NSC LMH6515SQX

LMH6515
600 MHz, Digital Controlled, Variable Gain Amplifier
General Description
Features
The LMH6515 is a high performance, digitally controlled variable gain amplifier (DVGA). It combines precision gain control
with a low noise, ultra-linear, differential amplifier. Typically,
the LMH6515 drives a high performance ADC in a broad
range of mixed signal and digital communication applications
such as mobile radio and cellular base stations where automatic gain control (AGC) is required to increase system dynamic range. When used in conjunction with a high speed
ADC, system dynamic range can be extended by up to 32 dB.
The LMH6515 has a differential input and output allowing
large signal swings on a single 5V supply. It is designed to
accept signals from RF elements and maintain a terminated
impedance environment. The input impedance is 200Ω resistive. The output impedance is either 200Ω or 400Ω and is
user selectable. A unique internal architecture allows use with
both single ended and differential input signals.
Input signals to the LMH6515 are scaled by a highly linear,
digitally controlled attenuator with 31 accurate 1 dB steps.
The attenuator output provides the input signal for a high gain,
ultra linear differential transconductor. The transconductor
differential output current can be converted into a voltage by
using the on-chip 200Ω or 400Ω loads. The transconductance
gain is 0.1 Amp/Volt resulting in a maximum voltage gain of
+26 dB when driving a 200Ω load, or 32 dB when driving the
400Ω load. On chip digital latches are provided for local storage of the gain setting. The gain step settling time is 5 ns and
care has been taken to reduce the sensitivity of bandwidth
and phase to gain setting.
The LMH6515 operates over the industrial temperature range
of −40°C to +85°C. The LMH6515 is available in a 16-Pin,
thermally enhanced, LLP package.
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Adjustable gain with a 31 dB range
Precise 1 dB gain steps
Parallel 5-bit gain control
On chip register stores gain setting
Fully differential signal path
Single ended to differential capable
200Ω input impedance
Small footprint (4 mm x 4 mm) LLP package
Key Specifications
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600 MHz bandwidth @ 100Ω load
40 dBm OIP3 @ 75 MHz, 200Ω load
20 dB to 30 dB maximum gain
Selectable output impedance of 200Ω or 400Ω
8.3 dB noise figure
5 ns gain step switching time
100 mA supply current
Applications
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Cellular base stations
IF sampling receivers
Instrumentation
Modems
Imaging
Differential line receiver
Typical Application
20214301
LMH™ is a trademark of National Semiconductor Corporation.
© 2007 National Semiconductor Corporation
202143
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LMH6515 600 MHz, Digital Controlled, Variable Gain Amplifier
October 2007
LMH6515
Storage Temperature Range
Soldering Information
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
ESD Tolerance (Note 2)
Human Body Model
Machine Model
Positive Supply Voltage (Pin 3)
Output Voltage (pin 14,15)
Differential Voltage Between Any
Two Grounds
Analog Input Voltage Range
Digital Input Voltage Range
Output Short Circuit Duration
(one pin to ground)
Junction Temperature
Infrared or Convection (20 sec)
Wave Soldering (10 sec)
Operating Ratings
2 kV
150V
−0.6V to 5.5V
−0.6V to 6.8V
<200 mV
−0.6V to VCC
−0.6V to 3.6V
Infinite
+150°C
5V Electrical Characteristics
−65°C to +150°C
235°C
260°C
(Note 1)
Supply Voltage (Pin 3)
Output Voltage Range (Pin 14, 15)
Differential Voltage Between Any
Two Grounds
Analog Input Voltage Range,
AC Coupled
Temperature Range (Note 3)
4V to 5.25V
1.4V to 6.4V
±1.4V
−40°C to +85°C
Package Thermal Resistance (θJA)
16-Pin LLP
47°C/W
<10 mV
(Note 4)
The following specifications apply for single supply with VCC = 5V, Maximum Gain , RL = 100Ω (200Ω external || 200Ω internal),
VOUT = 2 VPP, fin = 150 MHz. Boldface limits apply at temperature extremes.
