How it Works
Rainbow Electronics
Loading...
MAX98314
User Manual
14 pgs2.61 Mb0
Table of contents
Loading...

Rainbow Electronics MAX98314 User Manual

Download
EVALUATION KIT AVAILABLE
19-6124; Rev 0; 11/11
MAX98314
Mono 3.2W Class D Amplifier
with Integrated Input Coupling Capacitors

General Description

The MAX98314 mono 3.2W Class D amplifier provides Class AB audio performance with Class D efficiency. This device offers five selectable gain settings (0dB, 3dB, 6dB, 9dB, and 12dB) set by a single gain-select input (GAIN).
Active emissions limiting (AEL) edge rate and overshoot control circuitry and a filterless spread-spectrum modu­lation (SSM) scheme greatly reduce EMI and eliminate the need for output filtering found in traditional Class D devices.
The IC’s low 0.95mA at 3.7V, 1.2mA at 5.0V quiescent current extends battery life in portable applications.
Highly linear, integrated input coupling capacitors (CIN) reduce solution size and provide excellent THD+N, PSRR, and CMRR performance at low frequencies vs. standard Class D amplifiers using external input capacitors.
The IC is available in a small 9-bump, 0.3mm pitch WLP (1.0mm x 1.0mm x 0.80mm) package and is specified over the -40NC to +85NC extended temperature range.

Applications

Mobile Phones
Portable Audio
Notebook Computers
MP3 Players
Netbook Computers
VoIP Phones

Features

S Integrated Input Coupling Capacitors with
Excellent Linearity
fC = 100Hz (6dB)  fC = 200Hz (12dB)
S Low Quiescent Current
0.95mA at 3.7V 1.2mA at 5.0V
S Delivers High Output Power at 10% THD+N
3.2W into 4I, V960mW into 8I, V
S Ultra-Low Noise: 19µV
S Eliminates Output Filtering Requirement
Spread Spectrum and Active Emissions Limiting
S Click-and-Pop Suppression
S Thermal and Overcurrent Protection
S Low Current Shutdown Mode
S Small, Space-Saving Package
PVDD
PVDD
= 5V
= 3.7V

Simplified Block Diagram

C
IN
C
IN
MAX98314
CLASS D
MODULATOR
AND H-BRIDGE
Ordering Information appears at end of data sheet.
For related parts and recommended products to use with this part, refer to: www.maxim-ic.com/MAX98314.related
����������������������������������������������������������������� Maxim Integrated Products 1
GAIN CONTROL
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.
MAX98314
Mono 3.2W Class D Amplifier
with Integrated Input Coupling Capacitors

Functional Diagram/Typical Application Circuit

2.5V TO 5.5V
SHDN
GAIN
IN+
0.1µF
PVDD
A3
C1
UVLO/POWER
MANAGEMENT
MAX98314
B3
C3
C2
IN-
10µF*
CLICK-AND-POP
SUPPRESSION
CLASS D
MODULATOR
B1
PGND
LOW-EMI
DRIVER
LOW-EMI
DRIVER
PVDD
A1A2OUT-
PGND
PVDD
OUT+
PGND
*SYSTEM BULK CAPACITANCE.
����������������������������������������������������������������� Maxim Integrated Products 2
MAX98314
Mono 3.2W Class D Amplifier
with Integrated Input Coupling Capacitors

