LM4671ITLX [NSC]
Filterless High Efficiency 2.5W Switching Audio Amplifier; 滤波的高效2.5W开关音频放大器
| 型号： | LM4671ITLX |
| 厂家： | 
National Semiconductor |
| 描述： | Filterless High Efficiency 2.5W Switching Audio Amplifier |
| 文件： | 总20页 (文件大小：592K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
December 18, 2007
LM4671ꢀ
Filterless High Efficiency 2.5W Switching Audio Amplifier
General Description
Key Specifications
The LM4671 is a single supply, high efficiency 2.5W switching
audio amplifier. A low noise, filterless PWM architecture elim-
inates the output filter, reducing external component count,
board area consumption, system cost, and simplifying design.
■ꢀEfficiency @ 3.6V, 100mW into
ꢁꢁ8Ω speaker
80% (typ)
88% (typ)
■ꢀEfficiency @ 3.6V, 400mW into
ꢁꢁ 8Ω speaker
The LM4671 is designed to meet the demands of mobile
phones and other portable communication devices. Operat-
ing on a single 5V supply, it is capable of driving a 4Ω speaker
load at a continuous average output of 2.1W with less than
1% THD+N. Its flexible power supply requirements allow op-
eration from 2.4V to 5.5V.
■ꢀEfficiency @ 5V, 1W into 8Ω
speaker
86% (typ)
■ꢀQuiescent current, 3.6V supply
2.8mA (typ)
■ꢀTotal shutdown power supply
0.01µA (typ)
2.4V to 5.5V
The LM4671 has high efficiency with speaker loads compared
to a typical Class AB amplifier. With a 3V supply driving an
8Ω speaker, the IC's efficiency for a 100mW power level is
80%, reaching 88% at 400mW output power.
current
■ꢀSingle supply range
Features
The LM4671 features a low-power consumption shutdown
mode. Shutdown may be enabled by driving the Shutdown
pin to a logic low (GND).
No output filter required for inductive loads
■
■
Externally configurable gain
The gain of the LM4671 is externally configurable which al-
lows independent gain control from multiple sources by sum-
ming the signals.
Very fast turn on time: 17μs (typ)
Minimum external components
"Click and pop" suppression circuitry
Micro-power shutdown mode
■
■
■
■
■
Available in space-saving microSMD package
Applications
Mobile phones
■
■
■
PDAs
Portable electronic devices
Typical Application
201073j3
FIGURE 1. Typical Audio Amplifier Application Circuit
Boomer® is a registered trademark of National Semiconductor Corporation.
© 2007 National Semiconductor Corporation
201073
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Connection Diagrams
9 Bump micro SMD Package
micro SMD Marking
201073c6
Top View
X — Date Code
T— Die Traceability
G — Boomer Family
E7 — LM4671ITL
20107336
Top View
Order Number LM4671ITL, LM4671ITLX
See NS Package Number TLA09AAA
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Thermal Resistance
ꢁθJA (micro SMD)
Soldering Information
See AN-1112 "microSMD Wafers Level Chip Scale
Package."
Absolute Maximum Ratings (Notes 1, 2)
220°C/W
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage (Note 1)
Storage Temperature
Voltage at Any Input Pin
6.0V
−65°C to +150°C
Operating Ratings (Notes 1, 2)
Temperature Range
VDD + 0.3V ≥V ≥GND - 0.3V
Power Dissipation (Note 3)
Internally Limited
TMIN ≤ TA ≤ TMAX
Supply Voltage
−40°C ≤ TA ≤ 85°C
2.4V ≤ VDD ≤ 5.5V
ESD Susceptibility, all other pins (Note 4)
ESD Susceptibility (Note 5)
2.0kV
200V
Junction Temperature (TJMAX
)
150°C
Electrical Characteristics (Notes 1, 2)
The following specifications apply for AV = 2V/V (RI = 150kΩ), RL = 15µH + 8Ω + 15µH unless otherwise specified. Limits apply for
TA = 25°C.
