19-3766; Rev 0; 7/05
KIT
ATION
EVALU
E
L
B
AVAILA
2.6W Stereo Audio Power Amplifier and
DirectDrive Headphone Amplifier
Features
The MAX9779 combines a stereo, 2.6W audio power
amplifier and stereo DirectDrive™ 110mW headphone
amplifier in a single device. The headphone amplifier
uses Maxim’s DirectDrive architecture that produces a
ground-referenced output from a single supply, eliminating the need for large DC-blocking capacitors, saving
cost, space, and component height. A high 90dB PSRR
and low 0.01% THD+N ensures clean, low-distortion
amplification of the audio signal through the Class AB
speaker amplifiers.
The MAX9779 features a single-supply voltage, a shutdown mode, logic-selectable gain, and a headphone
sense input. Industry-leading click-and-pop suppression eliminates audible transients during power and
shutdown cycles.
♦ No DC-Blocking Capacitors Required—Provides
Industry’s Most Compact Notebook Audio
Solution
The MAX9779 is offered in a space-saving, thermally efficient 28-pin thin QFN (5mm x 5mm x 0.8mm) package.
The device has thermal-overload and output short-circuit
protection, and is specified over the extended -40°C to
+85°C temperature range.
♦ Short-Circuit and Thermal-Overload Protection
Applications
Notebook PCs
Flat-Panel TVs
Tablet PCs
Multimedia Monitors
♦ PC2001 Compliant
♦ 5V Single-Supply Operation
♦ Class AB 2.6W Stereo BTL Speaker Amplifiers
♦ 110mW DirectDrive Headphone Amplifiers
♦ High 90dB PSRR
♦ Low-Power Shutdown Mode
♦ Industry-Leading Click-and-Pop Suppression
♦ Low 0.01% THD+N at 1kHz
♦ Selectable Gain Settings (15dB, 16.5dB, 18dB,
and 19.5dB)
♦ ±8kV ESD-Protected Headphone Driver Outputs
♦ Available in Space-Saving, Thermally Efficient
Package
28-Pin Thin QFN (5mm x 5mm x 0.8mm)
Portable DVD Players LCD Projectors
Simplified Block Diagram
Ordering Information
PART
MAX9779ETI+
AB
TEMP RANGE
PIN-PACKAGE
-40°C to +85°C
28 Thin QFN-EP*
+Denotes
lead-free package.
*EP = Exposed paddle.
AB
MAX9779
GAIN
Pin Configuration appears at end of data sheet.
________________________________________________________________ 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
MAX9779
General Description
MAX9779
2.6W Stereo Audio Power Amplifier and
DirectDrive Headphone Amplifier
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (VDD, PVDD, HPVDD, CPVDD to GND)..........+6V
GND to PGND.....................................................................±0.3V
CPVSS, C1N, VSS to GND .........................-6.0V to (GND + 0.3V)
HPOUT_ to GND ....................................................................±3V
Any Other Pin .............................................-0.3V to (VDD + 0.3V)
Duration of OUT_ _ Short Circuit to GND or PVDD .....Continuous
Duration of OUT_+ Short Circuit to OUT_- .................Continuous
Duration of HPOUT_ Short Circuit to GND,
VSS or HPVDD .........................................................Continuous
Continuous Current (PVDD, OUT_ _, PGND) ........................1.7A
Continuous Current (CPVDD, C1N, C1P, CPVSS, VSS, HPVDD,
HPOUT_) .......................................................................850mA
Continuous Input Current (all other pins) .........................±20mA
Continuous Power Dissipation (TA = +70°C)
28-Pin Thin QFN (derate 20.8mW/°C above +70°C) ..1667mW
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
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
(VDD = PVDD = CPVDD = HPVDD = 5V, GND = PGND = CPGND = 0V, SHDN = VDD, CBIAS = 1µF, C1 = C2 = 1µF, speaker load
terminated between OUT_+ and OUT_-, headphone load terminated between HPOUT_ and GND, GAIN1 = GAIN2 = 0V, TA = TMIN to
TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
GENERAL
Supply Voltage Range
Headphone Supply Voltage
VDD, PVDD
Inferred from PSRR test
4.5
5.5
V
CPVDD,
HPVDD
Inferred from PSRR test
3.0
5.5
V
Quiescent Supply Current
IDD
Shutdown Supply Current
ISHDN
Bias Voltage
VBIAS
HPS = GND, speaker mode, RL = ∞
14
29
HPS = VDD, headphone mode, RL = ∞
7
13
SHDN = GND
Switching Time
tSW
Gain or input switching
Input Resistance
RIN
Amplifier inputs (Note 2)
Turn-On Time
mA
0.2
5
µA
1.7
1.8
1.9
V
10
20
30
kΩ
10
tSON
µs
25
ms
SPEAKER AMPLIFIER (HPS = GND)
Output Offset Voltage
VOS
Measured between OUT_+ and OUT_-,
TA = +25°C
PVDD or VDD = 4.5V to 5.5V (TA = +25°C)
Power-Supply Rejection Ratio
(Note 3)
2
PSRR
±1
75
±15
mV
90
f = 1kHz, VRIPPLE = 200mVP-P
80
f = 10kHz, VRIPPLE = 200mVP-P
55
_______________________________________________________________________________________
dB
2.6W Stereo Audio Power Amplifier and
DirectDrive Headphone Amplifier
(VDD = PVDD = CPVDD = HPVDD = 5V, GND = PGND = CPGND = 0V, SHDN = VDD, CBIAS = 1µF, C1 = C2 = 1µF, speaker load
terminated between OUT_+ and OUT_-, headphone load terminated between HPOUT_ and GND, GAIN1 = GAIN2 = 0V, TA = TMIN to
TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1)
PARAMETER
Output Power (Note 4)
