MAXIM MAX4297EWG

19-1746; Rev 1; 2/01
Mono/Stereo 2W Switch-Mode (Class-D)
Audio Power Amplifiers
Features
♦ +2.7V to +5.5V Single-Supply Operation
♦ 2W/Channel Output Power at 5V
0.7W/Channel Output Power at 3V
♦ 87% Efficiency (RL = 4Ω, PO = 2W, MAX4295)
♦ 0.4% THD+N (RL = 4Ω, fOSC = 125kHz)
♦ Logic-Programmable PWM Frequency Selection
(125kHz, 250kHz, 500kHz, 1MHz)
♦ Low-Power Shutdown Mode
♦ Clickless Transitions Into and Out of Shutdown
♦ 1A Current Limit and Thermal Protection
♦ Available in Space-Saving Packages
16-Pin QSOP (MAX4295)
24-Pin SSOP (MAX4297)
Ordering Information
PART
Applications
Palmtop/Notebook
Computers
Boom Boxes
AC Amplifiers
Battery-Powered Speakers
PDA Audio
Sound Cards
TEMP. RANGE
PIN-PACKAGE
MAX4295EEE
-40°C to +85°C
16 QSOP
MAX4295ESE
-40°C to +85°C
16 Narrow SO
MAX4297EAG
-40°C to +85°C
24 SSOP
MAX4297EWG
-40°C to +85°C
24 Wide SO
Pin Configurations appear at end of data sheet.
Cordless Phones
Portable Equipment
Game Cards
Typical Operating Circuit
VCC
RF
RIN
2
INPUTL
RF
CIN
INPUTR
RIN
VCC
1
VCC
VPVCC
AOUTL
OUT+L
INL
5
L1A
C1A
MAX4297
12
11
22
VCC
+
4, 9,
16, 21
3
CIN
VPVCC
14
15
AOUTR
OUT-L
20
L1B
C1B
INR
OUT+R
SHDN
8
C2A
FS1
17
OUT-R
13
VCM*
FS2
L2A
SS
24
CSS
AGND
10
L2B
C2B
PGND
6, 7,
18, 19
*DO NOT CONNECT.
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX4295/MAX4297
General Description
The MAX4295/MAX4297 mono/stereo, switch-mode
(Class-D) audio power amplifiers operate from a single
+2.7V to +5.5V supply. They have >85% efficiency and
are capable of delivering 2W continuous power to a 4Ω
load, making them ideal for portable multimedia and
general-purpose high-power audio applications.
The MAX4295/MAX4297 feature a total harmonic distortion plus noise (THD+N) of 0.4% (fOSC = 125kHz), low
quiescent current of 2.8mA (MAX4295) or 4.6mA
(MAX4297), high efficiency, and clickless power-up and
shutdown. The SHDN input disables the device and limits supply current to <1.5µA (MAX4295) or <2.3µA
(MAX4297). Other features include a 1A current limit,
thermal protection, and under-voltage lockout.
The MAX4295 (mono) and MAX4297 (stereo) reduce
the number of required external components. Both
devices have internal high-speed power-MOS transistors, allowing operation as bridge-tied load (BTL) amplifiers. The BTL configuration eliminates the need for
isolation capacitors on the output. The frequency-selectable pulse-width modulator (PWM) allows the user to
optimize the size and cost of the output filter.
The MAX4295 is offered in a space-saving 16-pin
QSOP package, and the MAX4297 is offered in a compact 24-pin SSOP package.
MAX4295/MAX4297
Mono/Stereo 2W Switch-Mode (Class-D)
Audio Power Amplifiers
ABSOLUTE MAXIMUM RATINGS
VCC, PVCC to GND or PGND....................................-0.3V to +6V
PGND to GND.....................................................................±0.3V
PVCC to VCC .......................................................................±0.3V
VCM, SS, AOUT_, IN_ ................................-0.3V to (VCC + 0.3V)
SHDN, FS1, FS2 .......................................................-0.3V to +6V
OUT_ _ .....................................................-0.3V to (PVCC + 0.3V)
Op Amp Output Short-Circuit
Duration (AOUT_) .......Indefinite Short Circuit to Either Supply
H-Bridge Short-Circuit
Duration (OUT_ _) .............Continuous Short Circuit to PGND,
PVCC or between OUT+_ & OUT-_
Continuous Power Dissipation (TA = +70°C)
16-Pin QSOP (derate 8.30mW/°C above +70°C)........667mW
24-Pin SSOP (derate 9.50mW/°C above +70°C) ........762mW
16-Pin Narrow SO
(derate 9.52mW/°C above +70°C) ..........................696mW
24-Pin Wide SO
(derate 11.76mW/°C above +70°C) ........................941mW
Operating Temperature Range
MAX4295E__/MAX4297E__ ............................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
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
(VCC = PVCC = +5V, SHDN = VCC, FS1 = GND, FS2 = VCC (fOSC = 250kHz), input amplifier gain = -1V/V, TA = TMIN to TMAX, unless
otherwise noted. Typical values are TA = +25°C.) (Note 1)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
5.5
V
GENERAL
Supply Voltage Range
(Note 2)
Quiescent Supply Current
Output load not
connected
Shutdown Supply Current
SHDN = GND
2.7
MAX4295
2.8
4
MAX4297
4.6
8
MAX4295
1.5
8
MAX4297
2.5
15
0.285 ×
VCC
0.3 ×
VCC
0.315 ×
VCC
FS1 = GND, FS2 = GND
105
125
145
FS1 = GND, FS2 = VCC
210
250
290
FS1 = VCC, FS2 = GND
420
500
580
FS1 = VCC, FS2 = VCC
840
1000
1160
±1
±3
Voltage at VCM Pin
PWM Frequency
PWM Frequency Change with
VCC
Duty Cycle
Duty Cycle Change with VCC
VCC = 2.7V to 5.5V
VIN = 0.06 × VCC
10.2
12
13.8
VIN = 0.30 × VCC
49.2
50
50.8
VIN = 0.54 × VCC
86.2
88
89.8
VIN = 0.3 × VCC, VCC = 2.7V to 5.5V
Switch On-Resistance
(each power device)
IOUT = 150mA
H-Bridge Output Leakage
SHDN = GND
±0.02
±0.15
VCC = 5V
0.25
0.5
VCC = 2.7V
0.35
1.0
0
±5
H-Bridge Current Limit
Soft-Start Capacitor Charging
Current
Undervoltage Lockout
Thermal Shutdown Trip Point
2
1
VSS = 0
0.75
1.8
1.95
2.2
2.6
_______________________________________________________________________________________
µA
V
kHz
kHz/V
%
%/V
Ω
µA
A
1.35
145
mA
µA
V
°C
Mono/Stereo 2W Switch-Mode (Class-D)
Audio Power Amplifiers
(VCC = PVCC = +5V, SHDN = VCC, FS1 = GND, FS2 = VCC (fOSC = 250kHz), input amplifier gain = -1V/V, TA = TMIN to TMAX, unless
otherwise noted. Typical values are TA = +25°C.)