LM4671
Units
Symbol
Parameter
Conditions
VI = 0V, AV = 2V/V,
Typical
Limit
(Limits)
(Note 6)
(Notes 7, 8)
|VOS
|
Differential Output Offset Voltage
GSM Power Supply Rejection Ratio
5
mV (max)
dB (min)
VDD = 2.4V to 5.0V
VDD = 2.4V to 5.0V
PSRRGSM
61
VDD = 2.4V to 5.0V
CMRRGSM
VIC = VDD/2 to 0.5V,
VIC = VDD/2 to VDD – 0.8V
GSM Common Mode Rejection Ratio
68
dB (min)
|IIH|
|IIL|
Logic High Input Current
Logic Low Input Current
VDD = 5.0V, VI = 5.5V
17
0.9
6.4
3.8
2.0
100
5
μA (max)
μA (max)
mA (max)
mA
VDD = 5.0V, VI = –0.3V
VIN = 0V, No Load, VDD = 5.0V
VIN = 0V, No Load, VDD = 3.6V
VIN = 0V, No Load, VDD =2.4V
IDD
6.2
3.0
Quiescent Power Supply Current
mA (max)
VSHUTDOWN = 0V
ISD
Shutdown Current
0.01
1
μA (max)
VDD = 2.4V to 5.0V
VSDIH
VSDIL
ROSD
Shutdown voltage input high
Shutdown voltage input low
Output Impedance
1.2
1.1
1.4
0.4
V (min)
V (max)
VSHUTDOWN = 0.4V
100
kΩ
270kΩ/RI
330kΩ/RI
V/V (min)
V/V (max)
AV
Gain
300kΩ/RI
Resistance from Shutdown Pin to
GND
RSD
300
kΩ
RL = 15μH + 4Ω + 15μH
THD = 10% (max)
f = 1kHz, 22kHz BW
VDD = 5V
2.5
1.3
W
W
VDD = 3.6V
VDD = 2.5V
520
mW
PO
Output Power
RL = 15μH + 4Ω + 15μH
THD = 1% (max)
f = 1kHz, 22kHz BW
VDD = 5V
2.21
1.06
420
W
W
mW
VDD = 3.6V
VDD = 2.5V
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LM4671
Typical
Units
(Limits)
Symbol
Parameter
Conditions
Limit
(Note 6)
(Notes 7, 8)
RL = 15μH + 8Ω + 15μH
THD = 10% (max)
f = 1kHz, 22kHz BW
VDD = 5V
1.7
870
425
W
VDD = 3.6V
VDD = 2.5V
mW
mW
PO
Output Power
RL = 15μH + 8Ω + 15μH
THD = 1% (max)
f = 1kHz, 22kHz BW
VDD = 5V
1.19
700
350
W
VDD = 3.6V
VDD = 2.5V
600
mW
mW
VDD = 5V, PO = 0.1WRMS
f = 1kHz
,
0.09
0.04
0.12
0.05
%
%
%
%
VDD = 3.6V, PO = 0.1WRMS
f = 1kHz
,
,
,
THD+N
Total Harmonic Distortion + Noise
VDD = 3.6V, PO = 0.1WRMS
f = 5kHz
VDD = 3.6V, PO = 0.1WRMS
f = 10kHz
VDD = 3.6V, 5V
VRipple = 200mVPP Sine,
fRipple = 217Hz
61.8
59.8
48.7
65.7
dB
dB
dB
dB
Inputs to AC GND, CI = 2μF
VDD = 3.6V, 5V
VRipple = 200mVPP Sine,
fRipple = 1kHz
Inputs to AC GND, CI = 2μF
PSRR
Power Supply Rejection Ratio
VDD = 3.6V, 5V
VRipple = 200mVPP Sine,
fRipple = 10kHz
Inputs to AC GND, CI = 2μF
VDD = 3.6V, 5V
VRipple = 200mVPP Sine,
fRipple = 217Hz
fIN = 1kHz, PO = 10mWRMS
VDD = 5V, PO = 1WRMS
SNR
Signal to Noise Ratio
Output Noise
93
58
dB
VDD = 3.6V, f = 20Hz – 20kHz
Inputs to AC GND, CI = 2μF
No Weighting
μVRMS
εOUT
VDD = 3.6V, Inputs to AC GND
CI = 2μF, A Weighted
38
μVRMS
VDD = 3.6V, VRipple = 1VPP Sine
fRipple = 217Hz
CMRR
Common Mode Rejection Ratio
68.3
dB
TWU
TSD
Wake-up Time
Shutdown Time
VDD = 3.6V
17
49
μs (max)
μs
140
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Note 1: All voltages are measured with respect to the ground pin, unless otherwise specified.
