Cirrus Logic CDB35L00-X4 User Manual
Control Switch
(S1)
Speaker
Output
(J11)
Optional
Gain
Adjustment
Analog
Input
(J10)
CS35L00
(U1)
Optional
Output
Filter
VBATT
Power (J1)
4 or 8
Speaker
Output
(J21)
Optional
Gain
Adjustment
Analog
Input
(J20)
CS35L00
(U2)
Optional
Output
Filter
4 or 8
Speaker
Output
(J31)
Optional
Gain
Adjustment
Analog
Input
(J30)
CS35L00
(U3)
Optional
Output
Filter
4 or 8
Speaker
Output
(J41)
Optional
Gain
Adjustment
Analog
Input
(J40)
CS35L00
(U4)
Optional
Output
Filter
4 or 8
CDB35L00-X4
2.7 W x 4 CS35L00 Amplifier Demonstration Board
Features
Contains 4 CS35L00 Hybrid Class-D Amplifiers
Selectable +6 dB or +12 dB Gain
Selectable Operational Modes
Device Shutdown Control
Delivers 2.7 W/Ch into 4 at 10 % THD+N
Delivers 1.6 W/Ch into 8 at 10 % THD+N
Differential Mono Analog Inputs for each
CS35L00 Amplifier
Demonstrates Recommended 4-Layer Layout
and Grounding Arrangements
– Optional Output Filter Connections
– Optional Gain Adjustment Resistors
Powered by Single +2.5-5.5 V Power Supply
Description
The CDB35L00-X4 demonstrates the CS35L00 high-efficiency Hybrid Class-D audio amplifier. This
demonstration board implements a four-channel, quad
amplifier system that delivers 2.7 W per full-bridge
channel into 4- loads using a single +5 V supply.
Differential audio inputs can easily be connected
through the J10, J20, J30, and J40 headers. If desired,
the gain can be adjusted through the optional input
resistors.
Component landings are available for an optional EMI
output filter.
The CDB35L00-X4 can be configured to evaluate the
four operational modes and two gain settings of the
CS35L00 amplifier. Mode, Gain, and Shutdown control
is available through the S1 switch. Hybrid control is
available through the R13, R23, R33, and R43 resistors.
ORDERING INFORMATION
CDB35L00 CS35L00-X4 Demo Board
http://www.cirrus.com
Copyright Cirrus Logic, Inc. 2010
(All Rights Reserved)
APR '10
DS913DB2
TABLE OF CONTENTS
1. SYSTEM OVERVIEW ............................................................................................................................. 3
1.1 CS35L00 Hybrid Class-D Amplifier .................................................................................................. 3
1.2 Power Supply ................................................................................................................................... 3
1.3 Operational Modes ........................................................................................................................... 3
1.3.1 Operational Mode Control ....................................................................................................... 3
1.4 Shutdown Control ............................................................................................................................ 4
1.4.1 Shutdown Control Resistors .................................................................................................... 5
1.5 Gain Control ..................................................................................................................................... 5
1.5.1 Optional Gain Adjustment Resistors .......................................................................................5
1.6 Differential Analog Inputs ................................................................................................................. 6
1.7 Speaker Outputs .............................................................................................................................. 6
1.7.1 Optional Speaker Output EMI Filter Components ........... ........................................................ 6
2. GROUNDING AND POWER SUPPLY DECOUPLING .......................................................................... 7
2.1 Power Supply Decoupling ................................................................................................................ 7
2.2 Electromagnetic Interference (EMI) ................................................................................................. 7
2.2.1 Suppression of EMI at the Source ......................... ... .... ... ... ... ... ............................................... 7
3. SYSTEM CONNECTORS AND JUMPERS ....... ... ... ... .... .......................................... ... ... ........................ 8
4. CDB SCHEMATIC .................................................................................................................................. 9
4.1 Bill of Materials ............................................................................................................................... 10
5. CDB LAYOUT ....................................................................................................................................... 11
6. REVISION HISTORY ............................................................................................................................ 12
CDB35L00-X4
LIST OF FIGURES
