MAXIM MAX97220AETE

19-5611; Rev 0; 1/11
TION KIT
EVALUA BLE
IL
AVA A
Differential Input DirectDrive
Line Drivers/Headphone Amplifiers
DirectDrive®
Features
The MAX97220_ is a differential input
line
driver/headphone amplifier. This device is capable of
driving line level loads with 3VRMS into 1kI with a 5V
supply and 2VRMS into 600I loads from a 3.3V supply. A
headphone load is capable of being driven with 125mW
into 32I with a 5V supply. The IC is offered with an internally fixed 6dB gain or an externally set gain through
external resistors. The external gain setting nodes can
also be used to configure filters for set-top box applications. The IC has exceptional THD+N over the full audio
bandwidth.
S Output Power 125mW into 32I with a 5V Supply
Two versions of the IC are available with different turnon times (tON). The A and C versions for headphone
applications feature a tON of 5.5ms while the B and D
versions, intended for set-top-box applications, feature a
130ms tON. An on-chip charge pump inverts the powersupply input, creating a negative rail. The output stage of
the amplifier is powered between the positive input supply and the output of the charge pump. The bipolar supplies bias the output about ground, eliminating the need
for large, distortion-introducing output coupling capacitors. The IC powers on and off without clicks or pops.
S Flat THD+N, Better Than 90dB in the Audio Band
The IC is available in a 3mm x 3mm x 0.8mm, 16-pin
TQFN and is specified over the extended -40NC to +85NC
temperature range.
Applications
Simple Multimedia Interfaces
Set-Top Boxes
Blu-rayK and DVD Players
LCD Televisions
S 3VRMS Output Drive into 1kI with a 5V Supply
S 2VRMS Output Drive into 600I with a 3.3V Supply
S Fully Differential Inputs
S Fixed or Externally Adjustable Gain with No
Clicks or Pops
S Wide 2.5V to 5.5V Operating Range
S DirectDrive Outputs Eliminate DC-Blocking
Capacitors
S 18-Bit SNR Performance, 112dB
S Footprint Compatible with the MAX9722
Ordering Information
PINPACKAGE
PART
GAIN SET
TURN-ON
TIME (ms)
MAX97220AETE+
16 TQFN-EP*
External
5.5
MAX97220BETE+
16 TQFN-EP*
External
130
MAX97220CETE+
16 TQFN-EP*
+6dB
5.5
MAX97220DETE+
16 TQFN-EP*
+6dB
130
Note: All devices operate over the -40NC to +85NC temperature
range.
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
DirectDrive is a registered trademark of Maxim Integrated
Products, Inc.
Blu-ray is a trademark of the Blu-ray Disc Association.
Functional Diagrams appear at end of data sheet.
Prosumer Audio Devices
Simplified Block Diagrams
RF
RIN
LEFT
AUDIO
INPUT
INL-
INLOUTL
RIN
INL+
LEFT
AUDIO
INPUT INL+
RF
RIN
OUTL
RIN
RF
RF
MAX97220C/D
MAX97220A/B
RIN
RIGHT
AUDIO
INPUT RIN
RF
INR+
INR+
OUTR
INR-
RIGHT
AUDIO
INPUT
RIN
RF
SGND
SGND
OUTR
INR-
RIN
RF
RF
________________________________________________________________ Maxim Integrated Products 1
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.
MAX97220A–MAX97220D
General Description
MAX97220A–MAX97220D
Differential Input DirectDrive
Line Drivers/Headphone Amplifiers
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to PGND.)
SVDD, SVDD2, and PVDD.......................................-0.3V to +6V
PVSS and BIAS........................................................-6V to +0.3V
SGND....................................................................-0.3V to +0.3V
INL-, INL+, INR-, and INR+ (A and B)..... -VSVDD/2 to +VSVDD/2
INL-, INL+, INR-,
and INR+ (C and D)........ (-0.75 x VSVDD) to (+0.75 x VSVDD)
OUTL and OUTR...................................................-4.5V to +4.5V
SHDN........................................................................-0.3V to +6V
C1P.........................................................-0.3V to (VPVDD + 0.3V)
C1N........................................................ (VPVSS - 0.3V) to +0.3V
OUT_ Short Circuit to PGND......................................Continuous
OUT_ Short Circuit to PVDD.......................................Continuous
Short Circuit Between OUTL and OUTR....................Continuous
Continuous Current Into/Out of All Pins..............................20mA
Continuous Power Dissipation (TA = +70NC) (Multilayer Board)
TQFN (derate 20.8mW/NC above +70NC)...............1666.7mW
Junction Temperature......................................................+150NC
Operating Temperature Range........................... -40NC to +85NC
Storage Temperature Range............................. -65NC to +150NC
Lead Temperature (soldering, 10s).................................+300NC
Soldering Temperature (reflow).......................................+260NC
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.
PACKAGE THERMAL CHARACTERISTICS (Note 1)
TQFN
Junction-to-Ambient Thermal Resistance (qJA)...........48°C/W
Junction-to-Case Thermal Resistance (qJC)..................7°C/W
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a fourlayer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.
