Datasheet

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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.

________________________Applications

Notebook and Desktop Audio

Hands-Free Headsets

USB Audio Peripherals

IP Telephones

Wireless Internet Devices

MP3 Players/Recorders

Features

♦ Audio System IC (MAX4299)

Ultra-High PSRR Stereo Headphone Driver

Ultra-High PSRR Microphone Amp

100mA, 3.3V Linear Regulator

♦ 93dB typ PSRR at 20kHz Operates Directly from

Noisy Digital Supplies

♦ Clickless/Popless Power-Up, Power-Down, Mute

and Unmute

♦ PC99-Compliant Output Drivers:

Better than 1V

RMS

Output into 16Ω Load and

1.5V

RMS

and 0.0008% THD+N into 10kΩ Load

♦ PC99-Compliant Microphone Amplifier:

0.005% THD+N into 10kΩ Load

♦ 22nF Capacitive Load Drive Capability

♦ 4.5V to 5.5V Single-Supply Operation

♦ Internally Generated Bias Voltage

♦ All Gains Externally Adjustable

♦ Available in Space-Saving Packages

10-Pin µMAX (MAX4298)

16-Pin TSSOP (MAX4299)

MAX4298/MAX4299

Ultra-High PSRR Stereo Drivers +

Microphone Amp + 100mA Linear Regulator

________________________________________________________________ Maxim Integrated Products 1

TOP VIEW

OUT2

IN2

BIAS

IN1

GND

OUT1

MAX4298

µMAX

MUTESV

BYPASS

PSRR vs. Frequency

19-1743; Rev 1; 2/01

Ordering Information

Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd.

Typical Operating Circuit appears at end of data sheet.

PART TEMP. RANGE PIN-PACKAGE

MAX4298EUB

-40ºC to +85°C

10 µMAX

MAX4298ESD

-40ºC to +85°C

14 SO

MAX4299EWP

-40ºC to +85°C

20 SO

MAX4299EUE

-40ºC to +85°C

16 TSSOP

Pin Configurations

100 1k 10k 100k

FREQUENCY (Hz)

PSRR (dB)

-50

-150

-140

-130

-120

-110

-100

-90

-60

-70

-80

MAX4298/9-13

Pin Configurations continued at end of data sheet.

Summary of content (14 pages)