ABSOLUTE MAXIMUM RATINGS

PVDD, IN+, IN-, SHDN, GAIN to PGND ................... 0.3V to +6V
OUT+, OUT- to PGND ............................0.3V to (V
Continuous Current In/Out of PVDD, PGND, OUT_ .........750mA
Continuous Input Current (all other pins) ........................ Q20mA
Duration of Short Circuit Between
OUT_ to PVDD, PGND ..........................................Continuous
Between OUT+ and OUT- Pins .............................Continuous
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.
PVDD
+ 0.3V)
PACKAGE THERMAL CHARACTERISTICS (Note 1)
WLP
Junction-to-Ambient Thermal Resistance (BJA) ........102NC/W
Junction-to-Case Thermal Resistance (BJC) ...............47NC/W
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-
layer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.
Continuous Power Dissipation (TA = +70NC) for Multilayer Board
WLP (derate 10.64mW/NC above +70NC) .....................851mW
Junction Temperature .....................................................+150NC
Operating Temperature Range .......................... -40NC to +85NC
Storage Temperature Range ............................ -65NC to +150NC
Soldering Temperature (reflow) ......................................+260NC

ELECTRICAL CHARACTERISTICS

(V
= V
PVDD
ment bandwidth 20Hz to 22kHz, TA = T
AMPLIFIER CHARACTERISTICS
Supply Voltage Range V Undervoltage Lockout UVLO PVDD falling 1.8 2.2 V
Quiescent Current I
Shutdown Supply Current
Turn-On Time t
Bias Voltage V
Voltage Gain A
Input Capacitance C
Highpass Corner Frequency f
= V
SHDN
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
GAIN
= 5V, V
= 0V, AV = 6dB (GAIN = PVDD), RL = J, RL connected between OUT+ to OUT-, AC measure-
PGND
MIN
PVDD
PVDD
I
SHDN
ON
BIAS
IN
C
to T
V
, unless otherwise noted. Typical values are at TA = +25NC.) (Note 2, 3)
MAX
Guaranteed by PSRR test 2.5 5.5 V
V
= 5V 1.2 1.8
PVDD
V
= 3.7V 0.95
PVDD
V
= 0V, TA = +25NC
SHDN
3.7 10 ms
V
GAIN connected to PGND 11.75 12 12.25 GAIN connected to PGND
through 100kI Q5% resistor
f = 1kHz
All gains 0.011
-3dB down
GAIN connected to PVDD 5.75 6 6.25
GAIN connected to PVDD through 100kI Q5% resistor
GAIN unconnected -0.25 0 +0.25
AV = 12dB 199
AV = 9dB 139
AV = 6dB 63 100 189
AV = 3dB 70
AV = 0dB 50
8.75 9 9.25
2.75 3 3.25
< 0.1 10
/2 V
PVDD
mA
FA
dB
FF
Hz
����������������������������������������������������������������� Maxim Integrated Products 3
MAX98314
Mono 3.2W Class D Amplifier
with Integrated Input Coupling Capacitors
ELECTRICAL CHARACTERISTICS (continued)
(V
= V
PVDD
ment bandwidth 20Hz to 22kHz, TA = T