Total Harmonic Distortion
Plus Noise
SYMBOL
POUT
THD+N
CONDITIONS
MIN
TYP
RL = 8Ω
0.9
1.4
THD+N = 1%,
f = 1kHz,
TA = +25°C
RL = 4Ω
MAX
W
2.3
RL = 3Ω
UNITS
2.6
RL = 8Ω, POUT = 500mW, f = 1kHz
0.01
RL = 4Ω, POUT = 1W, f = 1kHz
0.02
%
Noise
Vn
RL = 8Ω, POUT = 500mW,
BW = 22Hz to 22kHz
BW = 22Hz to 22kHz, A-weighted
Capacitive-Load Drive
CL
No sustained oscillations
200
pF
L to R, R to L, f = 10kHz
75
dB
1.4
V/µs
Signal-to-Noise Ratio
SNR
Crosstalk
Slew Rate
SR
Gain (Maximum Volume Setting)
AVMAX(SPKR)
90
dB
80
µVRMS
GAIN1 = 0, GAIN2 = 0
15
GAIN1 = 1, GAIN2 = 0
16.5
GAIN1 = 0, GAIN2 = 1
18
GAIN1 = 1, GAIN2 = 1
19.5
dB
HEADPHONE AMPLIFIER (HPS = VDD)
Output Offset Voltage
Power-Supply Rejection Ratio
(Note 3)
Output Power
VOS
HPVDD = 3V to 5.5V, TA = +25°C
PSRR
POUT
Total Harmonic Distortion
Plus Noise
Signal-to-Noise Ratio
±2
TA = +25°C
THD+N
SNR
60
f = 1kHz, VRIPPLE = 200mVP-P
73
f = 10kHz, VRIPPLE = 200mVP-P
63
THD+N = 1%,
f = 1kHz, TA = +25°C
RL = 32Ω
40
±7
mV
75
dB
50
mW
RL = 16Ω
110
RL = 32Ω, POUT = 20mW, f = 1kHz
0.007
RL = 16Ω, POUT = 75mW, f = 1kHz
0.03
RL = 32Ω, POUT = 50mW,
BW = 22Hz to 22kHz
%
95
dB
Noise
Vn
BW = 22Hz to 22kHz
12
µVRMS
Capacitive-Load Drive
CL
No sustained oscillations
200
pF
Crosstalk
L to R, R to L, f = 10kHz
88
Off-Isolation
Any unselected input to any active input,
f = 10kHz, input referred
74
Slew Rate
ESD
Gain
SR
ESD
AV
IEC air discharge
dB
0.4
V/µs
±8
kV
GAIN2 = 0, GAIN1 = X
0
GAIN2 = 1, GAIN1 = X
3
dB
_______________________________________________________________________________________
3
MAX9779
ELECTRICAL CHARACTERISTICS (continued)
MAX9779
2.6W Stereo Audio Power Amplifier and
DirectDrive Headphone Amplifier
ELECTRICAL CHARACTERISTICS (continued)
(VDD = PVDD = CPVDD = HPVDD = 5V, GND = PGND = CPGND = 0V, SHDN = VDD, CBIAS = 1µF, C1 = C2 = 1µF, speaker load
terminated between OUT_+ and OUT_-, headphone load terminated between HPOUT_ and GND, GAIN1 = GAIN2 = 0V, TA = TMIN to
TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
fOSC
500
550
600
kHz
Logic-Input High Voltage
VIH
2
Logic-Input Low Voltage
VIL
0.8
V
Logic-Input Current
IIN
±1
µA
CHARGE PUMP
Charge-Pump Frequency
LOGIC INPUT (SHDN, GAIN1, GAIN2)
V
LOGIC-INPUT HEADPHONE (HPS)
Logic-Input High Voltage
VIH
Logic-Input Low Voltage
VIL
Logic-Input Current
IIN
Note 1:
Note 2:
Note 3:
Note 4:
4
2
V
0.8
10
All devices are 100% production tested at room temperature. All temperature limits are guaranteed by design.
Guaranteed by design. Not production tested.
PSRR is specified with the amplifier input connected to GND through CIN.
Output power levels are measured with the thin QFN’s exposed paddle soldered to the ground plane.
_______________________________________________________________________________________
V
µA
2.6W Stereo Audio Power Amplifier and
DirectDrive Headphone Amplifier
0.01
OUTPUT POWER = 1.25W
0.1
0.01
OUTPUT POWER = 500mW
0.0001
10k
10
100
1k
10k
100k
10
100
1k
10k
100k
FREQUENCY (Hz)
FREQUENCY (Hz)
FREQUENCY (Hz)
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (SPEAKER MODE)
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (SPEAKER MODE)
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (SPEAKER MODE)
1
f = 10kHz
f = 1kHz
0.1
0.01
1
f = 10kHz
f = 1kHz
0.1
VDD = 5V
RL = 8Ω
10
THD+N (%)
10
0.01
0.5
1.0
1.5
2.0
2.5
3.0
f = 20Hz
0.001
0
3.5
f = 10kHz
f = 1kHz
0.1
f = 20Hz
0.001
0
1
0.01
f = 20Hz
0.001
MAX9779 toc06
VDD = 5V
RL = 4Ω
THD+N (%)
10
100
MAX9779 toc05
100
MAX9779 toc04
VDD = 5V
RL = 3Ω
0.5
1.0
1.5
2.0
2.5
3.0
0
0.5
1.0
1.5
OUTPUT POWER (W)
OUTPUT POWER (W)
OUTPUT POWER
vs. LOAD RESISTANCE (SPEAKER MODE)
POWER DISSIPATION vs. OUTPUT POWER
(SPEAKER MODE)
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY (SPEAKER MODE)
2.5
2.0
THD+N = 1%
1.5
1.0
VDD = 5V
f = 1kHz
POUT = POUTL + POUTR
4
0
VRIPPLE = 200mVP-P
OUTPUT REFERRED
-10
-20
-30
3
PSRR (dB)
THD+N = 10%
POWER DISSIPATION (W)
3.0
5
MAX9779 toc07
3.5
MAX9779 toc09
OUTPUT POWER (W)
MAX9779 toc08
THD+N (%)
0.01
0.0001
100k
100
OUTPUT POWER (W)
OUTPUT POWER = 100mW
0.1
0.001
0.0001
1k
1
OUTPUT POWER = 600mW
0.001
100
VDD = 5V
RL = 8Ω
OUTPUT POWER = 500mW
0.001
10
10
MAX9779 toc03
VDD = 5V
RL = 4Ω
1
THD+N (%)
OUTPUT POWER = 1.5W
0.1
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (SPEAKER MODE)
THD+N (%)
VDD = 5V
RL = 3Ω
1
THD+N (%)
10
MAX9779 toc01
10
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (SPEAKER MODE)
MAX9779 toc02
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (SPEAKER MODE)
RL = 4Ω
2
-50
-60
-70
RL = 8Ω
1
-40
-80
0.5
-90
0
0
1
10
LOAD RESISTANCE (Ω)
100
-100
0
1
2
OUTPUT POWER (W)
3
4
10
100
1k
10k
100k
FREQUENCY (Hz)
_______________________________________________________________________________________
5
MAX9779
Typical Operating Characteristics
(Measurement BW = 22Hz to 22kHz, TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)
(Measurement BW = 22Hz to 22kHz, TA = +25°C, unless otherwise noted.)
