SA58632 Datasheet, PDF (5/26 Pages) NXP Semiconductors – 2 x 2.2 W BTL audio amplifier

Philips Semiconductors
SA58632
2 × 2.2 W BTL audio amplifier
8. Functional description
The SA58632 is a two-channel BTL audio amplifier capable of delivering 2 × 1.5 W output
power to an 8 Ω load at THD+N = 10 % using a 6 V power supply. It is also capable of
delivering 2 × 2.2 W output power to an 8 Ω load at THD+N = 10 % using a 9 V power
supply. Using the MODE pin, the device can be switched to standby and mute condition.
The device is protected by an internal thermal shutdown protection mechanism. The gain
can be set within a range of 6 dB to 30 dB by external feedback resistors.
8.1 Power amplifier
The power amplifier is a Bridge-Tied Load (BTL) amplifier with a complementary
PNP-NPN output stage. The voltage loss on the positive supply line is the saturation
voltage of a PNP power transistor, on the negative side the saturation voltage of an NPN
power transistor. The total voltage loss is < 1 V. With a supply voltage of 6 V and an 8 Ω
loudspeaker, an output power of 1.5 W can be delivered to the load, and with a 9 V supply
voltage and an 8 Ω loudspeaker an output power of 2.2 W can be delivered.
8.2 Mode select pin (MODE)
The device is in Standby mode (with a very low current consumption) if the voltage at the
MODE pin is greater than V_CC − 0.5 V, or if this pin is floating. At a MODE voltage in the
range between 1.5 V and V_CC − 1.5 V the amplifier is in a mute condition. The mute
condition is useful to suppress plop noise at the output, caused by charging of the input
capacitor. The device is in Active mode if the MODE pin is grounded or less than 0.5 V
(see Figure 6).
8.3 BTL/SE output configuration
To invoke the BTL configuration (see Figure 3), the BTL/SE pin is taken to logic HIGH or
not connected. The output differentially drives the speakers, so there is no need for
coupling capacitors. The headphone can be connected to the amplifier negative outputs
using a coupling capacitor for each channel. The headphone common ground is
connected to the amplifier ground.
To invoke the Single-Ended (SE) configuration (see Figure 15), the BTL/SE pin is taken to
logic LOW or connected to ground. The positive outputs are muted with a DC level of
0.5V_CC. Using a coupling capacitor for each channel, speakers can be connected to the
amplifier negative outputs. The speaker common ground is connected to the amplifier
ground. Headphones can be connected to the negative outputs without using output
coupling capacitors. The headphone common ground pin is connected to one of the
amplifier positive output pins.
SA58632_1
Product data sheet
Rev. 01 — 27 June 2006
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
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