PARAMETER
CONDITIONS
MIN
TYP
MAX
0 to 0.6
x VCC
Input Voltage Range
VCC = +3V, fIN = 1kHz
Maximum Output Power
VCC = +5V, fIN = 1kHz
RL = 8Ω
0.4
RL = 4Ω
0.7
RL = 8Ω
1.2
RL = 4Ω
UNITS
V
W
2
THD Plus Noise
RL = 4Ω, fIN = 1kHz, PO = 1W, fOSC = 125kHz
0.4
%
Efficiency
MAX4295, RL = 4Ω, fIN = 1kHz, PO = 2W
87
%
Channel Isolation
MAX4297, fIN = 1kHz, PO = 2W
45
dB
LOGIC INPUTS (SHDN, FS1, FS2)
Logic Input Current
VLOGIC = 0 to VCC
1
100
0.7 ×
VCC
Logic Input High Voltage
nA
V
Logic Input Low Voltage
0.3 ×
VCC
V
±4
mV
INPUT AMPLIFIER
±0.5
Input Offset Voltage
±5
VOS Temp Coefficient
Input Bias Current
(Note 3)
Input Noise Voltage Density
f = 10kHz
±0.05
µV/°C
±25
nA
32
nV/√Hz
Input Capacitance
2.5
pF
Output Resistance
0.01
Ω
AOUT Disabled Mode Leakage
Current
Short-Circuit Current
SHDN = GND, VAOUT = 0 to VCC
±0.1
AOUT to GND
8
AOUT to VCC
65
Large-Signal Voltage Gain
VOUT = 0.2V to 4.6V, RL(OPAMP) = 10kΩ
AOUT Voltage Swing
VDIFF ≥ 10mV,
RL(OPAMP) = 10kΩ
78
VCC = +2.7V to +5.5V
Maximum Capacitive Load
No sustained oscillations
115
dB
40
250
VOL
40
100
66
µA
mA
VCC - VOH
Gain Bandwidth Product
Power-Supply Rejection
±1
mV
1.25
MHz
90
dB
200
pF
Note 1: All devices are 100% production tested at TA = 25°C. All temperature limits are guaranteed by design.
Note 2: Supply Voltage Range guaranteed by PSRR of input amplifier, frequency, duty cycle, and H-bridge on-resistance.
Note 3: Guaranteed by design, not production tested.
_______________________________________________________________________________________
3
MAX4295/MAX4297
ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics
(VCC = PVCC = +3V, input amplifier gain = -1, SHDN = VCC , TA = +25°C, unless otherwise noted.)
VCC = +5V
RL = 8Ω
1MHz
125kHz
1MHz
10
1MHz
1
0.1
500kHz
0.1
250kHz
500kHz
10
1k
10
100k
1k
10
100k
1k
100k
INPUT FREQUENCY (Hz)
INPUT FREQUENCY (Hz)
MAX4295
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 1kHz)
MAX4295
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 1kHz)
MAX4295
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 1kHz)
1MHz
10
100
MAX4295/7-05
100
MAX4295/7-04
VCC = +5V
RL = 4Ω
VCC = +5V
RL = 8Ω
250kHz
1
125kHz
VCC = +5V
RL = 32Ω
500kHz
10
125kHz
1MHz
THD + N (%)
THD + N (%)
10
MAX4295/7-06
INPUT FREQUENCY (Hz)
100
THD + N (%)
250kHz
0.01
0.01
0.01
125kHz
THD + N (%)
THD + N (%)
THD + N (%)
250kHz
500kHz
0.1
VCC = +5V
RL = 32Ω
125kHz
1
1
MAX4295/7-03
VCC = +5V
RL = 4Ω
MAX4295/7-02
10
MAX4295/7-01
10
MAX4295
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. INPUT FREQUENCY (VIN = 2.5Vp-p)
MAX4295
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. INPUT FREQUENCY (VIN = 2.5Vp-p)
MAX4295
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. INPUT FREQUENCY (VIN = 2.5Vp-p)
1
1MHz
1
250kHz
500kHz
0.1
0.1
0.1
500kHz 250kHz
125kHz
0.10
0.10
0
0.5
1.0
1.5
2.0
2.5
0.10
0
0.3
0.6
0.9
1.2
1.5
1.8
0
0.1
0.2
0.3
0.4
0.5
OUTPUT POWER (W)
OUTPUT POWER (W)
MAX4295
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 20kHz)
MAX4295
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 20kHz)
MAX4295
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 20kHz)
VCC = +5V
RL = 8Ω
100
MAX4295/7-08
10
MAX4295/7-07
VCC = +5V
RL = 4Ω
1MHz
10
MAX4295/7-09
OUTPUT POWER (W)
100
VCC = +5V
RL = 32Ω
10
1MHz
1MHz
125kHz
1
250kHz
THD + N (%)
THD + N (%)
1
THD + N (%)
MAX4295/MAX4297
Mono/Stereo 2W Switch-Mode (Class-D)
Audio Power Amplifiers
125kHz
1
125kHz
0.1
0.1
250kHz
0.1
250kHz
500kHz
500kHz
500kHz
0.10
0.5
1.0
1.5
OUTPUT POWER (W)
4
0.10
0.01
0
2.0
2.5
0
0.3
0.6
0.9
1.2
OUTPUT POWER (W)
1.5
1.8
0
0.1
0.2
0.3
OUTPUT POWER (W)
_______________________________________________________________________________________
0.4
0.5
Mono/Stereo 2W Switch-Mode (Class-D)
Audio Power Amplifiers
MAX4295
