TDA8954 TDA8953 high power Class-D amplifier circuit with PCB for 1X 420W mono bridge (BTL) or 2x 210W Single Enable (SE) stereo that is suitable for pin-to-pin compatible TDA8953TH, TDA8954TH or TDA8955TH NXP Semiconductors’ devices. Extension “TH” is referring to the HSOP24 package.
About the class d amplifier board
Our Power AMP circuit uses the TDA8953TH / 54th / 55th chips. Here the NXP Semiconductors CIS with Suffix Th with SMD mounting and Hsop24 encapsulation will be used. The board can be used in stereo or bridge mode by simply configuring a jumper on the PCB and changing the connection in the input and output. The power supply must be the symmetric type, and may be of a wide voltage range.
Features DA8954 high power Class-D amplifier 420W
- Wide symmetrical supply voltage range
- Single Ended (SE) or Bridge Tied Load (BTL) output configuration
- Very high power capability
- Low THD+N
- Low noise
- AC-coupled differential inputs
- High efficiency
- Selectable Thermal Fold Back and current limiting to avoid audio interruptions
- Low power consumption in standby-mode
- Fixed frequency
- Diag functionality for Protections and Temperature (not for TDA8953TH)
Table of use of different chips
|Power supply (V)||+-12 … +-42,5||+-12 … +-42,5||+-12 … +-42,5|
|Typical output power SE (WRMS)||2x 210¹||2x 210¹||2x 150¹|
|Typical output power BTL (WRMS)||1x 420²||1x 420²||1x 300²|
(1) – Note: Load: 4Ω
(2) – Note: Load: 8Ω
Pin description TDA8954, TDA8953. TDA8955
|VSSA||1||negative analog supply voltage|
|VDDA||3||positive analog supply voltage|
|IN2M||4||channel 2 negative audio input|
|IN2P||5||channel 2 positive audio input|
|MODE||6|| mode selection input: Standby, Mute or Operating
|OSC||7||oscillator frequency adjustment or tracking input|
|IN1P||8||channel 1 positive audio input|
|IN1M||9||channel 1 negative audio input|
|DIAG1||10||diagnostic output 1 (open drain; TFB)|
|OSCREF||11||reference for OSC pin|
|DIAG2||12||diagnostic output 2 (open drain; protection functions)|
|PROT||13||decoupling capacitor for protection (OCP)|
|VDDP1||14||channel 1 positive power supply voltage|
|BOOT1||15||channel 1 bootstrap capacitor|
|OUT1||16||channel 1 PWM output|
|VSSP1||17||channel 1 negative power supply voltage|
|STABI||18||decoupling of internal stabilizer for logic supply|
|VSSP2||20||channel 2 negative power supply voltage|
|OUT2||21||channel 2 PWM output|
|BOOT2||22||channel 2 bootstrap capacitor|
|VDDP2||23||channel 2 positive power supply voltage|
|VSSA||24||negative analog supply voltage|
- STANDBY mode – The STANDBY mode is incorporated to reduce the power consumption.
- MUTE mode – In MUTE mode, the stabilizer will be enabled (internal logic biased). The power stage is enabled and starts switching. The gain is reduced to zero
- OPERATING mode with thermal foldback. In the OPERATING mode, the gain of the device is gradually increased to 30 dB per channel to avoid pop-noise due to DC output offset voltage (see figure 5). The complete start-up sequence will take less than 500 ms in a typical application. Thermal foldback is active.
- OPERATING mode without thermal foldback. In the OPERATING mode, the gain of the device is gradually increased to 30 dB per channel to avoid pop-noise due to DC output offset voltage. The complete start-up sequence will take less than 500 ms in a typical application. Thermal foldback is disabled.
Operation of circuit mode
The impedance in the pin mode is 50k according to the datasheet, with the S1 switch connected to the ground we will have 0V on pin mode and the chip will be in stand-by (0 – 0.8v), with S1 (on-off) switch off from the ground have about 2.5V in the mode pin of the TDA9854, entering the MUTE mode (2.2 to 3V), with the S3 (MUTE) switch off from the ground we will have about 4.5V in the pin mode entering operating mode (4, 2 to 5.5V), with the S3 (TFB) switched off from the GND have about 6.5V on the mode pin, the chip will be in operation mode with active TFB (6.6 to 8V). With Zener DZ1, maximum voltage will be 7.5V. C39 will cause the process to fit soft, no noises on the speaker.
