LT5514
Ultralow Distortion IF
Amplifier/ADC Driver with
Digitally Controlled Gain
FEATURES
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DESCRIPTIO
Output IP3 at 100MHz: 47dBm
Maximum Output Power: 21dBm
Bandwidth: LF to 850MHz
Propagation Delay: 0.8ns
Maximum Gain: 33dB
Noise Figure: 7.3dB (Max Gain)
Gain Control Range: 22.5dB
Gain Control Step: 1.5dB
Gain Control Settling Time: 500ns
Output Noise Floor: –134dBm/Hz (Max Gain)
Reverse Isolation: –80dB
Single Supply: 4.75V to 5.25V
Low Power Mode
Shutdown Mode
Enable/Disable Time: 1µs
Differential I/O Interface
20-Lead TSSOP Package
The LT
®
5514 is a programmable gain amplifier (PGA) with
bandwidth extending from low frequency (LF) to 850MHz.
It consists of a digitally controlled variable attenuator,
followed by a high linearity amplifier. The amplifier is
configured with two identical transconductance amplifi-
ers, hard wired in parallel with individual dedicated enable
pins. When both amplifiers are enabled (Standard mode),
the LT5514 offers an OIP3 of +47dBm (at 100MHz).
Power dissipation can be reduced when a single amplifier
is enabled (Low Power mode). Four parallel digital inputs
control the gain over a 22.5dB range with 1.5dB step
resolution. An on-chip power supply regulator/filter helps
isolate the amplifier signal path from external noise sources.
The LT5514’s open-loop architecture offers stable opera-
tion for any practical load conditions, including peaking-
free AC response when driving capacitive loads, and
excellent reverse isolation.
The LT5514 may be operated broadband, where the out-
put differential RC time constant sets the bandwidth, or it
may be used as a narrowband driver with the appropriate
output filter.
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATIO S
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High Linearity ADC Driver
IF Sampling Receivers
VGA IF Power Amplifier
50Ω Driver
Instrumentation Applications
TYPICAL APPLICATIO
56
5V
53
CHOKE
0.1µF
RF
INPUT
LO
IF
BPF
IF
AMP
0.1µF
4 LINES
CHOKE
0.1µF
OIP3 (dBm)
50
R
OUT
= 200Ω
47
R
OUT
= 100Ω
44
41
38
35
0
50
100
FREQUENCY (MHz)
150
200
5514 TA02
LT5514
100Ω
0.1µF
GAIN CONTROL
ADC
5514 TA01
U
Output IP3 vs Frequency
(Standard Mode)
5514f
U
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1
LT5514
ABSOLUTE
MAXIMUM
RATINGS
(Notes 1, 2)
PACKAGE/ORDER INFORMATION
TOP VIEW
ENA 1
V
CC1
2
GND 3
GND 4
IN
+
Power Supply Voltage (V
CC1
, V
CC2
) .......................... 6V
Output Supply Voltage (OUT
+
, OUT
–
) ....................... 8V
Control Input Voltage (ENA, ENB, PGAx) .. –0.5V to V
CC
Signal Input Voltage (IN
+
, IN
–
) ................... –0.5V to 3V
Operating Ambient Temperature Range .. – 40°C to 85°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
20 ENB
19 V
CC2
18 GND
17 GND
21
16 OUT
–
15 OUT
+
14 GND
13 GND
12 PGA3
11 PGA2
ORDER PART
NUMBER
LT5514EFE
5
IN
–
6
GND 7
GND 8
PGA0 9
PGA1 10
FE PACKAGE
20-LEAD PLASTIC TSSOP
T
JMAX
= 150°C,
θ
JA
= 38°C/W
EXPOSED PAD (PIN 21) IS GND
MUST BE SOLDERED TO PCB
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ODES OF OPERATIO
MODES