Symbol
Parameter
Conditions
Min
(Note 6)
Typ
(Note 5)
Max
(Note 6)
Units
Dynamic Performance
SSBW
−3 dB Bandwidth
Average of all Gain Settings
600
f = 75 MHz, VOUT = 2 VPP
−76
f = 150 MHz, VOUT = 2 VPP
−72
f = 250 MHz, VOUT = 2 VPP
−66
f = 450 MHz, VOUT = 2 VPP
−58
f = 75 MHz, VOUT = 2 VPP,
Tone Spacing = 0.5 MHz
39
f = 150 MHz, VOUT = 2 VPP,
Tone Spacing = 2 MHz
37
f = 250 MHz, VOUT = 2 VPP,
Tone Spacing = 2 MHz
34
f = 75 MHz, RL = 200Ω, VOUT = 2 VPP,
Tone Spacing = 0.5 MHz
40
f = 150 MHz, RL = 200Ω, VOUT= 2 VPP,
Tone Spacing = 2 MHz
37
f = 250 MHz, RL = 200Ω, VOUT = 2 VPP,
Tone Spacing = 2 MHz
34
MHz
Noise and Distortion
Third Order Intermodulation
Products
OIP3
P1 dB
Output 3rd Order Intercept Point
Output Level for 1 dB Gain
Compression
f = 75 MHz, RL = 200Ω
16.7
f = 250 MHz, RL = 200Ω
14.7
f = 75 MHz
14.5
f = 450 MHz
13.2
dBc
dBm
dBm
VNI
Input Noise Voltage
Maximum Gain, f = 40 MHz
1.8
nV/
VNO
Output Noise Voltage
Maximum Gain, f = 40 MHz
18
nV/
NF
Noise Figure
Maximum Gain
8.3
dB
Analog I/O
Differential Input Resistance
165
160
186
210
220
Ω
Input Common Mode Resistance
825
785
971
1120
1160
Ω
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2
Parameter
Differential Output Impedance
Conditions
Min
(Note 6)
Low Gain Option
Typ
(Note 5)
Max
(Note 6)
Units
187
High Gain Option
330
325
370
410
415
Ω
Internal Load Resistors
Between Pins 13, 14 and Pins 15, 16
165
160
187
210
235
Ω
Input Signal Level (AC Coupled)
Max Gain, VO = 2 VPP, RL = 1 kΩ
126
Maximum Differential Input Signal AC Coupled
Input Common Mode Voltage
Self Biased
Input Common Mode Voltage
Range
Driven Externally
Minimum Input Voltage
Maximum Input Voltage
mVPP
5.6
1.3
1.1
1.4
VPP
1.5
1.7
V
0.9 to 2.0
V
DC
0
V
DC
3.3
V
Maximum Differential Output
Voltage Swing
VCC = 5V, Output Common Mode = 5V
5.5
VPP
VOS
Output Offset Voltage
All Gain Settings
30
mV
CMRR
Common Mode Rejection Ratio
85
dB
PSRR
Power Supply Rejection Ratio
63
61
83
23.9
23.4
24.2
24.6
24.8
dB
−7.2
−7.7
−6.9
−6.5
−6.4
dB
dB
Gain Parameters
Maximum Gain
DC, Internal RL = 200Ω,
External RL = 1280Ω
Minimum Gain
DC, Internal RL = 200Ω,
External RL = 1280Ω
Gain Step Size
DC
1.0
Gain Step Error
DC
0.02
f = 150 MHz
0.07
Cumulative Gain Step Error
DC, Gain Step 31 to Gain Step 0
−0.1
−0.2
Gain Step Switching Time
0.05
dB
dB
0.3
0.4
5
dB
ns
Digital Inputs/Timing
Logic Compatibility
CMOS Logic
3.3
V
VIL
Logic Input Low Voltage
0.8
VIH
Logic Input High Voltage
IIH
Logic Input High Input Current
32
TSU
Setup Time
3
ns
THOLD
Hold Time
3
ns
TPW
Minimum Latch Pulse Width
10
ns
2.0
V
V
40
μA
Power Requirements
ICC
Total Supply Current
VOUT = 0V Differential, VOUT Common
Mode = 5V
107
124
134
mA
Amplifier Supply Current
Pin 3 Only
56
66
74
mA
Output Stage Bias Currents
Pins 13, 14 and Pins 15, 16;
VOUT Common Mode = 5 V
48
58
60
mA
3
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LMH6515
Symbol
LMH6515
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
intended to be functional, but specific performance is not guaranteed. For guaranteed specifications, see the Electrical Characteristics tables.