ELECTRICAL CHARACTERISTICS
(VPVDD = VSVDD = VSVDD2 = 5V, VPGND = VSGND = 0V, CBIAS = 0.1µF, C1 = C2 = 1µF, RIN = 20kω, RF = 20kω (MAX97220A/
MAX97220B), typical values tested at TA = +25°C, unless otherwise noted.) (Notes 2 and 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
5.5
V
GENERAL
Supply Voltage Range
PVDD,
SVDD_
Quiescent Supply Current
IPVDD
Undervoltage Lockout
UVLO
Shutdown Supply Current
Turn-On Time
IPVDD_SD
Guaranteed by PSRR test
2.5
5.5
No load, TA = +25NC
No load, VPVDD = VSVDD_ = 3.3V
PVDD falling
tON
RIN
C/D versions only
mA
2.35
V
FA
1
10
A/C versions
4.8
5.5
6.3
B/D versions
117
130
143
7.4
10
12.7
SHDN = 0, TA = +25NC
Shutdown to full operation
time
7
5
ms
AMPLIFIERS
Input Resistance
Output Signal Attenuation in
Shutdown
Gain
Output Offset Voltage
VSHDN = 0V,
RL = 10kW
AV
VOS
Input Common-Mode Voltage
Range
VCM
Maximum Differential Input
Signal
VDIFF
2
A/B versions
76
C/D versions
45
C/D versions only
5.5
Unity gain, TA = +25NC
dB
6.5
dB
350
FV
A/B versions
-0.5 x
VPVDD
+0.5 x
VPVDD
C/D versions
-0.75 x
VPVDD
+0.75 x
VPVDD
Voltage at IN+ and IN-
(Note 4)
6
kI
PVDD
V
VP
Differential Input DirectDrive
Line Drivers/Headphone Amplifiers
(VPVDD = VSVDD = VSVDD2 = 5V, VPGND = VSGND = 0V, CBIAS = 0.1µF, C1 = C2 = 1µF, RIN = 20kω, RF = 20kω (MAX97220A/
MAX97220B), typical values tested at TA = +25°C, unless otherwise noted.) (Notes 2 and 3)
PARAMETER
SYMBOL
CONDITIONS
VPVDD = VSVDD_ = 2.5V to 5.5V
Power-Supply Rejection Ratio
Common-Mode Rejection Ratio
PSRR
CMRR
VOUT
TYP
74
90
fIN = 217Hz, 200mVP-P ripple 78
fIN = 10kHz, 200mVP-P ripple
63
-VPVDD/2 P VCM P
+VPVDD/2
A/B versions
70
86
-0.75 x VPVDD P VCM P
+0.75 x VPVDD
C/D versions
45
60
Total Harmonic Distortion Plus
Noise
POUT
THD+N
1kHz, RL = 600I load,
VPVDD = VSVDD_ = 3.3V, THD+N < 0.1%
RL = 16I, THD+N = 1%
2.15
110
125
1kHz, 22Hz to 22kHz BW, VOUT = 3VRMS,
RL = 10kI
103
10kHz, 22Hz to 22kHz BW,
VOUT = 3VRMS, RL = 10kI
90
1kHz, 22Hz to 22kHz BW, VOUT = 2VRMS,
RL = 600I
10kHz, 22Hz to 30kHz BW,
VOUT = 2VRMS, RL = 600I
Signal-to-Noise Ratio
mW
105
94
0.0035
VOUT = 3VRMS, THD+N =
0.1%, A-weighted, RIN =
RF = 10kI, RL = 1kI
112.5
C/D
versions
VRMS
dB
80
1kHz, 22Hz to 22kHz BW, POUT = 20mW,
RL = 32I
SNR
dB
3.5
40
RL = 32I, THD+N = 1%
A/B
versions
UNITS
3
1kHz, RL = 10kI load, THD+N < 0.1%
Output Power
MAX
dB
1kHz, 600I load, THD+N < 0.1%
Output Voltage Swing
MIN
VOUT = 2VRMS, VPVDD
= 3.3V, THD+N = 0.1%,
A-weighted, RIN = RF =
10kI, RL = 600I
109
VOUT = 3VRMS, THD+N =
0.1%, A-weighted,
RL = 1kI
106
VOUT = 2VRMS, VPVDD
= 3.3V, THD+N = 0.1%,
A-weighted, RL = 600I
103
%
dB
3
MAX97220A–MAX97220D
ELECTRICAL CHARACTERISTICS (continued)
MAX97220A–MAX97220D
Differential Input DirectDrive
Line Drivers/Headphone Amplifiers
ELECTRICAL CHARACTERISTICS (continued)
(VPVDD = VSVDD = VSVDD2 = 5V, VPGND = VSGND = 0V, CBIAS = 0.1µF, C1 = C2 = 1µF, RIN = 20kω, RF = 20kω (MAX97220A/
MAX97220B), typical values tested at TA = +25°C, unless otherwise noted.) (Notes 2 and 3)
PARAMETER
Output Noise Voltage
SYMBOL
VN
CONDITIONS
A-weighted,
RIN = RF = 10kI
7
C/D
versions
A-weighted
14
XTALK
C/D
versions
Maximum Capacitive Load
Drive
CL
External Feedback Resistor
Range
RF
Oscillator Frequency
4
fOSC
TYP
A/B
versions
A/B
versions
Crosstalk
MIN
MAX
FV
1kHz, VOUT = 3VRMS,
RL = 10kI
-125
10kHz, VOUT = 3VRMS,
RL = 10kI
-108
1kHz, VOUT = 2VRMS,
RL = 600I, VPVDD =
VSVDD_ = 3.3V
-123
10kHz, VOUT = 2VRMS,
RL = 600I, VPVDD =
VSVDD_ = 3.3V
-104
1kHz, POUT = 20mW,
RL = 32I
-102
10kHz, POUT = 20mW,
RL = 32I
-82
1kHz, VOUT = 2VRMS,
RL = 10kI
100
10kHz, VOUT = 2VRMS,
RL = 10kI
98
1kHz, VOUT = 2VRMS,
RL = 600I
100
10kHz, VOUT = 2VRMS,
RL = 600I
96
1kHz, POUT = 20mW,
RL = 32I
95
1kHz, POUT = 20mW,
RL = 16I
92
dB
470
A/B versions
UNITS
pF
4.7
20
100
kI
450
500
550
kHz
Differential Input DirectDrive
Line Drivers/Headphone Amplifiers
(VPVDD = VSVDD = VSVDD2 = 5V, VPGND = VSGND = 0V, CBIAS = 0.1µF, C1 = C2 = 1µF, RIN = 20kω, RF = 20kω (MAX97220A/
MAX97220B), typical values tested at TA = +25°C, unless otherwise noted.) (Notes 2 and 3)
PARAMETER
SYMBOL
Click-and-Pop Level (Note 5)
KCP
LOGIC INPUT (SHDN)
SHDN Input Logic-High
VIH
SHDN Input Logic-Low
VIL
SHDN Input Leakage Current
High
IIH
SHDN Input Leakage Current
Low
IIL
CONDITIONS
MIN
TYP
32 samples per second,
A-weighted, RL = 10kI,
unity gain
Into shutdown
-70
Out of
shutdown
-70
32 samples per second,
A-weighted, RL = 32I,
unity gain
Into shutdown
-76
Out of
shutdown
-76
MAX
UNITS
dBV
1.4
V
0.4
V
TA = +25NC
1
FA
TA = +25NC
1
FA
Note 2: 100% production tested at TA = +25NC. Specifications over temperature limits are guaranteed by design.
