19-1743; Rev 1; 2/01
Ultra-High PSRR Stereo Drivers +
Microphone Amp + 100mA Linear Regulator
General Description
The MAX4298 and MAX4299 are audio system ICs
designed for single +5V applications. The MAX4299
features a stereo headphone driver, a microphone
amplifier, and a +3.3V linear regulator; the MAX4298
features the stereo headphone driver only. The
MAX4298/ MAX4299 are designed specifically for harsh
digital environments where board space is at a premi-
um 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. The chip is 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. These
devices are fully compliant with PC99 standards.
The amplifiers exhibit 115dB of DC power-supply rejec-
tion and 80dB at 100kHz. The output amplifiers are
capable of driving a 1.5V
RMS
signal into a 10kΩ load
with 0.0008% THD+N. They can also drive 32Ω head-
phones to 1.2V
RMS
with 0.02% distortion. At +3.3V, the
linear regulator can output 100mA of current. The
MAX4298 is available in a tiny 10-pin µMAX while the
MAX4299 is available in the space-saving 16-pin
TSSOP package.
Features
o
Audio System IC (MAX4299)
Ultra-High PSRR Stereo Headphone Driver
Ultra-High PSRR Microphone Amp
100mA, 3.3V Linear Regulator
o
93dB typ PSRR at 20kHz Operates Directly from
Noisy Digital Supplies
o
Clickless/Popless Power-Up, Power-Down, Mute
and Unmute
o
PC99-Compliant Output Drivers:
Better than 1V
RMS
Output into 16Ω Load and
1.5V
RMS
and 0.0008% THD+N into 10kΩ Load
o
PC99-Compliant Microphone Amplifier:
0.005% THD+N into 10kΩ Load
o
22nF Capacitive Load Drive Capability
o
4.5V to 5.5V Single-Supply Operation
o
Internally Generated Bias Voltage
o
All Gains Externally Adjustable
o
Available in Space-Saving Packages
10-Pin µMAX (MAX4298)
16-Pin TSSOP (MAX4299)
MAX4298/MAX4299
________________________Applications
Notebook and Desktop Audio
Hands-Free Headsets
USB Audio Peripherals
IP Telephones
Wireless Internet Devices
MP3 Players/Recorders
Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd.
PART
MAX4298EUB
MAX4298ESD
MAX4299EWP
MAX4299EUE
Ordering Information
TEMP. RANGE
-40ºC to +85°C
-40ºC to +85°C
-40ºC to +85°C
-40ºC to +85°C
PIN-PACKAGE
10 µMAX
14 SO
20 SO
16 TSSOP
Typical Operating Circuit appears at end of data sheet.
PSRR vs. Frequency
MAX4298/9-13
Pin Configurations
TOP VIEW
OUT1 1
GND
IN1
BIAS
SV
CC
2
3
4
5
10 V
CC
9
OUT2
IN2
C
BYPASS
MUTE
-50
-60
-70
-80
PSRR (dB)
-90
-100
-110
-120
-130
-140
-150
100
1k
10k
MAX4298
8
7
6
100k
µMAX
Pin Configurations continued at end of data sheet.