TURN-ON RESPONSE
(SPEAKER MODE)
CROSSTALK vs. FREQUENCY
(SPEAKER MODE)
MAX9779 toc11
MAX9779 toc10
0
VDD = 5V
VRIPPLE = 200mVP-P
RL = 4Ω
-10
-20
CROSSTALK (dB)
MAX9779
2.6W Stereo Audio Power Amplifier and
DirectDrive Headphone Amplifier
5V/div
SHDN
-30
-40
-50
OUT_+
AND
OUT_-
-60
-70
-80
2V/div
LEFT TO RIGHT
-90
-100
-110
OUT_+
- OUT_-
RIGHT TO LEFT
100mV/div
RL = 8Ω
-120
10
100
1k
10k
100k
20ms/div
FREQUENCY (Hz)
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (HEADPHONE MODE)
MAX9779 toc12
VDD = 5V
RL = 16Ω
AV = 3dB
5V/div
1
SHDN
10
MAX9779 toc13
10
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (HEADPHONE MODE)
VDD = 5V
RL = 32Ω
AV = 3dB
1
OUT_+
- OUT_-
OUTPUT POWER = 45mW
THD+N (%)
2V/div
THD+N (%)
OUTPUT POWER = 90mW
OUT_+
AND
OUT_-
0.1
0.01
MAX9779 toc14
TURN-OFF RESPONSE
(SPEAKER MODE)
OUTPUT POWER = 30mW
0.1
0.01
OUTPUT POWER = 10mW
20mV/div
0.001
0.001
RL = 8Ω
0.0001
10
OUTPUT POWER = 10mW
VDD = 3.3V
RL = 32Ω
AV = 3dB
1000
VDD = 5V
RL = 16Ω
AV = 3dB
100
THD+N (%)
0.01
1
fIN = 10kHz
0.1
0.01
fIN = 20Hz
0.0001
10
100
1k
FREQUENCY (Hz)
6
10k
100k
100k
10
0.1
0.001
0.0001
10k
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (HEADPHONE MODE)
OUTPUT POWER = 10mW
0.001
1k
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (HEADPHONE MODE)
OUTPUT POWER = 45mW
0.1
100
FREQUENCY (Hz)
1
THD+N (%)
THD+N (%)
100k
FREQUENCY (Hz)
OUTPUT POWER = 30mW
0.01
10k
MAX9779 toc16
VDD = 3.3V
RL = 16Ω
AV = 3dB
1k
10
MAX9779 toc15
10
100
MAX9779 toc17
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. FREQUENCY (HEADPHONE MODE)
1
0.0001
10
20ms/div
fIN = 1kHz
0.001
10
100
1k
FREQUENCY (Hz)
10k
100k
0
25
50
75
100
OUTPUT POWER (mW)
_______________________________________________________________________________________
125
150
2.6W Stereo Audio Power Amplifier and
DirectDrive Headphone Amplifier
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (HEADPHONE MODE)
fIN = 10kHz
fIN = 1kHz
1
fIN = 20Hz
40
60
80
0.001
10
0
100
40
50
60
0
POWER DISSIPATION vs. OUTPUT POWER
(HEADPHONE MODE)
OUTPUT POWER vs. LOAD RESISTANCE
(HEADPHONE MODE)
160
THD+N = 10%
120
100
80
60
250
225
POWER DISSIPATION (mW)
MAX9779 toc21
180
40
RL = 16Ω
200
175
150
125
100
RL = 32Ω
75
25
RL = 16Ω
25
f = 1kHz
3.0
3.5
4.0
4.5
5.0
5.5
CROSSTALK vs. FREQUENCY
(HEADPHONE MODE)
0
MAX9779 toc24
-40
-50
-60
-70
VDD = 5V
VRIPPLE = 200mVP-P
RL = 32Ω
-20
CROSSTALK (dB)
-30
PSRR (dB)
RL = 32Ω
50
SUPPLY VOLTAGE (V)
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY (HEADPHONE MODE)
-20
90
75
OUTPUT POWER (mW)
VRIPPLE = 200mVP-P
OUTPUT REFERRED
80
100
25 50 75 100 125 150 175 200 225 250
LOAD RESISTANCE (Ω)
0
30 40 50 60 70
OUTPUT POWER (mW)
0
0
1000
100
-10
20
125
0
0
10
10
OUTPUT POWER vs. SUPPLY VOLTAGE
(HEADPHONE MODE)
VDD = 5V
f = 1kHz
POUT = POUTL + POUTR
50
THD+N = 1%
20
30
OUTPUT POWER (mW)
OUTPUT POWER (mW)
140
20
OUTPUT POWER (mW)
20
MAX9779 toc22
0
fIN = 10kHz
0.01
0.001
0.001
MAX9779 toc20
fIN = 20Hz
0.1
0.01
0.01
OUTPUT POWER (mW)
fIN = 10kHz
0.1
fIN = 20Hz
fIN = 1kHz
1
MAX9779 toc25
0.1
10
THD+N (%)
THD+N (%)
fIN = 1kHz
1
VDD = 3.3V
RL = 32Ω
AV = 3dB
100
10
10
THD+N (%)
VDD = 3.3V
RL = 16Ω
AV = 3dB
100
1000
MAX9779 toc19
VDD = 5V
RL = 32Ω
AV = 3dB
100
1000
MAX9779 toc18
1000
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (HEADPHONE MODE)
MAX9779 toc23
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT POWER (HEADPHONE MODE)
-40
-60
-80
RIGHT TO LEFT
-80
-100
-90
LEFT TO RIGHT
-120
-100
10
100
1k
FREQUENCY (Hz)
10k
100k
10
100
1k
10k
100k
FREQUENCY (Hz)
_______________________________________________________________________________________
7
MAX9779
Typical Operating Characteristics (continued)
(Measurement BW = 22Hz to 22kHz, TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)
(Measurement BW = 22Hz to 22kHz, TA = +25°C, unless otherwise noted.)
