19-4436; Rev 0; 2/09
KIT
ATION
EVALU
E
BL
AVAILA
Stereo Class D Audio Subsystem
with DirectDrive Headphone Amplifier
Features
♦
Better than 9dB Margin Under EN 55022 Class B
Limits with No Filter Components
♦
Low RF Susceptibility Design Rejects TDMA
Noise from GSM Radios
♦
Input Mixer with User Defined Input Mode
♦
Stereo 715mW Speaker Output (R
L
= 8Ω,
V
DD
= 3.7V)
♦
Stereo 58mW Headphone Output (16Ω,
V
DD
= 3.7V)
♦
Low 0.04% THD+N at 1kHz (Class D Power
Amplifier)
♦
Low 0.018% THD+N at 1kHz (Headphone
Amplifier)
♦
88% Efficiency (R
L
= 8Ω, P
OUT
= 750mW)
♦
1.6Ω Analog Switch for Speaker Amplifier Bypass
♦
High Speaker Amplifier PSRR (72dB at 217Hz)
♦
High Headphone Amplifier PSRR (84dB at 217Hz)
♦
I
2
C Control
♦
Hardware and Software Shutdown Mode
♦
Ultra-Low Click and Pop
♦
Robust Design with Current and Thermal
Protection
♦
Available in Space-Saving Package
5x6 UCSP (2.5mm x 3mm)
General Description
The MAX9879 combines a high-efficiency stereo Class D
audio power amplifier with a stereo capacitor-less
DirectDrive
®
headphone amplifier. Maxim’s filterless class
D amplifiers with active emissions limiting technology pro-
vide Class AB performance with Class D efficiency.
The Class D power amplifier delivers up to 715mW from
a 3.7V supply into an 8Ω load with 88% efficiency to
extend battery life. The filterless modulation scheme
combined with active emission limiting circuitry and
spread-spectrum modulation greatly reduces EMI while
eliminating the need for output filtering used in tradition-
al Class D devices.
The headphone amplifier delivers up to 58mW from a
3.7V supply into a 16Ω load. Maxim’s patented
DirectDrive architecture produces a ground-referenced
output from a single supply, eliminating the need for
large DC-blocking capacitors, saving cost, space and
component height.
The device utilizes a user-defined input architecture,
three preamplifier gain settings, an input mixer, volume
control, comprehensive click-and-pop suppression, and
I
2
C control. A bypass mode feature disables the integrat-
ed Class D amplifier and utilizes an internal DPST switch
to allow an external amplifier to drive the speaker that is
connected at the outputs of the MAX9879.
The MAX9879 is available in a thermally efficient,
space-saving 30-bump UCSP™ package.
MAX9879
Ordering Information
PART
MAX9879ERV+
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
30 UCSP (5x6)
Applications
Cell Phones
Portable Multimedia Players
DirectDrive is a registered trademark of Maxim Integrated
Products, Inc.
UCSP is a trademark of Maxim Integrated Products, Inc.
+Denotes
a lead(Pb)-free/RoHS-compliant package.
Simplified Block Diagram
SINGLE SUPPLY
2.7V TO 5.5V
Pin Configuration
TOP VIEW
(BUMP SIDE DOWN)
1
2
3
4
5
6
PREAMPLIFIER
VOLUME
CONTROL
A
C1P
B
C1N
RXIN-
PGNDL
RXIN+
PGNDR
PVDDR
OUTL-
PVDDL
OUTL+
PGNDR
OUTR-
MIXER
I
2
C
INTERFACE
VOLUME
CONTROL
C
V
SS
D
HPL
BIAS
INB1
INA1
SCL
SDA
GND
GND
GND
GND
OUTR+
BYPASS
E
HPR
V
DD
INB2
INA2
SHDN
V
CCIO
MAX9879
________________________________________________________________
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.