Note 2: Human Body Model, applicable std. MIL-STD-883, Method 3015.7. Machine Model, applicable std. JESD22-A115-A (ESD MM std. of JEDEC)
Field-Induced Charge-Device Model, applicable std. JESD22-C101-C (ESD FICDM std. of JEDEC).
Note 3: The maximum power dissipation is a function of TJ(MAX), θJA. The maximum allowable power dissipation at any ambient temperature is
PD = (TJ(MAX) – TA)/ θJA. All numbers apply for packages soldered directly onto a PC Board.
Note 4: Electrical Table values apply only for factory testing conditions at the temperature indicated. No guarantee of parametric performance is indicated in the
electrical tables under conditions different than those tested
Note 5: Typical values represent the most likely parametric norm as determined at the time of characterization. Actual typical values may vary over time and will
also depend on the application and configuration. The typical values are not tested and are not guaranteed on shipped production material.
Note 6: Limits are 100% production tested at 25°C. Limits over the operating temperature range are guaranteed through correlation using Statistical Quality
Control (SQC) methods.
Note 7: Negative input current implies current flowing out of the device.
Note 8: Drift determined by dividing the change in parameter at temperature extremes by the total temperature change.
Connection Diagram
16-Pin LLP
20214304
Top View
Gain Control Pins
Pin Number
Pin Name
Gain Step Size
1
GAIN_0
1 dB
12
GAIN_1
2 dB
11
GAIN_2
4 dB
10
GAIN_3
8 dB
9
GAIN_4
16 dB
Ordering Information
Package
16-Pin LLP
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Part Number
LMH6515SQ
LMH6515SQX
Package Marking
L6515SQ
4
Transport Media
1k Units Tape and Reel
4.5k Units Tape and Reel
NSC Drawing
SQA16A
LMH6515
Pin Descriptions
Pin Number
Symbol
Description
6
IN+
Non-inverting analog input. Internally biased to 1.4V. Input voltage should not exceed
VCC or go below GND by more than 0.5V.
7
IN−
Inverting analog input. Internally biased to 1.4V. Input voltage should not exceed VCC or
go below GND by more than 0.5V. If using amplifier single ended this input should be
capacitively coupled to ground.
15
OUT−
Open collector inverting output. This pin is an output that also requires a power source.
This pin should be connected to 5V through either an RF choke or an appropriately sized
inductor that can form part of a filter. See application section for details.
14
OUT+
Open collector non-inverting output. This pin is an output that also requires a power
source. This pin should be connected to 5V through either an RF choke or an
appropriately sized inductor that can form part of a filter. See application section for
details.
16
LOAD−
Internal 200Ω resistor connection to pin 15. This pin can be left floating for higher gain
or shorted to pin 13 for lower gain and lower effective output impedance. See application
section for details.
13
LOAD+
Internal 200Ω resistor connection to pin 14. This pin can be left floating for higher gain
or shorted to pin 16 for lower gain and lower effective output impedance. See application
section for details.
3
VCC
5V power supply pin. Use ceramic, low ESR bypass capacitors. This pin powers
everything except the output stage.
5,8
GND
Ground pins. Connect to low impedance ground plane. All pin voltages are specified with
respect to the voltage on these pins. The exposed thermal pad is also a ground
connection.
