DATASHEET
Intermediate Frequency Digital Variable Gain Amplifier
IDTF1200
G
ENERAL
D
ESCRIPTION
The IDTF1200 is a Digitally Controlled Intermediate
Frequency Differential Variable Gain Amplifier for
BaseStation and other commercial applications with a
low IF frequency. The device offers extremely low
Noise Figure over the entire gain control range. The
device is packaged in compact 5x5 Thin QFNs with 200
ohm differential input and output impedances for ease
of integration into the receiver lineup. Versions
covering IF frequencies up to 300 MHz with low
distortion are available.
F
EATURES
Ideal for high SNR systems
22 dB typ Maximum Gain
23 dB gain control range
7 bit parallel control
0.25 dB Gain Steps
Excellent
Noise Figure < 3.0 dB
5mm x 5mm 28 pin package
200
Ω Differential Input
200
Ω
Differential Output
NF degrades < 2dB @ 12dB reduced gain
50 MHz – 160 MHz frequency range
Ultra-Linear:
IP3
O
+48 dBm typical
External current setting resistor
Fast Gain Step Settling < 20 nsec
C
OMPETITIVE
A
DVANTAGE
The F1200 acts to enhance system SNR when VGA gain
is reduced. The F1200 noise figure (NF) degrades only
slightly (NF slope ~ -0.16
dB
/
dB
) over a 13 dB control
range while holding the Output IP3 approximately
constant. The resultant improvement in noise can
enhance the system SNR up to 2 decibels at low gain
settings relative to a standard VGA.
The device has excellent DNL and INL simplifying digital
compensation. The device also offers the extremely low
Harmonic, IM2, and IM3 distortion necessary to drive an
ADC directly in an IF sub-sampling application.
D
EVICE
B
LOCK
D
IAGRAM
ATTN
Out
`
AMP
In
A
PPLICATIONS
BaseStation Diversity Receivers
Digital Pre-Distortion
Wave
Point-to-Point Radios
Public Safety Receivers
ATTN
In
AMP
out
7
Gain
Control
Decode
Logic
Bias
Control
V
CC
`
Part#
Gain
Range
22 to -1
IP3
O
48
IF freq
range
50 - 160
NF
O
RDERING
I
NFORMATION
Omit IDT
prefix
F1200
2.6
F1206*
20 to -11
47
150 - 250
3.6
IDTF1200NBGI8
Pr
F1207*
20 to -11
46
230 - 300
3.7
RF product Line
*Future Product
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0.75 mm height Tape &
Reel
package
Green
Industrial
Temp range
P
ART
# M
ATRIX
V
CC
V
MODE
I
SET
y
STBY
DATASHEET
Intermediate Frequency Digital Variable Gain Amplifier
IDTF1200
A
BSOLUTE
M
AXIMUM
R
ATINGS
V
CC
to GND
All other Pins to GND
I
SET
to GND
RF Input Power (ATTN_IN+, ATTN_IN-) @G
MAX
Continuous Power Dissipation
θ
JA
(Junction – Ambient)
θ
JC
(Junction – Case)
The Case is defined as the exposed paddle
Operating Temperature Range (Case Temperature)
Maximum Junction Temperature
Storage Temperature Range
Lead Temperature (soldering, 10s) .
-0.3V to +5.5V
-0.3V to (V
CC
+0.25V)
-0.3V to +2.2V
+10 dBm
1.5W
+41°C/W
+4°C/W
T
C
= -40°C to +85°C
150°C
-65°C to +150°C
+260°C
K
EY
F
EATURE
– N
OISE
F
IGURE
S
LOPE
Standard Variable Gain amplifiers exhibit a [NF/Gain] slope of -1 dB/dB. Practically speaking, as gain is
reduced, Noise Figure degrades dB for dB. The F1200 utilizes new technology that flattens the Noise Figure
response (~ -0.16 dB/dB) for most of the gain control range while keeping distortion (Output IP3) constant.
The result is that NF is improved up to 16 dB vs. a standard VGA at low gain settings. The graph below
illustrates this by showing the IDTF1200 NF and IP3O vs. Gain setting contours.
50
45
Output IP3
NF (dB) and Output IP3 (dBm)
40
35
30
25
15
10
5
0
-2
0
2
4
6
8
10
12
14
Noise Figure
Gain (dB)
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18
20
22
20
y
DATASHEET
Intermediate Frequency Digital Variable Gain Amplifier
IDTF1200
IDTF1200 S
PECIFICATION
V
CC
= +5.0V,
f
RF
= 100MHz,
T
C
= +25°C, STBY = GND, R6 =
2.87K +/-1%,
P
OUT
= +3 dBm, unless otherwise noted in the condition column.
EVkit trace, transformer & matching losses are de-embedded for specification purposes (note: de-embedded losses = 0.4dB input and
0.4dB output at 100MHz).
Parameter
Operating Temp.