Common-Mode Rejection Ratio CMRR fIN = 1kHz, input referred 67 dB
Output Offset Voltage V
= V
SHDN
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
GAIN
= 5V, V
= 0V, AV = 6dB (GAIN = PVDD), RL = J, RL connected between OUT+ to OUT-, AC measure-
PGND
MIN
OS
to T
, unless otherwise noted. Typical values are at TA = +25NC.) (Note 2, 3)
MAX
TA = +25NC (Note 4) Q1 Q3
mV
RL = 8I + 68FH, peak voltage, TA = +25NC,
Click-and-Pop Level K
Power-Supply Rejection Ratio (Note 4)
Output Power P
Total Harmonic Distortion Plus Noise
Output Noise V
Efficiency
Oscillator Frequency f
Spread-Spectrum Bandwidth 20 kHz
Current Limit 2.8 A
Thermal Shutdown Level 155
CP
PSRR
OUT
THD+N fIN = 1kHz
N
E RL = 8I, P
OSC
A-weighted, 32 samples per second, TA = +25NC (Notes 4, 5)
V
= 2.5V to 5.5V, TA = +25NC
PVDD
V
THD+N = 10% f = 1kHz RL = 4I + 33FH
THD+N = 1% f = 1kHz RL = 4I + 33FH
THD+N = 10% f = 1kHz RL = 8I + 68FH
THD+N = 1% f = 1kHz RL = 8I + 68FH
A-weighted (Note 4)
RIPPLE
= 200mV
= 1.8W, f = 1kHz
OUT
P-P
Into shutdown -59
Out of shutdown -82
70 90 f = 217Hz 74 f = 1kHz 72 f = 20kHz 49 V
= 5.0V 3.2
PVDD
V
= 4.2V 2.2
PVDD
V
= 3.7V 1.7
PVDD
V
= 5.0V 2.6
PVDD
V
= 4.2V 1.8
PVDD
V
= 3.7V 1.4
PVDD
V
= 5.0V 1.8
PVDD
V
= 4.2V 1.2
PVDD
V
= 3.7V 0.96
PVDD
V
= 5.0V 1.4
PVDD
V
= 4.2V 1
PVDD
V
= 3.7V 0.8
PVDD
RL = 4I, P
= 1W
OUT
RL = 8I P
= 0.725W
OUT
AV = 12dB 31
AV = 9dB 26
AV = 6dB 23
AV = 3dB 21
AV = 0dB 19
0.03 0.1
0.03
93 %
300 kHz
FV
dBV
dB
W
%
RMS
NC
����������������������������������������������������������������� Maxim Integrated Products 4
MAX98314
Mono 3.2W Class D Amplifier
with Integrated Input Coupling Capacitors
ELECTRICAL CHARACTERISTICS (continued)
(V
= V
PVDD
ment bandwidth 20Hz to 22kHz, TA = T
Thermal Hysteresis 15
DIGITAL INPUT (SHDN)
Input Voltage High V
Input Voltage Low V
Input Leakage Current
Note 2: All devices are 100% production tested at TA = +25NC. Specifications over temperature limits are guaranteed by design. Note 3: Testing performed with a resistive load in series with an inductor to simulate an actual speaker load. For RL = 4I,
Note 4: Amplifier inputs AC-coupled to ground. Note 5: Mode transitions controlled by SHDN control pin.
(V
= V
PVDD
to 22kHz, TA = +25NC, unless otherwise noted.)
10
1
SHDN
= V
GAIN
= 5V, V
= 0V, AV = 6dB (GAIN = PVDD), RL = J, RL connected between OUT+ to OUT-, AC measure-
PGND
MIN
to T
, unless otherwise noted. Typical values are at TA = +25NC.) (Note 2, 3)
MAX
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
V
INH
INL
= 2.5V to 5.5V 1.4 V
PVDD
V
= 2.5V to 5.5V 0.4 V
PVDD
TA = +25NC Q1 FA
L = 33FH. For RL = 8I, L = 68FH.