OUTPUT POWER vs. CHARGE-PUMP
CAPACITANCE AND LOAD RESISTANCE
140
120
C1 = C2 = 2.2µF
100
80
VDD = 5V
f = 1kHz
VOUT = -60dB
RL = 32Ω
-20
MAGNITUDE (dB)
OUTPUT POWER (mW)
160
60
MAX9779 toc27
VDD = 5V
f = 1kHz
THD+N = 1%
180
HEADPHONE OUTPUT SPECTRUM
0
MAX9779 toc26
200
-40
-60
-80
-100
C1 = C2 = 1µF
40
-120
20
-140
0
10
20
30
0
50
40
5
10
15
LOAD RESISTANCE (Ω)
FREQUENCY (Hz)
TURN-ON RESPONSE
(HEADPHONE MODE)
TURN-OFF RESPONSE
(HEADPHONE MODE)
20
MAX9750/51 toc29
MAX9750/51 toc28
5V/div
5V/div
SHDN
SHDN
20mV/div
HPOUT_
20mV/div
HPOUT_
RL = 32Ω
RL = 32Ω
10ms/div
10ms/div
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
SHUTDOWN SUPPLY CURRENT
vs. SUPPLY VOLTAGE
HPS = GND
14
12
HPS = VDD
10
8
6
MAX9779 toc31
0.35
0.30
SUPPLY CURRENT (µA)
16
MAX9779 toc30
18
SUPPLY CURRENT (mA)
MAX9779
2.6W Stereo Audio Power Amplifier and
DirectDrive Headphone Amplifier
0.25
0.20
0.15
0.10
4
0.05
2
0
0
4.50
4.75
5.00
5.25
SUPPLY VOLTAGE (V)
8
5.50
4.50
4.75
5.00
5.25
SUPPLY VOLTAGE (V)
_______________________________________________________________________________________
5.50
2.6W Stereo Audio Power Amplifier and
DirectDrive Headphone Amplifier
PIN
NAME
FUNCTION
1
INL
2
N.C.
3, 19
PGND
4
OUTL+
Left-Channel Positive Speaker Output
5
OUTL-
Left-Channel Negative Speaker Output
6, 16
PVDD
Speaker Amplifier Power Supply
7
CPVDD
8
C1P
9
CPGND
10
C1N
11
CPVSS
Left-Channel Audio Input
No Connection. Not internally connected.
Power Ground
Charge-Pump Power Supply
Charge-Pump Flying-Capacitor Positive Terminal
Charge-Pump Ground
Charge-Pump Flying-Capacitor Negative Terminal
Charge-Pump Output. Connect to VSS.
12
VSS
13
HPOUTR
Headphone Amplifier Negative Power Supply
Right-Channel Headphone Output
14
HPOUTL
Left-Channel Headphone Output
15
HPVDD
Headphone Positive Power Supply
17
OUTR-
Right-Channel Negative Speaker Output
18
OUTR+
Right-Channel Positive Speaker Output
20
HPS
Headphone Sense Input
21
BIAS
Common-Mode Bias Voltage. Bypass with a 1µF capacitor to GND.
22
SHDN
Shutdown. Drive SHDN low to disable the device. Connect SHDN to VDD for normal operation.
23
GAIN2
Gain Control Input 2
24
GAIN1
25
VDD
Power Supply
26, 28
GND
Ground
27
INR
Right-Channel Audio Input
EP
EP
Exposed Paddle. Connect EP to GND.
Gain Control Input 1
_______________________________________________________________________________________
9
MAX9779
Pin Description
MAX9779
2.6W Stereo Audio Power Amplifier and
DirectDrive Headphone Amplifier
VDD
IN_
VOUT
VDD / 2
GND
OUT_+
BIAS
BIAS
CONVENTIONAL DRIVER-BIASING SCHEME
+VDD
OUT_BIAS
GND
HPOUT_
-VDD
GND
DirectDrive BIASING SCHEME
Figure 1. MAX9779 Signal Path
Detailed Description
The MAX9779 combines a 2.6W BTL speaker amplifier
and a 110mW DirectDrive headphone amplifier with
integrated headphone sensing and comprehensive
click-and-pop suppression. The MAX9779 features fourlevel gain control. The device features high 90dB PSRR,
low 0.01% THD+N, industry-leading click-pop performance, and a low-power shutdown mode.
Each signal path consists of an input amplifier that sets
the gain of the signal path and feeds both the speaker
and headphone amplifier (Figure 1). The speaker
amplifier uses a BTL architecture, doubling the voltage
drive to the speakers and eliminating the need for DCblocking capacitors. The output consists of two signals,
identical in magnitude, but 180° out of phase.
The headphone amplifiers use Maxim’s DirectDrive
architecture that eliminates the bulky output DC-blocking capacitors required by traditional headphone amplifiers. A charge pump inverts the positive supply
(CPV DD ), creating a negative supply (CPV SS ). The
headphone amplifiers operate from these bipolar supplies with their outputs biased about GND (Figure 2).
The amplifiers have almost twice the supply range
compared to other single-supply amplifiers, nearly quadrupling the available output power. The benefit of the
10
Figure 2. Traditional Headphone Amplifier Output Waveform
vs. DirectDrive Headphone Amplifier Output Waveform
GND bias is that the amplifier outputs no longer have a
DC component (typically VDD / 2). This eliminates the
large DC-blocking capacitors required with conventional headphone amplifiers, conserving board space and
system cost, and improving frequency response.
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. The amplifiers include
thermal-overload and short-circuit protection, and can
withstand ±8kV ESD strikes on the headphone amplifier
outputs (IEC air discharge). An additional feature of the
speaker amplifiers is that there is no phase inversion
from input to output.
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 headphones. Without these capacitors, a
significant amount of DC current flows to the headphone,
resulting in unnecessary power dissipation and possible
damage to both headphone and headphone amplifier.
Maxim’s DirectDrive architecture uses a charge pump
to create an internal negative supply voltage. This
______________________________________________________________________________________
2.6W Stereo Audio Power Amplifier and
DirectDrive Headphone Amplifier
Low-Frequency Response
In addition to the cost and size disadvantages, the DCblocking capacitors limit the low-frequency response of
the amplifier and distort the audio signal:
1) The impedance of the headphone load to the DCblocking capacitor forms a highpass filter with the
-3dB point determined by:
f−3dB =
1
2πRLCOUT
where RL is the impedance of the headphone and
COUT is the value of the DC-blocking capacitor.