Note 2: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
functional, but do not guarantee specific performance limits. Electrical Characteristics state DC and AC electrical specifications under particular test conditions
which guarantee specific performance limits. This assumes that the device is within the Operating Ratings. Specifications are not guaranteed for parameters
where no limit is given, however, the typical value is a good indication of device performance.
Note 3: The maximum power dissipation must be derated at elevated temperatures and is dictated by TJMAX, θJA, and the ambient temperature TA. The maximum
allowable power dissipation is PDMAX = (TJMAX–TA)/θJA or the number given in Absolute Maximum Ratings, whichever is lower. For the LM4671, TJMAX = 150°C.
The typical θJA is 220°C/W for the microSMD package.
Note 4: Human body model, 100pF discharged through a 1.5kΩ resistor.
Note 5: Machine Model, 220pF–240pF discharged through all pins.
Note 6: Typical specifications are specified at 25°C and represent the parametric norm.
Note 7: Tested limits are guaranteed to National's AOQL (Average Outgoing Quality Level).
Note 8: Datasheet min/max specification limits are guaranteed by design, test, or statistical analysis.
Note 9: Shutdown current is measured in a normal room environment. Exposure to direct sunlight will increase ISD by a maximum of 2µA. The Shutdown pin
should be driven as close as possible to GND for minimal shutdown current and to VDD for the best THD performance in PLAY mode. See the Application
Information section under SHUTDOWN FUNCTION for more information.
Note 10: The performance graphs were taken using the Audio Precision AUX-0025 Switching Amplifier measurement Filter in series with the LC filter on the
demo board.
External Components Description
(Figure 1)
Components
Functional Description
1.
CS
Supply bypass capacitor which provides power supply filtering. Refer to the Power Supply Bypassing section
for information concerning proper placement and selection of the supply bypass capacitor.
2.
CI
Input AC coupling capacitor which blocks the DC voltage at the amplifier's input terminals.
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Typical Performance Characteristics
THD+N vs Frequency
VDD = 2.4V, RL = 15μH+4Ω+15μH,
PO = 375mW, 22kHz BW
THD+N vs Frequency
VDD = 3.6V, RL = 15μH+4Ω+15μH,
PO = 750mW, 22kHz BW
20107303
20107304
THD+N vs Frequency
VDD = 5V, RL = 15μH+4Ω+15μH,
PO = 1.5mW, 22kHz BW
THD+N vs Frequency
VDD = 2.4V, RL = 15μH+8Ω+15μH,
PO = 200mW, 22kHz BW
20107305
20107306
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THD+N vs Frequency
VDD = 3.6V, RL = 15μH+8Ω+15μH,
PO = 500mW, 22kHz BW
THD+N vs Frequency
VDD = 5V, RL = 15μH+8Ω+15μH,
PO = 1W, 22kHz BW
20107307
20107308
THD+N vs Output Power
VDD = 5V, RL = 15μH+4Ω+15μH,
f = 1kHz, 22kHz BW
THD+N vs Output Power
VDD = 5V, RL = 15μH+8Ω+15μH,
f = 1kHz, 22kHz BW
20107310
20107309
CMRR vs Frequency
PSRR vs Frequency
VDD = 3.6V, RL = 15μH+8Ω+15μH,
Vripple = 200mVp-p, 22kHz BW
VDD = 3.6V, RL = 15μH+8Ω+15μH,
Vripple = 1Vp-p, 22kHz BW
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20107312
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Efficiency vs Output Power
RL = 15μH+4Ω+15μH,
f = 1kHz, 22kHz BW
Efficiency vs Output Power
RL = 15μH+8Ω+15μH,
f = 1kHz, 22kHz BW
20107314
20107313
Power Dissipation vs Output Power
RL = 15μH+4Ω+15μH,
Power Dissipation vs Output Power
RL = 15μH+8Ω+15μH,
f = 1kHz, 22kHz BW
f = 1kHz, 22kHz BW
20107316
20107315
Output Power vs Supply Voltage
RL = 15μH+4Ω+15μH,
VDD = 3.6V
Output Power vs Supply Voltage
RL = 15μH+8Ω+15μH,
VDD = 3.6V
20107318
20107317
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Gain vs Supply Voltage
Supply Current vs Supply Voltage
Rin = 150kΩ
RL = 15μH+8Ω+15μH
20107319
20107320
Shutdown Current vs Supply Voltage
RL = 15μH+8Ω+15μH
20107321
Application Information
GENERAL AMPLIFIER FUNCTION
duce it with the difference being the power dissipated, typi-
cally, in the IC. The key here is “useful” work. For audio
systems, the energy delivered in the audible bands is con-
sidered useful including the distortion products of the input
signal. Sub-sonic (DC) and super-sonic components
(>22kHz) are not useful. The difference between the power
flowing from the power supply and the audio band power be-
ing transduced is dissipated in the LM4671 and in the trans-
ducer load. The amount of power dissipation in the LM4671
is very low. This is because the ON resistance of the switches
used to form the output waveforms is typically less than
0.25Ω. This leaves only the transducer load as a potential
"sink" for the small excess of input power over audio band
output power. The LM4671 dissipates only a fraction of the
excess power requiring no additional PCB area or copper
plane to act as a heat sink.
