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General Description

The MAX9820 Windows Vista

-compliant stereo head-

phone amplifier is designed for portable equipment

where board space is at a premium. It features Maxim’s

patented DirectDrive

architecture to produce a

ground-referenced output from a single supply, elimi-

nating the large output-coupling capacitors required by

conventional single-supply headphone amplifiers.

The MAX9820 features an undervoltage lockout that

prevents over discharging of the battery during

brownout conditions, click-and-pop suppression that

eliminates audible transients on startup, a low-power

shutdown mode, and thermal-overload and short-circuit

protection. Additionally, the MAX9820 suppresses RF

radiation received by input and supply traces acting as

antennas and prevents the amplifier from demodulating

the coupled noise.

The MAX9820 is available in a 10-pin TDFN package

(3mm x 3mm x 0.8mm) and specified over the -40°C to

+85°C extended temperature range.

Applications

Cell Phones

MP3 Players

Notebook PCs

PDAs

Features

o Clickless/Popless Operation

o High RF Noise Rejection

o Windows Vista Premium Mobile Compliant

o 2.7V to 5.5V Single-Supply Operation

o 95mW Output Power (32Ω, V

= 5V)

o Low-Current Shutdown Mode, < 1µA

o Low 3mA (V

= 3.3V) Quiescent Current

o Space-Saving, 3mm x 3mm, 10-Pin TDFN Package

MAX9820

DirectDrive Headphone Amplifier

with External Gain

________________________________________________________________

Maxim Integrated Products

19-4666; Rev 0; 7/09

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

EVALUATION KIT

AVAILABLE

GND

INL

C1P

OUTL

MAX9820

C1N

INROUTR

*EP

*EXPOSED PAD.

TDFN

TOP VIEW

SHDN

Pin Configuration

Ordering Information

PART TEMP RANGE

PIN-

PACKAGE

TOP MARK

MAX9820ETB+ -40°C to +85°C 10 TDFN-EP* AUU

Denotes a lead(Pb)-free/RoHS-compliant package.

EP = Exposed pad.

LEFT

AUDIO

INPUT

RIGHT

AUDIO

INPUT

SHDN

MAX9820

DirectDrive OUTPUTS

ELIMINATE DC-BLOCKING

CAPACITORS

Simplified Block Diagram

Windows Vista is a registered trademark of Microsoft Corp.

DirectDrive is a registered trademark of Maxim Integrated Products, Inc.

Summary of content (13 pages)