1,12,11,
10,9
GAIN_0 to
GAIN_4
Gain setting pins. See above table for gain step sizes for each pin. These pins are 3.3V
CMOS logic compatible. 5V inputs may cause damage.
2
LATCH
This pin controls the function of the gain setting pins mentioned above. With LATCH in
the logic HIGH state the gain is fixed and will not change. With the LATCH in the logic
LOW state the gain is set by the state of the gain control pins. Any changes in gain made
with the LATCH pin in the LOW state will take effect immediately. This pin is 3.3V CMOS
logic compatible. 5V inputs may cause damage.
4
NC
This pin is not connected. It can be grounded or left floating.
Analog I/O
Power
Digital Inputs
5
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LMH6515
Typical Performance Characteristics
VCC = 5V
Frequency Response All Gain Settings
Frequency Response with Capacitive Load
20214322
20214325
Frequency Response Over Temperature, Maximum Gain
Frequency Response Over Temperature, Minimum Gain
20214349
20214350
OIP3 High Gain Mode
OIP3 Low Gain Mode
20214343
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20214342
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LMH6515
OIP3 Over Temperature
OIP3 High Gain Mode
20214326
20214324
IMD3 Low Gain Mode
IMD3 High Gain Mode
20214340
20214341
IMD3 High Gain Mode
HD2 vs. Frequency
20214323
20214336
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LMH6515
HD3 vs. Frequency
HD2 vs. Frequency
20214339
20214338
HD3 vs. Frequency
Noise Figure for All Gain Settings
20214314
20214337
Noise Figure vs. Frequency
Differential Output Noise
20214317
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20214318
8
LMH6515
Maximum Gain vs. Supply Voltage
Gain vs. External Load
20214312
20214327
Maximum Gain Over Temperature
Worst Case Gain Step Error vs. Frequency
20214345
20214344
Worst Case Gain Step Error vs. Frequency
Worst Case Gain Step Error Over Temperature
20214351
20214346
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LMH6515
Digital Crosstalk
Digital Crosstalk
20214347
20214348
Digital Pin to Output Isolation
Minimum Gain to Maximum Gain Switching
Using Latch Pin
20214319
20214330
Maximum Gain to Minimum Gain Switching
Using Latch Pin
16 dB Gain Step Using Latch Pin
20214332
20214335
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LMH6515
16 dB Gain Step with Latch Pin Low
Switching Gain Pin 4
8 dB Gain Step with Latch Pin Low
Switching Gain Pin 3
20214329
20214328
4 dB Gain Step Using Latch Pin
Power On Timing, Maximum Gain
20214333
20214353
Power On Timing, Minimum Gain
Power Off Timing, Maximum Gain
20214354
20214356
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LMH6515
Power Off Timing, Minimum Gain
20214355
In order to help with system design National Semiconductor
offers the ADC14V155KDRB High IF Receiver reference design board. This board combines the LMH6515 DVGA with
the ADC14V155 ADC and provides a ready made solution for
many IF receiver applications. Using an IF frequency of 169
MHz it achieves a small signal SNR of 72 dBFS and an SFDR
of greater than 90 DBFS. Large signal measurements show
an SNR of 68 dBFS and an SFDR of 77 dBFS. The High IF
Receiver board also features the LMK03000 low-jitter precision clock conditioner.
Application Information
The LMH6515 is a fully differential amplifier optimized for signal path applications up to 400 MHz. The LMH6515 has a
200Ω input. The absolute gain is load dependent, however
the gain steps are always 1 dB. The LMH6515 output stage
is a class A amplifier. This class A operation results in excellent distortion and linearity characteristics. This makes the
LMH6515 ideal for voltage amplification and an ideal ADC
driver where high linearity is necessary.
20214311
FIGURE 2. LMH6515 Block Diagram
20214303
INPUT CHARACTERISTICS
The LMH6515 input impedance is set by internal resistors to
a nominal 200Ω. Process variations will result in a range of
values as shown in the 5V Electrical Characteristics table. At
higher frequencies parasitics will start to impact the
impedance. This characteristic will also depend on board layout and should be verified on the customer’s system board.