The highpass filter is required by conventional single-ended, single-supply headphone amplifiers to
block the midrail DC component of the audio signal
from the headphones. Depending on the -3dB point,
the filter can attenuate low-frequency signals within
the audio band. Larger values of COUT reduce the
attenuation but are physically larger, more expensive capacitors. Figure 3 shows the relationship
between the size of COUT and the resulting low-frequency attenuation. Note that the -3dB point for a
MAX9779
LOW-FREQUENCY ROLLOFF
(RL = 16Ω)
0
-5
ATTENUATION (dB)
allows the MAX9779 headphone amplifier output to be
biased about GND, almost doubling the dynamic range
while operating from a single supply. With no DC component, there is no need for the large DC-blocking capacitors. Instead of two large capacitors (220µF typ), the
charge pump requires only two small ceramic capacitors
(1µF typ), conserving board space, reducing cost, and
improving the frequency response of the headphone
amplifier. See the Output Power vs. Charge-Pump
Capacitance and Load Resistance graph in the Typical
Operating Characteristics for details of the possible
capacitor values.
Previous attempts to eliminate the output-coupling
capacitors involved biasing the headphone return
(sleeve) to the DC bias voltage of the headphone
amplifiers. This method raised some issues:
1) The sleeve is typically grounded to the chassis. Using
this biasing approach, the sleeve must be isolated
from system ground, complicating product design.
2) During an ESD strike, the amplifier’s ESD structures
are the only path to system ground. The amplifier
must be able to withstand the full ESD strike.
3) When using the headphone jack as a lineout to other
equipment, the bias voltage on the sleeve may conflict with the ground potential from other equipment,
resulting in large ground-loop current and possible
damage to the amplifiers.
-10
-15
DirectDrive
330µF
220µF
100µF
33µF
-20
-25
-30
-35
10
100
1000
FREQUENCY (Hz)
Figure 3. Low-Frequency Attenuation of Common DC-Blocking
Capacitor Values
16Ω headphone with a 100µF blocking capacitor is
100Hz, well within the audio band.
2) The voltage coefficient of the capacitor, the change
in capacitance due to a change in the voltage
across the capacitor, distorts the audio signal. At
frequencies around the -3dB point, the reactance of
the capacitor dominates, and the voltage coefficient
appears as frequency-dependent distortion. Figure
4 shows the THD+N introduced by two different
capacitor dielectrics. Note that around the -3dB
point, THD+N increases dramatically.
The combination of low-frequency attenuation and frequency-dependent distortion compromises audio
reproduction. DirectDrive improves low-frequency
reproduction in portable audio equipment that emphasizes low-frequency effects such as multimedia laptops, and MP3, CD, and DVD players.
Charge Pump
The MAX9779 features a low-noise charge pump. The
550kHz switching frequency is well beyond the audio
range, and 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. Limiting the switching speed of the charge pump
minimizes the di/dt noise caused by the parasitic bond
wire and trace inductance. Although not typically
required, additional high-frequency ripple attenuation
can be achieved by increasing the size of C2 (see the
Block Diagram).
______________________________________________________________________________________
11
MAX9779
2.6W Stereo Audio Power Amplifier and
DirectDrive Headphone Amplifier
VDD
ADDITIONAL THD+N DUE
TO DC-BLOCKING CAPACITORS
MAX9779
10
THD+N (%)
1
10µA
SHUTDOWN
CONTROL
20
HPS
0.1
14
HPOUTL
TANTALUM
0.01
13
HPOUTR
1kΩ
0.001
1kΩ
ALUM/ELEC
0.0001
10
100
1k
10k
100k
FREQUENCY (Hz)
Figure 4. Distortion Contributed by DC-Blocking Capacitors
Figure 5. HPS Configuration
Headphone Sense Input (HPS)
Gain Selection
The headphone sense input (HPS) monitors the headphone jack and automatically configures the device
based upon the voltage applied at HPS. A voltage of
less than 0.8V sets the device to speaker mode. A voltage of greater than 2V disables the bridge amplifiers
and enables the headphone amplifiers.
For automatic headphone detection, connect HPS to the
control pin of a 3-wire headphone jack as shown in
Figure 5. With no headphone present, the output impedance of the headphone amplifier pulls HPS low. When a
headphone plug is inserted into the jack, the control pin
is disconnected from the tip contact and HPS is pulled
to VDD through a 10µA current source.
The MAX9779 features an internally set, selectable gain.
The GAIN1 and GAIN2 inputs set the maximum gain
of the MAX9779 speaker and headphone amplifiers
(Table 1).
BIAS
The MAX9779 features an internally generated, powersupply independent, common-mode bias voltage of
1.8V referenced to GND. BIAS provides both click-andpop suppression and sets the DC bias level for the
amplifiers. Choose the value of the bypass capacitor as
described in the BIAS Capacitor section. No external load
should be applied to BIAS. Any load lowers the BIAS voltage, affecting the overall performance of the device.
12
Shutdown
The MAX9779 features a 0.2µA, low-power shutdown
mode that reduces quiescent current consumption and
extends battery life. Driving SHDN low disables the
drive amplifiers, bias circuitry, and charge pump, and
drives BIAS and all outputs to GND. Connect SHDN to
VDD for normal operation.
Click-and-Pop Suppression
Speaker Amplifier
The MAX9779 speaker amplifiers feature Maxim’s comprehensive, industry-leading click-and-pop suppression. During startup, the click-pop suppression circuitry
eliminates any audible transient sources internal to the
device. When entering shutdown, both amplifier outputs ramp to GND quickly and simultaneously.
______________________________________________________________________________________
2.6W Stereo Audio Power Amplifier and
DirectDrive Headphone Amplifier
MAX9779
Table 1. MAX9779 Maximum Gain Settings
GAIN2
GAIN1
SPEAKER-MODE GAIN (dB)
0
0
15
0
0
1
16.5
0
1
0
18
3
1
1
19.5
3
Headphone Amplifier
In conventional single-supply headphone amplifiers,
the output-coupling capacitor is a major contributor of
audible clicks and pops. Upon startup, the amplifier
charges the coupling capacitor to its bias voltage, typically half the supply. Likewise, during shutdown, the capacitor is discharged to GND. A DC shift across the capacitor
results, which in turn appears as an audible transient at
the speaker. Since the MAX9779 does not require outputcoupling capacitors, no audible transient occurs.