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. INPUT FREQUENCY (VIN = 1.5Vp-p)
125kHz 1MHz
10
VCC = +3V
RL = 8Ω
1MHz
10
1MHz
1
THD + N (%)
500kHz
0.1
250kHz
0.1
250kHz
10
1k
0.01
10
100k
500kHz
250kHz
0.01
0.01
125kHz
1
THD + N (%)
THD + N (%)
500kHz
0.1
VCC = +3V
RL = 32Ω
125kHz
1
MAX4295/7-12
VCC = +3V
RL = 4Ω
MAX4295/7-10
10
MAX4295
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. INPUT FREQUENCY (VIN = 1.5Vp-p)
MAX4295/7-11
MAX4295
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. INPUT FREQUENCY (VIN = 1.5Vp-p)
1k
100k
10
1k
100k
INPUT FREQUENCY (Hz)
INPUT FREQUENCY (Hz)
MAX4295
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 1kHz)
MAX4295
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 1kHz)
MAX4295
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 1kHz)
VCC = +3V
RL = 4Ω
VCC = +3V
RL = 8Ω
1MHz
10
10
500kHz
THD + N (%)
500kHz
THD + N (%)
250kHz
VCC = +3V
RL = 32Ω
1MHz
10
1MHz
THD + N (%)
100
MAX4295/7-14
100
MAX4295/7-13
100
MAX4295/7-15
INPUT FREQUENCY (Hz)
1
125kHz
500kHz
1
1
125kHz
0.1
0.1
250kHz
250kHz
125kHz
0.10
0.1
0
0.1
0.2
0.3
0.4
0.5
0.6 0.7
0.10
0
0.8
0.1
0.2
0.3
0.4
0.5
0.6 0.7
0.8
0
0.05
0.15
0.20
OUTPUT POWER (W)
MAX4295
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 20kHz)
MAX4295
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 20kHz)
MAX4295
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 20kHz)
10
100
MAX4295/7-17
1MHz
100
MAX4295/7-16
VCC = +3V
RL = 4Ω
VCC = +3V
RL = 8Ω
1MHz
10
MAX4295/7-18
OUTPUT POWER (W)
100
VCC = +3V
RL = 32Ω
10
1MHz
1
125kHz
THD + N (%)
THD + N (%)
250kHz
THD + N (%)
0.10
OUTPUT POWER (W)
1
500kHz
0.1
1
125kHz
500kHz
250kHz
0.1
0.1
125kHz
250kHz
0.10
500kHz
0.10
0.10
0
0.1
0.2
0.3
0.4
0.5
OUTPUT POWER (W)
0.6 0.7
0.8
0
0.1
0.2
0.3
0.4
0.5
OUTPUT POWER (W)
0.6 0.7
0.8
0
0.05
0.10
0.15
0.20
OUTPUT POWER (W)
_______________________________________________________________________________________
5
MAX4295/MAX4297
Typical Operating Characteristics (continued)
(VCC = PVCC = +3V, input amplifier gain = -1, SHDN = VCC , TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)
(VCC = PVCC = +3V, input amplifier gain = -1, SHDN = VCC , TA = +25°C, unless otherwise noted.)
MAX4297
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. INPUT FREQUENCY (VIN = 2.5Vp-p)
VCC = +5V
RL = 4Ω
1MHz
VCC = +5V
RL = 8Ω
250kHz
1
THD + N (%)
125kHz
0.1
500kHz
125kHz
0.1
0.01
10
1k
1k
100k
1k
100k
INPUT FREQUENCY (Hz)
MAX4297
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 1kHz)
MAX4297
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 1kHz)
MAX4297
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 1kHz)
VCC = +5V
RL = 8Ω
250kHz
10
250kHz
125kHz
500kHz
250kHz
1
0.1
0.10
2.0
500kHz
2.5
125kHz
0.1
125kHz
0.10
0.10
1.5
1
500kHz
0.1
1.0
1MHz
10
THD + N (%)
THD + N (%)
1
0.5
VCC = +5V
RL = 32Ω
1MHz
1MHz
0
100
MAX4295/7-23
100
MAX4295/7-22
VCC = +5V
RL = 4Ω
MAX4295/7-24
INPUT FREQUENCY (Hz)
10
0
0.3
0.6
0.9
1.2
0
1.5
0.1
0.2
0.3
0.4
0.5
OUTPUT POWER (W)
OUTPUT POWER (W)
MAX4297
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 20kHz)
MAX4297
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 20kHz)
MAX4297
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 20kHz)
1MHz
VCC = +5V
RL = 8Ω
THD + N (%)
125kHz
1
125kHz
1MHz
1
0.1
500kHz
0.5
1.0
1.5
OUTPUT POWER (W)
125kHz
1
2.0
2.5
250kHz
0.1
500kHz
500kHz
0.10
0.10
0.10
0
1MHz
250kHz
250kHz
0.1
VCC = +5V
RL = 32Ω
10
10
THD + N (%)
10
100
MAX4295/7-26
100
MAX4295/7-25
VCC = +5V
RL = 4Ω
MAX4295/7-27
OUTPUT POWER (W)
100
6
10
INPUT FREQUENCY (Hz)
100
THD + N (%)
0.01
10
100k
125kHz
500kHz
500kHz
0.01
1MHz
250kHz
1
THD + N (%)
1
THD + N (%)
VCC = +5V
RL = 32Ω
1MHz
250kHz
0.1
10
MAX4295/7-21
10
MAX4295/7-19
10
MAX4297
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. INPUT FREQUENCY (VIN = 2.5Vp-p)