Full Power (Standard)
Low Power A
Low Power B
Shutdown
ENA
High
High
Low
Low
1
2
3
4
ENB
High
Low
High
Low
AMP A
On
On
Off
Off
AMP B
On
Off
On
Off
LT5514 STATE
Enable Amp A and Amp B
Enable Amp A
Enable Amp B
Sleep, All Amps Disabled
PROGRA
ABLE GAI SETTI GS
PGA0
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
High
Low
PGA1
High
High
Low
Low
High
High
Low
Low
High
High
Low
Low
High
High
Low
Low
PGA2
High
High
High
High
Low
Low
Low
Low
High
High
High
High
Low
Low
Low
Low
PGA3
High
High
High
High
High
High
High
High
Low
Low
Low
Low
Low
Low
Low
Low
POWER GAIN
STANDARD MODE*
LOW POWER MODE**
33.0dB
30.0dB
31.5dB
28.5dB
30.0dB
27.0dB
28.5dB
25.5dB
27.0dB
24.0dB
25.5dB
22.5dB
24.0dB
21.0dB
22.5dB
19.5dB
21.0dB
18.0dB
19.5dB
16.5dB
18.0dB
15.0dB
16.5dB
13.5dB
15.0dB
12.0dB
13.5dB
10.5dB
12.0dB
9.0dB
10.5dB (Note 3)
7.5dB (Note 3)
5514f
ATTENUATION STEP
RELATIVE TO MAX GAIN
1
0dB
2
–1.5dB
3
–3.0dB
4
–4.5dB
5
–6.0dB
6
–7.5dB
7
–9.0dB
8
–10.5dB
9
–12.0dB
10
–13.5dB
11
–15.0dB
12
–16.5dB
13
–18.0dB
14
–19.5dB
15
–21.0dB
16
–22.5dB
*R
OUT
= 200Ω **R
OUT
= 400Ω
2
U
W
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U
U
U
U
W W
WW
W
W
LT5514
DC ELECTRICAL CHARACTERISTICS
V
CC
= 5V, V
CCO
= 5V, ENA = ENB = 3V, T
A
= 25°C, unless otherwise
noted. (Note 7) (Test circuits shown in Figures 9 and 10)
PARAMETER
Supply Voltage (Pins 2, 19)
OUT
+
, OUT
–
Output Pin DC Common Mode Voltage
OUT
+
, OUT
–
Pin Instantaneous Voltage with
Respect to GND
IN
+
, IN
–
Bias Voltage
PGAO, PGA1, PGA2, PGA3 Input Current
PGAO, PGA1, PGA2, PGA3 Input Current
OUT
+
, OUT
–
Current
V
CC
Supply Current
ENA, ENB and PGAx Input Low Voltage
ENA, ENB and PGAx Input High Voltage
PGAO, PGA1, PGA2, PGA3 Input Current
PGAO, PGA1, PGA2, PGA3 Input Current
ENA, ENB Input Current
ENA, ENB Input Current
SYMBOL
V
CC
V
CCO
V
OUT
CONDITIONS
(Note 4)
OUT
+
, OUT
–
Connected to V
OSUP
via
Choke Inductors or Resistors (Note 5)
Min/Max Limits Apply
MIN
4.75
3
2
TYP
5
5
MAX
5.25
6
8
UNITS
V
V
V
Normal Operating Conditions
Shutdown DC Characteristics, ENA = ENB = 0.6V
V
IN(BIAS)
I
IL(PGA)
I
IH(PGA)
I
OUT
I
CC
V
IL
V
IH
I
IL(PGA)
I
IH(PGA)
I
IL(EN)
I
IH(EN)
Max Gain (Note 6)
V
IN
= 0.6V
V
IN
= 5V
All Gain Settings
All Gain Settings (Note 4)
x = 0, 1, 2, 3
x = 0, 1, 2, 3
V
IN
= 0.6V
V
IN
= 3V and 5V
V
IN
= 0.6V
V
IN
= 3V
V
IN
= 5V
Max Gain (Note 6)
All Gain Settings (DC)
Max Gain
All Gain Settings, V
OUT
= 5V
All Gain Settings, IN
+
, IN
–
Open
Max Gain (Note 4)
Min Gain (Note 4)
I
CC
+ 2 • I
OUT
(Max Gain)
Max Gain (Note 6)
All Gain Settings (DC)
Max Gain
All Gain Settings, V
OUT
= 5V
All Gain Settings, IN
+
, IN
–
Open
Max Gain (Note 4)
Min Gain (Note 4)
I
CC
+ 2 • I
OUT
(Max Gain)
17
1.34
33
1.34
15
4
18
38
1.49
108
0.3
40
200
64
68
148
1.48
122
0.15
20
100
34
36
76
40
43
91
24
75
80
174
1.65
47
3
20
30
20
100
1.65
44
1.15
1.3
1.5
20
20
20
100
0.6
V
µA
µA
µA
µA
V
V
µA
µA
µA
µA
µA
V
Ω
S
mA
µA
mA
mA
mA
V
Ω
S
mA
µA
mA
mA
mA
Enable and PGA Inputs DC Characteristics
Standard Mode DC Characteristics, ENA = ENB = 3V
V
IN(BIAS)
R
IN
g
m
I
OUT
I
CC
I
CC(TOTAL)
V
IN(BIAS)
R
IN
g
m
I
OUT
I
CC
I
