Datasheet

MAX4298/MAX4299
Ultra-High PSRR Stereo Drivers +
Microphone Amp + 100mA Linear Regulator
_______________________________________________________________________________________ 7
Detailed Description
The MAX4298/MAX4299 are audio system ICs de-
signed for single +5V applications. The MAX4299 has a
stereo headphone driver, a microphone amplifier, and
a 100mA +3.3V linear regulator; the MAX4298 has the
stereo headphone driver only. The MAX4298/MAX4299
are designed specifically for harsh digital environments
where board space is at a premium and the digital
power supply is noisy. The design uses innovative
design techniques to achieve ultra-high power-supply
rejection across the audio signal band while, at the
same time, delivering a high current rail-to-rail output
drive capability. These devices are designed to drive
highly capacitive loads that may be encountered when
driving long cables to a remote load such as
desktop/notebook headphones or speakers. They are
fully compliant to PC99 standards. Figure 1 is the
Pin Description
PIN
MAX4298
MAX4298 MAX4299
MAX4299
10-PIN
µMAX
14-PIN SO
16-PIN
TSSOP
20-PIN SO
NAME FUNCTION
——16 1 REG
Regulator Output. Bypass REG to GND with a 10µF
capacitor.
——12FB
Regulator Feedback. Internal resistors from this point
to REG and GND define the regulator output value.
Adjustments can be made to the output value by
adding resistors in the same place externally.
122
4
OUT1 Driver Amplifier Output
——3
5
PGND Power Ground for Driver Outputs
234
6
GND Ground
345
7
IN1 Inverting Input for Driver Amplifier
4568BIAS
Bias Point for Amplifiers. Bypass BIAS to GND with a
1µF capacitor.
5679SV
CC
Standby Power Supply. Connect to a standby +5V
supply that is always on, or bypass with 220µF and
connect a Schottky diode from V
CC
to SV
CC
. Short to
V
CC
if clickless power-down is not essential.
——8
10
MICOUT Microphone Amplifier Output
——9
11
MICIN Inverting Input for Microphone Amplifier
6 9 10 13 MUTE
Mute Digital Input. Connect to GND for normal
operation. When MUTE is connected to V
CC
, OUT1
and OUT2 are muted, REG stays on, and MICOUT
stays on.
71011
14
C
BYPASS
Bypass to GND with a 1µF Capacitor
81112
15
IN2 Inverting Input for Driver Amplifier
91213
16
OUT2 Driver Amplifier Output
10 13 14
17
V
CC
Power Supply. Connect to +5V.
—
1, 7, 8, 14
—
3, 12, 18, 19
N.C. No Connection. Not internally connected.
——15 20 REGON
Regulator Control. Connect to V
CC
for normal
operation. Connect to GND to shut off the regulator.