Cirrus 公司的CS35L00是 2.7 W 高效单声道D类音频放大器，采用无滤波器混合型D类架构，静态电流小于1mA，10% THD+N时能向4欧姆提供2.7W功率，A加权SNR为-98dB，主要用于手机，上网本，PND，有源扬声器和手提游戏机。本文介绍了CS35L00主要特性，方框图，SD和FSD模式以及HD和FHD模式的典型连接框图，CDB35L00-X4 放大器演示板主要特性，电路图和材料清单（BOM）。
The CS35L00 is a 2.7 W high efficiency Hybrid Class-D audio amplifier with low idle current consumption and a selectable gain.
The CS35L00 features an advanced closed-loop architecture to provide 0.02% THD+N at 1 W and -75 dB PSRR at 217 Hz.
A flexible Hybrid Class-D output stage offers four modes of operation: Standard Class-D (SD) mode offers full audio bandwidth and high audio performance; Hybrid Class-D (HD) mode offers a substantial reduction in idle power consumption with an integrated Class-H controller; Reduced Frequency Class-D (FSD) mode reduces the output switching frequency, producing lower electromagnetic interference (EMI); and Reduced Frequency Hybrid Class-D (FHD) mode produces both the lower idle power consumption of HD mode and the reduced EMI benefits of FSD mode.
Requiring minimal external components and PCB space, the CS35L00 is available in a 3.0 mm x 3.0 mm, 10-pin DFN package in Commercial grade (-10℃ to +70℃).

CS35L00主要特性：
Filterless Hybrid Class-D Architecture
– <1 mA Quiescent Current
– 1 x 2.7 W into 4 ohm (10% THD+N)
– 1 x 2.1 W into 4ohm (1% THD+N)
– 1 x 1.6 W into 8 ohm (10% THD+N)
– 1 x 1.3 W into 8 ohm (1% THD+N)
Advanced Delta-Sigma Closed-loop Modulation
– 98 dB Signal-to-Noise Ratio (A-Weighted)
– 0.02% THD+N @ 1 W (SD & HD Mode)
Integrated Protection and Automatic Recovery for Output Short-circuit and Thermal Overload
Pin-compatible 9-ball WLCSP family for easy upgrade path
– CS35L01: +6 dB default Gain
CS35L03: +12 dB default Gain
Pop and Click Suppression

CS35L00主要应用：
Mobile Phones
Laptops/Netbooks
Portable Navigation Devices
Active Speakers
Portable Gaming

图1。CS35L00方框图

图2。CS35L00 SD和FSD模式典型连接框图

图3。CS35L00 HD和FHD模式典型连接框图

Note:3. The value of the capacitance connected to the LFILT+ net should not exceed 4.7uF. Presence of a capacitance above 4.7uF will prevent proper HD and FHD operation.

2.7 W x 4 CS35L00 放大器演示板
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-ohm 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 vailable through the R13, R23, R33, and R43 resistors.

图4。2.7 W x 4 CS35L00 放大器演示板外形图

主要特性：
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 4ohm at 10 % THD+N
Delivers 1.6 W/Ch into 8 ohm 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


图5。CDB35L00-X4 放大器演示板框图

图6。CDB35L00-X4 放大器演示板电路图
CDB35L00-X4 放大器演示板材料清单（BOM）：