The LM4671 features a filterless modulation scheme. The
differential outputs of the device switch at 300kHz from VDD
to GND. When there is no input signal applied, the two outputs
(VO1 and VO2) switch with a 50% duty cycle, with both outputs
in phase. Because the outputs of the LM4671 are differential,
the two signals cancel each other. This results in no net volt-
age across the speaker, thus there is no load current during
an idle state, conserving power.
With an input signal applied, the duty cycle (pulse width) of
the LM4671 outputs changes. For increasing output voltages,
the duty cycle of VO1 increases, while the duty cycle of VO2
decreases. For decreasing output voltages, the converse oc-
curs, the duty cycle of VO2 increases while the duty cycle of
VO1 decreases. The difference between the two pulse widths
yields the differential output voltage.
DIFFERENTIAL AMPLIFIER EXPLANATION
POWER DISSIPATION AND EFFICIENCY
As logic supply voltages continue to shrink, designers are in-
creasingly turning to differential analog signal handling to
In general terms, efficiency is considered to be the ratio of
useful work output divided by the total energy required to pro-
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preserve signal to noise ratios with restricted voltage swing.
The LM4671 is a fully differential amplifier that features dif-
ferential input and output stages. A differential amplifier am-
plifies the difference between the two input signals. Tradition-
al audio power amplifiers have typically offered only single-
ended inputs resulting in a 6dB reduction in signal to noise
ratio relative to differential inputs. The LM4671 also offers the
possibility of DC input coupling which eliminates the two ex-
ternal AC coupling, DC blocking capacitors. The LM4671 can
be used, however, as a single ended input amplifier while still
retaining it's fully differential benefits. In fact, completely un-
related signals may be placed on the input pins. The LM4671
simply amplifies the difference between the signals. A major
benefit of a differential amplifier is the improved common
mode rejection ratio (CMRR) over single input amplifiers. The
common-mode rejection characteristic of the differential am-
plifier reduces sensitivity to ground offset related noise injec-
tion, especially important in high noise applications.
SHUTDOWN FUNCTION
In order to reduce power consumption while not in use, the
LM4671 contains shutdown circuitry that reduces current
draw to less than 0.01µA. The trigger point for shutdown is
shown as a typical value in the Electrical Characteristics Ta-
bles and in the Shutdown Hysteresis Voltage graphs found in
the Typical Performance Characteristics section. It is best
to switch between ground and supply for minimum current
usage while in the shutdown state. While the LM4671 may be
disabled with shutdown voltages in between ground and sup-
ply, the idle current will be greater than the typical 0.01µA
value. Increased THD may also be observed with voltages
less than VDD on the Shutdown pin when in PLAY mode.
The LM4671 has an internal resistor connected between
GND and Shutdown pins. The purpose of this resistor is to
eliminate any unwanted state changes when the Shutdown
pin is floating. The LM4671 will enter the shutdown state when
the Shutdown pin is left floating or if not floating, when the
shutdown voltage has crossed the threshold. To minimize the
supply current while in the shutdown state, the Shutdown pin
should be driven to GND or left floating. If the Shutdown pin
is not driven to GND, the amount of additional resistor current
due to the internal shutdown resistor can be found by Equa-
tion (1) below.