Typical Operating Characteristics

= 5.0V, V
SHDN
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
V
= 5V
PVDD
Z
= 4I + 33µH
LOAD
P
= 2W
OUT
= 0V, AV = 6dB, RL = J, RL connected between OUT+ to OUT-, AC measurement bandwidth 20Hz
PGND
MAX98314 toc01
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
10
V
= 4.2V
PVDD
Z
= 4I + 33µH
LOAD
1
P
= 1W
OUT
MAX98314 toc02
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
10
V
= 3.7V
PVDD
Z
= 4I + 33µH
LOAD
P
= 0.8W
1
OUT
NC
MAX98314 toc03
0.1
THD+N (%)
0.01
0.001
P
= 1.5W
OUT
10 100k
FREQUENCY (Hz)
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
10
V
= 5V
PVDD
Z
= 8I + 68µH
LOAD
P
= 1.2W
1
0.1
THD+N (%)
0.01
0.001 10 100k
OUT
P
= 0.2W
OUT
FREQUENCY (Hz)
����������������������������������������������������������������� Maxim Integrated Products 5
0.1
THD+N (%)
0.01
P
= 0.5W
OUT
10k1k100
0.001 10 100k
FREQUENCY (Hz)
10k1k100
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
10
V
= 4.2V
PVDD
Z
= 8I + 68µH
MAX98314 toc04
THD+N (%)
10k1k100
LOAD
1
0.1
0.01
0.001 10 100k
P
= 0.6W
OUT
P
= 0.3W
OUT
FREQUENCY (Hz)
10k1k100
MAX98314 toc05
0.1
THD+N (%)
0.01
P
= 0.2W
OUT
0.001 10 100k
FREQUENCY (Hz)
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
10
V
= 3.7V
PVDD
Z
= 8I + 68µH
LOAD
1
0.1
THD+N (%)
0.01
0.001
P
= 0.2W
OUT
10 100k
FREQUENCY (Hz)
10k1k100
= 0.4W
MAX98314 toc06
P
OUT
10k1k100
with Integrated Input Coupling Capacitors
TOTAL HARMONIC DISTORTION PLUS
TOTAL HARMONIC DISTORTION PLUS
TOTAL HARMONIC DISTORTION PLUS
TOTAL HARMONIC DISTORTION PLUS
TOTAL HARMONIC DISTORTION PLUS
TOTAL HARMONIC DISTORTION PLUS
(V
= V
PVDD
to 22kHz, TA = +25NC, unless otherwise noted.)
TOTAL HARMONIC DISTORTION PLUS
100
10
= 5.0V, V
SHDN
NOISE vs. OUTPUT POWER
V
= 5V
PVDD
Z
= 4I + 33µH
LOAD
= 0V, AV = 6dB, RL = J, RL connected between OUT+ to OUT-, AC measurement bandwidth 20Hz
PGND
MAX98314 toc07
MAX98314
Mono 3.2W Class D Amplifier
Typical Operating Characteristics (continued)
TOTAL HARMONIC DISTORTION PLUS
100
NOISE vs. OUTPUT POWER
MAX98314 toc08
100
10
V
= 4.2V
PVDD
= 4I + 33µH
Z
LOAD
10
NOISE vs. OUTPUT POWER
NOISE vs. OUTPUT POWER
V
= 3.7V
PVDD
Z
= 4I + 33µH
LOAD
MAX98314 toc09
1
THD+N (%)
0.1
0.01
0.001 0 4.0
100
V Z
10
1
THD+N (%)
0.1
0.01
0.001
f = 6kHz
f = 1kHz
f = 100Hz
OUTPUT POWER (W)
NOISE vs. OUTPUT POWER
NOISE vs. OUTPUT POWER
= 5V
PVDD
= 8I + 68µH
LOAD
f = 6kHz
f = 1kHz
f = 100Hz
OUTPUT POWER (W)
1
THD+N (%)
0.1
0.01
3.53.02.52.01.51.00.5
0.001 0 2.5
f = 6kHz
f = 1kHz
OUTPUT POWER (W)
f = 100Hz
1
THD+N (%)
0.1
0.01
2.01.51.00.5
0.001
NOISE vs. OUTPUT POWER
MAX98314 toc11
100
10
1
THD+N (%)
0.1
0.01
0.001 0 1.2
100
V
= 4.3V
PVDD
Z
= 8I + 68µH
MAX98314 toc10
THD+N (%)
1.51.00.50
2.0
LOAD
10
1
0.1
0.01
0.001 0 1.5
f = 6kHz
f = 1kHz
f = 100Hz
OUTPUT POWER (W)
1.20.90.60.3
f = 6kHz
f = 1kHz
f = 100Hz
OUTPUT POWER (W)
NOISE vs. OUTPUT POWER
V
= 3.7V
PVDD
= 8I + 68µH
Z
LOAD
f = 6kHz
f = 1kHz
f = 100Hz
0.3 OUTPUT POWER (W)
1.51.00.50
0.90.6
2.0
MAX98314 toc12
OUTPUT POWER vs. LOAD RESISTANCE
4.5
4.0
3.5
3.0
2.5
2.0
1.5
OUTPUT POWER (W)
1.0
0.5
0
1 1000
THD+N = 10%
THD+N = 1%
R
LOAD