At maximum gain the digital attenuator is set to 0 dB and the
input signal will be much smaller than the output. At minimum
gain the output is 12 dB or more smaller than the input. In this
configuration the input signal size may limit the amplifier output amplitude, depending on the output configuration and the
desired output signal voltage. The input signal cannot swing
more than 0.5V below the negative supply voltage (normally
0V) nor should it exceed the positive supply voltage. The input
signal will clip and cause severe distortion if it is too large.
Because the input stage self biases to approximately 1.4V the
lower supply voltage will impose the limit for input voltage
swing. To drive larger input signals the input common mode
can be forced higher than 1.4V to allow for more swing. An
FIGURE 1. LMH6515 Typical Application
The LMH6515 output common mode should be set carefully.
Using inductors to set the output common mode is one preferred method and will give maximum output swing. AC coupling of the output is recommended. The inductors mentioned
above will shift the idling output common mode to the positive
supply. Also, with the inductors, the output voltage can exceed the supply voltage. Other options for setting the output
common mode require supply voltages above 5V. If using a
supply higher than 5V care should be taken to make sure the
output common mode does not exceed the 5.25V supply rating.
It is also important to note the maximum voltage limits for the
OUT+ and OUT− pins, which is 6.4V. When using inductors
these pins will experience voltage swings beyond the supply
voltage. With a 5V output common mode operating point this
makes the effective maximum swing 5.6 VPP differential. System calibration and automatic gain control algorithms should
be tailored to avoid exceeding this limit.
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20214307
FIGURE 3. Single Ended Input
(Note capacitor on grounded input)
OUTPUT CHARACTERISTICS
The LMH6515 has the option of two different output configurations. The LMH6515 is an open collector topology. As
shown in Figure 8 each output has an on chip 200Ω pull up
resistor. In addition there is an internal 400Ω resistor between
the two outputs. This results in a 200Ω or a 400Ω differential
load in parallel with the external load. The 400Ω option is the
high gain option and the 200Ω provides for less gain. The
200Ω configuration is recommended unless more gain is required.
The output common mode of the LMH6515 must be set by
external components. Most applications will benefit from the
use of inductors on the output stage. In particular, the 400Ω
option, as shown in Figure 9, will require inductors in order to
be able to develop an output voltage. The 200Ω option as
shown in Figure 10 or Figure 11 will also require inductors
since the voltage drop due to the on chip 200Ω resistors will
saturate the output transistors. It is also possible to use resistors and high voltage power supplies to set the output
common mode. This operation is not recommended, unless
it is necessary to DC couple the output. If DC coupling is required the input common mode and output common mode
voltages must be taken into account.
Maximum bandwidth with the LMH6515 is achieved by using
the low gain, low impedance output option and using a low
load resistance. With an effective load of 67Ω a bandwidth of
nearly 1 GHz can be realized. As the effective resistance on
the output stage goes up the capacitance of the board traces
and amplifier output stage limit bandwidth in a roughly linear
fashion. At an output impedance of 100Ω the bandwidth is
down to 600 MHz, and at 200Ω the bandwidth is 260 MHz.
For this reason driving very high impedance loads is not recommended.
Although bandwidth goes down with higher values of load resistance, the distortion performance improves and gain increases. The LMH6515 has a common emitter Class A output
stage and minimizing the amount of current swing in the output devices improves distortion substantially.
The LMH6515 output stage is powered through the collectors
of the output transistors. Power for the output stage is fed
through inductors and the reactance of the inductors allows
the output voltage to develop. In Figure 1 the inductors are
shown with a value of 44.4 nH. The value of the inductors
used will be different for different applications. In Figure 1 the
20214315
FIGURE 4. Bandwidth Changes Due to Different Inductor
Values
20214312
FIGURE 5. Gain vs. External Load
DIGITAL CONTROL
The LMH6515 has 32 gain settings covering a range of 31 dB.