Small keys have been added to the printed circuit board, however, the front of the cabinet can be added and connected by wires the printed circuit board. Also prefer can skip the mute key and add only stand-by key, it is also recommended to make a jumper instead of the TFB key, leaving enabled.
But if you prefer not required to use any of the keys.
The TDA8954TH and TDA8955TH are both equipped with advanced diagnostic circuitry that shows activity of the protections (DIAG ALARM) or a temperature warning above 139°C (DIAG TEMP). The board is equipped with two LED’s that show activity of both diagnostic lines.
The TDA8953TH/54TH/55TH devices utilize two advanced limiting features, respectively the Thermal. Fold Back and cycle-by-cycle current limiting, to avoid audio holes (interruptions) during normal operation. The Thermal Fold Back feature will reduce gradually the output power until the global junction
temperature reaches the threshold level of 154°C (OTP). Therefore the amplifier junction temperature will always stay within the Safe Operating Area. In addition to these limiting features the device has several protection features that makes the TDA8953TH/54TH/55TH family very robust during a fault condition.
The following protections are incorporated:
- Window Protection WP
- Under Voltage Protections UVP
- Over Voltage Protection OVP
- Unbalance Protection UBP
- Over Current Protection OCP
- Over Temperature Protection OTP
- Clock protection
Speaker configuration and impedance Class-D amplifier
For a flat-frequency response (second order Butterworth filter) it is necessary to change the low pass filter components L3 and C15/C25 according to the speaker configuration and impedance. The table below is showing some practical example values for a resonance frequency of 50kHz:
|Configuration||Impedance (Ω)||L1/L2 (μH)||C29/C30 (nF)|
|SE||3 – 6||15||680|
|4 – 6||22||470|
|6 – 8||33||330|
|BTL||6 – 12||15||680|
|8 – 12||22||470|
|12 – 16||33||330|
The boards are standard equipped with 15μH and 680nF for 2 x 4Ω SE or 1 x 8Ω BTL.
The inductor should have value selected according to the table above. Here I used 15uh commercial inductors using core T80-2, has 22mm diameter core and about 52 AWG wire turns. Finally you can use Ready or wrapped inductor your own.
A 35mm (l) x 100mm (C) x 30mm (A) heat sinkwas used, the heat sink must have a flat part where 2 holes will be made to be screwed. You should add an insulation between the sink and the CI metallic pad is connected to the VSS. Also the heat sink will be connected to the ground via R3 of 10 ohms or C9 100NF (use the resistor or capacitor) for better EMC performance.
You can use symmetric power supply with wide voltage range, here in the tests I used a + -35V symmetric switch with CI TDA8954 on the PCB. The circuit around Q1 will be the 5V is the source to alarm and temperature diagnostic circuit.
Stereo connection (SE) and bridge (BTL) of the power amplifier
To connect stereo is only to connect the SJ1 and SJ2 jumpers 1 to 2. The input connection will be on both connectors, respecting the polarity, same thing for audio output.
To (BTL) is only connecting the SJ1 and SJ2 jumpers from 2 to 3. The audio input connection will be on pin in1 (J1), respecting polarity. The audio output will be connected to the Pins (+) of the OUT1 connectors (J5) and OUT2 (J4).
For a version 2.1 with 3 channels, simply mount 2 boards and use a stereo and another as a bridge bass channel to the subwoofer.