Stereo Class D Audio Subsystem
with DirectDrive Headphone Amplifier
MAX9879
ABSOLUTE MAXIMUM RATINGS
V
DD
, PVDDL, PVDDR to GND ..................................-0.3V to +6V
V
DD
, PVDDL to PVDDR .........................................-0.3V to +0.3V
V
DD
to PVDDL .......................................................-0.3V to +0.3V
V
CCIO
to GND...........................................................-0.3V to +4V
PGNDL, PGNDR, to GND......................................-0.3V to +0.3V
PGNDL to PGNDR.................................................-0.3V to +0.3V
V
SS
to GND...............................................................-6V to +0.3V
C1N to GND ................................................(V
SS
- 0.3V) to +0.3V
C1P to GND ...........................................-0.3V to (PVDD_ + 0.3V)
HPL, HPR to V
SS
(Note 1).............................-0.3V to the lower of
(V
DD
- V
SS
+ 0.3V) or +9V
HPL, HPR to V
DD
(Note 2) .........................+0.3V to the higher of
(V
SS
- PVDD_ - 0.3V) or -9V
INA1, INA2, INB1, INB2, BIAS..................................-0.3V to +4V
SDA, SCL,
SHDN......................................................-0.3V
to +4V
All Other Pins to GND ............................-0.3V to (PVDD_ + 0.3V)
Continuous Current In/Out of PVDD_, PGND_, OUT_ ....±800mA
Continuous Current In/Out of HPR and HPL .....................140mA
Continuous Current In/Out of RXIN+ and RXIN- ...............150mA
Continuous Input Current V
SS
...........................................100mA
Continuous Input Current (All Other Pins) ........................±20mA
Duration of OUT_ Short Circuit
to PGND_ or PVDD_...............................................Continuous
Duration of Short Circuit
Between OUT_+ and OUT_- ..................................Continuous
Duration of HP_ Short Circuit to GND or PVDDL........Continuous
Continuous Power Dissipation (T
A
= +70°C)
5x6 UCSP Multilayer Board
(derate 16.5mW/°C above +70°C) .............................1250mW
Junction Temperature ......................................................+150°C
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1:
HPR and HPL should be limited to no more than 9V above V
SS
, or above PV
DD
+ 0.3V, whichever limits first.
Note 2:
HPR and HPL should be limited to no more than 9V below PV
DD
, or below V
SS
- 0.3V, whichever limits first.
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
DD
= V
PVDDL
= V
PVDDR
= 3.7V, V
CCIO
= 1.8V, V
GND
= V
PGNDL
= V
PGNDR
= 0. Single-ended inputs, preamp = 0, volume controls =
0dB, BYPASS = 0,
SHDN
= 1. Speaker loads connected between OUT_+ and OUT_-. Headphone loads connected from HPL or HPR to
GND. R
SPK
=
∞,
R
HP
=
∞.
C1 = C2 = C
BIAS
= 1µF. T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
(Notes 3, 4)
PARAMETER
Analog Supply Voltage Range
Digital Supply Voltage Range
SYMBOL
V
DD
,
PVDDR
PVDDL
V
CCIO
CONDITIONS
Guaranteed by PSRR Test
MIN
2.7
1.7
HP mode, R
HP
=
∞
Quiescent Current
I
DD
Stereo SPK mode, R
SPK
=
∞
Mono SPK mode, R
SPK
=
∞
Stereo SPK + HP mode, R
HP
= R
SPK
=
∞
I
SHDN
= I
DD
+ I
PVDDR
+
I
PVDDL
+ I
CC
; T
A
= +25°C
Software
shutdown
Hardware
shutdown
5.6
9.8
6.6
13.2
5
0.1
10
11
3
21
5.5
2.3
1.2
0.230
V
P-P
31
8
TYP
MAX
5.5
3.6
9.0
18
10
24
10
µA
1
ms
kΩ
mA
UNITS
V
V
Shutdown Current
I
SHDN
Turn-On Time
Input Resistance
t
ON
R
IN
Time from shutdown or power-on to full
operation
T
A
= +25°C, preamp = 0dB or +5.5dB
T
A
= +25°C, preamp = +20dB
Preamp = 0
Preamp = +5.5dB
Preamp = +20dB
Maximum Input Signal Swing
2
_______________________________________________________________________________________
Stereo Class D Audio Subsystem
with DirectDrive Headphone Amplifier
MAX9879
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= V
PVDDL
= V
PVDDR
= 3.7V, V
CCIO
= 1.8V, V
GND
= V
PGNDL
= V
PGNDR
= 0. Single-ended inputs, preamp = 0, volume controls =
0dB, BYPASS = 0,
SHDN
= 1. Speaker loads connected between OUT_+ and OUT_-. Headphone loads connected from HPL or HPR to
GND. R
SPK
=
∞,
R
HP
=
∞.