CC(TOTAL)
IN
+
, IN
–
Bias Voltage
Input Differential Resistance
Amplifier Transconductance
OUT
+
, OUT
–
Quiescent Current
V
CC1
+ V
CC2
Supply Current
Total Supply Current
IN
+
, IN
–
Bias Voltage
Input Differential Resistance
Amplifier Transconductance
OUT
+
, OUT
–
Quiescent Current
V
CC1
+ V
CC2
Supply Current
Total Supply Current
I
OUT(OFFSET)
Output Current Mismatch
Low Power Mode DC Characteristics, ENA = O.6V, ENB = 3V or ENA = 3V, ENB = 0.6V
I
OUT(OFFSET)
Output Current Mismatch
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LT5514
AC ELECTRICAL CHARACTERISTICS
(Standard Mode)
SYMBOL
BW
PARAMETER
Large-Signal –3dB Bandwidth
CONDITIONS
Dynamic Performance
V
CC
= 5V, V
CCO
= 5V, ENA = ENB = 3V, T
A
= 25°C, R
OUT
= 200Ω. Maximum gain specifications are with respect to differential inputs
and differential outputs, unless otherwise noted. (Note 7) (Test circuits shown in Figures 9 and 10)
MIN
TYP
MAX
UNITS
All Gain Settings (Note 8)
R
OUT
= 100Ω
R
OUT
= 200Ω; L1, L2 = 33nH (Figure 9)
All Gain Settings, Single Tone, R
OUT
= 150Ω
f
IN
= 100MHz (Note 10)
Max Gain, f
IN
= 100MHz
PGA1 = Low, f
IN
= 100MHz
f
IN
= 100MHz (Note 9)
f
IN
= 400MHz (Note 9)
All Gain Settings, 10% to 90%, R
OUT
= 100Ω
All Gain Settings, R
OUT
= 100Ω
30MHz to 300MHz Frequency Range,
R
OUT
= 100Ω
LF to 850
LF to 500
21
0.30
0.21
–92
–78
500
800
±50
500
600
MHz
MHz
dBm
S
S
dB
dB
ps
ps
ps
ns
ns
P
OUT(MAX)
Clipping Limited Maximum Sinusoidal
Output Power
g
m
S12
t
r
, t
f
Amplifier Transconductance
Reverse Isolation
Step Response Rise and Fall Time
Group Delay
Group Delay Variation
PGA Settling Time
Enable/Disable Time
Distortion and Noise
OIP3
Output Third Order Intercept Point for
PGA0 = High (PGA1, PGA2, PGA3 Any State)
Output Third Order Intercept Point for
PGA0 = Low (PGA1, PGA2, PGA3 Any State)
HD2
HD3
N
FLOOR
NF
Second Harmonic Distortion
Third Harmonic Distortion
Output Noise Floor
(PGAO, PGA2, PGA3 Any State)
Noise Figure
P
OUT
= 9dBm (Each Tone), 200kHz Tone Spacing
f
IN
= 100MHz
f
IN
= 200MHz
P
OUT
= 9dBm (Each Tone), 200kHz Tone Spacing
f
IN
= 100MHz
f
IN
= 200MHz
P
OUT
= 11dBm (Single Tone), f
IN
= 50MHz
P
OUT
= 11dBm (Single Tone), f
IN
= 50MHz
PGA1 = High, f
IN
= 100MHz
PGA1 = Low, f
IN
= 100MHz
Max Gain, f
IN
= 100MHz
–3dB Step, f
IN
= 100MHz
f
IN
= 20MHz and 200MHz
f
IN
= 20MHz and 200MHz
f
IN
= 20MHz and 200MHz
f
IN
= 20MHz and 200MHz
f
IN
= 100MHz
f
IN
= 100MHz
f
IN
= 100MHz
f
IN
= 100MHz
1.05
+47.0
+40.5
+42.0
+37.5
–82
–72
–134
–136
7.4
7.7
33
10.5
1.5
±0.1
108
2.8
3.4
1.9
1.95
dBm
dBm
dBm
dBm
dBc
dBc
dBm/Hz
dBm/Hz
dB
dB
dB
dB
dB
dB
Ω
pF
kΩ
pF
Amplifier Power Gain and Gain Step
G
MAX
G
MIN
G
STEP
Maximum Gain
Minimum Gain
Gain Step Size
Gain Step Accuracy
R
IN
C
IN
R
O
C
O
Input Resistance
Input Capacitance
Output Resistance
Output Capacitance
Amplifier I/O Impedance (Parallel Values Specified Differentially)
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LT5514
AC ELECTRICAL CHARACTERISTICS
(Low Power Mode)
SYMBOL
BW
PARAMETER
Large-Signal –3dB Bandwidth
CONDITIONS
All Gain Settings (Note 8),
R
OUT
= 100Ω
All Gain Settings, Single Tone,
f