Note 3: Dynamic specifications are taken over 2.5V to 5.5V supply range. Inputs AC-coupled to PGND.
Note 4: The maximum differential input signal does not cause any excess distortion due to violation of the common-mode input
range.
Note 5: Test performed with a resistive load connected to PGND. Mode transitions are controlled by SHDN. KCP level is calculated as 20 x log (peak voltage during mode transition, no input signal).
Typical Operating Characteristics
(VPVDD = VSVDD = VSVDD2 = 5V, VPGND = VSGND = 0V, CBIAS = 0.1µF, C1 = C2 = 1µF, RIN = 10kω, RF = 10kω, unless otherwise noted.)
-40
-50
-60
-70
-80
-90
-100
-110
VOUT = 1VRMS
VOUT = 2VRMS
-120
0.01
0.1
1
FREQUENCY (kHz)
10
VPVDD = 5V
RL = 10kI
BW = 22Hz TO 22kHz
10
VPVDD = 3.3V
RL = 32I
1
-40
-50
-60
-70
-80
-90
-100
-110
VOUT = 1VRMS
0.1
POUT = 30mW
0.01
0.001
VOUT = 3VRMS
-120
100
100
MAX97220 toc03
-20
-30
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
THD+N (%)
VPVDD = 3.3V
RL = 600I
BW = 22Hz TO 22kHz
THD+N (dB)
THD+N (dB)
-20
-30
0
-10
MAX97220 toc01
0
-10
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
MAX97220 toc02
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
0.01
0.1
1
FREQUENCY (kHz)
10
POUT = 10mW
0.0001
100
0.01
0.1
1
10
100
FREQUENCY (kHz)
5
MAX97220A–MAX97220D
ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics (continued)
(VPVDD = VSVDD = VSVDD2 = 5V, VPGND = VSGND = 0V, CBIAS = 0.1µF, C1 = C2 = 1µF, RIN = 10kω, RF = 10kω, unless otherwise noted.)
POUT = 20mW
1
0.1
POUT = 25mW
0.01
0.01
0.001
0.001
0.001
0.0001
10
100
0.0001
0.01
0.1
100
0.1
1
10
100
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. OUTPUT POWER
1.5
2.0
2.5
THD+N (%)
0.001
100
MAX97220 toc10
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
0.01
40
60
80 100 120 140 160 180
OUTPUT POWER (mW)
20
30
40
50
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. OUTPUT POWER
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. OUTPUT POWER
100
VPVDD = 5V
RL = 16I
10
THD+N (%)
0.1
FREQ = 1kHz
60
0.1
FREQ = 1kHz
0.01
0.001
0.001
20
10
1
FREQ = 300Hz
fIN = 300Hz
0.0001
0
OUTPUT POWER (mW)
0.01
0.001
fIN = 300Hz
0.0001
OUTPUT VOLTAGE (VRMS)
VPVDD = 3.3V
RL = 16I
10
THD+N (%)
fIN = 1kHz
fIN = 1kHz
fIN = 1kHz
1
0.1
0.1
0.01
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. OUTPUT POWER
1
MAX97220 toc08
fIN = 10kHz
OUTPUT VOLTAGE (VRMS)
VPVDD = 5V
RL = 32I
VPVDD = 3.3V
RL = 32I
10
1
0
3.0
100
MAX97220 toc12
1.0
VPVDD = 5V
RL = 10kI
MAX97220 toc11
0.5
0
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
-120
-130
-140
MAX97220 toc09
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. OUTPUT VOLTAGE
MAX97220 toc07
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. OUTPUT VOLTAGE
fIN = 10kHz
0
0.01
FREQUENCY (kHz)
fIN = 1kHz
10
10
FREQUENCY (kHz)
VPVDD = 3.3V
RL = 600I
100
1
FREQUENCY (kHz)