To avoid undesirable signal transients the LMH6515 should
be powered on at the minimum gain state (all logic input pins
at 0V). The LMH6515 has a 5-bit gain control bus as well as
a latch pin. When the latch pin is low, data from the gain control pins is immediately sent to the gain circuit (i.e. gain is
changed immediately). When the latch pin transitions high the
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LMH6515
inductors have been chosen to resonate with the ADC and
the load capacitor to provide a weak band pass filter effect.
For broad band applications higher value inductors will allow
for better low frequency operation. However, large valued inductors will reduce high frequency performance, particularly
inductors of small physical sizes like 0603 or smaller. Larger
inductors will tend to perform better than smaller ones of the
same value even for narrow band applications. This is because the larger inductors will have a lower DC resistance
and less inter-winding capacitance and hence a higher Q and
a higher self resonance frequency. The self resonance frequency should be higher than any desired signal content by
at least a factor of two. Another consideration is that the power
inductors and the filter inductors need to be placed on the
circuit board such that their magnetic fields do not cause coupling. Mutual coupling of inductors can compromise filter
characteristics and lead to unwanted distortion products.
input common mode of 2.0V will allow an 8 VPP maximum
input signal. The trade off for input signal swing is that as the
input common mode is shifted away from the 1.4V internal
bias point the distortion performance will suffer slightly.
LMH6515
current gain state is held and subsequent changes to the gain
set pins are ignored. To minimize gain change glitches multiple gain control pins should not change while the latch pin is
low. In order to achieve the very fast gain step switching time
of 5 ns the internal gain change circuit is very fast. Gain glitches could result from timing skew between the gain set bits.
This is especially the case when a small gain change requires
a change in state of three or more gain control pins. If continuous gain control is desired the latch pin can be tied to
ground. This state is called transparent mode and the gain
pins are always active. In this state the timing of the gain pin
logic transitions should be planned carefully to avoid undesirable transients.
The LMH6515 was designed to interface with 3.3V CMOS
logic circuits. If operation with 5V logic is required a simple
voltage divider at each logic pin will allow for this. To properly
terminate 100Ω transmission lines a divider with a 66.5Ω resistor to ground and a 33.2Ω series resistor will properly
terminate the line as well as give the 3.3V logic levels. Care
should be taken not to exceed the 3.6V absolute maximum
voltage rating of the logic pins.
20214306
FIGURE 6. Bandpass Filter
Center Frequency is 140 MHz with a 20 MHz Bandwidth
Designed for 200Ω Impedance
EXPOSED PAD LLP PACKAGE
The LMH6515 is in a thermally enhanced package. The exposed pad is connected to the GND pins. It is recommended,
but not necessary, that the exposed pad be connected to the
supply ground plane. In any case, the thermal dissipation of
the device is largely dependent on the attachment of this pad.
The exposed pad should be attached to as much copper on
the circuit board as possible, preferably external copper.
However, it is also very important to maintain good high speed
layout practices when designing a system board. Please refer
to the LMH6515 evaluation board for suggested layout techniques.
Package information is available on the National web site.
http://www.national.com/packaging/folders/sqa16a.html
ADC Noise Filter
Figure 6 shows a filter schematic and the following table of
values are for some common IF frequencies. The filter shown
offers a good compromise between bandwidth, noise rejection and cost. This filter topology is the same as used on the
ADC14V155KDRB High IF Receiver reference design board.
This filter topology works best with the 12 and 14-bit subsampling analog to digital converters shown in the Compatible High Speed Analog to Digital Converters table.
Filter Component Values
Filter Component Values
INTERFACING TO ADC
The LMH6515 was designed to be used with high speed
ADCs such as the ADC14155. As shown in the Typical Application schematic on page 1, AC coupling provides the best
flexibility especially for IF sub-sampling applications. Any resistive networks on the output will also cause a gain loss
because the output signal is developed across the output resistors. The chart Maximum Gain vs. External Load shows the
change in gain when an external load is added.
