specifics of each operational mode can be found in the
CS35L00 product datasheet.
• SD: Standard Class-D Mode
• FSD: Reduced Frequency Standard Class-D Mode
• HD: Hybrid Class-D Mode
• FHD: Reduced Frequency Hybrid Class-D Mode
The CDB35L00-X4 demonstration board schematic is shown in Figure 4 on page 9 .
1.3.1 Operational Mode Control
Using a combination of the S1 switch and the hybrid control resistors, as described in Section 1.3.1.1 ,
allows the CDB35L00-X4 to be configured in all 4 of the operational modes listed in Section 1.3 .
Each CS35L00’s MODE pin on the CDB35L00-X4
board is connected to the S1 switch labeled MODE as
shown in
Figure 4 on page 9 . The MODE pin controls
whether all four of the CS35L00 devices on the
CDB35L00-X4 board are operating in one of the re-
duced frequency modes (FSD or FHD) or in one of the
higher frequency modes (SD or HD).
Table 1 on page 3 and Table 3 on page 5 show the S1 switch-controlled configuration options on the
CDB35L00-X4 board. More configuration options are available by removing or repopulating 0
 resistors
as described in Section 1.4 .
Note: In order to avoid transient audio signals, the CS35L00 devices should be shutdown either via the
S1 switch or by removing power when the operational mode is being changed.
Table 1. S1 Switch GAIN & MODE
Configurations
GAIN MODE
LOW +12 dB FSD / FHD
HIGH +6 dB SD / HD