THD+N (dB)
THD+N (dB)
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
-120
-130
1
POUT = 20mW
POUT = 10mW
POUT = 90mW
0.1
POUT = 80mW
0.1
0.01
0.01
VPVDD = 5V
RL = 16I
10
THD+N (%)
0.1
0.0001
6
100
1
THD+N (%)
1
THD+N (%)
VPVDD = 3.3V
RL = 16I
10
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
MAX97220 toc06
VPVDD = 5V
RL = 32I
10
100
MAX97220 toc04
100
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
MAX97220 toc05
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
THD+N (%)
MAX97220A–MAX97220D
Differential Input DirectDrive
Line Drivers/Headphone Amplifiers
FREQ = 300Hz
0.0001
0.0001
0
10
20
30
40
OUTPUT POWER (mW)
50
60
0
20
40
60
80
100
120
OUTPUT POWER (mW)
140
160
Differential Input DirectDrive
Line Drivers/Headphone Amplifiers
OUTPUT VOLTAGE vs. SUPPLY VOLTAGE
3.0
2.5
THD+N = 1%
2.0
1.5
3.5
3.0
2.5
THD+N = 1%
2.0
1.5
175
125
100
75
50
0.5
25
0
4.0
4.5
5.0
3.0
OUTPUT POWER vs. SUPPLY VOLTAGE
120
100
80
60
40
4.5
5.0
5.5
2.5
VPVDD = 3.3V
fIN = 1kHz
3.5
THD+N = 1%
THD+N = 10%
3.0
3.0
3.5
4.0
4.5
5.0
5.5
SUPPLY VOLTAGE (V)
4.0
OUTPUT VOLTAGE (VRMS)
THD+N = 10%
140
4.0
OUTPUT VOLTAGE vs. LOAD RESISTANCE
OUTPUT VOLTAGE vs. LOAD RESISTANCE
MAX97220 toc16
fIN = 1kHz
RL = 16I
160
3.5
SUPPLY VOLTAGE (V)
200
180
THD+N = 1%
0
2.5
5.5
2.5
2.0
THD+N = 1%
5.0
VPVDD = 5V
fIN = 1kHz
4.5
OUTPUT VOLTAGE (VRMS)
3.5
MAX97220 toc17
3.0
THD+N = 10%
150
0.5
SUPPLY VOLTAGE (V)
OUTPUT POWER (mW)
200
1.0
2.5
fIN = 1kHz
RL = 32I
225
1.0
0
MAX97220 toc15
4.0
THD+N = 10%
OUTPUT POWER (mW)
3.5
fIN = 1kHz
RL = 10kI
4.5
OUTPUT POWER vs. SUPPLY VOLTAGE
250
MAX97220 toc14
THD+N = 10%
OUTPUT VOLTAGE (VRMS)
OUTPUT VOLTAGE (VRMS)
4.0
MAX97220 toc13
fIN = 1kHz
RL = 600I
4.5
5.0
MAX97220 toc18
OUTPUT VOLTAGE vs. SUPPLY VOLTAGE
5.0
THD+N = 10%
4.0
3.5
THD+N = 1%
3.0
2.5
1.5
20
2.0
1.0
3.0
3.5
4.0
4.5
5.0
5.5
1
0.1
OUTPUT POWER vs. LOAD RESISTANCE
THD+N = 10%
70
60
50
40
THD+N = 1%
30
20
MAX97220 toc20
THD+N = 10%
150
125
100
THD+N = 1%
75
100
LOAD RESISTANCE (I)
1000
100
200
VPVDD = 3.3V
RL = 32I
180
160
140
120
100
80
60
40
25
0
10
175
10
POWER DISSIPATION vs. OUTPUT POWER
50
VPVDD = 3.3V
fIN = 1kHz
10
200
OUTPUT POWER (mW)
OUTPUT POWER (mW)
80
225
1
LOAD RESISTANCE (kI)
OUTPUT POWER vs. LOAD RESISTANCE
250
MAX97220 toc19
90
0.1
100
LOAD RESISTANCE (kI)
SUPPLY VOLTAGE (V)
100
10
POWER DISSIPATION (mW)
2.5
MAX97220 toc21
0
20
fIN = 1kHz
0
0
10
100
LOAD RESISTANCE (I)
1000
0
15 30 45 60 75 90 105 120 135 150
OUTPUT POWER (mW)
7
MAX97220A–MAX97220D
Typical Operating Characteristics (continued)
(VPVDD = VSVDD = VSVDD2 = 5V, VPGND = VSGND = 0V, CBIAS = 0.1µF, C1 = C2 = 1µF, RIN = 10kω, RF = 10kω, unless otherwise noted.)
Typical Operating Characteristics (continued)
(VPVDD = VSVDD = VSVDD2 = 5V, VPGND = VSGND = 0V, CBIAS = 0.1µF, C1 = C2 = 1µF, RIN = 10kω, RF = 10kω, unless otherwise noted.)
