Features

Stevid Sound Direct Path #8482; Audio Line Driver

—2 VRMS access 10 k 3.3-v power supply

] 2 VRMS low THD+N LT; 0.01%, becoming 10 k

high signal -to -noise ratio, gt; 90 decibels

# 8226; 600Ω output load compatible

Differential input and single -end output

External gain setting resistor adjustable gain

Low -DC offset, lt; 1 mv

ground reference output to eliminate DC blocking capacitors

-reduce circuit board area

- Reduce component cost

- Improve THD+N performance

-Eversion capacitor will not reduce low frequency response

short circuit protection

123]

Orthodontic stabilization of the outside

Active silence control, realizing no audio open/off control

Tssop package saving space saving TSSOP package

Application

Motytop box

Blu -ray CD #8482;, DVD player

LCD and LCD and LCD and LCD and LCD and LCD and PDP TV

Mini/Mini Combination System

Sound Card

Notebook Computer Instructions

DRV632

is a 2-VRMS non-pop-up stereo line drive. The design allows removing output DC blocking capacitors to reduce the number and cost of the component. This device is very suitable for single -power electronic products with key design parameters.

Directpath design #8482; technically, DRV632 can drive 2 VRMs to 10-k load and 3.3-V power supply voltage. This device has differential inputs, and uses an external gain setting resistor to support the gain range of ± 1 V/V to ± 10 V/V, and can configure the gain separately for each channel. The output of the line has a protection of ± 8-KV IEC ESD, and only a simple resistance capacitance ESD protection circuit is required. DRV632 has built -in active silenceControl, you can open/turn off without pop -up audio control. The DRV632 has an external pressure detector. When the power supply is broken, it will make the output mute and ensure that there is no pop -up.

Compared with the traditional 2-VRMS generation method, the use of DRV632 in audio products can greatly reduce the number of components output DRV632 without more than 3.3V power to generate its 5.6-VPP output, and it does not need to be interlimished. power supply. DRV632 integrates its own charge pump to generate a negative power rail and provide a clean, non-pop-up ground bias 2-VRMS output.

DRV632 provides 14 stitches TSSOP.

Equipment information

(1), please refer to the appointment of the doctor's order content at the end of the data table.

Simplified Figure

Typical features VDD 3.3 V, TA 25 ° C, C (pump) c (vss VSS ) 1 μF, CIN 2.2 μF, RIN 15 K , RFB 30 K , ROUT 32 , COUT 1 NF (unless otherwise explained).

Parameter measurement information

All parameters are measured according to the conditions described in the specification.

Detailed instructions

Overview

DRV632 combines TI's patented DirectPath technology and built-in clicks and pop-up reduction circuits. Avoid using the output DC blocking capacitors, thereby reducing the number and cost of components. DRV632 can drive 2-VRMS to enter a line load from 600Ω to 10 kΩ, with a power supply voltage of 3.3-V. The use of charge pump flight, PVSS and decoupled capacitors ensure the performance of the amplifier. The device has two channels with differential inputs, which requires DC input to block the capacitor to block the DC parts of the audio source. These allow DRV632 to input appropriate bias to provide maximum performance. DRV632 allows external gain setting resistors to support the gain range of ± 1 V/V to ± 10 V/V. The gain can be configured separately for each channel. In addition, when you need to remove external noise, both channels can be used as a second -order filter. DRV632 has a built -in active mute control, which is used to open/turn off without pop -up audio, and avoid clicking and popping by using external underwriting detection. When unloading or placing the power device, the device will not generate pop -up or click.

Figure Figure

Feature description

9.3.1 Line driver amplifier

Single -power source line driver amplifier usually requires a DC blocking capacitor. The above figure in FIG. 6 illustrates the connection between the traditional line drive amplifier and the load and output signal. The value of DC closed lock capacitors is often very large. Line load (typical resistance value is 600Ω to 10 kΩ) with DC closed lock capacitors to form a high -pass filter. Formula 1 shows the relationship between load impedance (RL), capacitors (CO) and cut -off frequency (FC).

CO can be determined by equal 2, where the load impedance and cut -off frequency are known.

If the FC is very low, the capacitor must have a high value because the load resistance is small. Large capacitors require large packaging size. The large package size consumes PCB area, which is higher than PCB, increases assembly costs, and reduces the preservation of audio output signals.

Direct channel amplifier structure runs from a single power supply, but uses internal charge pumps to provide negative voltage tracks. Combined with the positive tracks provided by the user and the negative of the IC, the device runs in an effective division mode. The output voltage is now concentrated in zero, which can swing to the right or negative. Combined with the built -in clicks and pop -up reduction circuits, the direct path releases large instruments without output DC blocking capacitors. Figure 6 The bottom block diagram and waveforms show the ground reference line driver architecture. This is the architecture of DRV632.

The charge pump flight capacitor and PVSS capacitor

The charge pump flying capacitor is used to transfer the charge during the production of the negative power supply voltage. PVSS capacitors must be at least equal to the charge pump capacitor to allow maximum charge transfer. Low ESR capacitor is an ideal choice, and 1 μF is a typical value. The capacitance value of less than 1 μF can be used, but the maximum output voltage may be reduced, and the device may not be able to run according to specifications. If DRV632 is used for high -noise sensitive circuits, TI recommends adding a small LC filter to the VDD connection.