PAGE 1
9-1743; Rev 1; 2/01 Ultra-High PSRR Stereo Drivers + Microphone Amp + 100mA Linear Regulator 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 premium and the digital power supply is noisy.
PAGE 2
MAX4298/MAX4299 Ultra-High PSRR Stereo Drivers + Microphone Amp + 100mA Linear Regulator ABSOLUTE MAXIMUM RATINGS Supply Voltage (VCC) to GND ...............................................+6V Standby Supply Voltage (SVCC) to GND ...............................+6V REG, FB, REGON to GND ..........................-0.3V to (VCC + 0.3V) BIAS, CBYPASS, MUTE, IN_, MICIN to GND ..............-0.3V to the Larger of (VCC +0.3V) or (SVCC +0.3V) OUT_, MICOUT to GND ................................-0.
PAGE 3
Ultra-High PSRR Stereo Drivers + Microphone Amp + 100mA Linear Regulator (VCC = SVCC = +5V, RL = ∞ on all outputs, CBYPASS = 1µF, CBIAS = 1µF, CREG = 10µF (MAX4299), TA = TMIN to TMAX, unless otherwise noted. Load resistors (RL) are terminated to 2.25V. Typical values are at TA = +25°C. Specifications apply to both MAX4298 and MAX4299, unless otherwise noted.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX 2.13 2.25 2.
PAGE 4
Typical Operating Characteristics (VCC = SVCC = +5V, typical operating circuit, TA = +25°C, unless otherwise noted.) 10.0 2.0 TA = +25°C 9.5 OUT 1.5 1.0 SPEAKER 0.5 OUT 3 OUTPUT VOLTAGE (V) ICC (mA) 10.5 RL = 32Ω OUTPUT VOLTAGE (V) TA = +85°C 4 MAX4298/9-02 11.0 MUTE PERFORMANCE POWER-UP/POWER-DOWN 2.5 MAX4298/99-01 11.5 MAX4298/9-03 MAX4298 SUPPLY CURRENT vs. SUPPLY VOLTAGE 2 1 0 TA = -40°C 9.0 0 -1 8.5 -0.5 -2 RL = 32Ω CAC = 220µF SPEAKER 4.2 4.4 4.6 4.8 5.0 5.2 5.4 5.
PAGE 5
Ultra-High PSRR Stereo Drivers + Microphone Amp + 100mA Linear Regulator MAX4298/MAX4299 Typical Operating Characteristics (continued) (VCC = SVCC = +5V, typical operating circuit, TA = +25°C, unless otherwise noted.) DRIVER OUT CHANNEL SEPARATION vs. INPUT FREQUENCY 0.001 0 0.5 1 1.
PAGE 6
Typical Operating Characteristics (continued) (VCC = SVCC = +5V, typical operating circuit, TA = +25°C, unless otherwise noted.) 60 140 120 PHASE 40 100 30 80 20 60 GAIN 10 40 0 20 10kΩ || 22nF 1 10 180 70 160 60 140 50 120 40 80 30 60 GAIN 0.1 1 10 20 0 10kΩ || 15pF -10 0.01 0.1 1 100 40 10 100 0 1000 10,000 INPUT FREQUENCY (kHz) INPUT FREQUENCY (kHz) INPUT FREQUENCY (kHz) MICOUT OPEN LOOP FREQUENCY RESPONSE MICOUT THD+N vs. AMPLITUDE REGOUT OUTPUT VOLTAGE vs.
PAGE 7
Ultra-High PSRR Stereo Drivers + Microphone Amp + 100mA Linear Regulator PIN MAX4298 MAX4299 MAX4299 10-PIN µMAX 14-PIN SO 16-PIN TSSOP 20-PIN SO — — 16 1 MAX4298 NAME REG FUNCTION Regulator Output. Bypass REG to GND with a 10µF capacitor. 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.
PAGE 8
MAX4298/MAX4299 Ultra-High PSRR Stereo Drivers + Microphone Amp + 100mA Linear Regulator VCC VCC SVCC IN1 BIAS _ SVCC 18.4kΩ REGON FB OUT1 + 50kΩ 1.233V + _ REG MAX4298 11kΩ 2.25V MUTE MAX4299 IN2 + _ OUT2 IN1 CBYPASS _ OUT1 + GND BIAS 2.25V 50kΩ IN2 Figure 1. MAX4298 Block Diagram + _ OUT2 N.C. MUTE The amplifiers exhibit better than 115dB of DC powersupply rejection and 93dB at 20kHz. The output amplifiers are capable of driving a 1.5VRMS signal into 10kΩ load with 0.
PAGE 9
Ultra-High PSRR Stereo Drivers + Microphone Amp + 100mA Linear Regulator Layout Good layout improves performance by decreasing the amount of stray capacitance and noise at the power amplifier’s inputs and output. To decrease stray capacitance, minimize PC board trace lengths and resistor leads, and place external components as close to the pins as possible.
PAGE 10
Ultra-High PSRR Stereo Drivers + Microphone Amp + 100mA Linear Regulator MAX4298/MAX4299 Typical Operating Circuits RF 10kΩ VCC OPTIONAL VCC MAX4298 SVCC 220µF RI 10kΩ LEFT _ + IN1 OUT1 MUTE BIAS 1µF RI 10kΩ VCC CAC 220µF 2.25V RIGHT IN2 + _ OUT2 1µF CAC 220µF GND CBYPASS RF 10kΩ 20kΩ VCC REGON 10µF AVDD 3.3V REG FB LDO MAX4299 IN1 LEFT AUDIO CODEC 0.33µF 20kΩ BIAS _ + VCC OPTIONAL SVCC 220µF CAC 220µF OUT MUTE VCC 2.25V 1µF IN2 RIGHT + _ CAC 220µF 0.
PAGE 11
Ultra-High PSRR Stereo Drivers + Microphone Amp + 100mA Linear Regulator TOP VIEW REG 1 20 REGON 16 REG FB 1 FB 2 19 N.C. OUT1 2 15 REGON N.C. 3 18 N.C. PGND 3 14 VCC OUT1 4 17 VCC GND 4 16 OUT2 IN1 5 PGND 5 MAX4299 GND 6 IN1 7 13 OUT2 12 IN2 15 IN2 BIAS 6 11 CBYPASS 14 CBYPASS SVCC 7 10 MUTE BIAS 8 13 MUTE SVCC 9 12 N.C. MICOUT 10 MAX4299 MICOUT 8 9 TSSOP N.C. 1 14 N.C. OUT1 2 13 VCC GND 3 IN1 4 12 OUT2 MAX4298 BIAS 5 11 IN2 10 CBYPASS SVCC 6 9 MUTE N.C.
PAGE 12
MAX4298/MAX4299 Ultra-High PSRR Stereo Drivers + Microphone Amp + 100mA Linear Regulator SOICW.
PAGE 13
Ultra-High PSRR Stereo Drivers + Microphone Amp + 100mA Linear Regulator SOICN.
PAGE 14
Ultra-High PSRR Stereo Drivers + Microphone Amp + 100mA Linear Regulator TSSOP,NO PADS.EPS MAX4298/MAX4299 Package Information (continued) Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.