DA9560.001
20 January, 2005
DETAILED BLOCK DESCRIPTION
The reference block, which provides reference level
for analog audio signals, has two modes:
◆ DAC
MAS9560 contains two digital-to-analog converters
(DACs), which values are set through I2S bus (see
I2S section for further description). The sampling
rate of DACs is defined by WSI or CLI. In over
sampling mode the sampling frequency is the
frequency of CLI pin divided by four (fCLI/4). WSI is
used as a sampling clock in default mode.
LDO mode: Audio reference level = VLDO/2.
(SREF pin). This is half of integrated voltage
regulator's output voltage.
Non-LDO mode: Audio reference level =
VLDO/2. VLDO should be connected to VBAT
in Non-LDO mode.
◆ I2C/SPI Control Interface
◆ Audio Drivers
MAS9560 has many user selectable options. These
selections are mainly made by using registers,
which are programmed via one of the two standard
control interface protocols: I2C or SPI. The used
control interface type is selected with MODE pin.
MAS9560 contains three audio drivers, all of which
can be used simultaneously or separately. One
driver is for loudspeaker, one for earpiece and one
for headphone. The two latter ones have analog
volume control from –30 dB gain to +6 dB gain in
1.5 dB steps, whereas the control range for
loudspeaker driver is from –30 dB to +12 dB in 1.5
dB steps (see Control Register section p.18) The
main features of each driver is as follows:
◆ Registers
MAS9560 has 11 on-chip registers, which byte
length is 8 bits. Reset register is write-only, all other
registers permit read and write access.
Loudspeaker Driver: mono, differential output,
output power: 410 mW @ VDD = 2.7 V, 1100
mW @ VDD = 5.0 V
◆ Power Management
Earpiece Driver: mono, differential output,
output power: 100 mW @ VDD = 2.7 V, 300 mW
@ VDD = 5.0 V
MAS9560 has Block Control Register, which allows
separate blocks to be turned on and off
independently. This can be used to reduce power
consumption, since typically all the blocks are not
needed at the same time. If, for example, only
loudspeaker is used as an output, the drivers for
earpiece and headphone can be disabled.
Headphone Driver: stereo, single-ended output,
output power: 25 mW @ VDD = 2.7 V, 80 mW
@ VDD = 5.0 V
All the drivers are short-circuit protected.
Additionally MAS9560 has Mode Control Register,
which can be used to select operating mode for
MAS9560. These four modes are as follows:
◆ Digital Audio Interface
Inter-IC Sound (I2S) bus is a 3-wire serial interface
for transmission of 2-channel (stereo) Pulse Code
Modulation digital data between MAS9560 and
external digital audio source, for example MP3
player.
Zero Power, where all digital and analog blocks
are in power down mode. This is a default
mode after startup.
Analog stand-by, which is intended to be used
as a wait state when starting the device. The
purpose of this operating mode is to suppress
audible plops caused by abrupt amplification
changes when blocks in audio chain are waking
up.
◆ LDO Voltage Regulator
MAS9560 has integrated low dropout voltage
regulator, which output voltage is fixed 2.86 V. In
power supply noisy environments the usage of this
LDO in powering headphone and earpiece drivers
improves the PSRR of these drivers to 100 dB and
over. 10 nF bypass capacitor can be connected to
CBP pin further improving the performance. In case
LDO is not used (non-LDO mode) its output pin
(VLDO) must be connected to external voltage
source since it is supplying power for analog front-
end.
Aux to Line, where DACs are disabled and only
analog signaling is used.
Full Power, where all blocks are active.
◆ Temperature Protection
MAS9560 is equipped with over temperature
protection.
The integrated LDO can also be disabled by using
Mode-Control-Register.
◆ Reference Block
3 (25)
MAS [ MICRO ANALOG SYSTEMS ]