160
2
1
0
120
40
-1
-2
-3
0
-4
80
20 40 60 80 100 120 140 160 180 200
MAX97220A/MAX97220B
AV = 0dB
0.01
0.1
OUTPUT POWER (mW)
LEFT TO RIGHT
10
RIGHT TO LEFT
LEFT TO RIGHT
0.1
1
10
10
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
-120
-130
-140
100
RL = 16I
POUT = 20mW
RIGHT TO LEFT
LEFT TO RIGHT
0.01
0.1
1
10
FREQUENCY (kHz)
CROSSTALK vs. FREQUENCY
C/D VERSIONS
CROSSTALK vs. FREQUENCY
C/D VERSIONS
CROSSTALK vs. FREQUENCY
C/D VERSIONS
-20
-30
CROSSTALK (dB)
-60
LEFT TO RIGHT
0
-10
RIGHT TO LEFT
RL = 10kI
VOUT = 2VRMS
-40
-50
-60
-70
-80
LEFT TO RIGHT
RIGHT TO LEFT
1
FREQUENCY (kHz)
10
100
-20
-30
RL = 32I
POUT = 20mW
-40
-50
-60
-70
-80
LEFT TO RIGHT
RIGHT TO LEFT
-120
-120
0.1
0
-10
100
-90
-100
-110
-90
-100
-110
-120
100
CROSSTALK vs. FREQUENCY
CROSSTALK (dB)
RL = 32I
POUT = 20mW
0.01
1
FREQUENCY (kHz)
MAX97220 toc26
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
-120
-130
-140
100
-90
-100
-110
8
0.1
FREQUENCY (kHz)
VPVDD = 3.3V
RL = 600I
VOUT = 2VRMS
0.01
0.01
1000
FREQUENCY (kHz)
-40
-50
-70
-80
LEFT TO RIGHT
MAX97220 toc30
-20
-30
CROSSTALK (dB)
RIGHT TO LEFT
1
100
CROSSTALK (dB)
0
-10
MAX97220 toc25
RL = 10kI
VOUT = 3VRMS
0.1
10
RIGHT TO LEFT
CROSSTALK vs. FREQUENCY
MAX97220 toc28
CROSSTALK (dB)
CROSSTALK vs. FREQUENCY
0.01
1
VPVDD = 3.3V
RL = 600I
VOUT = 2VRMS
FREQUENCY (kHz)
MAX97220 toc29
0
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
-120
-130
-140
CROSSTALK (dB)
200
MAX97220C/MAX97220D
AV = 6dB
4
3
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
-120
-130
-140
MAX97220 toc24
6
5
280
240
MAX97220 toc23
320
GAIN (dB)
POWER DISSIPATION (mW)
MAX97220 toc22
VPVDD = 5V
RL = 32I
360
CROSSTALK vs. FREQUENCY
GAIN FLATNESS vs. FREQUENCY
8
7
MAX97220 toc27
POWER DISSIPATION vs. OUTPUT POWER
400
CROSSTALK (dB)
MAX97220A–MAX97220D
Differential Input DirectDrive
Line Drivers/Headphone Amplifiers
0.01
0.1
1
FREQUENCY (kHz)
10
100
0.01
0.1
1
FREQUENCY (kHz)
10
100
Differential Input DirectDrive
Line Drivers/Headphone Amplifiers
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
CROSSTALK vs. FREQUENCY
C/D VERSIONS
VRIPPLE = 200mVP-P
-20
-40
-40
-50
-60
-70
-80
RIGHT TO LEFT
LEFT TO RIGHT
VPVDD = 3.3V
RL = 32I
-60
-80
-90
-100
-110
-100
VPVDD = 5V
RL = 10kI
-120
-120
0.01
0.1
1
10
0.01
100
0.1
1
10
FREQUENCY (kHz)
COMMON-MODE REJECTION RATIO
vs. FREQUENCY
COMMON-MODE REJECTION RATIO
vs. FREQUENCY
MAX97220 toc33
0
VPVDD = 3.3V
RL = 32I
-20
-30
CMRR (dB)
-40
-50
-60
-70
-80
-90
0.1
1
10
RL = 1kI
-110
-120
-100
0.01
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
100
MAX97220 toc34
FREQUENCY (kHz)
-10
CMRR (dB)
MAX97220 toc32
RL = 16I
POUT = 20mW
PSRR (dB)
CROSSTALK (dB)
-20
-30
0
MAX97220 toc31
0
-10
100
0.01
FREQUENCY (kHz)
0.1
1
10
100
FREQUENCY (kHz)
EXITING SHUTDOWN
ENTERING SHUTDOWN
MAX97220 toc36
MAX97220 toc35
MAX97220B/MAX97220D
SHDN
2V/div
SHDN
2V/div
OUT_
5V/div
OUT_
1V/div
40µs/div
20ms/div
9
MAX97220A–MAX97220D
Typical Operating Characteristics (continued)
(VPVDD = VSVDD = VSVDD2 = 5V, VPGND = VSGND = 0V, CBIAS = 0.1µF, C1 = C2 = 1µF, RIN = 10kω, RF = 10kω, unless otherwise noted.)
Typical Operating Characteristics (continued)
(VPVDD = VSVDD = VSVDD2 = 5V, VPGND = VSGND = 0V, CBIAS = 0.1µF, C1 = C2 = 1µF, RIN = 10kω, RF = 10kω, unless otherwise noted.)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
EXITING SHUTDOWN
MAX97220 toc37
NO LOAD
9
OUT_
5V/div
8
SUPPLY CURRENT (mA)
SHDN
2V/div
MAX97220 toc38
10
MAX97220A/MAX97220C
7
6
5
4
3
2
1
0
2.5
2ms/div
3.0
3.5
4.0
4.5
5.0
5.5
5.0
5.5
SUPPLY VOLTAGE (V)
SHUTDOWN CURRENT
vs. SUPPLY VOLTAGE
7
VPVDD = 5V
6
5
4
3
VPVDD = 3.3V
2
NO LOAD
1.4
1.2
1.0
0.8
0.6
0.4
0.2
1
0
0
-40
-15
10
35
60
2.5
85
3.0
SHUTDOWN CURRENT
vs. TEMPERATURE
NO LOAD
1.4
RF IMMUNITY (dB)
1.2
1.0
0.8
VPVDD = 5V
0.6
0.4
0.2
VPVDD = 3.3V
0
-0.2
-40
-15
10
35
TEMPERATURE (°C)
10
4.0
4.5
RF IMMUNITY vs. FREQUENCY
MAX97220 toc41
1.6
3.5
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
60
85
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
-120
-130
MAX97220 toc42
SUPPLY CURRENT (mA)
8
1.6
MAX97220 toc40
NO LOAD
9
SHUTDOWN CURRENT (µA)
10
MAX97220 toc39
SUPPLY CURRENT vs. TEMPERATURE
SHUTDOWN CURRENT (µA)
MAX97220A–MAX97220D
Differential Input DirectDrive
Line Drivers/Headphone Amplifiers
RL = 32I
LEFT CHANNEL
RIGHT CHANNEL
100
600
1100
1600
2100
FREQUENCY (MHz)
2600
3100
Differential Input DirectDrive
Line Drivers/Headphone Amplifiers
OUTL
BIAS
OUTR
SVDD2
TOP VIEW
12
11
10
9
SVDD 13
INL- 14
MAX97220
INL+ 15
EP
1
2
3
4
C1P
PGND
C1N
+
PVDD
SHDN 16
8
INR-
7
INR+
6
SGND
5
PVSS
TQFN
Pin Description
PIN
NAME
1
PVDD
FUNCTION
Charge-Pump Power-Supply Input. Bypass to PGND with 1FF.