PAGE 1
9-4666; Rev 0; 7/09 KIT ATION EVALU LE B A IL A AV DirectDrive Headphone Amplifier with External Gain Vista®-compliant The MAX9820 Windows stereo headphone amplifier is designed for portable equipment where board space is at a premium. It features Maxim’s patented DirectDrive ® architecture to produce a ground-referenced output from a single supply, eliminating the large output-coupling capacitors required by conventional single-supply headphone amplifiers.
PAGE 2
MAX9820 DirectDrive Headphone Amplifier with External Gain ABSOLUTE MAXIMUM RATINGS VDD to GND ..............................................................-0.3V to +6V C1P to GND................................................-0.3V to (VDD + 0.3V) C1N to GND ................................................(VSS - 0.3V) to +0.3V VSS to GND...............................................................-6V to +0.3V OUTR, OUTL to GND.............................................................±3V SHDN to GND.
PAGE 3
DirectDrive Headphone Amplifier with External Gain (VDD = VSHDN = 5V, VGND = 0V, RIN = RFB = 40.2kΩ (gain = -1V/V), C1 = C2 = 1µF, C3 = 10µF, RLOAD = ∞, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C, unless otherwise noted.) (Note 2) PARAMETER SYMBOL CONDITIONS VDD = 2.7V to 5.
PAGE 4
Typical Operating Characteristics (VDD = VSHDN = 5V, VGND = 0V, RIN = RFB = 40.2kΩ (gain = -1V/V), C1 = C2 = 1µF, C3 = 10µF, RLOAD = ∞. Typical values are at TA = +25°C, unless otherwise noted.) THD+N vs. OUTPUT POWER THD+N vs. OUTPUT POWER f = 100Hz THD+N (%) THD+N (%) 0.1 VDD = 5.0V RLOAD = 32I LLOAD = 1FH 1 f = 6kHz f = 100Hz f = 6kHz 0.1 f = 1kHz 0.01 MAX9820 toc02 VDD = 5.0V RLOAD = 16I LLOAD = 1FH 1 10 MAX9820 toc01 10 0.01 f = 1kHz 0.001 0.001 0.02 0.04 0.06 0.08 0.10 0.
PAGE 5
DirectDrive Headphone Amplifier with External Gain THD+N vs. FREQUENCY THD+N vs. FREQUENCY THD+N (%) THD+N (%) VDD = 3.6V RLOAD = 32I LLOAD = 1FH 1 0.1 POUT = 20mW MAX9820 toc08 VDD = 3.6V RLOAD = 16I LLOAD = 1FH 1 10 MAX9820 toc07 10 0.1 POUT = 30mW 0.01 0.01 POUT = 10mW POUT = 10mW 0.001 0.001 100 1000 10,000 100,000 10 100 FREQUENCY (Hz) VISTA THD+N vs. FREQUENCY FS = 300mVRMS VDD = 5.
PAGE 6
Typical Operating Characteristics (continued) (VDD = VSHDN = 5V, VGND = 0V, RIN = RFB = 40.2kΩ (gain = -1V/V), C1 = C2 = 1µF, C3 = 10µF, RLOAD = ∞. Typical values are at TA = +25°C, unless otherwise noted.) OUTPUT POWER vs. LOAD RESISTANCE 60 THD+N = 10% POUT (mW) 90 60 45 30 THD+N = 1% THD+N = 1% 15 0 0 1 10 1000 100 10 POWER DISSIPATION vs. OUTPUT POWER POWER DISSIPATION vs. OUTPUT POWER 300 RLOAD = 32I 200 VDD = 3.
PAGE 7
DirectDrive Headphone Amplifier with External Gain -80 -40 OUTPUT SPECTRUM MAX9820 toc20 0 LEFT TO RIGHT -60 -80 -100 -100 RIGHT TO LEFT RIGHT TO LEFT -120 -120 100 1000 100,000 10,000 -40 -60 -80 -100 -120 -140 10 f = 1kHz RLOAD = 32I LLOAD = 1µH -20 OUTPUT MAGNITUDE (dBV) LEFT TO RIGHT -60 RLOAD = 1kI LLOAD = 1µH FS = 707mVRMS VOUT = -20dBFS -20 CROSSTALK (dB) -40 -140 10 FREQUENCY (Hz) 100 1000 10,000 100,000 0 2 4 FREQUENCY (Hz) 6 10 12 14 16 18 20 8 FREQUENCY (kHz)
PAGE 8
DirectDrive Headphone Amplifier with External Gain MAX9820 Pin Description PIN NAME 1 C1P Flying Capacitor Positive Terminal. Connect a 1µF ceramic capacitor from C1P to C1N. FUNCTION 2 C1N Flying Capacitor Negative Terminal. Connect a 1µF ceramic capacitor from C1N to C1P. 3 VSS Charge-Pump Output. Bypass with a 1µF capacitor to GND. 4 OUTL Left-Channel Output 5 OUTR Right-Channel Output 6 INR Right-Channel Input 7 INL Left-Channel Input 8 VDD Positive Power-Supply Input.
PAGE 9
DirectDrive Headphone Amplifier with External Gain MAX9820 VOUT RF IMMUNITY vs. FREQUENCY VDD -20 VDD RF IMMUNITY (dBV) VDD/2 GND MAX9820 fig02 0 -40 LEFT CHANNEL -60 -80 CONVENTIONAL DRIVER OUTPUT WAVEFORMS -100 VOUT RIGHT CHANNEL -120 0.8 VDD 1.35 1.90 2.45 3.00 FREQUENCY (GHz) Figure 2. MAX9820 RF Susceptibility GND 2VDD Click-and-Pop Suppression -VDD MAX9820 OUTPUT WAVEFORMS Figure 1. Conventional Driver Output Waveform vs. MAX9820 Output Waveform GND (Figure 1).
PAGE 10
MAX9820 DirectDrive Headphone Amplifier with External Gain Shutdown Undervoltage Lockout (UVLO) The MAX9820 features a low-power shutdown mode that reduces quiescent current consumption to less than 1µA, extending battery life for portable applications. Drive SHDN low to disable the amplifiers and the charge pump. In shutdown mode, the amplifier output impedance is set to 600Ω || RFB. The amplifiers and charge pump are enabled once SHDN is driven high.
PAGE 11
DirectDrive Headphone Amplifier with External Gain Layout and Grounding Proper layout and grounding are essential for optimum performance. Connect EP and GND together at a single point on the PCB. Ensure ground return resistance is minimized for optimum crosstalk performance. Place the power-supply bypass capacitor, the charge-pump hold capacitor, and the charge-pump flying capacitor as close as possible to the MAX9820. Route all traces that carry switching transients away from the audio signal path.
PAGE 12
Package Information For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 10 TDFN-EP T1033+1 21-0137 6, 8, &10L, DFN THIN.
PAGE 13
DirectDrive Headphone Amplifier with External Gain COMMON DIMENSIONS PACKAGE VARIATIONS SYMBOL MIN. MAX. PKG. CODE N D2 E2 e JEDEC SPEC b [(N/2)-1] x e A 0.70 0.80 T633-2 6 1.50±0.10 2.30±0.10 0.95 BSC MO229 / WEEA 0.40±0.05 1.90 REF D 2.90 3.10 T833-2 8 1.50±0.10 2.30±0.10 0.65 BSC MO229 / WEEC 0.30±0.05 1.95 REF E 2.90 3.10 T833-3 8 1.50±0.10 2.30±0.10 0.65 BSC MO229 / WEEC 0.30±0.05 1.95 REF A1 0.00 0.05 T1033-1 10 1.50±0.10 2.30±0.10 0.