MAX4295/7-20
MAX4297
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. INPUT FREQUENCY (VIN = 2.5Vp-p)
THD + N (%)
MAX4295/MAX4297
Mono/Stereo 2W Switch-Mode (Class-D)
Audio Power Amplifiers
0
0.3
0.6
0.9
OUTPUT POWER (W)
1.2
1.5
0
0.1
0.2
0.3
OUTPUT POWER (W)
_______________________________________________________________________________________
0.4
0.5
Mono/Stereo 2W Switch-Mode (Class-D)
Audio Power Amplifiers
10
1MHz
250kHz
1MHz
1
500kHz
THD + N (%)
1
VCC = +3V
RL = 32Ω
250kHz
1
1MHz
250kHz
VCC = +3V
RL = 8Ω
MAX4295/7-29
10
MAX4295/7-28
VCC = +3V
RL = 4Ω
THD + N (%)
THD + N (%)
10
MAX4297
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. INPUT FREQUENCY (VIN = 1.5Vp-p)
MAX4297
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. INPUT FREQUENCY (VIN = 1.5Vp-p)
MAX4295/7-30
MAX4297
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. INPUT FREQUENCY (VIN = 1.5Vp-p)
125kHz
125kHz
500kHz
0.1
0.1
500kHz 125kHz
0.1
0.01
0.01
10
1k
100k
10
1k
10
100k
1k
100k
INPUT FREQUENCY (Hz)
INPUT FREQUENCY (Hz)
MAX4297
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 1kHz)
MAX4297
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 1kHz)
MAX4297
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 1kHz)
VCC = +3V
RL = 4Ω
100
MAX4295/7-32
100
MAX4295/7-31
100
VCC = +3V
RL = 8Ω
VCC = +3V
RL = 32Ω
250kHz
10
THD + N (%)
THD + N (%)
10
250kHz
1MHz
1
1MHz
1MHz
THD + N (%)
10
250kHz
MAX4295/7-33
INPUT FREQUENCY (Hz)
1
500kHz
1
500kHz
125kHz
0.1
500kHz
125kHz
125kHz
0.1
0.10
0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
0
0.1
0.2
0.3
0.4
0.5
0
0.6
0.05
0.10
0.15
0.20
OUTPUT POWER (W)
OUTPUT POWER (W)
MAX4297
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 20kHz)
MAX4297
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 20kHz)
MAX4297
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (fIN = 20kHz)
VCC = +3V
RL = 8Ω
10
1MHz
THD + N (%)
THD + N (%)
1MHz
125khz
1
1
VCC = +3V
RL = 32Ω
10
1MHz
10
125kHz
100
THD + N (%)
VCC = +3V
RL = 4Ω
MAX4295/7-35
100
MAX4295/7-34
100
MAX4295/7-36
OUTPUT POWER (W)
125kHz
1
500kHz
0.1
500kHz
0.1
250kHz
250kHz
500kHz
250kHz
0.1
0.10
0.10
0
0.1
0.2
0.3
0.4
OUTPUT POWER (W)
0.5
0.6
0
0.1
0.2
0.3
0.4
OUTPUT POWER (W)
0.5
0.6
0
0.05
0.10
0.15
0.20
OUTPUT POWER (W)
_______________________________________________________________________________________
7
MAX4295/MAX4297
Typical Operating Characteristics (continued)
(VCC = PVCC = +3V, input amplifier gain = -1, SHDN = VCC , TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)
(VCC = PVCC = +3V, input amplifier gain = -1, SHDN = VCC , TA = +25°C, unless otherwise noted.)
250kHz
1MHz
50
125kHz
40
30
20
RL = 4Ω
0.5
1.0
1.5
2.0
20
VCC = +5V
0
0.3
0.6
0.9
1.2
1.5
RL = 32Ω
0
1.8
0
0.1
0.2
0.3
0.4
MAX4295 EFFICIENCY
vs. OUTPUT POWER (fIN = 1kHz)
50
40
70
250kHz
50
40
125kHz
30
125kHz
1MHz
60
80
VCC = +3V
10
VCC = +3V
0.2
0.4
0.6
500kHz
40
125kHz
VCC = +3V
RL = 32Ω
0
0
0.8
1MHz
50
10
RL = 8Ω
0
0
60
20
10
RL = 4Ω
0.2
0.4
0.6
0.8
0
0.05
0.10
0.15
OUTPUT POWER (W)
OUTPUT POWER (W)
OUTPUT POWER (W)
MAX4297 EFFICIENCY
vs. OUTPUT POWER (fIN = 1kHz)
MAX4297 EFFICIENCY
vs. OUTPUT POWER (fIN = 1kHz)
MAX4297 EFFICIENCY
vs. OUTPUT POWER (fIN = 1kHz)
80
70
90
80
500kHz
EFFICIENCY (%)
1MHz
250kHz
50
40
500kHz
70
1MHz
60
250kHz
50
40
30
30
125kHz
0.5
1.0
1.5
OUTPUT POWER (W)
2.0
2.5
80
500kHz
250kHz
70
60
1MHz
50
125kHz
40
0
0.3
0.6
0.9
OUTPUT POWER (W)
1.2
VCC = +5V
10
RL = 8Ω
RL = 32Ω
0
0
0
90
20
VCC = +5V
10
RL = 4Ω
0.20
30
125kHz
20
VCC = +5V
10
100
EFFICIENCY (%)
90
MAX4295/7-44
100
MAX4295/7-43
100
0.5
70
30
20
20
250kHz
90
EFFICIENCY (%)
80
EFFICIENCY (%)
1MHz
500kHz
90
100
MAX4295/7-41
100
MAX4295/7-40
250kHz
0
VCC = +5V
10
RL = 8Ω
MAX4295 EFFICIENCY
vs. OUTPUT POWER (fIN = 1kHz)