Figure 1.Hybrid Control Resistors ............................................................................................................... 4
Figure 2.Shutdown Control Resistors .......................... ... .... ... ... ... .... ... ... ... ... .... ... ... ... .................................. 5
Figure 3.Optional Bypass Trace Cut Locations for U1 ................................................................................ 6
Figure 4.CDB35L00-X4 Schematic .... .... ... ... ... ... .... ... ... ... .... ... ... ... .... ... ... ... ... .... ... ... ... .... ... ........................... 9
Figure 5.CDB35L00-X4 Top Side Component Placement ........................................................................ 11
Figure 6.CDB35L00-X4 Bottom Side Component Placement ................................................................... 11
Figure 7.CDB35L00-X4 Layer 1 Copper ................................ ................................................................... 11
Figure 8.CDB35L00-X4 Layer 2 Copper ................................ ................................................................... 11
Figure 9.CDB35L00-X4 Layer 3 Copper ................................ ................................................................... 11
Figure 10.CDB35L00-X4 Layer 4 Copper ................................................................................................. 11
LIST OF TABLES
Table 1. S1 Switch GAIN & MODE Configurations ..................................................................................... 3
Table 2. Hybrid Control Resistor & S1 Switch MODE Configurations . ............. ............. ............ ............. ..... 4
Table 3. S1 Switch Default Shutdown Configurations ................................................................................. 5
Table 4. System Input and Output Connections ......................................................................................... 8
Table 5. S1 Switch Settings ........................................................................................................................ 8
Table 6. Bill of Materials Listing ................................................................................................................ 10
2 DS913DB2
CDB35L00-X4
Table 1. S1 Switch GAIN & MODE
Configurations
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 pl aceholders 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 amplif ier availa ble
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 capable of delivering sufficient current for the intended power output. The supply provides power to each of the
four CS35L00 amplifiers. The power supp ly connection to the board is provid ed by the header J1. The positive 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 ope ra tiona l mod e can b e found in th e
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 reduced 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 repopula ting 0 resistors
as described in Section 1.4.
LOW
HIGH
GAIN MODE
+12 dB FSD / FHD
+6 dB SD / HD
Note: In order to avoid transient audio signals, the CS 35L00 devices sh ould be shutdown either via the
S1 switch or by removing power when the operational mode is being changed.
DS913DB2 3
1.3.1.1 Hybrid Control Resistor Configuration
Figure 1. Hybrid Control Resistors
Each CS35L00 device has a hybrid control resistor. When
the hybrid control resistor for each CS35L00 is populated,
it connects the LFILT+ pin to VBATT and enables the
Standard Class-D functionality (SD or FSD modes) for the
corresponding device. When the hybrid control resistor
for each CS35L00 is not populated, LFILT+ is floating,
and the Hybrid Class-D functionality (HD or FHD modes)
is enabled.
The hybrid control resistors (R13, R23, R33, R43) are located on the bottom side of the board adjacent to the
LFILT+ decoupling capacitor and are highlighted in blue
in Figure 1.
A combination of the hybrid control resistors and the S1
MODE switch allow the CS35L00 devices (U1-U4) on the
CDB35L00-X4 board to be configured in all 4 of the op erational modes. There is no requirement to have the all
four of the CS35L00 devices configured in the same
mode. Each device can be configured to the user’s requirements. Table 2 lists the configuration options available using the hybrid control resistors and the S1 MODE
switch.
CDB35L00-X4
Hybrid Control Resistor
Table 2. Hybrid Control Resistor & S1 Switch MODE Configurations
1.4 Shutdown Control
The S1 switch implements shutdown control for the four CS35L00 devices on the CDB35L00-X4. SD1-2
controls the shutdown for U1 and U2. SD3-4 contro ls the shu tdown for U3 and U4 as shown in Table 3 and
on the schematic in Figure 4 on page 9.
S1 MODE Switch:
GND VBATT
R13: VBATT U1 = FSD U1 = SD
R13: Removed U1 = FHD U1 = HD
R23: VBATT U2 = FSD U2 = SD
R23: Removed U2 = FHD U2 = HD
R33: VBATT U3 = FSD U3 = SD
R33: Removed U3 = FHD U3 = HD
R43: VBATT U4 = FSD U4 = SD
R43: Removed U4 = FHD U4 = HD
4 DS913DB2
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