����������������������������������������������������������������� Maxim Integrated Products 6
(I)
OUTPUT POWER vs. LOAD RESISTANCE
MAX98314 toc13
OUTPUT POWER (W)
2.5
2.0
1.5
1.0
THD+N = 1%
0.5
0
1 1000
THD+N = 10%
R
LOAD
(I)
V
PVDD
10010
= 3.7V
MAX98314 toc14
V
= 5V
PVDD
10010
OUTPUT POWER vs. SUPPLY VOLTAGE
4.5 f = 1kHz
4.0 Z
= 4I + 33µH
LOAD
3.5
3.0
2.5
2.0
1.5
OUTPUT POWER (W)
1.0
0.5
0
2.5 5.5
THD+N = 10%
THD+N = 1%
SUPPLY VOLTAGE (V)
MAX98314 toc15
5.04.54.03.53.0
with Integrated Input Coupling Capacitors
(V
= V
PVDD
to 22kHz, TA = +25NC, unless otherwise noted.)
OUTPUT POWER vs. SUPPLY VOLTAGE
2.5
2.0
1.5
1.0
OUTPUT POWER (W)
0.5
0
2.5 5.5
100
90
80
70
60
50
40
EFFICIENCY (%)
30
20
10
0
0 2.0
SHDN
f = 1kHz Z
LOAD
= 8I + 68µH
= 5.0V, V
THD+N = 10%
THD+N = 1%
SUPPLY VOLTAGE (V)
= 0V, AV = 6dB, RL = J, RL connected between OUT+ to OUT-, AC measurement bandwidth 20Hz
PGND
EFFICIENCY vs. OUTPUT POWER
V
PVDD
Z
= 8I + 68µH
LOAD
OUTPUT POWER (W)
Z
LOAD
= 4I + 33µH
1.51.00.5
POWER-SUPPLY REJECTION RATIO vs. SUPPLY VOLTAGE
0
f = 1kHz
-10 V
RIPPLE
-20
-30
-40
-50
PSRR (dB)
-60
-70
-80
-90
-100
2.5 5.5
MAX98304 toc16
5.04.54.03.53.0
= 3.7V
MAX98314 toc19
= 200mV
P-P
SUPPLY VOLTAGE (V)
MAX98314
Mono 3.2W Class D Amplifier
Typical Operating Characteristics (continued)
GAIN vs. FREQUENCY
20
15
10
5
0
GAIN (dB)
-5
-10
-15
-20
GAIN = 9dB
GAIN = 3dB
GAIN = 0dB
1k 100k
FREQUENCY (Hz)
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
SUPPLY CURRENT (mA)
0.4
0.2
0
2.5 5.5 SUPPLY VOLTAGE (V)
120 110
MAX98314 toc22
5.04.54.03.53.0
100
90 80 70 60
CMRR (dB)
50 40 30 20 10
0
GAIN = 12dB
MAX98314 toc17
GAIN = 6dB
10k10010
5.04.54.03.53.0
EFFICIENCY (%)
MAX98314 toc20
PSRR (dB)
COMMON-MODE REJECTION RATIO
vs. FREQUENCY
Z
= 8I + 68µH
LOAD
AV = 9dB
AV = 12dB
AV = 3dB
AV = 6dB
FREQUENCY (Hz)
EFFICIENCY vs. OUTPUT POWER
100
90
80
Z
= 8I + 68µH
LOAD
70
60
50
40
30
20
10
0
0 3.5
OUTPUT POWER (W)
Z
LOAD
V
PVDD
= 4I + 33µH
POWER-SUPPLY REJECTION
RATIO vs. FREQUENCY
100
V
= 200mV
RIPPLE
90
Z
LOAD
80
70
60
50
40
30
20
10
0
10 100k
AV = 0dB
10k1k10010 100k
= 8I + 68µH
FREQUENCY (Hz)
MAX98314 toc23
P-P
10k1k100
= 5V
MAX98314 toc18
3.02.51.5 2.01.00.5
MAX98314 toc21
����������������������������������������������������������������� Maxim Integrated Products 7
with Integrated Input Coupling Capacitors
(V
= V
PVDD
to 22kHz, TA = +25NC, unless otherwise noted.)
SHDN
= 5.0V, V
= 0V, AV = 6dB, RL = J, RL connected between OUT+ to OUT-, AC measurement bandwidth 20Hz
PGND
MAX98314
Mono 3.2W Class D Amplifier
Typical Operating Characteristics (continued)
STARTUP RESPONSE
WIDEBAND vs. FREQUENCY
0
-20
-40
-60
-80
OUTPUT MAGNITUDE (dBV)
-100
MAX98314 toc24
RBW = 100Hz
V
SHDN
2V/div
I
SPKR_OUT
100mA/div
MAX98314 toc26
SHUTDOWN RESPONSE
NARROWBAND vs. FREQUENCY
0
f = 1kHz V
= -60dBV
OUT
-20
-40
-60
-80
-100
OUTPUT MAGNITUDE (dBV)
-120
1ms/div
MAX98314 toc25
V
SHDN
2V/div
I
SPKR_OUT
100mA/div
MAX98314 toc27
-120
1010.1 100
FREQUENCY (MHz)
-140 10 100k
FREQUENCY (Hz)
10k1k100
����������������������������������������������������������������� Maxim Integrated Products 8
MAX98314
Mono 3.2W Class D Amplifier
with Integrated Input Coupling Capacitors