1
FREQUENCY (Hz)
________________________________________________________________
Maxim Integrated Products
For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
Ultra-High PSRR Stereo Drivers +
Microphone Amp + 100mA Linear Regulator
MAX4298/MAX4299
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (V
CC
) to GND ...............................................+6V
Standby Supply Voltage (SV
CC
) to GND ...............................+6V
REG, FB, REGON to GND ..........................-0.3V to (V
CC
+ 0.3V)
BIAS, C
BYPASS
, MUTE, IN_, MICIN to GND ..............-0.3V to the
Larger of (V
CC
+0.3V) or (SV
CC
+0.3V)
OUT_, MICOUT to GND ................................-0.3V to the Smaller
of +5.5V, or (V
CC
+ 0.3V)
Duration of Output Short-Circuit to GND or V
CC
................10min
Continuous Power Dissipation
10-Pin µMAX (derate 5.6mW/°C above +70°C) ...........444mW
14-Pin SO (derate 8.3mW/°C above +70°C)................667mW
20-Pin SO (derate 10.0mW/°C above +70°C)..............800mW
16-Pin TSSOP (derate 9.4mW/°C above +70°C) .........755mW
Operating Temperature Range ..........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
CC
= SV
CC
= +5V, R
L
=
∞
on all outputs, C
BYPASS
= 1µF, C
BIAS
= 1µF, C
REG
= 10µF (MAX4299), T
A
= T
MIN
to T
MAX
, unless other-
wise noted. Load resistors (R
L
) are terminated to 2.25V. Typical values are at T
A
= +25°C. Specifications apply to both MAX4298 and
MAX4299, unless otherwise noted.) (Note 1)
PARAMETER
Supply Voltage Range
Quiescent Current
Mute Quiescent Current
SV
CC
Current (Note 2)
DRIVER AMPLIFIERS
Input Offset Voltage
Input Bias Current
Power-Supply Rejection
Ratio
V
OS
I
BIAS
DC, V
CC
= 4.5V to 5.5V
PSRR
f = 20kHz
f = 100kHz
R
L
= 10kΩ
Output Drive
V
OUT
R
L
= 32Ω
R
L
= 16Ω
A
V
= -1V/V, f = 1kHz, R
L
= 10kΩ,
V
OUT
= 1.5V
RMS
THD + Noise
A
V
= -1V/V, f = 1kHz, R
L
= 32Ω,
V
OUT
= 1.2V
RMS
, (Notes 3, 4)
A
V
= -1V/V, f = 1kHz, R
L
= 16Ω,
V
OUT
= 1.0V
RMS
Full-Scale Signal-to-Noise Ratio
(Note 4)
Capacitive Drive
Open-Loop Voltage Gain
Unity-Gain Bandwidth
A
VOL
GBW
R
L
= 32Ω, 0.55V
≤
V
OUT
≤
V
CC
- 0.55V
76
SNR
R
L
= 10kΩ,
V
OUT
= 1.06V
RMS
, A
V
= -1V/V
1.45
1.2
1.0
±1
0.2
115
93
80
1.59
1.53
1.48
0.0008
0.02
0.04
105
22
87
1.3
dB
nF
dB
MHz
0.1
%
V
RMS
dB
±10
mV
nA
I
SVCC
SYMBOL
V
CC
I
CC
MAX4298
MAX4299
MAX4298
MAX4299
V
BIAS
= 1.125V, V
CC
= 0
V
BIAS
= 2.25V, V
CC
= 5.0V
CONDITIONS
Inferred from PSRR test
MIN
4.5
10.2
10.6
10.2
10.6
300
7
TYP
MAX
5.5
17.5
18.0
17.5
18.0
500
UNITS
V
mA
mA
µA
2
_______________________________________________________________________________________
Ultra-High PSRR Stereo Drivers +
Microphone Amp + 100mA Linear Regulator
MAX4298/MAX4299
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= SV
CC
= +5V, R
L
=
∞
on all outputs, C
BYPASS
= 1µF, C
BIAS
= 1µF, C
REG
= 10µF (MAX4299), T
A
= T
MIN
to T
MAX
, unless other-
wise noted. Load resistors (R
L
) are terminated to 2.25V. Typical values are at T
A
= +25°C. Specifications apply to both MAX4298 and
MAX4299, unless otherwise noted.) (Note 1)
PARAMETER
BIAS VOLTAGE OUTPUT
DC BIAS Voltage
Line Regulation
Load Regulation
Input Voltage High
Input Voltage Low
Input Leakage Current
Input Offset Voltage
Input Bias Current
Power-Supply Rejection Ratio
Voltage Gain
Output Drive
THD + Noise (Note 4)
Full-Scale Signal-to-Noise Ratio
(Note 4)
All-Hostile Crosstalk
Unity Gain Bandwidth
REGULATOR
(MAX4299 only)
Regulator Output Voltage
Line Regulation
Load Regulation
FB Voltage
V
FB
V
REG
V
CC
= 4.5V to 5.5V. I
L
= 0 to 100mA, using
internal feedback
V
CC
= 4.5V to 5.5V, I
L
= 50mA
I
L
= 10mA to 100mA
I
L
= 0 to 100mA
Reference for regulator adjustment
3.15
3.3
0.2
30
50
1.233
3.45
V
mV
mV
mV
V
GBW
V
INH
V
INL
I
IN
V
OS
I
BIAS
DC, V
CC
= 4.5V to 5.5V
PSRR
A
VOL
V
OUT
THD+N
SNR
f = 20kHz
f = 100kHz
R
L
= 10kΩ, 0.13V
≤
V
MICOUT
≤
V
CC
- 0.13V
R
L
= 10kΩ
f = 1kHz, R
L
= 10kΩ,
V
MICOUT
= 1.5V
RMS
A
V
= -1V/V
A
V
= -10V/V
80
1.4
V
IN
= 0 or V
CC
±2
0.2
115
93
80
100
1.58
0.005
0.03
80
80
1
dB
V
RMS
%
dB
dB
MHz
dB
I
L
= 0 to 1µA
2.4
0.8
±1
±10
DIGITAL INPUTS
(MUTE for MAX4298/MAX4299, and REG
ON
for MAX4299)
V
V
µA
mV
nA
V
BIAS
I
L
= 0
2.13
2.25
120
50
2.37
V
dB
mV
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MICROPHONE AMPLIFIER
(MAX4299 only)
R
L
= 10kΩ, V
MICOUT
= 1.06V
RMS
, A
V
= -10V/V
f = 10kHz (Note 5)
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
All devices are 100% production tested at T
A
= +25°C. All temperature limits are guaranteed by design.