The inputs of the LMH6515 will self bias to the optimum voltage for normal operation. The internal bias voltage for the
inputs is approximately 1.4V. In most applications the
LMH6515 input will need to be AC coupled.
The output common mode voltage is not self biasing, it needs
to be pulled up to the positive supply rail with external inductors as shown in Figure 1. This gives the LMH6515 the
capability for large signal swings with very low distortion on a
single 5V supply. The internal load resistors provide the
LMH6515 with very consistent gain.
A unique internal architecture allows the LMH6515 to be driven by either a differential or single ended source. If driving the
LMH6515 single ended, the unused input should be terminated to ground with a 0.01 µF capacitor. Directly shorting the
unused input to ground will disrupt the internal bias circuitry
and will result in poor performance.
Fc
75
MHz
140
MHz
170
MHz
250
MHz
BW
40
MHz
20
MHz
25
MHz
Narrow
Band
10 µH
10 µH
10 µH
10 µH
Components L1, L2
L3, L4 390 nH 390 nH 560 nH
—
C1, C2
10 pF
3 pF
1.4 pF
47 pF
C3
22 pF
41 pF
32 pF
11 pF
L5
220 nH
27 nH
30 nH
22 nH
R1, R2
100
200
100
499
20214313
FIGURE 7. Sample Filter
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LMH6515
POWER SUPPLIES
As shown in Figure 8, the LMH6515 has a number of options
for power supply connections on the output pins. Pin 3 (VCC)
is always connected. The output stage can be connected as
shown in Figure 9, Figure 10, or Figure 11. The supply voltage
range for VCC is 4V to 5.25V. A 5V supply provides the best
performance while lower supplies will result in less power
consumption. Power supply regulation of 2.5% or better is
advised.
Of special note is that the digital circuits are powered from an
internal supply voltage of 3.3V. The logic pins should not be
driven above the absolute maximum value of 3.6V. See the
Digital Control section for details.
20214309
FIGURE 10. Using Low Gain Mode (200Ω Load)
20214302
FIGURE 8. Internal Load Resistors
20214310
FIGURE 11. Alternate Connection for Low Gain Mode
(200Ω Load)
20214308
FIGURE 9. Using High Gain Mode (400Ω Load)
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LMH6515
Compatible High Speed Analog to Digital Converters
Product Number
Max Sampling Rate (MSPS)
Resolution
Channels
ADC12L063
62
12
SINGLE
ADC12DL065
65
12
DUAL
ADC12L066
66
12
SINGLE
ADC12DL066
66
12
DUAL
CLC5957
70
12
SINGLE
ADC12L080
80
12
SINGLE
ADC12DL080
80
12
DUAL
ADC12C080
80
12
SINGLE
ADC12C105
105
12
SINGLE
ADC12C170
170
12
SINGLE
ADC12V170
170
12
SINGLE
ADC14C080
80
14
SINGLE
ADC14C105
105
14
SINGLE
ADC14DS105
105
14
DUAL
ADC14155
155
14
SINGLE
ADC14V155
155
14
SINGLE
ADC08D500
500
8
DUAL
ADC08500
500
8
SINGLE
ADC08D1000
1000
8
DUAL
ADC081000
1000
8
SINGLE
ADC08D1500
1500
8
DUAL
ADC081500
1500
8
SINGLE
ADC08(B)3000
3000
8
SINGLE
ADC08L060
60
8
SINGLE
ADC08060
60
8
SINGLE
ADC10DL065
65
10
DUAL
ADC10065
65
10
SINGLE
ADC10080
80
10
SINGLE
ADC08100
100
8
SINGLE
ADCS9888
170
8
SINGLE
ADC08(B)200
200
8
SINGLE
ADC11C125
125
11
SINGLE
ADC11C170
170
11
SINGLE
www.national.com
16
LMH6515
Physical Dimensions inches (millimeters) unless otherwise noted
16-Pin Package
NS Package Number SQA16A
17
www.national.com
LMH6515 600 MHz, Digital Controlled, Variable Gain Amplifier
Notes
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