Pin Configuration

TOP VIEW
(BUMP-SIDE DOWN)
A
MAX98314
12 3
+
OUT-
PVDDOUT+
PGND
B
C
SHDN
BUMP NAME FUNCTION
A1 OUT- Negative Speaker Output A2 OUT+ Positive Speaker Output A3 PVDD B1 PGND Power Ground B2 N.C. No Connection. Can be left unconnected or connected to PGND. B3 GAIN Gain Select. See Table 1 for GAIN settings. C1 C2 IN- Inverting Audio Input C3 IN+ Noninverting Audio Input
SHDN Active-Low Shutdown Input. Drive SHDN low to place the device in shutdown.
Power Supply. Bypass PVDD with a 0.1FF and 10FF capacitor to PGND.
N.C.
IN- IN+
WLP
(0.3mm pitch)
GAIN

Pin Description

����������������������������������������������������������������� Maxim Integrated Products 9
MAX98314
Mono 3.2W Class D Amplifier
with Integrated Input Coupling Capacitors

Detailed Description

The MAX98314 features low quiescent current, a low­power shutdown mode, comprehensive click-and-pop suppression, and excellent RF immunity.
The IC offers Class AB audio performance with Class D efficiency in a minimal board-space solution. The Class D amplifier features spread-spectrum modulation, edge­rate, and overshoot control circuitry that offers significant improvements to switch-mode amplifier radiated emis­sions.
The amplifier features click-and-pop suppression that reduces audible transients on startup and shutdown. The amplifier additionally includes thermal overload and short-circuit protection.
Highly linear, integrated input coupling capacitors (CIN) reduce solution size and provide excellent THD+N, PSRR, and CMRR performance at low frequencies vs. standard Class D amplifiers using external input capaci­tors.

Class D Speaker Amplifier

The IC’s filterless Class D amplifier offers much higher efficiency than Class AB amplifiers. The high efficiency of a Class D amplifier is due to the switching operation of the output stage transistors. Any power loss associated with the Class D output stage is mostly due to the I2R loss of the MOSFET on-resistance and quiescent switching current overhead.