Current drawn from SV
CC
when V
CC
< 4V.
Guaranteed by design.
Measurement bandwidth is 20Hz to 22kHz.
Voltage at MICOUT with OUT1 = OUT2 = 1V
RMS
into 32Ω.
_______________________________________________________________________________________
3
Ultra-High PSRR Stereo Drivers +
Microphone Amp + 100mA Linear Regulator
MAX4298/MAX4299
Typical Operating Characteristics
(V
CC
= SV
CC
= +5V, typical operating circuit, T
A
= +25°C, unless otherwise noted.)
MAX4298
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX4298/99-01
POWER-UP/POWER-DOWN
MAX4298/9-02
MUTE PERFORMANCE
OUT
3
OUTPUT VOLTAGE (V)
2
1
0
-1
SPEAKER
-2
R
L
= 32Ω
C
AC
= 220µF
1.5
2.0
MAX4298/9-03
11.5
11.0
10.5
I
CC
(mA)
10.0
9.5
T
A
= -40°C
9.0
8.5
4.2
4.4
4.6
4.8
5.0
5.2
5.4
T
A
= +85°C
2.5
R
L
= 32Ω
2.0
OUTPUT VOLTAGE (V)
OUT
1.5
1.0
0.5
0
-0.5
SPEAKER
4
T
A
= +25°C
5.6
0
1.0
TIME (s)
2.0
0
0.5
1.0
TIME (s)
V
CC
(V)
POWER-DOWN/POWER-UP with SCHOTTKY
DIODE AND RESERVOIR CAPACITOR
V
CC
= 0
V
CC
= 5V
SV
CC
THD+N (%)
MAX4298/99-04
DRIVER OUT
THD+N vs. FREQUENCY
MAX4298/99-05
DRIVER OUT
THD+N vs. FREQUENCY
MAX4298/99-06
6
5
4
VOLTAGE (V)
3
2
1
0
-1
0
0.5
1.0
TIME (s)
R
L
= 32Ω
C
AC
= 22OµF
1.5
V
OUT
1
1
0.1
THD+N (%)
0.1
BW = 80kHz
BW = 22kHz
0.01
BW = 80kHz
BW = 22kHz
0.01
0.001
R
L
= 10kΩ
A
V
= -1
V
OUT
= 1.5V
RMS
100
1k
10k
100k
0.001
0.0001
0.0001
100
1k
R
L
= 32Ω
A
V
= -1
V
OUT
= 1.2V
RMS
10k
100k
2.0
INPUT FREQUENCY (Hz)
INPUT FREQUENCY (Hz)
DRIVER OUT
THD+N vs. FREQUENCY
MAX4298/99-07
DRIVER OUT
THD+N vs. AMPLITUDE
MAX4298/99toc08
DRIVER OUT
THD+N vs. AMPLITUDE
BW = 22kHz
1
f
IN
= 1kHz
MAX4298/99toc09
1
10
BW = 22kHz
10
0.1
THD+N (%)
BW = 80kHz
BW = 22kHz
THD+N (%)
1
0.01
0.01
THD+N (%)
A
V
= -1
R
L
= 10kΩ
0.1
0.1
0.01
0.001
0.0001
100
1k
R
L
= 16Ω
A
V
= -1
V
OUT
= 1V
RMS
10k
100k
0.001
f
IN
= 1kHz
0.0001
0
0.5
1
0.001
0.0001
1.5
2
0
0.5
1
OUTPUT VOLTAGE (V
RMS
)
OUTPUT VOLTAGE (V
RMS
)
R
L
= 32Ω
A
V
= -1
1.5
2
INPUT FREQUENCY (Hz)
4
_______________________________________________________________________________________
Ultra-High PSRR Stereo Drivers +
Microphone Amp + 100mA Linear Regulator
MAX4298/MAX4299
Typical Operating Characteristics (continued)
(V
CC
= SV
CC
= +5V, typical operating circuit, T
A
= +25°C, unless otherwise noted.)
