ETC RF9936

RF9936
8
PCS LOW NOISE AMPLIFIER/MIXER
Typical Applications
• CDMA/TDMA/DCS1900 PCS Systems
• General Purpose Downconverter
• PHS 1500/WLAN 2400 Systems
• Micro-Cell PCS Base Stations
• Receivers Employing Diversity Antennas
• Portable Battery Powered Equipment
D
R ES
F9
98 IG
6 N
S
Optimum Technology Matching® Applied
!
Si BJT
Si Bi-CMOS
GaAs HBT
LNA SEL 1
.010
.004
.033
1
.012
.008
.344
.337
.025
.244
.228
.069
.053
.050
.016
.010
.008
Package Style: SSOP-24
Si CMOS
Features
• Complete Receiver Front-End
24 GC
VCC1 2
GAIN
ADJUST
23 GND9
• Analog RF Gain Control
22 VCC4
• Single 3.6V Power Supply
GND1 4
21 GND8
• Digitally Selectable LNA Inputs
N
S O
ee T
VCC2 3
LNA2 IN 5
GND2 6
GND3 7
LNA1 IN 8
20 LNA OUT
SEL.
LOGIC
18 MIX RF IN
VCC3 10
15 IF+
14 GND5
Ordering Information
RF9936
RF9936 PCBA
PCS Low Noise Amplifier/Mixer
Fully Assembled Evaluation Board
13 LO BUFF OUT
Functional Block Diagram
Rev A8 000822
• 1500MHz to 2500MHz Operation
17 GND6
16 IF-
LO IN 12
• Digitally Selectable Buffered LO Output
19 GND7
GND4 9
LO BUFF EN 11
8
8°MAX
0°MIN
GaAs MESFET
U F
pg O
ra R
de
d
P
SiGe HBT
.157
.150
uc
t
N
E
ro W
d
The RF9936 is a monolithic integrated receiver front-end
for PCS applications. The IC contains all of the required
components to implement the RF functions of the
receiver front-end except for the passive filtering and LO
generation. It contains two LNAs (low-noise amplifiers), a
double-balanced Gilbert cell mixer, a balanced IF output,
an LO isolation buffer amplifier, and an LO output buffer
amplifier for providing the buffered LO signal as an output. On-chip digital logic is used to enable the appropriate
LNA. The LNAs share a common output that permits
insertion of a bandpass filter between the LNA output and
the Mixer section. Analog gain adjustment is provided
which allows 10dB variation in gain. The IC is designed to
operate from a single 3.6V power supply.
FRONT-ENDS
Product Description
RF Micro Devices, Inc.
7625 Thorndike Road
Greensboro, NC 27409, USA
Tel (336) 664 1233
Fax (336) 664 0454
http://www.rfmd.com
8-121
RF9936
Absolute Maximum Ratings
Parameter
Supply Voltage
Input LO and RF Levels
Ambient Operating Temperature
Storage Temperature
Parameter
Rating
Unit
-0.5 to 7.0
+6
-40 to +85
-40 to +150
VDC
dBm
°C
°C
Specification
Min.
Typ.
Max.
Caution! ESD sensitive device.
RF Micro Devices believes the furnished information is correct and accurate
at the time of this printing. However, RF Micro Devices reserves the right to
make changes to its products without notice. RF Micro Devices does not
assume responsibility for the use of the described product(s).
Unit
Condition
RF Frequency Range
LO Frequency Range
IF Frequency Range
1500 to 2500
1200 to 2500
DC to 500
D
R ES
F9
98 IG
6 N
S
T = 25°C, VCC =3.6V, RF=1959MHz,
LO=1749MHz @ -2dBm
Overall
MHz
MHz
MHz
1kΩ balanced load, 2.5dB Image Filter Loss.