Ultra-Low EMI Filterless Output Stage

Traditional Class D amplifiers require the use of external LC filters, or shielding, to meet electromagnetic inter­ference (EMI) regulation standards. Maxim’s patented active emissions limiting edge-rate control circuitry and spread-spectrum modulation reduces EMI emissions, while maintaining up to 93% efficiency.
The spread-spectrum modulation mode flattens wide­band spectral components, while proprietary techniques ensure that the cycle-to-cycle variation of the switching period does not degrade audio reproduction or effi­ciency. The IC’s spread-spectrum modulator randomly varies the switching frequency by Q20kHz around the center frequency (300kHz). Above 10MHz, the wideband spectrum looks like noise for EMI purposes (Figure 1).

Amplifier Current Limit

If the output current of the speaker amplifier exceeds the current limit (2.8A typ), the IC disables the outputs for approximately 100Fs. At the end of 100Fs, the outputs are reenabled. If the fault condition still exists, the IC continues to disable and reenable the outputs until the fault condition is removed.

Selectable Amplifier Gain

The IC offers five programmable gain settings, selectable by a single gain input (GAIN).

Table 1. GAIN Selection

GAIN PIN MAXIMUM GAIN (dB)
Connect to PGND 12
Connect to PGND through 100kI Q5%
Connect to PVDD 6
Connect to PVDD through 100kI Q5%
Unconnected 0

Integrated Input Coupling Capacitors (CIN)

The IC integrates two 0.011FF input coupling capacitors, CIN. The input coupling capacitors, in conjunction with the amplifier’s internal input resistance (RIN), form a first­order highpass filter that removes the DC bias from the incoming signal. These capacitors allow the amplifier to bias the signal to an optimum DC level.
90
70
50
EN5502B LIMIT
30
EMISSIONS LEVEL (dBµV/m)
10
-10
HORIZONTAL
VERTICAL
0 100 200 300 400 500 600 700 800 900 1000
FREQUENCY (MHz)
9
3

Figure 1. EMI Performance with 60cm of Speaker Cable, No Output Filter

���������������������������������������������������������������� Maxim Integrated Products 10
MAX98314
Mono 3.2W Class D Amplifier
with Integrated Input Coupling Capacitors
Assuming zero source impedance, the -3dB corner frequency, f
-3dB
, is:
f
= 1/2GRINCIN [Hz]
-3dB
The 100ppm/V voltage coefficient of the integrated input coupling capacitor results in excellent low-frequency THD+N performance. Figure 2 illustrates the superior linearity of the IC’s integrated input coupling capacitors compared to a similar amplifier with external 0.01FF X7R and X5R 0402 input coupling capacitors.
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
10
V
= 4.2V
PVDD
Z
= 8I + 68µH
LOAD
= 600mW
P
OUT
1.0
X7R CAPS
0.1
THD+N (%)
0.01
0.001 10 100k

Figure 2. Low-Frequency THD+N Performance

X5R CAPS
MAX98314 INTERNAL CAPS
10k1k100
FREQUENCY (Hz)

Shutdown

The IC features a low-power shutdown mode, drawing < 0.1FA (typ) of supply current. Drive SHDN low to put the IC into shutdown.

Click-and-Pop Suppression

The speaker amplifier features Maxim’s comprehensive click-and-pop suppression. During startup, the click­and-pop suppression circuitry reduces any audible transient sources internal to the device. When entering shutdown, the differential speaker outputs ramp down to PGND quickly and simultaneously.

Applications Information

Filterless Class D Operation

Traditional Class D amplifiers require an output filter. The filter adds cost and size, and decreases efficiency and THD+N performance. The IC’s filterless modulation scheme does not require an output filter.
Because the switching frequency of the IC is well beyond the bandwidth of most speakers, voice coil movement due to the switching frequency is very small. Use a speaker with a series inductance > 10FH. Typical 8I speakers exhibit series inductances in the 20FH to 100FH range.