60
20
125kHz
40
MAX4295 EFFICIENCY
vs. OUTPUT POWER (fIN = 1kHz)
70
60
50
OUTPUT POWER (W)
80
0
1MHz
OUTPUT POWER (W)
500kHz
30
500kHz
60
OUTPUT POWER (W)
100
90
2.5
70
30
0
0
80
125kHz
10
0
EFFICIENCY (%)
1MHz
50
20
VCC = +5V
250kHz
60
30
10
8
70
MAX4295/7-42
40
80
250kHz
90
MAX4295/7-45
60
100
EFFICIENCY (%)
70
EFFICIENCY (%)
EFFICIENCY (%)
80
500kHz
90
MAX4295 EFFICIENCY
vs. OUTPUT POWER (fIN = 1kHz)
MAX4295/7-38
500kHz
90
100
MAX4295/7-37
100
MAX4295 EFFICIENCY
vs. OUTPUT POWER (fIN = 1kHz)
MAX4295/7-39
MAX4295 EFFICIENCY
vs. OUTPUT POWER (fIN = 1kHz)
EFFICIENCY (%)
MAX4295/MAX4297
Mono/Stereo 2W Switch-Mode (Class-D)
Audio Power Amplifiers
1.5
0
0.1
0.2
0.3
OUTPUT POWER (W)
_______________________________________________________________________________________
0.4
0.5
Mono/Stereo 2W Switch-Mode (Class-D)
Audio Power Amplifiers
60
1MHz
50
250kHz
80
30
70
60
1MHz
50
40
80
0
0.1
0.2
0.3
0.4
0.5
0.6
1MHz
60
50
250kHz
40
125kHz
VCC = +3V
RL = 8Ω
10
RL = 32Ω
0
0
0
70
20
VCC = +3V
10
RL = 4Ω
500kHz
90
30
20
VCC = +3V
10
0
0.05
0.10
0.15
0
0.20
0.1
0.2
0.3
0.4
0.5
0.6
OUTPUT POWER (W)
OUTPUT POWER (W)
OUTPUT POWER (W)
MAX4295
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX4297
SUPPLY CURRENT vs. TEMPERATURE
OSCILLATOR FREQUENCY DEVIATION
vs. SUPPLY VOLTAGE
C
4
B
2
5
MAX4295
VCC = +5V
MAX4297
VCC = +3V
4
3
2
1
A
MAX4295
VCC = +3V
0
1
2
3
4
0
-0.005
-0.01
250kHz
500kHz
-0.015
1MHz
-0.025
-40
5
125kHz
0.005
-0.02
0
0
0.01
FREQUECNY DEVIATION (%)
6
MAX4297
VCC = +5V
6
0.015
MAX4295/7-51
7
MAX4295/7-50
8
D
SUPPLY CURRENT (mA)
A: fOSC = 125kHz
B: fOSC = 250kHz
C: fOSC = 500kHz
D: fOSC = 1MHz
MAX4295/7-49
10
-15
10
35
60
2.5
85
3.0
3.5
4.0
4.5
5.0
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
MAX4297
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX4297 SHUTDOWN SUPPLY
CURRENT vs. TEMPERATURE
START-UP/SHUTDOWN
WAVEFORM
18
16
14
D
12
10
C
8
6
B
7
6
MAX4297
VCC = +5V
A
5
4
MAX4295
VCC = +5V
MAX4297
VCC = +3V
3
2
SHDN
1
MAX4295
VCC = +3V
0
0
0
1
2
3
4
SUPPLY VOLTAGE (V)
5
4V/div
VOUT
4
2
5.5
MAX4295/7 toc54
8
SUPPLY CURRENT (µA)
A: fOSC = 125kHz
B: fOSC = 250kHz
C: fOSC = 500kHz
D: fOSC = 1MHz
MAX4295/7-52
20
MAX4295/7 toc53
SUPPLY CURRENT (mA)
125kHz
100
30
125kHz
20
SUPPLY CURRENT (mA)
500kHz
250kHz
EFFICIENCY (%)
70
EFFICIENCY (%)
EFFICIENCY (%)
80
90
MAX4295/7-47
500kHz
40
100
MAX4295/7-46
100
90
MAX4297 EFFICIENCY
vs. OUTPUT POWER (fIN = 1kHz)
MAX4297 EFFICIENCY
vs. OUTPUT POWER (fIN = 1kHz)
MAX4295/7-48
MAX4297 EFFICIENCY
vs. OUTPUT POWER (fIN = 1kHz)
MAX4295/MAX4297
Typical Operating Characteristics (continued)
(VCC = PVCC = +3V, input amplifier gain = -1, SHDN = VCC , TA = +25°C, unless otherwise noted.)
-40
-15
10
35
60
85
RL = 4Ω
fOSC = 250kHz
fIN = 10kHz
CSS = 560pF
2.5V/div
400µs/div
TEMPERATURE (°C)
_______________________________________________________________________________________
9
MAX4295/MAX4297
Mono/Stereo 2W Switch-Mode (Class-D)
Audio Power Amplifiers
Pin Description
PIN
NAME
MAX4295
FUNCTION
MAX4297
1, 12
10
GND
Analog Ground
2, 15
4, 9, 16, 21
PVCC
H-Bridge Power Supply
3
—
OUT+
Positive H-Bridge Output
—
5
OUT+L
Positive Left-Channel H-Bridge Output
—
8
OUT+R
Positive Right-Channel H-Bridge Output
4, 13
6, 7, 18, 19
PGND
Power Ground
5
3, 23
VCC
Analog Power Supply
Audio Input Common-Mode Voltage. Do not connect. Minimize parasitic
coupling to this pin.
6
13
VCM
7
—
IN
Audio Input
—
2
INL
Left-Channel Audio Input
—
11
INR
Right-Channel Audio Input
8
—
AOUT
Input Amplifier Output
—
1
AOUTL
Left-Channel Input Amplifier Output
—
12
AOUTR
Right-Channel Input Amplifier Output
9
22
SHDN
10
14
FS1
Frequency Select Input 1
11
15
FS2
Frequency Select Input 2
Active-Low Shutdown Input. Connect to VCC for normal operation. Do not
leave floating.