C1 = C2 = C
BIAS
= 1µF. T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
(Notes 3, 4)
PARAMETER
Common-Mode Rejection Ratio
Input DC Voltage
Bias Voltage
SPEAKER AMPLIFIER
T
A
= +25°C (volume at mute)
Output Offset Voltage
V
OS
T
A
= +25°C (volume at 0dB, ENA = 1 and
ENB = 0 or ENB = 1 and ENA = 0,
ΔIN
_ = 0)
Peak voltage,
T
A
= +25°C
A-weighted, 32 samples
per second, volume at
mute (Note 5)
Into shutdown
Out of shutdown
PVDD_ = V
DD
= 2.7V to 5.5V
f = 217Hz,
100mV
P-P
ripple
f = 1kHz,
100mV
P-P
ripple
f = 20kHz,
100mV
P-P
ripple
Output Power
P
OUT
THD+N
≤
1%, R
SPK
=
8Ω
V
DD
= 3.7V
V
DD
= 3.3V
V
DD
= 3.0V
Total Harmonic Distortion + Noise
THD+N
f = 1kHz, P
OUT
= 350mW, T
A
= +25°C,
R
SPK
= 8Ω
A-weighted, ENA = 1
and ENB = 0 or ENB = 1
and ENA = 0
Signal-to-Noise Ratio
SNR
A-weighted ENA =
ENB = 1
ΔIN_
= 0
(single-ended)
ΔIN_
= 1
(differential)
ΔIN_
= 0
(single-ended)
ΔIN_
= 1
(differential)
50
±0.5
±4.5
-70
dBV
-70
76
72
dB
68
55
715
565
470
0.04
92
94
dB
88
92
700
±40
kHz
0.2
%
mW
±4
mV
mV
V
BIAS
SYMBOL
CMRR
CONDITIONS
Preamp = 0
f
IN
= 1kHz (differential
input mode)
IN__ inputs
Preamp = 5.5dB
Preamp = 20dB
1.22
1.13
MIN
TYP
58
55
43
1.3
1.2
1.38
1.272
V
V
dB
MAX
UNITS
Click-and-Pop Level
K
CP
Power-Supply Rejection Ratio
(Note 5)
PSRR
T
A
= +25°C
Output Frequency
_______________________________________________________________________________________
3
Stereo Class D Audio Subsystem
with DirectDrive Headphone Amplifier
MAX9879
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= V
PVDDL
= V
PVDDR
= 3.7V, V
CCIO
= 1.8V, V
GND
= V
PGNDL
= V
PGNDR
= 0. Single-ended inputs, preamp = 0, volume controls =
0dB, BYPASS = 0,
SHDN
= 1. Speaker loads connected between OUT_+ and OUT_-. Headphone loads connected from HPL or HPR to
GND. R
SPK
=
∞,
R
HP
=
∞.