Additionally, the MAX9779 features extensive click-andpop suppression that eliminates any audible transient
sources internal to the device. The Power-Up/Down
Waveform in the Typical Operating Characteristics
shows that there are minimal spectral components in the
audible range at the output upon startup and shutdown.
Applications Information
BTL Speaker Amplifiers
The MAX9779 features speaker amplifiers designed to
drive a load differentially, a configuration referred to as
bridge-tied load (BTL). The BTL configuration (Figure 6)
offers advantages over the single-ended configuration,
where one side of the load is connected to ground.
Driving the load differentially doubles the output voltage compared to a single-ended amplifier under similar
conditions. Thus, the device’s differential gain is twice
the closed-loop gain of the input amplifier. The effective
gain is given by:
A VD = 2 ×
RF
RIN
Substituting 2 x VOUT(P-P) into the following equation
yields four times the output power due to double the
output voltage:
VRMS =
VOUT(P−P)
2 2
2
V
POUT = RMS
RL
HEADPHONE-MODE GAIN (dB)
VOUT(P-P)
+1
2 x VOUT(P-P)
-1
VOUT(P-P)
Figure 6. Bridge-Tied Load Configuration
Since the differential outputs are biased at midsupply,
there is no net DC voltage across the load. This eliminates the need for DC-blocking capacitors required for
single-ended amplifiers. These capacitors can be large
and expensive, can consume board space, and can
degrade low-frequency performance.
Power Dissipation and Heatsinking
Under normal operating conditions, the MAX9779 can dissipate a significant amount of power. The maximum power
dissipation for the TQFN package is given in the Absolute
Maximum Ratings under Continuous Power Dissipation,
or can be calculated by the following equation:
PDISSPKG(MAX) =
TJ(MAX) − TA
θJA
where TJ(MAX) is +150°C, TA is the ambient temperature, and θJA is the reciprocal of the derating factor in
°C/W as specified in the Absolute Maximum Ratings
section. For example, θJA of the thin QFN package is
+42°C/W. For optimum power dissipation, the exposed
paddle of the package should be connected to the
ground plane (see the Layout and Grounding section).
______________________________________________________________________________________
13
2.6W Stereo Audio Power Amplifier and
DirectDrive Headphone Amplifier
MAX9779
Output Power (Headphone Amplifier)
The headphone amplifiers have been specified for the
worst-case scenario—when both inputs are in phase.
Under this condition, the drivers simultaneously draw
current from the charge pump, leading to a slight loss in
headroom of VSS. In typical stereo audio applications,
the left and right signals have differences in both magnitude and phase, subsequently leading to an increase in
the maximum attainable output power. Figure 7 shows
the two extreme cases for in and out of phase. In reality,
the available power lies between these extremes.
1000
VDD = 5V
RL = 16Ω
AV = 3dB
100
THD+N (%)
10
OUTPUTS IN PHASE
1
0.1
0.01
OUTPUTS 180° OUT OF PHASE
Power Supplies
0.001
0
25
50
75
100
125
150
OUTPUT POWER (mW)
Figure 7. Total Harmonic Distortion Plus Noise vs. Output Power
with Inputs In/Out of Phase (Headphone Mode)
For 8Ω applications, the worst-case power dissipation
occurs when the output power is 1.1W/channel, resulting
in a power dissipation of approximately 1W. In this case,
the TQFN package can be used without violating the
maximum power dissipation or exceeding the thermal
protection threshold. For 4Ω applications, the TQFN
package may require heatsinking or forced air cooling to
prevent the device from reaching its thermal limit. The
more thermally efficient TQFN package is suggested for
speaker loads less than 8Ω.
Output Power (Speaker Amplifier)
The increase in power delivered by the BTL configuration directly results in an increase in internal power dissipation over the single-ended configuration. The
maximum power dissipation for a given VDD and load is
given by the following equation:
PDISS(MAX) =
Component Selection
Input Filtering
The input capacitor (CIN), in conjunction with the amplifier input resistance (RIN), forms a highpass filter that
removes the DC bias from an incoming signal (see the
Block Diagram). The AC-coupling capacitor allows the
amplifier to bias the signal to an optimum DC level.
Assuming zero source impedance, the -3dB point of
the highpass filter is given by:
2VDD2
π 2RL
If the power dissipation for a given application exceeds
the maximum allowed for a given package, either reduce
VDD, increase load impedance, decrease the ambient
temperature, or add heatsinking to the device. Large
output, supply, and ground PC board traces improve the
maximum power dissipation in the package.
Thermal-overload protection limits total power dissipation in these devices. When the junction temperature
exceeds +160°C, the thermal-protection circuitry disables the amplifier output stage. The amplifiers are
enabled once the junction temperature cools by 15°C.
This results in a pulsing output under continuous thermal-overload conditions as the device heats and cools.
14
The MAX9779 has different supplies for each portion of
the device, allowing for the optimum combination of
headroom, power dissipation, and noise immunity. The
speaker amplifiers are powered from PV DD . PV DD
ranges from 4.5V to 5.5V. The headphone amplifiers are
powered from HPVDD and VSS. HPVDD is the positive
supply of the headphone amplifiers and ranges from 3V
to 5.5V. VSS is the negative supply of the headphone
amplifiers. Connect VSS to CPVSS. The charge pump is
powered by CPVDD. CPVDD ranges from 3V to 5.5V and
should be the same potential as HPVDD. The charge
pump inverts the voltage at CPVDD, and the resulting
voltage appears at CPVSS. The remainder of the device
is powered by VDD.
f−3dB =
1
2πRINCIN
RIN is the amplifier’s internal input resistance value
given in the Electrical Characteristics. Choose CIN such
that f-3dB is well below the lowest frequency of interest.
Setting f-3dB too high affects the amplifier’s low-frequency response. Use capacitors with low-voltage
coefficient dielectrics, such as tantalum or aluminum
electrolytic. Capacitors with high-voltage coefficients,
such as ceramics, may result in increased distortion at
low frequencies.
