ft2920
8W Boosted Class-G Audio Power Amplifier
with Automatic Level Control & Battery Tracking AGC
GENERAL DESCRIPTION
FEATURES
Wide range of supply voltages from 3V to 5.5V
The ft2920 is a highly efficient 8W boosted Class-G
audio power amplifier with automatic level control (ALC)
and battery tracking AGC. It integrates a filterless
Class-D audio amplifier with an adaptive multi-level
Class-G boost regulator and operates with a range of
supply voltages from 3V to 5.5V. When a supply
voltage at 3.6V, the ft2920 can deliver an output power
of 8W with 10% THD+N, or an ALC output power of 6W
with 0.4% THD+N, into a 4Ω speaker load.
Filterless Class-D audio amplifier integrated with an
adaptive multi-level Class-G boost regulator
Automatic level control to eliminate output clipping
Battery tracking AGC to prevent battery collapse
Soft drive mode for EMI reduction
Three boosted voltage settings: 8.0V/7.4V/6.8V
Maximum output power in Non-ALC mode
(VBAT=3.6V, 4Ω load, ALC=High, THD+N=10%)
In ft2920, the power supply rail of the audio amplifier’s
output stage is internally boosted and regulated by an
asynchronous PWM switching regulator with an
integrated power switch. The boost regulator employs
current-mode PWM control with proprietary multi-level
operation to regulate the boosted supply voltage in
response to the voltage level of the audio output. To
facilitate various output power applications, three
boosted supply voltage settings are available. The
adaptive nature of the multi-level Class-G boost
regulator improves overall efficiency.
PVDD (V)
8.0
Po (W)
8.0
6.8
7.4
6.8
5.7
ALC output power in ALC mode
(VBAT=3.6V, 4Ω load, ALC=Low, THD+N=0.4%)
PVDD (V)
8.0
Po (W)
6.0
5.1
7.4
6.8
4.2
Wide ALC dynamic range: 11dB
Three gain settings: 26dB/30dB/34dB
High efficiency up to 82%
The ft2920 features ALC function to constantly monitor
and safeguards the audio output against the boosted
supply voltage of the audio amplifier’s output stage,
preventing output clipping distortion, excessive power
dissipation, and speaker over-load. Once an over-level
condition is detected, the ALC lowers the voltage gain
of the audio amplifier proportionally to limit the peak
audio output.
Auto-recovering over-current & short-circuit
protection
Available in TSSOP-24L package
APPLICATIONS
Blue Tooth Speakers
In conjunction with ALC, as the battery supply voltage
drops, the battery tracking AGC lowers the voltage gain
of the audio amplifier to limit the peak audio output,
preventing the collapse of battery voltage.
Portable Audio Docks
Consumer Audio Electronics
APPLICATION CIRCUIT
CVBAT
1uF
Audio Input
Cin
0.22uF
0Ω
0Ω
Rin
Rin
1
24
23
22
21
20
19
18
17
16
15
14
13
AGND
INP
INN
Cin
0.22uF
RVKNEE 0Ω
2
VKNEE
3
GAIN
VBAT
4
CPVDD2
1uF
MUTE
PVDD
VOP
5
EN
EN
LS
6
7
SDRIVE
ALC
PGVND
VON
RALC 0Ω
SPEAKER
8
CPVDD1
1uF
NC
PVDD
AVDD
PVDDS1
PVDDS0
BVDD
RAVDD 10Ω
9
PGNDB
PGNDB
LX
RVBAT
10
11
12
PVDDS1
PVDDS0
10Ω
VDD
L1 2.2uH
CBVDD
1uF
LX
ft2920P
CS
22uF
CS
0.1uF
RLX
1Ω
CAVDD
1uF
D1 SS34
CLX
CPVOUT
220uF
CPVOUT
0.1uF
CPVOUT
22uF
+
D2 SS34
10nF
Figure 1: Typical Application Circuit of ft2920
DEC, 2017
www.fangtek.com.cn
1
5秒后页面跳转
STM32H743技术深度剖析与应用案例探索
LM321中文资料解析：引脚功能介绍、技术特点、技术特性分析
74HC14芯片资料介绍：性能特性分析、引脚介绍
LM1875芯片手册：功放参数分析、引脚说明、电路设计要点
微信公众号
抖音公众号
浙公网安备 33010502006866号 浙ICP备10014259号-119
营业执照ICP证
数据手册
如果您发现信息不准确，