C1 = C2 = C
BIAS
= 1µF. T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
(Notes 3, 4)
PARAMETER
Current Limit
Efficiency
Speaker Gain
Output Noise
Crosstalk
HEADPHONE AMPLIFIERS
T
A
= +25°C (volume at mute)
Output Offset Voltage
V
OS
T
A
= +25°C (Volume at 0dB, ENA = 1 and
ENB = 0 or ENA = 0 and ENB = 1,
ΔIN
_ = 0)
Peak voltage, T
A
= 25°C
A-weighted, 32 samples
per second, volume at
mute (Note 5)
Into shutdown
Out of shutdown
PVDD_ = V
DD
= 2.7V to 5.5V
f = 217Hz,
V
RIPPLE
= 100mV
P-P
f = 1kHz,
V
RIPPLE
= 100mV
P-P
f = 20kHz,
V
RIPPLE
= 100mV
P-P
R
HP
= 16Ω
R
HP
= 32Ω
2.6
T
A
= +25°C, HPL to HPR, volume at 0dB,
ENA=1 and ENB = 0 or ENA = 1 and ENB
= 0,
ΔIN_
= 0
R
HP
= 32Ω
(P
OUT
= 10mW, f = 1kHz)
R
HP
= 16Ω
(P
OUT
= 10mW, f = 1kHz)
70
±0.22
±1.5
-75
dBV
-75
85
84
dB
80
±0.85
mV
mV
η
A
V
A-weighted, (ENA = 1 and ENB = 0
or ENA = 0 and ENB = 1),
ΔIN_
= 0
OUTL to OUTR, OUTR to OUTL,
f = 20Hz to 20kHz
P
OUT
= 600mW, f = 1kHz
17.4
SYMBOL
CONDITIONS
MIN
TYP
1.5
88
18
63
75
18.4
MAX
UNITS
A
%
dB
µV
RMS
dB
Click-and-Pop Level
K
CP
Power-Supply Rejection Ratio
(Note 5)
PSRR
T
A
= +25°C
62
58
54
3
±0.3
3.4
±2.5
Output Power
Headphone Gain
Channel-to-Channel Gain
Tracking
P
OUT
A
V
THD+N = 1%
mW
dB
%
0.018
%
0.037
0.08
Total Harmonic Distortion + Noise
THD+N
4
_______________________________________________________________________________________
Stereo Class D Audio Subsystem
with DirectDrive Headphone Amplifier
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= V
PVDDL
= V
PVDDR
= 3.7V, V
CCIO
= 1.8V, V
GND
= V
PGNDL
= V
PGNDR
= 0. Single-ended inputs, preamp = 0, volume controls =
0dB, BYPASS = 0,
SHDN
= 1. Speaker loads connected between OUT_+ and OUT_-. Headphone loads connected from HPL or HPR to
GND. R
SPK
=
∞,
R
HP
=
∞.
C1 = C2 = C
BIAS
= 1µF. T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
(Notes 3, 4)
PARAMETER
SYMBOL
CONDITIONS
ENA = 1 and
ENB = 0 or
ENA = 1 and
ENB = 0
ENA = 1 and
ENB = 1
Slew Rate
Capacitive Drive
Crosstalk
Charge-Pump Frequency
VOLUME CONTROL
Minimum Setting
Maximum Setting
Input Gain
_VOL = 1
_VOL = 31
PGAIN_ = 00
Input A or B
PGAIN_ = 01
PGAIN_ = 10
Mute Attenuation
Zero-Crossing Detection Time
Out
ANALOG SWITCH
On-Resistance
R
ON
I
RXIN__
= 20mA,
RXIN_ = 0 and V
DD,
BYPASS = 1
T
A
= +25°C
T
A
= T
MIN
to T
MAX
0.3
0.3
88
dB
2.4
4
5.2
0.25
%
Ω
f = 1kHz, _VOL = 0
ZCD = 1
Speaker
Headphone
-75
0
0
5.5
20
100
110
60
dB
ms
dB
dB
dB
SR
C
L
HPL to HPR, HPR to HPL, f = 20Hz to 20kHz
ΔIN_
= 0
ΔIN_
= 1
ΔIN_
= 0
ΔIN_
= 1
MIN
TYP
98
98
96
96
0.35
100
67
350
±20
V/µs
pF
dB
kHz
dB
MAX
UNITS
MAX9879
Signal-to-Noise Ratio
SNR
A-weighted,
R
HP
= 16Ω
Total Harmonic Distortion + Noise
Series resistance is
V
DIFRXIN
= 2V
P-P
,
10Ω per switch
V
CMRXIN
= V
DD
/2,
f = 1kHz, BYPASS = 1 No series resistors
BYPASS = 0, RXIN+ and RXIN- to GND =
50Ω, R
SPK
= 8Ω, f = 10kHz, referred to
speaker output signal
Off-Isolation
DIGITAL INPUTS (SDA, SCL,
SHDN)
Input Voltage High (SDA, SCL)
Input Voltage Low (SDA, SCL)
Input Hysteresis (SDA, SCL)
V
IH
V
IL
V
HYS
0.7 x
V
CCIO
0.3 x
V
CCIO
200
V
V
mV
_______________________________________________________________________________________
5
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