Define capacitor

DRV632 is a direct path line driver amplifier, which requires sufficient power supply to ensure that the noise and total harmonic distortion (THD) are low. A good, low -equate series resistance (ESR) ceramic capacitor, usually 1 μF, is placed where the VDD lead is as close to the device as possible, the effect is the best. Putting this off -coupled container near DRV632 is important for the performance of the amplifier. In order to filter a low -frequency noise signal, a 10μF or larger capacitor is also helpful to place a 10μF or larger capacitor near the audio power amplifier, but it does not need it in most applications, because the PSRR of this device is very high.

Increase setting resistance range

You must choose the gain setting resistor RIN and RFB to make DRV632Noise, stability, and input capacitor size remain within the acceptable range. The voltage gain is defined as RFB divided by Rin.

The value of too low input requires a large input AC coupling capacitor, CIN. Choosing a high value will increase the noise of the amplifier. Table 1 lists recommended resistance values u200bu200bfor different inverting input gains.

Input the locking capacitor

DC input blocking capacitor needs to be connected to the input pin of DRV632 with the audio signal. These capacitors block the DC parts of the audio source and allow DRV632 to input appropriate bias to provide maximum performance.

These capacitors and input resistance RIN form high -pass filter. Calculated by Formula 3 for the deadline. In this calculation, the capacitor used is input blocking capacitors, and the resistance is the input resistance selected from Table 1; then, when one of the two values u200bu200bis given, the frequency and/or capacitance can be determined.

It is recommended to use electrolytic capacitors or high -voltage rated capacitors as the input atresia capacitor to ensure that the capacitor is minimized with the input voltage. This capacitor is common in ceramic capacitors with the change of input voltage, which will increase low -frequency audio distortion.

DRV632 UVP operation

The shutdown threshold at the UVP pin is 1.25 V. Customers must use the resistor division to obtain the shutdown threshold and stagnation required for specific applications. The threshold selected by the customer can be determined as follows:

External underwriting

External underwriting detection can be used to make DRV632 silent/off before entering the device to generate POP.

The shutdown threshold at the UVP pin was 1.25 V. The user selects a resistor division to obtain the shutdown threshold and lag of specific applications. The threshold can be determined as follows:

For example, to obtain VUVP 3.8 V and 1-V lag behind, please use R1 3 K , R2 1 K #8486 ; R3 50 k .

Equipment function mode

Use DRV632 as a second -order filter

Some audio DAC currently used requires an external low -pass filter. To eliminate external noise. This is possible on DRV632 because it can be used like a standard operation amplifier. It can achieve several filter topology, including single -end and differential. In FIG. 8, multiple feedback (MFB) with differential input and single -end input is displayed.

The figure shows an AC coupling capacitor to remove the DC component from the source; it is used to prevent any DC component in the source and reduce the DC gain to 1, which helps the output DC biasMove to minimize.

To calculate the component value, use Ti Webench #174; filter designer.

The resistance value should have a low value to get low noise, but it should also have sufficient high value to obtain a small -sized AC coupling capacitor. When R1 15kΩ, R2 30kΩ, R3 43KΩ, the dynamic range of 1 μF input AC coupling container can reach 106DB.

Silent mode

DRV632 can use low -activated mute pin (pin 5) silent. Clicking and pop -up inhibitory capabilities to ensure that when the mute mode is used, it does not produce additional clicks or pop -up.

Application and implementation

Note

The information in the following application chapters is not part of the TI component specification, TI does not guarantee its accuracy or integrity. TI's customers are responsible for determining the applicability of the component. Customers should verify and test their design implementation to confirm the system function.

Application information

This typical connection diagram highlights the external component and system -level connection required for the normal operation of the device. This configuration can be implemented using the device's evaluation module (EVM). This flexible module allows the device to comprehensively evaluate the device in all available operation mode. Please refer to the DRV632 product page to learn about the information about ordering EVM.

Typical application

Design requirements

In this design example, use the parameters listed in Table 2.

Detailed design program

charge pump flight, PVSS and decoupled capacitors

In order This design uses 1-μF low-equate series resistance (ESR) charge pump flyover capacitor. Similar 1-μF capacitors are placed in VSS and as close to VDD as much as possible. For details, please refer to the charge pump flying capacitor, PVSS capacitor and decoupled capacitor.

Second -order active low -pass filter

With the help of the Ti Webench filter designer designer, R1 15kΩ, R2 30kΩ, R3 43KΩ, C1 47pf, C2 C2 180pf second -order low -pass filter. For details, see using DRV632 as a second -order filter.

UVP resistor division

R11 and R12 are placed in the design of the resistor division. The shutdown threshold at the UVP pin is 1.25 V. For more information, see external pressure detection.

Application curve

[12]3]

Power suggestion

The device is designed to work within the input voltage range of 3V to 3.6V.The input power must be adjusted well.If the input power is located more than a few inches from the DRV632 device, in addition to the ceramic side electric container, additional large capacitors may be needed.Typical electrolytic capacitors with 47μF.

Placing an decoupled electric container near DRV632 can improve the performance of the line -driven amplifier.The typical choice is the low -equate series resistor (ESR) ceramic capacitor with a value of 1 μF.

If DRV632 is used for high noise sensitive circuits, TI recommends adding a small LC filter to the VDD connection.

Layout

layout guide

gain setting resistor

gain setting resistor RIN and RFB must be close to pin 13 and pin 17, respectively,To minimize the capacitor load on these input pins and ensure the maximum stability of DRV632.For PCB layouts, please refer to the DRV632EVM user guide.

layout example