PCB LAYOUT CONSIDERATIONS
As output power increases, interconnect resistance (PCB
traces and wires) between the amplifier, load and power sup-
ply create a voltage drop. The voltage loss on the traces
between the LM4671 and the load results is lower output
power and decreased efficiency. Higher trace resistance be-
tween the supply and the LM4671 has the same effect as a
poorly regulated supply, increase ripple on the supply line al-
so reducing the peak output power. The effects of residual
trace resistance increases as output current increases due to
higher output power, decreased load impedance or both. To
maintain the highest output voltage swing and corresponding
peak output power, the PCB traces that connect the output
pins to the load and the supply pins to the power supply
should be as wide as possible to minimize trace resistance.
(VSD - GND) / 60kΩ
(1)
With only a 0.5V difference, an additional 8.3µA of current will
be drawn while in the shutdown state.
PROPER SELECTION OF EXTERNAL COMPONENTS
The gain of the LM4671 is set by the external resistors, Ri in
Figure 1, The Gain is given by Equation (2) below. Best THD
+N performance is achieved with a gain of 2V/V (6dB).
The use of power and ground planes will give the best THD
+N performance. While reducing trace resistance, the use of
power planes also creates parasite capacitors that help to fil-
ter the power supply line.
AV = 2 * 150 kΩ / Ri (V/V)
(2)
The inductive nature of the transducer load can also result in
overshoot on one or both edges, clamped by the parasitic
diodes to GND and VDD in each case. From an EMI stand-
point, this is an aggressive waveform that can radiate or
conduct to other components in the system and cause inter-
ference. It is essential to keep the power and output traces
short and well shielded if possible. Use of ground planes,
beads, and micro-strip layout techniques are all useful in pre-
venting unwanted interference.
It is recommended that resistors with 1% tolerance or better
be used to set the gain of the LM4671. The Ri resistors should
be placed close to the input pins of the LM4671. Keeping the
input traces close to each other and of the same length in a
high noise environment will aid in noise rejection due to the
good CMRR of the LM4671. Noise coupled onto input traces
which are physically close to each other will be common mode
and easily rejected by the LM4671.
Input capacitors may be needed for some applications or
when the source is single-ended (see Figures 3, 5). Input ca-
pacitors are needed to block any DC voltage at the source so
that the DC voltage seen between the input terminals of the
LM4671 is 0V. Input capacitors create a high-pass filter with
the input resistors, Ri. The –3dB point of the high-pass filter
is found using Equation (3) below.
As the distance from the LM4671 and the speaker increase,
the amount of EMI radiation will increase since the output
wires or traces acting as antenna become more efficient with
length. What is acceptable EMI is highly application specific.
Ferrite chip inductors placed close to the LM4671 may be
needed to reduce EMI radiation. The value of the ferrite chip
is very application specific.
POWER SUPPLY BYPASSING
fC = 1 / (2πRi Ci ) (Hz)
(3)
As with any power amplifier, proper supply bypassing is crit-
ical for low noise performance and high power supply rejec-
tion ratio (PSRR). The capacitor (CS) location should be as
close as possible to the LM4671. Typical applications employ
a voltage regulator with a 10µF and a 0.1µF bypass capacitors
that increase supply stability. These capacitors do not elimi-
nate the need for bypassing on the supply pin of the LM4671.
A 1µF tantalum capacitor is recommended.
The input capacitors may also be used to remove low audio
frequencies. Small speakers cannot reproduce low bass fre-
quencies so filtering may be desired . When the LM4671 is
using a single-ended source, power supply noise on the
ground is seen as an input signal by the +IN input pin that is
capacitor coupled to ground (See Figures 5 – 7). Setting the
high-pass filter point above the power supply noise frequen-
cies, 217Hz in a GSM phone, for example, will filter out this
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10
noise so it is not amplified and heard on the output. Capacitors
with a tolerance of 10% or better are recommended for
impedance matching.
terminals. Figure 5 shows the typical single-ended application
configuration. The equations for Gain, Equation (2), and fre-
quency response, Equation (3), hold for the single-ended
configuration as shown in Figure 5.
DIFFERENTIAL CIRCUIT CONFIGURATIONS
When using more than one single-ended source as shown in
Figure 6, the impedance seen from each input terminal should
be equal. To find the correct values for Ci3 and Ri3 connected
to the +IN input pin the equivalent impedance of all the single-
ended sources are calculated. The single-ended sources are
in parallel to each other. The equivalent capacitor and resis-
tor, Ci3 and Ri3, are found by calculating the parallel combi-
nation of all Civalues and then all Ri values. Equations (4) and
(5) below are for any number of single-ended sources.