DRIVER OUT
CHANNEL SEPARATION
vs. INPUT FREQUENCY
MAX4298/99toc10
MAX4298/9-11
DRIVER OUT
THD+N vs. AMPLITUDE
10
-60
-70
CHANNEL SEPARATION (dB)
BW = 22kHz
DRIVER OUT
MUTED OUTPUT ATTENUATION
vs. INPUT FREQUENCY
-85
-90
-95
-100
-105
-110
-115
-120
100
1k
R
L
= 16Ω
A = R
I
= 20kΩ, R
F
= 20kΩ
B = R
I
= 10kΩ, R
F
= 10kΩ
C = R
I
= 10kΩ, R
F
= 20kΩ
10k
100k
B
C
A
MAX4298/9-12
-80
MUTED OUTPUT ATTENUATION (dB)
1
f
IN
= 1kHz
THD+N (%)
0.1
OUT2 TO OUT1
-80
-90
-100
-110
-120
0.01
OUT1 TO OUT2
R
L
= 10kΩ
A
V
= -1
V
OUT
= 1V
RMS
100
1k
10k
100k
0.001
0.0001
0
0.5
1
OUTPUT VOLTAGE (V
RMS
)
R
L
= 16Ω
A
V
= -1
1.5
2
INPUT FREQUENCY (Hz)
INPUT FREQUENCY (Hz)
DRIVER OUT
POWER-SUPPLY REJECTION
RATIO vs. FREQUENCY
MAX4298/9-13
DRIVER OUT
OPEN-LOOP FREQUENCY RESPONSE
90
80
70
60
GAIN (dB)
50
40
30
20
10
0
32Ω || 15pF
0.1
1
10
100
GAIN
PHASE
MAX4298/9-14
DRIVER OUT
OPEN-LOOP FREQUENCY RESPONSE
200
180
160
140
PHASE (deg)
GAIN (dB)
120
100
80
60
40
20
90
80
70
60
50
40
30
20
10
0
-10
0.01
32Ω || 1.5nF
0.1
1
10
100
GAIN
PHASE
MAX4298/9-15
-50
-60
-70
-80
PSRR (dB)
-90
-100
-110
-120
-130
-140
-150
100
1k
10k
200
180
160
140
PHASE (deg)
PHASE (deg)
120
100
80
60
40
20
100k
-10
0.01
0
1000 10,000
0
1000 10,000
FREQUENCY (Hz)
INPUT FREQUENCY (kHz)
INPUT FREQUENCY (kHz)
DRIVER OUT
OPEN-LOOP FREQUENCY RESPONSE
90
80
70
60
GAIN (dB)
50
40
30
20
10
0
-10
0.01
32kΩ || 22nF
0.1
1
10
100
GAIN
PHASE
MAX4298/9-16
DRIVER OUT
OPEN-LOOP FREQUENCY RESPONSE
200
180
160
140
PHASE (deg)
GAIN (dB)
120
100
80
60
40
20
90
80
70
60
50
40
30
20
10
0
-10
0.01
10kΩ || 15pF
0.1
1
10
100
GAIN
PHASE
MAX4298/9-17
DRIVER OUT
OPEN-LOOP FREQUENCY RESPONSE
200
180
160
140
PHASE (deg)
GAIN (dB)
120
100
80
60
40
20
90
80
70
60
50
40
30
20
10
0
-10
0.01
10kΩ || 1.5nF
0.1
1
10
100
GAIN
PHASE
MAX4298/9-18
200
180
160
140
120
100
80
60
40
20
0
1000 10,000
0
1000 10,000
0
1000 10,000
INPUT FREQUENCY (kHz)
INPUT FREQUENCY (kHz)
INPUT FREQUENCY (kHz)
_______________________________________________________________________________________
5