2
C1P
3
PGND
4
C1N
Negative Flying Capacitor Connection. Connect a 1FF capacitor between C1P and C1N.
5
PVSS
Negative Charge-Pump Output. Bypass to PGND with 1FF.
6
SGND
Signal Ground. Connect PGND and SGND together at the system ground plane.
7
INR+
Right Positive Polarity Input
8
INR-
Right Negative Polarity Input
9
SVDD2
Signal Path Power-Supply Input. Bypass to PGND with 1FF. Connect directly to PVDD.
10
OUTR
Right DirectDrive Output
Positive Flying Capacitor Connection. Connect a 1FF capacitor between C1P and C1N.
Power Ground. Connect PGND and SGND together at the system ground plane.
11
BIAS
Internal Supply Node. Bypass to PGND with 0.1FF.
12
OUTL
Left DirectDrive Output
13
SVDD
Signal Path Power-Supply Input. Bypass to PGND with 1FF. Connect directly to PVDD.
14
INL-
Left Negative Polarity Input
15
INL+
Left Positive Polarity Input
16
SHDN
EP
Active-Low Shutdown. Drive SHDN high for normal operation.
Exposed Pad. Electrically connect to PGND or leave unconnected.
—
11
MAX97220A–MAX97220D
Pin Configuration
MAX97220A–MAX97220D
Differential Input DirectDrive
Line Drivers/Headphone Amplifiers
Detailed Description
The MAX97220_ is a fully differential input line driver/
headphone amplifier for set-top boxes, LCD TV, and
home theater applications where audio fidelity is of primary importance. Power consumption of the amplifier is
reduced while maintaining high SNR and THD+N performance. The MAX97220A/MAX97220B require external input and feedback resistors to set amplifier gain.
The MAX97220C/MAX97220D feature internal input and
feedback resistors for a set gain of +6dB. Output swings
of 3VRMS with a 5V supply and 2VRMS with a 3.3V supply
are perfect for line driver applications.
High fidelity is maintained through the differential input
connection. An output noise voltage of 7FVRMS allows
for 112dB SNR when powered from 5V and 109dB SNR
when powered from 3.3V. The IC has better than 90dB
THD+N across the entire audio bandwidth.
The MAX97220_ operates from a single supply ranging
from 2.5V to 5.5V. An on-chip charge pump inverts the
positive supply (PVDD), creating an equal magnitude
negative supply (PVSS). The headphone amplifiers
PVDD
VOUT
PVDD/2
PGND
operate from bipolar supplies with their outputs biased
about PGND (Figure 1). The benefit of this PGND bias is
that the amplifier outputs do not have a DC component,
typically PVDD/2. The large DC-blocking capacitors
required with conventional headphone amplifiers are
unnecessary, thus conserving board space, reducing
system cost, and improving frequency response. Output
power of 125mW into 32I is achievable from a 5V supply. The device features an undervoltage lockout that
prevents operation from an insufficient power supply
and click-and-pop suppression that eliminates audible
transients on startup and shutdown.
Differential Input
The IC can be configured as differential or pseudodifferential input amplifiers (Figures 2 and 3), making
it compatible with all codecs. A differential input offers
improved noise immunity over a single-ended input. In
devices such as cellular phones, high-frequency signals
from the RF transmitter can couple into the amplifier’s
input traces. The signals appear at the amplifier’s inputs
as common-mode noise. A differential input amplifier
amplifies the difference of the two inputs while signals
common to both inputs are cancelled. Configured differentially, the gain of the MAX97220A/MAX97220B is
set by:
AV = RF/RIN
The common-mode rejection ratio (CMRR) is limited by
the external resistor matching, and if used, input capacitor matching at low frequencies. For example, the worstcase variation of 1% tolerant resistors results in 40dB
CMRR, while 0.1% resistors result in 60dB CMRR. For
best matching, use resistor arrays.
CONVENTIONAL DRIVER-BIASING SCHEME
RF1*
RIN1*
+PVDD
IN-
VOUT
PGND
OUT
RIN2
IN+
RF2
-PVDD
DirectDrive BIASING SCHEME
Figure 1. Conventional Driver Output Waveform vs.