______________________________________________________________________________________
2.6W Stereo Audio Power Amplifier and
DirectDrive Headphone Amplifier
PHONE
FAX
Taiyo Yuden
SUPPLIER
800-348-2496
847-925-0899
www.t-yuden.com
TDK
807-803-6100
847-390-4405
www.component.tdk.com
BIAS Capacitor
BIAS is the output of the internally generated DC bias
voltage. The BIAS bypass capacitor, CBIAS, improves
PSRR and THD+N by reducing power supply and other
noise sources at the common-mode bias node, and
also generates the clickless/popless, startup/shutdown
DC bias waveforms for the speaker amplifiers. Bypass
BIAS with a 1µF capacitor to GND.
Charge-Pump Capacitor Selection
Use capacitors with an ESR less than 100mΩ 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. Table 4
lists suggested manufacturers.
Flying Capacitor (C1)
The value of the flying capacitor (C1) affects the load
regulation and output resistance of the charge pump. 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. See the Output Power vs.
Charge-Pump Capacitance and Load Resistance
graph in the Typical Operating Characteristics. Above
2.2µF, the on-resistance of the switches and the ESR of
C1 and C2 dominate.
Output Capacitor (C2)
The output capacitor value and ESR directly affect the
ripple at CPVSS. Increasing the value of C2 reduces
output ripple. Likewise, decreasing the ESR of C2
reduces both ripple and output resistance. Lower
capacitance values can be used in systems with low
maximum output power levels. See the Output Power
vs. Charge-Pump Capacitance and Load Resistance
graph in the Typical Operating Characteristics.
CPVDD Bypass Capacitor
The CPVDD bypass capacitor (C3) lowers the output
impedance of the power supply and reduces the
impact of the MAX9779’s charge-pump switching
WEBSITE
transients. Bypass CPVDD with C3, the same value as C1,
and place it physically close to CPVDD and PGND (refer
to the MAX9779 Evaluation Kit for a suggested layout).
Powering Other Circuits from a
Negative Supply
An additional benefit of the MAX9779 is the internally generated negative supply voltage (CPVSS). CPVSS is used
by the MAX9779 to provide the negative supply for the
headphone amplifiers. It can also be used to power other
devices within a design. Current draw from CPVSS should
be limited to 5mA; exceeding this affects the operation of
the headphone amplifier. A typical application is a negative supply to adjust the contrast of LCD modules.
When considering the use of CPVSS in this manner,
note that the charge-pump voltage of CPVSS is roughly
proportional to CPVDD and is not a regulated voltage.
The charge-pump output impedance plot appears in
the Typical Operating Characteristics.
Layout and Grounding
Proper layout and grounding are essential for optimum
performance. Use large traces for the power-supply
inputs and amplifier outputs to minimize losses due to
parasitic trace resistance, as well as route head away
from the device. Good grounding improves audio performance, minimizes crosstalk between channels, and
prevents any switching noise from coupling into the audio
signal. Connect CPGND, PGND, and GND together at a
single point on the PC board. Route CPGND and all traces
that carry switching transients away from GND, PGND,
and the traces and components in the audio signal path.
Connect all components associated with the charge
pump (C2 and C3) to the CPGND plane. Connect VSS
and CPVSS together at the device. Place the chargepump capacitors (C1, C2, and C3) as close to the
device as possible. Bypass HPVDD and PVDD with a
0.1µF capacitor to GND. Place the bypass capacitors
as close to the device as possible.
Use large, low-resistance output traces. As load impedance decreases, the current drawn from the device outputs increase. At higher current, the resistance of the
output traces decrease the power delivered to the load.
______________________________________________________________________________________
15
MAX9779
Table 2. Suggested Capacitor Manufacturers
MAX9779
2.6W Stereo Audio Power Amplifier and
DirectDrive Headphone Amplifier
For example, when compared to a 0Ω trace, a 100mΩ
trace reduces the power delivered to a 4Ω load from
2.1W to 2W. Large output, supply, and GND traces also
improve the power dissipation of the device.
The MAX9779 thin QFN package features an exposed
thermal pad on its underside. This pad lowers the
package’s thermal resistance by providing a direct
heat-conduction path from the die to the PC board.
Connect the exposed thermal pad to GND by using a
large pad and multiple vias to the GND plane.
Block Diagram
4.5V TO 5.5V
0.1µF
VDD
25
6, 16 PVDD
MAX9779
CIN
1µF
LEFT-CHANNEL
AUDIO INPUT
CIN
1µF
RIGHT-CHANNEL
AUDIO INPUT
4.5V TO 5.5V
0.1µF
4 OUTL+
INL 1
GAIN/
CONTROL
BTL
AMPLIFIER
GAIN/
CONTROL
BTL
AMPLIFIER
5 OUTL-
18 OUTR+
INR 27
17 OUTR-
BIAS 21
CBIAS
1µF
GND 28
VDD GAIN1
VDD GAIN2
15 HPVDD
GAIN
20 HPS
24
23
HEADPHONE
DETECTION
14 HPOUTL
SHUTDOWN
CONTROL
13 HPOUTR
3V TO 5.5V
10µF
N.C. 2
VDD SHDN
22
CPVDD 7
3V TO 5.5V
1µF
C1P 8
C1
1µF
CHARGE
PUMP
C1N 10
CPGND 9
11
CPVSS
16
12
VSS
C2
1µF
26
3, 19
GND
PGND
______________________________________________________________________________________
2.6W Stereo Audio Power Amplifier and
DirectDrive Headphone Amplifier
Chip Information
BIAS
HPS
PGND
OUTR+
OUTR-
PVDD
HPVDD
PROCESS: BiCMOS
TOP VIEW
21
20
19
18
17
16
15
SHDN
22
14
HPOUTL
GAIN2
23
13
HPOUTR
GAIN1
24
12
VSS
VDD
25
11
CPVSS
GND
26
10
C1N
INR
27
9
CPGND
GND
28
8
C1P
4
5
6
7
OUTL-
PVDD
CPVDD
N.C.
3
OUTL+
2
PGND
1
INL
MAX9779
THIN QFN
______________________________________________________________________________________
17
MAX9779
Pin Configuration
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
QFN THIN.EPS
MAX9779
2.6W Stereo Audio Power Amplifier and
DirectDrive Headphone Amplifier
D2
D
MARKING
b
C
L
0.10 M C A B
D2/2
D/2
k
L
XXXXX
E/2
E2/2
C
L
(NE-1) X e
E
DETAIL A
PIN # 1
I.D.
e/2
E2
PIN # 1 I.D.
