illustrate

The FAN7040 is a single bridge tied load (BTL) output amplifier with DC volume control. Designed for use with TVs and monitors, but also for battery-operated portable recorders and radios. This unit is housed in a 20mm wire with a small profile package. Built-in leakage current limiter (MCL). When each amplifier output exceeds 130mA. This level of 130 mA allows single-ended (SE) headphone applications.

application

TVs and Monitors

laptop

desktop computer

Low Voltage Audio System

Electrical Characteristics

(VCC=12V, Ta=25°C, RL=16Ω, unless otherwise specified)

notes

1. When a load is connected to the output, the quiescent current will increase by dividing the DC output offset voltage by RL.

2. The maximum gain of the amplifier is typically reached at VC = 1.4V.

Performance characteristics

Performance Characteristics (continued)

Performance Characteristics (continued)

Typical Application Circuit

Typical Application Information

Function description

The FAN7040 is a single BTL output amplifier with DC volume control. It is designed for use with TVs and monitors, but also works with battery-operated portable recorders and radios. In traditional DC capacity circuits, the control stage or input stage is AC coupled to the output stage through an external capacitor to keep the offset voltage low. In the FAN7040, the DC volume control stage is integrated into the input stage, so no coupling needs capacitors. In this configuration, the offset voltage remains low and the minimum supply voltage remains low.

The BTL principle has the advantage that supply current peaks are lower at supply voltage ripple at twice the frequency of the signal. Therefore, a reduced power supply with smaller capacitors can be used, which also reduces cost. Portable applications have a tendency to lower supply voltages, resulting in regular output power reduction stages. The output power is improved by using the BTL principle. The maximum gain of the amplifier is fixed at 37 dB. The DC volume control stage has logarithmic control characteristics. The overall gain can be controlled from 37dB to -52dB. If the DC volume control voltage falls below 0.3V, the device will switch to silent mode. The amplifier is shorted to ground and Vcc goes through the cargo. A thermal protection circuit is also designed. If the crystal temperature rises above +150°C, the TSD is operational, shutting down the output power. Special attention was paid to the opening and closing click, low high frequency radiation and overall good stability. Voltage Gain The maximum closed loop voltage gain has been fixed internally at 37dB. Output Power Output power as a function of supply voltage was measured at THD = 10%. Maximum output power is limited. The maximum allowable power dissipation at TA=25°C is about 1.8W, and the maximum available output current is 1.25A. Repetitive peak current. The short-circuit protected outputs (pins 14 and 17) can be shorted to +VDD, respectively, to ground. The lack of a current limiter (MCL) protection circuit will shut down the amplifier. Removing the short will automatically reset the amplifier. A short across the load (pins 14 and 17) will activate the thermal protection circuit; this will cause thermal shutdown protection. For single-ended applications, the output peak current must not exceed 130mA; at higher output currents, short circuit protection (MCL) will be activated.

Power consumption

Power consumption is a major concern when designing any power amplifier and must be thoroughly understood to ensure a successful design. Equation (1) represents the point of maximum power dissipation for a bridge amplifier operating on a given supply. voltage and drive the specified output load.

Since the FAN7040 drives the bridge amplifier, the internal maximum power dissipation point of the FAN7040 comes from equation (1). Even if the internal power consumption is high, the fan 7040 does not need to be at ambient temperature. From equation (1), assuming a 12V supply and a 16Ω load, the point of maximum power dissipation. The maximum power dissipation point obtained from equation (1) cannot be greater than the power dissipation. The result of equation (2):

For 20SOP package, Rthja=70-C/W, TJMAX=150-C for fan 7040.