The LM4671 can be used in many different circuit configura-
tions. The simplest and best performing is the DC coupled,
differential input configuration shown in Figure 2. Equation (2)
above is used to determine the value of the Ri resistors for a
desired gain.
Input capacitors can be used in a differential configuration as
shown in Figure 3. Equation (3) above is used to determine
the value of the Ci capacitors for a desired frequency re-
sponse due to the high-pass filter created by Ci and Ri.
Equation (2) above is used to determine the value of the Ri
resistors for a desired gain
Ci3 = Ci1 + Ci2 + Cin ... (μF)
(4)
(5)
The LM4671 can be used to amplify more than one audio
source. Figure 4 shows a dual differential input configuration.
The gain for each input can be independently set for maxi-
mum design flexibility using the Ri resistors for each input and
Equation (2). Input capacitors can be used with one or more
sources as well to have different frequency responses de-
pending on the source or if a DC voltage needs to be blocked
from a source.
Ri3 = 1 / (1/Ri1 + 1/Ri2 + 1/Rin ...) (Ω)
The LM4671 may also use a combination of single-ended and
differential sources. A typical application with one single-end-
ed source and one differential source is shown in Figure 7.
Using the principle of superposition, the external component
values can be determined with the above equations corre-
sponding to the configuration.
SINGLE-ENDED CIRCUIT CONFIGURATIONS
The LM4671 can also be used with single-ended sources but
input capacitors will be needed to block any DC at the input
201073i7
FIGURE 2. Differential input configuration
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201073i8
FIGURE 3. Differential input configuration with input capacitors
201073i9
FIGURE 4. Dual differential input configuration
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201073j0
FIGURE 5. Single-ended input configuration
201073j1
FIGURE 6. Dual single-ended input configuration
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201073j2
FIGURE 7. Dual input with a single-ended input and a differential input
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REFERENCE DESIGN BOARD SCHEMATIC
201073j4
FIGURE 8.
The commonly used Audio Precision analyzer is differential,
but its ability to accurately reject high frequency signals is
questionable necessitating the on board measurement filter.
When in doubt or when the signal needs to be single-ended,
use an audio signal transformer to convert the differential out-
put to a single ended output. Depending on the audio
transformer's characteristics, there may be some attenuation
of the audio signal which needs to be taken into account for
correct measurement of performance.
In addition to the minimal parts required for the application
circuit, a measurement filter is provided on the evaluation cir-
cuit board so that conventional audio measurements can be
conveniently made without additional equipment. This is a
balanced input, grounded differential output low pass filter
with a 3dB frequency of approximately 35kHz and an on board
termination resistor of 300Ω (see schematic). Note that the
capacitive load elements are returned to ground. This is not
optimal for common mode rejection purposes, but due to the
independent pulse format at each output there is a significant
amount of high frequency common mode component on the
outputs. The grounded capacitive filter elements attenuate
this component at the board to reduce the high frequency
CMRR requirement placed on the analysis instruments.
Measurements made at the output of the measurement filter
suffer attenuation relative to the primary, unfiltered outputs
even at audio frequencies. This is due to the resistance of the
inductors interacting with the termination resistor (300Ω) and
is typically about -0.25dB (3%). In other words, the voltage
levels (and corresponding power levels) indicated through the
measurement filter are slightly lower than those that actually
occur at the load placed on the unfiltered outputs. This small
loss in the filter for measurement gives a lower output power
reading than what is really occurring on the unfiltered outputs
and its load.
Even with the grounded filter the audio signal is still differen-
tial, necessitating a differential input on any analysis instru-
ment connected to it. Most lab instruments that feature BNC
connectors on their inputs are NOT differential responding
because the ring of the BNC is usually grounded.
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LM4671 micro SMD BOARD ARTWORK
Composite View
Silk Screen
Internal Layer 1, GND
Bottom Layer
201073j6
201073k0
201073j8
201073j9
201073j7
201073j5
Top Layer
Internal Layer 2, GND
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Revision History
Rev
1.0
Date
Description
03/16/05
12/17/07
Initial release.
1.01
Some text edits.
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Physical Dimensions inches (millimeters) unless otherwise noted
9 Bump micro SMD
Order Number LM4671ITL, LM4671ITLX
NS Package Number TLA09AAA
X1 = 1.514 X2 = 1.514 X3 = 0.600
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18
Notes
19
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Notes
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