14
—
OUT-
Negative H-Bridge Output
—
20
OUT-L
Negative Left-Channel H-Bridge Output
—
17
OUT-R
16
24
SS
Negative Right-Channel H-Bridge Output
Soft-Start
Detailed Description
The MAX4295/MAX4297 switch-mode, Class-D audio
power amplifiers are intended for portable multimedia
and general-purpose audio applications. Linear amplifiers in the 1W to 2W output range are inefficient; they
overheat when operated near rated output power levels. The efficiency of linear amplifiers is <50% when the
output voltage is equal to 1/2 the supply. The
MAX4295/MAX4297 Class-D amplifiers achieve efficiencies of 87% or greater and are capable of delivering up to 2W of continuous maximum power to a 4Ω
load. The lost power is due mainly to the on-resistance
of the power switches and ripple current in the output.
In a Class-D amplifier, a PWM controller converts the
analog input to a variable pulse-width signal. The pulse
width is proportional to the input voltage, ideally 0% for
10
a 0V input signal and 100% for full-scale input voltages.
A passive lowpass LC network filters the PWM output
waveform to reconstruct the analog signal. The switching frequency is selected much higher than the maximum input frequencies so that intermodulation
products are outside the input signal bandwidth.
Higher switching frequencies also simplify the filtering
requirements.
The MAX4295/MAX4297 consist of an inverting input
operational amplifier, a PWM ramp oscillator, a controller that converts the analog input to a variable pulse
width signal, and a MOSFET H-bridge power stage
(Figures 1a and 1b). The control signal is generated by
the PWM comparator; its pulse width is proportional to
the input voltage. Ideally the pulse width varies linearly
between 0% for a 0V input signal and 100% for fullscale input voltages (Figure 2). This signal controls the
______________________________________________________________________________________
Mono/Stereo 2W Switch-Mode (Class-D)
Audio Power Amplifiers
MAX4295/MAX4297
AOUT
PVCC
IN
OUT+
GATE
DRIVE
PGND
0.3 ✕ VCC
(VCM)
PVCC
FS1
GATE
DRIVE
PWM
OSC
FS2
OUT-
VCC
SS
PGND
POWER MANAGEMENT
AND PROTECTION
GND
CSS
Figure 1a. MAX4295 Functional Diagram
H-bridge. The switches work in pairs to reverse the
polarity of the signal in the load. Break-before-make
switching of the H-bridge MOSFETs by the driver circuit
keeps supply current glitches and crowbar current in
the MOSFETs at a low level. The output swing of the Hbridge is a direct function of the supply voltage.
Varying the oscillator swing in proportion to the supply
voltage maintains constant gain with varying supply
voltage.
FS1 and FS2 program the oscillator to a frequency of
125kHz, 250kHz, 500kHz, and 1MHz. The sawtooth
oscillator swings between GND and 0.6 ✕ VCC. The
input signal is typically AC-coupled to the internal input
op amp, whose gain can be controlled through external
feedback components. The common-mode voltage of
the input amplifier is 0.3 ✕ VCC and is internally generated from the same resistive divider used to generate
the 0.6 ✕ VCC reference for the PWM oscillator.
Current Limit
A current-limiting circuit in the H-bridge monitors the
current in the H-bridge transistors and disables the Hbridge if the current in any of the H-bridge transistors
exceeds 1A. The H-bridge is enabled after a period of
100µs. A continuous short circuit at the output results in
a pulsating output.
Thermal Overload Protection
Thermal overload protection limits total power dissipation in the MAX4295/MAX4297. When the junction temperature exceeds +145°C, the thermal detection
disables the H-bridge transistors. The H-bridge transistors are enabled after the IC’s junction temperature
cools by 10°C. This results in a pulsating output under
continuous thermal overload conditions. Junction temperature does not exceed the thermal overload trip
point in normal operation, but only in the event of fault
conditions, such as when the H-bridge outputs are
short circuited.
Undervoltage Lockout
At low supply voltages, the MOSFETs in the H-bridge
may have inadequate gate drive thus dissipating
excessive power. The undervoltage lockout circuit prevents the device from operating at supply voltages
below +2.2V.
______________________________________________________________________________________
11
MAX4295/MAX4297
Mono/Stereo 2W Switch-Mode (Class-D)
Audio Power Amplifiers
PVCC OUT+R OUT-R
GATE
DRIVE
GATE
DRIVE
AOUTR
INR
PGND
VCC
FS1
PWM
OSC
FS2
SS
POWER MANAGEMENT
AND PROTECTION
CSS
GND
PGND
INL
AOUTL
GATE
DRIVE
GATE
DRIVE
0.3 ✕ VCC
(VCM)
PVCC OUT+L OUT-L
Figure 1b. MAX4297 Functional Diagram
Low-Power Shutdown Mode
The MAX4295/MAX4297 have a shutdown mode that
reduces power consumption and extends battery life.
Driving SHDN low disables the H-bridge, turns off the
circuit, and places the MAX4295/MAX4297 in a lowpower shutdown mode. Connect SHDN to VCC for normal operation.
12
Applications Information
Component Selection
Gain Setting
External feedback components set the gain of the
MAX4295/MAX4297. Resistors RF and RIN set the gain
of the input amplifier to -(RF/RIN). The amplifier’s noninverting input is connected to the internally generated
0.3 ✕ V CC (VCM) that sets the amplifier’s commonmode voltage.
______________________________________________________________________________________
Mono/Stereo 2W Switch-Mode (Class-D)
Audio Power Amplifiers
The optimum impedance seen by the inverting input is
between 5kΩ and 20kΩ. The effective impedance is
given by (RF ✕ RIN)/(RF + RIN). For values of RF >
50kΩ, a small capacitor (≈3pF) connected across RF
compensates for the pole formed by the input capacitance and the effective resistance at the inverting input.