0.35x45°
e
(ND-1) X e
DETAIL B
e
L1
L
C
L
C
L
L
L
e
e
0.10 C
A
C
0.08 C
A1 A3
PACKAGE OUTLINE,
16, 20, 28, 32, 40L THIN QFN, 5x5x0.8mm
-DRAWING NOT TO SCALE-
18
21-0140
______________________________________________________________________________________
H
1
2
2.6W Stereo Audio Power Amplifier and
DirectDrive Headphone Amplifier
COMMON DIMENSIONS
PKG.
16L 5x5
20L 5x5
EXPOSED PAD VARIATIONS
28L 5x5
32L 5x5
40L 5x5
SYMBOL MIN. NOM. MAX. MIN. NOM. MAX. MIN. NOM. MAX. MIN. NOM. MAX. MIN. NOM. MAX.
A
A1
A3
b
D
E
e
k
L
L1
N
ND
NE
JEDEC
0.70 0.75 0.80 0.70 0.75 0.80 0.70 0.75 0.80 0.70 0.75 0.80 0.70 0.75 0.80
0
0.02 0.05
0.20 REF.
0
0.02 0.05
0
0.20 REF.
0.02 0.05
0
0.02 0.05
0.20 REF.
0.20 REF.
0.25 0.30 0.35 0.25 0.30 0.35 0.20 0.25 0.30 0.20 0.25 0.30
4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10
4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10 4.90 5.00 5.10
0.80 BSC.
0.65 BSC.
0.50 BSC.
0.50 BSC.
0.25 - 0.25 - 0.25 - 0.25
0
0.02 0.05
0.20 REF.
0.15 0.20 0.25
4.90 5.00 5.10
4.90 5.00 5.10
0.40 BSC.
0.25 0.35 0.45
0.30 0.40 0.50 0.45 0.55 0.65 0.45 0.55 0.65 0.30 0.40 0.50 0.40 0.50 0.60
- 0.30 0.40 0.50
16
20
28
32
40
4
5
7
8
10
4
5
7
8
10
WHHB
WHHC
WHHD-1
WHHD-2
-----
NOTES:
1. DIMENSIONING & TOLERANCING CONFORM TO ASME Y14.5M-1994.
2. ALL DIMENSIONS ARE IN MILLIMETERS. ANGLES ARE IN DEGREES.
3. N IS THE TOTAL NUMBER OF TERMINALS.
4. THE TERMINAL #1 IDENTIFIER AND TERMINAL NUMBERING CONVENTION SHALL
CONFORM TO JESD 95-1 SPP-012. DETAILS OF TERMINAL #1 IDENTIFIER ARE
OPTIONAL, BUT MUST BE LOCATED WITHIN THE ZONE INDICATED. THE TERMINAL #1
IDENTIFIER MAY BE EITHER A MOLD OR MARKED FEATURE.
D2
L
E2
PKG.
CODES
MIN.
NOM. MAX.
T1655-1
T1655-2
T1655N-1
3.00
3.00
3.00
3.10 3.20 3.00
3.10 3.20 3.00
3.10 3.20 3.00
3.10
3.10
3.10
3.20
3.20
3.20
T2055-2
T2055-3
T2055-4
3.00
3.00
3.00
3.10 3.20 3.00
3.10 3.20 3.00
3.10 3.20 3.00
3.10
3.10
3.10
3.20
3.20
3.20
T2055-5
T2855-1
T2855-2
T2855-3
T2855-4
T2855-5
T2855-6
T2855-7
T2855-8
T2855N-1
T3255-2
T3255-3
T3255-4
T3255N-1
3.15
3.15
2.60
3.15
2.60
2.60
3.15
2.60
3.15
3.15
3.00
3.00
3.00
3.00
3.25
3.25
2.70
3.25
2.70
2.70
3.25
2.70
3.25
3.25
3.10
3.10
3.10
3.10
3.15
3.15
2.60
3.15
2.60
2.60
3.15
2.60
3.15
3.15
3.00
3.00
3.00
3.00
3.25
3.25
2.70
3.25
2.70
2.70
3.25
2.70
3.25
3.25
3.10
3.10
3.10
3.10
3.35
3.35
2.80
3.35
2.80
2.80
3.35
2.80
3.35
3.35
3.20
3.20
3.20
3.20
T4055-1
3.20
3.30 3.40 3.20
3.30
3.40
3.35
3.35
2.80
3.35
2.80
2.80
3.35
2.80
3.35
3.35
3.20
3.20
3.20
3.20
MIN.
NOM. MAX.
±0.15
**
**
**
**
**
**
0.40
DOWN
BONDS
ALLOWED
NO
YES
NO
NO
YES
NO
YES
**
NO
NO
YES
YES
NO
**
**
0.40
**
**
**
**
**
NO
YES
YES
NO
NO
YES
NO
NO
**
YES
**
**
**
**
** SEE COMMON DIMENSIONS TABLE
5. DIMENSION b APPLIES TO METALLIZED TERMINAL AND IS MEASURED BETWEEN
0.25 mm AND 0.30 mm FROM TERMINAL TIP.
6. ND AND NE REFER TO THE NUMBER OF TERMINALS ON EACH D AND E SIDE RESPECTIVELY.
7. DEPOPULATION IS POSSIBLE IN A SYMMETRICAL FASHION.
8. COPLANARITY APPLIES TO THE EXPOSED HEAT SINK SLUG AS WELL AS THE TERMINALS.
9. DRAWING CONFORMS TO JEDEC MO220, EXCEPT EXPOSED PAD DIMENSION FOR T2855-1,
T2855-3, AND T2855-6.
10. WARPAGE SHALL NOT EXCEED 0.10 mm.
11. MARKING IS FOR PACKAGE ORIENTATION REFERENCE ONLY.
12. NUMBER OF LEADS SHOWN ARE FOR REFERENCE ONLY.
13. LEAD CENTERLINES TO BE AT TRUE POSITION AS DEFINED BY BASIC DIMENSION "e", ±0.05.
PACKAGE OUTLINE,
16, 20, 28, 32, 40L THIN QFN, 5x5x0.8mm
21-0140
-DRAWING NOT TO SCALE-
H
2
2
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 ____________________ 19
© 2005 Maxim Integrated Products
Heaney
Printed USA
is a registered trademark of Maxim Integrated Products, Inc.
MAX9779
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
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