MAX97220_ Output Waveform
12
RIN1 = RIN2, RF1 = RF2
*RIN1 AND RF1 ARE INTERNAL FOR MAX97220C/MAX97220D
Figure 2. Differential Input Configuration
Differential Input DirectDrive
Line Drivers/Headphone Amplifiers
OUT
AUDIO
CODEC
GND
IN-
IN+
RIN1*
OUT
RIN2
f-3dB =
RF2
RIN1 = RIN2, RF1 = RF2
*RIN1 AND RF1 ARE INTERNAL FOR MAX97220C/MAX97220D
Figure 3. Pseudo-Differential Input Configuration
DirectDrive
Conventional single-supply headphone amplifiers have
their outputs biased about a nominal DC voltage (typically
half the supply) for maximum dynamic range. Large coupling capacitors are needed to block this DC bias from
the headphone. Without these capacitors, a significant
amount of DC current flows to the headphone, resulting in
unnecessary power dissipation and possible damage to
both the headphone and the headphone amplifier.
Maxim’s patented DirectDrive architecture uses a charge
pump to create an internal negative supply voltage,
allowing the IC's outputs to be biased about PGND.
With no DC component, there is no need for the large
DC-blocking capacitors. Instead of two large (220FF,
typ) tantalum capacitors, the IC charge pump requires
two small ceramic capacitors, conserving board space,
reducing cost, and improving the frequency response of
the headphone amplifier.
Input Filter
In addition to the cost and size disadvantages of
DC-blocking capacitors required by conventional headphone amplifiers, these capacitors limit the amplifier’s
low-frequency response and can distort the audio signal.
If input capacitors are used, input capacitor CIN, in conjunction with internal input resistor RIN, forms a highpass
1
2πRINCIN
Setting f-3dB too high affects the low-frequency response
of the amplifier. Use capacitors with adequately low voltage coefficients, such as X7R ceramic capacitors with a
high voltage rating. Capacitors with higher voltage coefficients result in increased distortion at low frequencies.
BIAS Capacitor
Bypass BIAS with a 0.1FF capacitor to PGND. Do not
connect external loads to BIAS.
Charge Pump
The MAX97220_ features a low-noise charge pump. The
500kHz switching frequency is well beyond the audio
range and, thus, does not interfere with the audio signals. The switch drivers feature a controlled switching
speed that minimizes noise generated by turn-on and
turn-off transients. By limiting the switching speed of the
charge pump, the di/dt noise caused by the parasitic
bond wire and trace inductance is minimized. The IC
requires a 1FF flying capacitor between C1P and C1N
and a 1FF hold capacitor from PVSS to PGND.
Click-and-Pop Suppression
The IC features Maxim’s industry-leading click-and-pop
suppression circuitry. When entering shutdown, the
amplifier outputs are high impedance to ground. This
scheme minimizes the energy present in the audio band.
Shutdown
The IC features a 1FA low-power shutdown mode
that reduces power consumption. When the active-low
shutdown mode is entered, the device’s internal bias
circuitry is disabled, the amplifier outputs go high impedance, and BIAS is driven to PGND. The MAX97220A/
MAX97220B inputs are driven to PGND.
13
MAX97220A–MAX97220D
filter that removes the DC bias from an incoming signal.
The AC-coupling capacitor allows the amplifier to bias
the signal to an optimum DC level. Assuming zerosource impedance, the -3dB point of the highpass filter
is given by:
RF1*
MAX97220A–MAX97220D
Differential Input DirectDrive
Line Drivers/Headphone Amplifiers
Applications Information
T
− TA
PD(MAX) = J(MAX)
qJA
MAX9722 Compatibility
The MAX97220_ is compatible with the footprint of the
MAX9722. BIAS on the MAX97220_ is in the same position as SVSS. On the MAX9722, SVSS is connected to
PVSS. For the MAX97220_, there is only one chargepump output that doubles as the amplifier’s negative
power-supply input. The connection of negative chargepump output and amplifier negative power-supply input
is internal on the MAX97220_ and external on the
MAX9722.
To implement a PCB that is compatible with both the MAX9722
and MAX97220_, put a capacitor pad from BIAS/SVSS
(MAX97220_/MAX9722 pin 11) to PGND. Also, place a 0I
resistor pad from BIAS/SVSS (MAX97220_/MAX9722 pin
11) to PVSS (pin 5 on both parts). Install the 0I resistor
when the MAX9722 is used and leave the resistor out of
circuit when the MAX97220_ is used (Figure 4).
Power Dissipation
While driving a headphone load, the IC dissipates a significant amount of power. The maximum power dissipation is given in the Continuous Power Dissipation of the
Absolute Maximum Ratings section or can be calculated
by the following equation:
where TJ(MAX) is +150NC, TA is the ambient temperature,
and BJA is the reciprocal of the derating factor in NC/W
as specified in the Absolute Maximum Ratings section.
Since the IC is a stereo amplifier, the total maximum
internal power dissipation for a given VDD and load is
given by the following equation:
PD(MAX) =
If the internal power dissipation for a given application
exceeds the maximum allowed for a given package,
reduce power dissipation by decreasing supply voltage,
ambient temperature, input signal, or gain, or by increasing
load impedance.
The TQFN package features an exposed thermal pad
on its underside. This pad lowers the package's thermal
impedance by providing a direct heat conduction path
from the die to the PCB. Connect the exposed thermal
pad to PGND or an isolated plane.