Soft-Start (Clickless Startup)
The H-bridge is disabled under any of the following
conditions:
• SHDN low
• H-bridge current exceeds the 1A current limit
• Thermal overload
• Undervoltage lockout
The circuit re-enters normal operation if none of the
above conditions are present. A soft-start function prevents an audible pop on restart. An external capacitor
connected to SS is charged by an internal 1.2µA current source and controls the soft-start rate. VSS is held
low while the H-bridge is disabled and allowed to ramp
up to begin a soft-start. Until VSS reaches 0.3 ✕ VCC,
the H-bridge output is limited to a 50% duty cycle,
independent of the input voltage. The H-bridge duty
cycle is then gradually allowed to track the input signal
at a rate determined by the ramp on SS. The soft-start
cycle is complete after VSS reaches 0.6 ✕ VCC.
Input Filter
High-fidelity audio applications require gain flatness
between 20Hz to 20kHz. Set the low-frequency cutoff
point with an AC-coupling capacitor in series with the
input resistor of the amplifier, creating a highpass filter
(Figure 3). Assuming the input node of the amplifier is a
virtual ground, the -3dB point of the highpass filter is
determined by: fLO = 1/(2π ✕ RIN ✕ CIN), where RIN is
the input resistor, and CIN is the AC-coupling capacitor. Choose RIN as described in the Gain Setting section. Choose CIN such that the corner frequency is
below 20Hz.
Frequency Selection
The MAX4295/MAX4297 have an internal logic-programmable oscillator controlled by FS1 and FS2 (Table
1). The oscillator can be programmed to frequencies of
125kHz, 250kHz, 500kHz, and 1MHz. The frequency
should be chosen to best fit the application. As a rule of
thumb, choose fOSC to be 10 times the audio bandwidth. A lower switching frequency offers higher amplifier efficiency and lower THD but requires larger
external filter components. A higher switching frequency reduces the size and cost of the filter components at
the expense of THD and efficiency. In most applications, the optimal fOSC is 250kHz.
Table 1. Frequency Select Logic
FS1
FS2
0
0
125k
0
1
250k
1
0
500k
1
1
1M
RF
INPUT CIN
VIN
RIN
FREQUENCY (Hz)
AOUT
IN
VCM
VRAMP
+5V
VOUT
Figure 3. Input Amplifier Configuration
0
Figure 2. PWM Waveforms
______________________________________________________________________________________
13
MAX4295/MAX4297
The amplifier’s input bias current is low, ±50pA, and does
not affect the choice of feedback resistors. The noise in
the circuit increases as the value of RF increases.
MAX4295/MAX4297
Mono/Stereo 2W Switch-Mode (Class-D)
Audio Power Amplifiers
Output Filter
An output filter is required to attenuate the PWM switching frequency. Without the filter, the ripple in the load
can substantially degrade efficiency and may cause
interference problems with other electronic equipment.
A Butterworth lowpass filter is chosen for its flat pass
band and nice phase response, though other filter
implementations may also be used. Three examples
are presented below. The filter parameters for balanced 2-pole (Figure 4b) and 4-pole (Figure 4d)
Butterworth filters are taken from Electronic Filter
Design Handbook by Arthur B. Williams, McGraw Hill,
Inc. These filter designs assume that the load is purely
resistive and load impedance is constant over frequency. Calculation of filter component values should
include the DC resistance of the inductors and take into
account the worst-case load scenario:
• Single Ended 2-Pole Filter (Figure 4a)
C = 1 / (√2 ✕ RL ✕ ωo), L = √2 ✕ RL / ωo
where ωo = 2 ✕ π ✕ fo (fo = filter cutoff frequency);
choosing fo = 30kHz and RL = 4Ω, C = 0.937µF, L =
30µH.
A single-ended 2-pole filter uses the minimum number
of external components, but the load (speaker) sees
the large common-mode switching voltage, which can
increase power dissipation and cause EMI problems.
• Balanced 2-Pole (Figure 4b):
A balanced 2-Pole filter does not have the commonmode swing problem of the single-ended filter.
C = 2 / (√2 ✕ RL ✕ ωo), L = (√2 ✕ RL)/(2 ✕ ωo); choosing
fo = 30kHz and RL = 4Ω, C1a = C1b = 2.0µF, L1a =
L1b = 15µH.
A single capacitor connected across RL, with a value of
CL = 1/(√2 ✕ RL ✕ ωo), can be used in place of C1a and
C1b. However, the configuration as shown gives an
improved rejection to common-mode signal components of OUT+_ and OUT-_. If the single capacitor
scheme is used, additional capacitors (Ca and Cb) can
be added from each side of RL, providing a high-frequency short to ground (Figure 4c). These capacitors
should be approximately 0.2 ✕ CL.
• Balanced 4-Pole Filter (Figure 4d)
A balanced 4-pole filter is more effective in suppressing the switching frequency and its harmonics.
For the 4-pole Butterworth filter, the normalized values
are: L1N = 1.5307, L2N = 1.0824, C1N = 1.5772, C2N =
0.3827.
The actual inductance and capacitance values for fo =
30kHz and a bridge-tied load of RL = 4Ω are given by:
L1 = (L1N ✕ RL ) / (2 ✕ ωo) = 16.24µH, L2 = (L2N ✕ RL) /
(2 ✕ ωo) = 11.5µH, C1 = C1N / (RL ✕ ωo) = 2.1µF, C2a =
C2b = (2 ✕ C2N) / (RL ✕ ωo) = 1.0µF.