Speaker Amplifier Power-Supply Input (PVDD)

PVDD powers the speaker amplifier and ranges from
2.5V to 5.5V. Bypass PVDD with a 0.1FF and 10FF capacitor to PGND. Apply additional bulk capacitance at the device if long input traces between PVDD and the power source are used.

Layout and Grounding

Proper layout and grounding are essential for optimum performance. Good grounding improves audio perfor­mance and prevents switching noise from coupling into the audio signal.
Use wide, low-resistance output traces. As the load impedance decreases, the current drawn from the device increases. At higher current, the resistance of the output traces decrease the power delivered to the load. For example, if 2W is delivered from the device output to a 4I load through 100mI of total speaker trace, 1.904W is delivered to the speaker. If power is delivered through 10mI of total speaker trace, 1.99W is delivered to the speaker. Wide output, supply, and ground traces also improve the power dissipation of the device.
The IC is inherently designed for excellent RF immunity. For best performance, add ground fills around all signal traces on top or bottom PCB layers.
���������������������������������������������������������������� Maxim Integrated Products 11
MAX98314
Mono 3.2W Class D Amplifier
with Integrated Input Coupling Capacitors

WLP Applications Information

For the latest application details on WLP construction, dimensions, tape carrier information, PCB techniques, bump-pad layout, and recommended reflow temperature profile, as well as the latest information on reliability test­ing results, refer to Application Note 1891: Wafer-Level
Packaging (WLP) and Its Applications. Figure 3 shows
the dimensions of the WLP balls used on the IC.

Ordering Information

PART TEMP RANGE PIN-PACKAGE
MAX98314EWL+
+Denotes a lead(Pb)-free/RoHS-compliant package.
-40NC to +85NC
9 WLP
0.18mm
0.18mm

Figure 3. WLP Ball Dimensions

���������������������������������������������������������������� Maxim Integrated Products 12
MAX98314
Mono 3.2W Class D Amplifier
with Integrated Input Coupling Capacitors

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.
PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO.
9 WLP (0.3mm pitch) W90A0+1
PIN 1 INDICATOR
E
1
A
AAAA
TOP VIEW
MARKING
D
0.05
S
21-0539
A3
A1
S
SIDE VIEW
See Note 7
A2
A
Refer to
Application Note 1891
COMMON DIMENSIONS
0.75
A
A1
A2
A3
b
D1
E1
e
SD
SE
0.16
0.59
0.040
0.21
0.60
0.60
0.30
0.00 BASIC
0.00 BASIC
0.05
0.03
REF
BASIC
0.03
BASIC
BASIC
BASIC
B
C
B
A
1 2 3
A
BOTTOM VIEW
-DRAWING NOT TO SCALE-
E
MAX
PKG. CODE
E1
SE
e
SD
D1
b
NOTES:
1. Terminal pitch is defined by terminal center to center value.
2. Outer dimension is defined by center lines between scribe lines.
3. All dimensions in millimeter.
4. Marking shown is for package orientation reference only.
5. Tolerance is ± 0.02 unless specified otherwise.
6. All dimensions apply to PbFree (+) package codes only.
7. Front - side finish can be either Black or Clear.
W90A0+1
MIN
0.95 0.98 0.95 0.98
TITLE
Package Outline 9 bumps, WLP Pkg. 0.3MM Pitch
APPROVAL
DOCUMENT CONTROL NO.
D
MAX
MIN
21-0539 B
DEPOPULATED
BUMPS
NONE
REV.
1
1
���������������������������������������������������������������� Maxim Integrated Products 13
MAX98314
Mono 3.2W Class D Amplifier
with Integrated Input Coupling Capacitors

Revision History

REVISION
NUMBER
0 11/11 Initial release —
REVISION
DATE
DESCRIPTION
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. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 14
©
2011 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
Loading...
Buy Points How it Works FAQ Contact Us Questions and Suggestions Privacy Policy Cookie Policy Terms of Use