IN
= 100MHz (Note 10)
Max Gain, f
IN
= 100MHz
f
IN
= 100MHz (Note 9)
Dynamic Performance
V
CC
= 5V, V
CCO
= 5V, ENA = 3V, ENB = 0.6V, T
A
= 25°C, R
OUT
= 200Ω. Maximum gain specifications are with respect to differential
inputs and differential outputs, unless otherwise noted. (Note 7) (Test circuits shown in Figures 9 and 10)
MIN
TYP
MAX
UNITS
LF to 540
16
0.15
–92
MHz
dBm
S
dB
P
OUT(MAX)
Clipping Limited Maximum Sinusoidal
Output Power
g
m
S12
OIP3
Amplifier Transconductance
Reverse Isolation
Output Third Order Intercept Point for
PGA0 = High (PGA1, PGA2, PGA3 Any State)
Output Third Order Intercept Point for
PGA0 = Low (PGA1, PGA2, PGA3 Any State)
HD2
HD3
N
FLOOR
NF
G
MAX
G
MIN
G
STEP
Second Harmonic Distortion
Third Harmonic Distortion
Output Noise Floor
(PGAO, PGA2, PGA3 Any State)
Noise Figure
Maximum Gain
Minimum Gain
Gain Step Size
Gain Step Accuracy
Amplifier I/O Impedance
R
IN
C
IN
R
O
C
O
Input Resistance
Input Capacitance
Output Resistance
Output Capacitance
Distortion and Noise
P
OUT
= 4dBm (Each Tone), 200kHz Tone Spacing,
f
IN
= 100MHz
P
OUT
= 4dBm (Each Tone), 200kHz Tone Spacing,
f
IN
= 100MHz
P
OUT
= 5dBm (Single Tone), f
IN
= 50MHz
P
OUT
= 5dBm (Single Tone), f
IN
= 50MHz
PGA1 = High, f
IN
= 100MHz
PGA1 = Low, f
IN
= 100MHz
Max Gain Setting, f
IN
= 100MHz
f
IN
= 20MHz and 200MHz
f
IN
= 20MHz and 200MHz
f
IN
= 20MHz and 200MHz
f
IN
= 20MHz and 200MHz
f
IN
= 100MHz, Parallel Values Specified
Differentially
f
IN
= 100MHz, Parallel Values Specified
Differentially
f
IN
= 100MHz, Parallel Values Specified
Differentially
f
IN
= 100MHz, Parallel Values Specified
Differentially
1.05
+40
+36
–76
–72
–138
–140
8.6
27
4.5
1.5
±0.1
122
2
5
1.7
1.95
dBm
dBm
dBc
dBc
dBm/Hz
dBm/Hz
dB
dB
dB
dB
dB
Ω
pF
kΩ
pF
Amplifier Power Gain and Gain Step
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of the device may be impaired.
Note 2:
All voltage values are with respect to ground.
Note 3:
Default state for open PGA inputs.
Note 4:
V
CC1
and V
CC2
(Pins 2 and 19) are internally connected.
Note 5:
External V
OSUP
is adjusted such that V
CCO
output pin common
mode voltage is as specified when resistors are used. For choke inductors
or transformer, V
OSUP
= V
CCO
= 5V typ.
Note 6:
Internally generated common mode input bias voltage requires
capacitive or transformer coupling to the signal source.
Note 7:
Specifications over the –40°C to 85°C operating temperature
range are assured by design, characterization and correlation with
statistical process controls. Gain always refers to power gain. Input
matching is assumed. P
IN
is the available input power. P
OUT
is the power
into the external load, R
OUT
, as seen by the LT5514 differential outputs. All
dBm figures are with respect to 50Ω.
Note 8:
High frequency operation is limited by the RC time constants at
the input and output ports. The low frequency (LF) roll-off is set by I/O
interface choice.
Note 9:
Limited by package and board isolation.
Note 10:
See “Clipping Free Operation” in the Applications Information
section. Refer to Figure 7.
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