Class D Power Amplifier Schematic
Printed circuit board for tda8954 power amplifier
Part list the amplifier with TDA8954th
|C1, C38||100pF/50V||Capacitor SMD 0805 NP0 5%||2|
|C2, C15||47uF/50V||Electrolytic capacitor L2 mm, D5.6 mm||2|
|C3, C4||470uF/50V||Electrolytic capacitor L5mm, D13mm||2|
|C5||22µF/160V||Electrolytic capacitor L3.5mm, D8mm||1|
|C6, C7, C35, C36||470n/63 or 100V||Film Capacitor L5mm, D5.5mm||4|
|C8, C9||100nF 50V||Capacitor SMD 0805 10%||7|
|C10, C37||330p/50V||Capacitor SMD 0805 NP0 5%||2|
|C12, C13||220nF/50V||Capacitor SMD 0805 X7R 10%||2|
|C14||220pF/50V||Capacitor SMD 0805 NP0 10%||1|
|C16||470nF/50V||Capacitor SMD 0805 X7R10%||1|
|C17, C18, C19, C20,C21, C22, C31, C32||100nF/100V||Capacitor SMD 1206 X7R 10%||8|
|C23, C24||15nF/50V||Capacitor SMD 0805 X5R 10%||2|
|C25, C26, C27, C28||220p/100V||Capacitor SMD 0805 NP0 10%||4|
|C29, C30||680n/63 or 100V||Film Capacitor L5mm, D5.5mm||2|
|C31, C32||100n/100v||Capacitor SMD 1206 X7R 10%||2|
|C33, C34||1n/100V||Capacitor SMD 0805 X7R 10%||2|
|C39||100uF/16V||Electrolytic capacitor L2.5 mm, D5.6 mm||1|
|J1||IN1||Terminal block 2 pin 5.08mm||1|
|J2||IN2||Terminal block 2 pin 5.08mm||1|
|J3||DC||Terminal block 2 pin 5.08mm||1|
|J4||OUT2||Terminal block 2 pin 5.08mm||1|
|J5||OUT1||Terminal block 2 pin 5.08mm||1|
|FB1, FB2||Murata BL01RN1A1D2 or equivalent||Bead Axial 7A||2|
|L1, L2||15uH||Coil > 10A||2|
|IC1||TDA8953TH or TDA8954TH or TDA8955TH||Integrated Circuit Audio Amplifier Class-D – NXP Semiconductors||1|
|LED1||TEMP||Led 3mm Yellow (DIAG TEMP)||1|
|LED2||ALARM||Led 3mm red ( DIAG ALARM)||1|
|D3, D4, D5, D6||US1MG or equivalent||Diodo Fast Recovery 1kV 1A SMA||4|
|DZ1||5V6 – Zener 5.6V 500mW||Zener Diode SMD LL-34||1|
|DZ2||7V5 – Zener 7.5V 500mW||Zener Diode SMD LL-34||1|
|Q1||MBT5551 (G1) or equivalent||Transistor NPN 160V SMD SOT23||1|
|Q2, Q3||S9015 (M6) or equivalent||Transistor NPN -50V SMD SOT23||2|
|R1, R4, R20, R22||220 (221)||Resistor SMD 0805 5%||4|
|R2||0 (0)||Resistor SMD 0805||1|
|R3||10 (100 or 10R0)||Resistor SMD 0805 5% (optional)||1|
|R6, R7, R19, R21||5.6K (562 or 5601)||Resistor SMD 0805 1%||4|
|R9, R10, R13, R14||10 (100 or 10R0) 0.25W||Resistor SMD 1206 1%||4|
|R11||30K (303 or 3002)||Resistor SMD 0805 1%||1|
|R12, R25, R26, R28, R29||10k (103)||Resistor SMD 0805 5%||5|
|R15, R16||22 Ohms 1W (220)||Resistor SMD 2512 5%||2|
|R27, R30||1k (102)||Resistor SMD 0805 5%||2|
|R31, R32||5.6k (562)||Resistor SMD 0805 5%||2|
|R33||3.3k (332)||Resistor SMD 0805 5%||1|
|R34||12k (123)||Resistor SMD 0805 5%||1|
|S1||ON/OFF (On Off)||Chave SPDT SS-12D02-VG4 -Korean Hroparts Elec||1|
|S2||MUTE (Mute)||Chave SPDT SS-12D02-VG4 – Korean Hroparts Elec||1|
|S3||TFB ( Thermal FoldBack )||Chave SPDT SS-12D02-VG4 – Korean Hroparts Elec||1|
|Weld, wires, PCB, box, power supply, heat sink|
Download the file to assembly the power amp Class D
Included files in PDF, PNG and Gerber of the boards.
Download of Datasheet in PDF of the components used
- Datasheet PDF TDA8953TH
- Datasheet PDF TDA8954TH
- Datasheet PDF S9015
- Datasheet PDF MMBT5551
- Datasheet PDF US1MG