1/10
October 2005
SMA661AS
GPS HIGH GAIN LNA ICs
Rev. 2
GENERAL FEATURES
LOW NOISE FIGURE 1.4 dB @ 1.575 GHz
HIGH GAIN 17 dB @ 1.575 GHz
POWER DOWN FUNCTION
TEMPERATURE COMPENSATED
UNCONDITIONALLY STABLE
INTEGRATED OUTPUT MATCHING
ESD PROTECTION (
2kV HBM)
70 GHz Silicon Germanium TECHNOLOGY
LEAD-FREE STRAIGHT PACKAGE (SOT666)
APPLICATIONS
GPS
DESCRIPTION
SMA661AS is a product of the SMA Family
(Silicon MMIC Amplifiers), it uses ST state-of-the
art SiGe BiCMOS technology.
The excellent RF performances (17dB Gain and
1.4dB NF at 1.575GHz) and the few external
component counts (just one capacitor) make the
SMA661AS an ideal solution for GPS Low Noise
Amplifier. SMA661AS embeds a power down
function avoiding to use an external switch; in
power down mode (V
PD
V
PDL
) the current con-
sumption is about 10 nA. It is housed in ultra min-
iature SOT666 plastic package (1.65mm x
1.2mm x 1.57mm).
Figure 1. Package
Table 1. Pin Connection
Table 2. Order Codes
Figure 2. Circuit Schematic
Pin No.
Pin Name
1
RF IN
2
GND
3
PD
4
RF OUT
5
GND
6
Vcc
Top View
3
4
1
2
5
6
SOT666 (Lead-Free)
1.65 x 1.2 x 0.57 mm
Package
Tape and Reel
SOT666
SMA661ASTR
SMA661AS
RF input
RF IN (1)
VCC (6)
GND (2,5)
RF Output
C1
RF OUT(4)
PD (3)
33nF
PRELIMINARY DATA
SMA661AS
2/10
Table 3. Absolute Maximum Ratings
ELECTRICAL CHARACTERISTICS
(T
a
= +25
o
C, V
cc
= 2.7 V, Z
L
= Z
S
= 50 ohm, unless otherwise specified; measured according to Figure 13)
Table 4. Electrical Characteristics
Note: (1) The device is switched to OFF state
(2) The device is switched to ON state
Symbol
Parameter
Conditions Value
Unit
V
cc
Supply voltage
3.3
V
T
stg
Storage temperature
-60 to +150
o
C
T
a
Operating ambient temperature
-40 to +85
o
C
V
ESD
Electrostatic Discharge
HBM (ALL PINs)
2000
V
V
ESD
Electrostatic Discharge
MM (ALL PINs)
200
V
Symbol
Parameters
Test Conditions
Min.
Typ.
Max.
Unit
f
Frequency
1575
MHz
V
cc
Supply voltage
2.53
2.7
2.87
V
I
cc
Current Consumption
8.5
mA
I
PD
Power Down Mode
Current Consumption
V
PD
V
PDL
10
nA
G
p
Power gain
17
dB
NF
Noise figure
1.4
dB
IIP2
Input IP2
f1 = 849 MHz, f2 = 2424 MHz,
Pin = -30 dBm
0.5
dBm
IIP3
Input IP3
f1 = 1574.5 MHz, f2 = 1575.5 MHz,
Pin = -30 dBm
3
dBm
ISL
Reverse Isolation
-28
dB
RLin
Input Return Loss
f = 1500-1650 MHz
10
dB
RLout
Output Return Loss
f = 1500-1650 MHz
10
dB
V
PDL
(1)
Power Down Low State
0.5
V
V
PDH
(2)
Power Down High State
1.0
V
Stability
100 - 10000 MHz
Unconditionally stable
3/10
SMA661AS
TYPICAL PERFORMANCE (V
cc
= 2.7 V, Z
L
= Z
S
= 50 ohm, unless otherwise specified; measured
according to Figure 13)
Figure 3. Power Gain Vs Frequency
Figure 4. Input Return Loss Vs Frequency
Figure 5. Noise Figure Vs Frequency
Figure 6. Reverse Isolation Vs Frequency
Figure 7. Output Return Loss Vs Frequency
Figure 8. IIP3 Vs Temperature
10
11
12
13
14
15
16
17
18
19
20
21
22
1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000
f (MHz)
Gp
(
d
B
)
Ta = -40 C
Ta = +25 C
Ta = +85 C
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000
f (MHz)
IR
L
(
d
B
)
Ta = +85 C
Ta = -40 C
Ta = +25 C
0.0
0.5
1.0
1.5
2.0
2.5
3.0
1500
1520
1540
1560
1580
1600
f (MHz)
NF
(
d
B
)
Ta = +85 C
Ta = +25 C
Ta = -40 C
-40
-38
-36
-34
-32
-30
-28
-26
-24
-22
-20
1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000
f (MHz)
IS
L
(
d
B
)
Ta = +85 C
Ta = -40 C
Ta = +25 C
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000
f (MHz)
OR
L
(
d
B
)
Ta = -40 C
Ta = +85 C
Ta = +25 C
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
-40
25
85
T (C)
IIP
3
(
d
B
m
)
SMA661AS
4/10
TYPICAL PERFORMANCE (V
cc
= 2.7 V, Z
L
= Z
S
= 50 ohm, unless otherwise specified; measured
according to Figure 13)
Figure 9. Current Consumption vs Temp.
Figure 10. Gain Power Down Vs Temperature
Figure 11. Power Down Current Vs Temp.
7.5
7.6
7.7
7.8
7.9
8
8.1
8.2
8.3
8.4
8.5
-40
25
+85
T (C)
Ic
c
(
m
A
)
-25
-24
-23
-22
-21
-20
-19
-18
-17
-16
-15
-40
25
+85
T (C)
Gp
d
(
d
B
)
0
10
20
30
40
50
60
-40
-15
10
35
60
85
T (C)
I
pd
(
n
A)
5/10
SMA661AS
TYPICAL PERFORMANCE (V
cc
= 2.7 V, Z
L
= Z
S
= 50 ohm, unless otherwise specified; measured
according to Figure 13)
Figure 12. Stability
1
2
3
4
5
6
7
8
9
10
0
-K
f (GHz)
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
K
PDF 
ZIP