L1
L
OUT+
OUT+
Ca
C
CL
RL
RL
Cb
OUT-
OUT-
L2
Figure 4c. Alternate Balanced 2-Pole Filter
Figure 4a. Single-Ended 2-Pole Filter
L2a
L1a
L1
OUT+
OUT+
C2a
C1a
C1
RL
RL
C2b
C1b
OUT-
OUTL2
Figure 4b. Balanced 2-Pole Filter
14
L1b
L2b
Figure 4d. Balanced 4-Pole Filter
______________________________________________________________________________________
Mono/Stereo 2W Switch-Mode (Class-D)
Audio Power Amplifiers
The capacitors should have a voltage rating 2 to 3
times the maximum expected RMS voltage—allowing
for high peak voltages and transient spikes—and be
stable over-temperature. Good quality capacitors with
low equivalent series resistance (ESR) and equivalent
series inductance (ESL) are necessary to achieve optimum performance. Low-ESR capacitors will decrease
power dissipation. High ESL will shift the cutoff frequency, and high ESR will reduce filter rolloff.
Bridge-Tied Load/Single-Ended
Configuration
The MAX4295/MAX4297 can be used as either a BTL
or single-ended configured amplifier. The BTL configuration offers several advantages over a single-ended
configuration. By driving the load differentially, the output voltage swing is doubled and the output power is
quadrupled in comparison to a single-ended configura-
OUT+
1
Cc
L1a
C1
RL
MAX4295
OUT-
16
Figure 5. MAX4295 Single-Ended Configuration
tion. Because the differential outputs are biased at half
supply, there is no DC voltage across the load, eliminating the need for large DC blocking capacitors at the
output.
The MAX4295/MAX4297 can be configured as singleended amplifiers. In such a case, the load must be
capacitively coupled to the filter to block the half-supply DC voltage from the load. The unused output pin
TIP RING
(LEFT) (RIGHT)
SLEEVE
(GND)
Figure 6. Typical 3-Wire Headphone Plug
OUT+L
5
CC
L1
LEFT
C1a
OUT-L 20
HEADPHONE JACK
GND
MAX4297
OUT+R
8
OUT-R 17
CC
L2
RIGHT
C2a
Figure 7. Headphone Application Circuit
must also be left open (Figure 5). Do not connect the
unused output pin to ground.
Headphone Applications
The MAX4295/MAX4297 can be used to drive a set of
headphones. A typical 3-wire headphone plug consists
of a tip, ring, and sleeve. The tip and ring are signal
carriers, while the sleeve is the ground connection
(Figure 6). Figure 7 shows the MAX4297 configured to
drive a set of headphones. The OUT+L and OUT+R
pins are connected to the tip and ring and deliver the
signal to the headphone jack, while the OUT-L and
OUT-R pins remain unconnected. The ground connection in the jack should be connected to the same
ground plane as the output filter.
Total Harmonic Distortion
The MAX4295/MAX4297 exhibit typical THD plus noise
of <1% for input frequencies <10kHz. The PWM frequency affects THD performance. THD can be reduced
by limiting the input bandwidth through the input highpass filter, choosing the lowest fOSC possible, and carefully selecting the output filter and its components.
Bypassing and Layout Considerations
Distortion caused by supply ripple due to H-bridge
switching can be reduced through proper bypassing of
PV CC . For optimal performance, a 330µF, low-ESR
POSCAP capacitor to PGND and a 1µF ceramic capacitor to GND at each PVCC input is suggested. Place the
1µF capacitor close to the PVCC pin. Bypass VCC with
______________________________________________________________________________________
15
MAX4295/MAX4297
Filter Components
The inductor current rating should be higher than the
peak current for a given output power requirement and
should have relatively constant inductance over temperature and frequency. Typically, an open-core inductor is desirable since these types of inductors are more
linear. Toroidal inductors without an air gap are not recommended. Q-shielded inductors may be required if
the amplifier is placed in an EMI-sensitive system. The
series resistance of the inductors will reduce the attenuation of the switching frequency and reduce efficiency
due to the ripple current in the inductor.
MAX4295/MAX4297
Mono/Stereo 2W Switch-Mode (Class-D)
Audio Power Amplifiers
a 10µF capacitor in parallel with a 1µF capacitor to
GND. Ceramic capacitors are recommended due to
their low ESR.
Good PC board layout techniques optimize performance by decreasing the amount of stray capacitance
at the amplifier’s inputs and outputs. To decrease stray
capacitance, minimize trace lengths by placing external components as close as possible to the amplifier.
Surface-mount components are recommended.
The MAX4295/MAX4297 require two separate ground
planes to prevent switching noise from the MOSFETs in
the H-bridge from coupling into the rest of the circuit.
PGND, the power ground, is utilized by the H-bridge
and any external output components, while GND is
used by the rest of the circuit. Connect the PGND and
GND planes at only one point, as close to the power
supply as possible. Any external components associated with the output of the MAX4295/MAX4297 must be
connected to the PGND plane where applicable. Use
the Typical Operating Circuit diagram as a reference.
Refer to the evaluation kit manual for suggested component values, component suppliers, and layout.
Chip Information
TRANSISTOR COUNT: MAX4295: 846
MAX4297: 1191
PROCESS: BiCMOS
Pin Configurations
TOP VIEW
AOUTL 1
24 SS
GND 1
16 SS
INL 2
23 VCC
PVCC 2
15 PVCC
VCC 3
22 SHDN
OUT+ 3
14 OUT-
PVCC 4
PGND 4
MAX4295
21 PVCC
13 PGND
OUT+ L 5
VCC 5
12 GND
PGND 6
19 PGND
VCM 6
11 FS2
PGND 7
18 PGND
IN 7
10 FS1
OUT+ R 8
17 OUT-R
9
AOUT 8
SO/QSOP
SHDN
MAX4297
20 OUT- L
PVCC 9
16 PVCC
GND 10
15 FS2
INR 11
14 FS1
AOUTR 12
13 VCM
SO/SSOP
16
______________________________________________________________________________________
Mono/Stereo 2W Switch-Mode (Class-D)
Audio Power Amplifiers
SSOP.EPS
QSOP.EPS
______________________________________________________________________________________
17
MAX4295/MAX4297
Package Information
MAX4295/MAX4297
Mono/Stereo 2W Switch-Mode (Class-D)
Audio Power Amplifiers
SOICW.EPS
SOICN.EPS
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.
18 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2001 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.