Range
Logic Input High
Logic Input Low
Logic Current
Operating voltage
range
Supply Current
Standby Current
Frequency Range
Input Resistance
Output Resistance
Maximum Gain
Minimum Gain
Gain Step
Phase Slope
Differential Gain Error
Integral Gain Error
Noise Figure
Noise Figure
Output IP3
Output IP3 –
at Gback
Settling Time
2 Harmonic
# Control Bits
1 dB Compression
nd
Condition
Case Temperature Measured
at the exposed paddle
Symbol
T
C
V
IH
V
IL
I
IH,
I
IL
min
1
typ
-40 to +85
max
units
C
V
2.0
-1
0.8
+1
4.75 to 5.25
103
110
117
2.5
50 to 160
200
200
20.7
-2.8
21.7
-1.7
0.25
0.3
.05
+/-0.20
2.6
4.55
48
44
22.6
-0.7
V
μA
V
mA
mA
MHz
Ω
Ω
dB
dB
dB
deg/dB
dB
dB
dB
dB
dBm
Analog & Digital Supplies
Total, All V
CC;
R6= 2.87K +/-1%
Total, All V
CC
All digital inputs at 2.0VDC
VCC=5.25VDC
Output IP3 > +40 dBm
Differential
Differential
GC = [0000000]
GC = [1011101]
ΔΦ due to change in gain
Between adjacent 1dB steps
V
CC
I
SUPP
I
STBY
f
RF
R
IN
R
OUT
G
MAX
G
MIN
LSB
Φ
SLOPE
DNL
INL
NF
NF
BACK
IP3
O1
IP3
O2
T
1dB
H2
CB
P1dB
O
Error vs. straight line
At Maximum Gain
GC = [0110100] (gain = 9dB)
Set code = 0000000, (G
MAX
)
Pout = +3 dBm per tone
800 KHz Tone Separation
Set code
=
0110100
,
,
(Gain = 9dB)
Pout = +3 dBm per tone
800 KHz Tone Separation
Gain Step from 22 to 21 dB setting
Settles to within 0.1 dB of final
value
F
RF
= 100 MHz
Set code = 0000000, (G
MAX
)
Pout = +3 dBm
Parallel
Set code = 0000000, (G
MAX
)
Single Tone Test
1 –Items in
bold italics
are Guaranteed by Test
2 – See Graph on Page 8
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7
+19.4
y
dBm
nsec
dBc
#
dBm
April, 2011
DATASHEET
Intermediate Frequency Digital Variable Gain Amplifier
IDTF1200
T
YPICAL
O
PERATING
P
ARAMETRIC
C
URVES
(G
MAX
, 5.00V, 25C, P
OUT
+3 dBm, 100MHz unless otherwise noted)
Gain vs. Temperature
25
Gain vs. Voltage
25
20
20
Gain (dB)
10
Gain (dB)
15
15
10
5
-40C
25C
85C
5
4.75V
5.00V
5.25V
0
0
50
100
150
200
250
300
0
0
50
100
150
200
250
300
Frequency (MHz)
Frequency (MHz)
S11 vs. Temperature
0
S22 vs. Temperature
0
-10
-10
-20
Output Gamma [s22] (dB)
Input Gamma [s11] (dB)
-20
-30
-30
-40
-40C
25C
85C
-40
-40C
25C
85C
-50
0
50
100
150
200
250
300
-50
0
50
100
150
200
250
300
Frequency (MHz)
Frequency (MHz)
S12 vs. Temperature
0
Gain and NF vs. Frequency
(measured w/NF meter)
22
-10
20
18
-20
Gain and NF (dB)
16
14
12
10
8
6
-30
-40
2
-50
0
50
100
150
200
250
300
0
30
Pr
50
70
-40C
25C
85C
4
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Gain
Noise Figure
90
110
130
150
170
24
Reverse Isolation [s12] (dB)
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Frequency (MHz)
Frequency (MHz)
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DATASHEET
Intermediate Frequency Digital Variable Gain Amplifier
TOC
S CONTINUED
S11 vs. Gain Setting
0
-5
-10
IDTF1200
S22 vs. Gain Setting
0
-5
-10
Output Gamma (dB)
-15
-15
-20
-25
-30
-35
-40
-45
-50
50 MHz
100 MHz
150 MHz
Input Gamma (dB)
-20
-25
-30
-35
-40
-45
-50
-1
3
7
11
15
19
23
50 MHz
100 MHz
150 MHz
-1
3
7
11
15
19
23
Gain Setting (dB)
Gain Setting (dB)
S21 vs. Gain Setting
22
20
18
16
14
S21 Phase vs. Gain Setting
40
50 MHz
Normalized S21 Phase response (degrees)
35
30
25
20
15
10
5
0
-5
-10
100 MHz
150 MHz
Gain (dB)
12
10
8
6
4
2
0
-2
-1
3
7
11
15
19
23
50 MHz
100 MHz
150 MHz
-1
3
7
11
15
19
23
Gain Setting (dB)
Gain Setting (dB)
EVKit NF & Output IP3 Correction
1.6
1.2
0.8
Correct EVkit measured Output
IP3 by this amount to account for
trace & transformer losses
EVKit Gain Correction
2.0
NF correction
IP3 correction
1.8
1.6
1.4
Correction (dB)
0.4
0.0
-0.4
-0.8
-1.2
-1.6
0
50
100
150
200
250
300
Correct EVkit measured Noise
Figure by this amount to account
for trace & transformer losses
1.2
1.0
0.8
0.6
0.4
0.2
0.0
0
Pr
50
100
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Correct EVkit measured Gain
by this amount to account for
trace & transformer losses
EVkit Loss (dB)
150
200
Frequency (MHz)
y
250
300
April, 2011