2.5V TO 5.5V
2.5V TO 5.5V
1µF
1µF
1µF
10kI
0.47µF
10kI
PVDD SVDD
OUTL
10kI
10kI
CHARGE
MAX97220A PUMP
0.47µF
10kI
10kI
10kI
SGND PGND
10kI
Figure 4. MAX97220A vs. MAX9722 PCB Layout
14
SVSS
C1P
10kI
10kI
OPEN
MAX9722
C1N
OUTR
SHDN
+INL
0.47µF
0.47µF
PVSS
+INR
-INR
0.47µF
C1
1µF
PVDD SVDD
-INL
OUTL
0.1µF
BIAS
C1P
1µF
10kI
0.47µF 10kI
-INL
+INL
0.47µF
4VDD2
π2RL
10kI
10kI
C2
1µF
10kI
C1
1µF
0I
C1N
PVSS
+INR
OUTR
-INR
0.47µF
CHARGE
PUMP
1µF
SHDN
10kI
SGND PGND
1µF
Differential Input DirectDrive
Line Drivers/Headphone Amplifiers
Charge-Pump Capacitor Selection
Use capacitors with an ESR less than 100mI for optimum performance. Low-ESR ceramic capacitors minimize the output resistance of the charge pump. For best
performance over the extended temperature range,
select capacitors with an X7R dielectric.
Flying Capacitor (C1)
The value of the flying capacitor (C1) affects the charge
pump’s load regulation and output resistance. A C1
value that is too small degrades the device’s ability to
provide sufficient current drive, which leads to a loss of
output voltage. Increasing the value of C1 improves load
regulation and reduces the charge-pump output resistance to an extent. Above 1FF, the on-resistance of the
switches and the ESR of C1 and C2 dominate.
Hold Capacitor (C2)
PCB Layout and Grounding
Good PCB layout is essential for optimizing performance.
Use large traces for the power-supply inputs and amplifier outputs to minimize losses due to parasitic trace
resistance and route heat away from the device. Good
grounding improves audio performance, and prevents
any digital switching noise from coupling into the audio.
Connect PGND and SGND together at a single point
on the PCB. Connect all components associated with
the charge pump (C1 and C2) to the PGND plane.
Connect PVDD and SVDD together at the device. Place
capacitors C1 and C2 as close as possible to the device.
Ensure the PCB layout is partisioned so that the large
switching currents in the ground plane do not return
through SGND and the traces and components in the
audio signal path. Refer to the MAX97220 Evaluation Kit
for layout guidelines.
The IC is inherently designed for excellent RF immunity.
For best performance, add ground fills around all signal
traces on top or bottom PCB planes. Also, ensure a solid
ground plane is used in multilayer PCB designs.
The hold capacitor value and ESR directly affect the
ripple at PVSS. Use a low-ESR 1FF capacitor for C2.
RF
Amplifier Gain
The gain of the MAX97220C/MAX97220D is internally
set at 6dB where all gain-setting resistors are integrated
into the device. The internally set gain, in combination
with DirectDrive, results in a headphone amplifier that
requires only tiny 1FF capacitors to complete the amplifier circuit.
RIN
LEFT
AUDIO
INPUT
INLOUTL
RIN
INL+
RF
The gain of the MAX97220A/MAX97220B amplifier is set
externally as shown in Figure 5. The gain is:
AV = -RF/RIN
Choose feedback resistor values between the 4.7kI
and 100kI range.
Supply Bypassing
Proper power-supply bypassing ensures low-noise, lowdistortion performance. Connect a 1FF ceramic capacitor from PVDD to PGND and a 1FF ceramic capacitor
from SVDD to PGND. Add additional bulk capacitance
as required by the application. Locate the bypass
capacitor as close as possible to the device.
RIN
RIGHT
AUDIO
INPUT RIN
MAX97220A
MAX97220B
RF
INR+
OUTR
INR-
RF
Figure 5. Setting the MAX97220A/MAX97220B Gain
15
MAX97220A–MAX97220D
Thermal-overload protection limits total power dissipation in the IC. When the junction temperature exceeds
+160NC, the thermal protection circuitry disables the
amplifier. Operation returns to normal once the die cools
by 15NC.
Differential Input DirectDrive
Line Drivers/Headphone Amplifiers
MAX97220A–MAX97220D
Functional Diagrams
2.5V TO 5.5V
2.5V TO 5.5V
1µF
1µF
1µF
10kI
0.47µF
10kI
PVDD SVDD
-INL
10kI
10kI
MAX97220A
MAX97220B
0.47µF
10kI
10kI
CHARGE
PUMP
C1N
SHDN SGND PGND
10kI
Chip Information
PROCESS: BiCMOS
16
0.47µF
+INR
10kI
20kI
0.47µF
CHARGE
PUMP
20kI
C1
1µF
C1N
PVSS
OUTR
-INR
CBIAS
0.1µF
OUTL
BIAS
C1P
MAX97220C
MAX97220D
OUTR
10kI
10kI
0.47µF
C2
1µF
10kI
+INL
C1
1µF
PVSS
+INR
-INR
0.47µF
CBIAS
0.1µF
OUTL
BIAS
C1P
+INL
0.47µF
20kI
0.47µF
-INL
1µF
PVDD SVDD
20kI
10kI
SHDN SGND PGND
C2
1µF
Differential Input DirectDrive
Line Drivers/Headphone Amplifiers
PACKAGE TYPE
PACKAGE CODE
OUTLINE NO.
LAND PATTERN NO.
16 TQFN
T1633-4
21-0136
90-0031
17
MAX97220A–MAX97220D
Package Information
For the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages. Note that a “+”, “#”,
or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
MAX97220A–MAX97220D
Differential Input DirectDrive
Line Drivers/Headphone Amplifiers
Package Information (continued)
For the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages. Note that a “+”, “#”,
or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
18
Differential Input DirectDrive
Line Drivers/Headphone Amplifiers
REVISION
NUMBER
REVISION
DATE
0
1/11
DESCRIPTION
Initial release
PAGES
CHANGED
—
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2011
Maxim Integrated Products 19
Maxim is a registered trademark of Maxim Integrated Products, Inc.
MAX97220A–MAX97220D
Revision History