Cascaded Performance
Input IP3
-14
-9
2.5
5.1
Gain
Reverse Isolation
Output VSWR
dB
VG ≥2.5V
dBm
dBm
dB
dB
1.4
<2.5:1
dB
+2
dBm
13.5
23
<1.5:1
dB
dB
U F
pg O
ra R
de
d
P
Noise Figure
Input VSWR
15.5
dB
uc
t
First Section (LNA)
N
S O
ee T
FRONT-ENDS
Cascade Noise Figure
27.5
N
E
ro W
d
8
Cascade Conversion Gain, Maximum
Cascade Conversion Gain, Minimum
Cascade Input IP3
By varying the gain of the second stage, a
trade-off of gain and noise figure against IP3
can be made.
VG ≤0.5V
Input VSWR
Input IP3
Conversion Gain, Maximum
Conversion Gain, Minimum
Output Impedance
8-122
6.5
13.5
1.5:1
-3
+2
16
6
1
Input is internally matched for optimum noise
figure from a 50Ω source.
IP3 may be increased 10dB by connecting
pin 22 to VCC through the matching inductor.
The LNA’s current then increases by 10mA.
Other in-between IP3 vs. ICC trade-offs may
be made. See pin description for pin 20.
With 1kΩ balanced load.
Second Section (Mixer)
Noise Figure
Maximum Gain
Minimum Gain
Single sideband, at Maximum Gain Setting
Single sideband, at Minimum Gain Setting
The LNA section may be left unused. Power
is not connected to pin 1. The performance
is then as specified for the Second Section
(Mixer).
dB
dB
dBm
dBm
dB
dB
kΩ
By varying the gain of the second stage, a
trade-off of gain and noise figure against IP3
can be made. Please see data plots.
Single Sideband, at maximum gain
Single Sideband, at minimum gain
At maximum gain
At minimum gain
VG ≤0.2V
VG ≥2.5V
Balanced
Rev A8 000822
RF9936
Parameter
Specification
Min.
Typ.
Max.
Unit
Condition
LO Input
LO Input Range
LO Output Level
LO to RF (Mix In) Rejection
LO to IF1, IF2 Rejection
LO Input VSWR
-5 to +3
-5
-25
30
20
<2:1
dBm
dBm
dBm
dB
dB
3.6±5%
5
46
43
V
mA
mA
mA
Buffer On, -2dBm input
Buffer Off, -2dBm input
Single ended
Power Supply
LNA only
LNA + Mixer, LO Buffer On
LNA + Mixer, LO Buffer Off
D
R ES
F9
98 IG
6 N
S
50
47
8
N
S O
ee T
U F
pg O
ra R
de
d
P
uc
t
FRONT-ENDS
N
E
ro W
d
Voltage
Current Consumption
Rev A8 000822
8-123
RF9936
VCC2
4
GND1
5
LNA2 IN
6
7
GND2
GND3
8
LNA1 IN
9
10
GND4
VCC3
11
LO BUFF
EN
12
LO IN
13
LO BUFF
OUT
14
GND5
15
IF+
16
17
IFGND6
18
MIX RF IN
19
GND7
8-124
10 kΩ
150 Ω
VCC1
VCC4
BIAS
Ground connection for LNA1. Keep traces physically short and connect
immediately to ground plane for best performance.
RF Input pin for LNA1. This pin is internally DC blocked and internally
matched for minimum noise figure (NOT for minimum VSWR), given a
50Ω source impedance.
Same as pin 7.
Supply voltage for both LO buffer amplifiers. External RF bypassing is
required. The trace length between the pin and the bypass capacitor
should be minimized. The ground side of the bypass capacitor should
connect immediately to ground plane.
Enable pin for the LO output buffer amplifier. This is a digitally controlled input. A logic "high" (≥3.1V.) turns the buffer amplifier on, and
the current consumption increases by 3mA (with -2dBm LO input). A
logic "low" (≤0.5V.) turns the buffer amplifier off.
Mixer LO Input pin. This pin is internally DC blocked and matched to
50Ω.
Optional Buffered LO Output. This pin is internally DC blocked and
matched to 50Ω. The buffer amplifier is switched on or off by the voltage level at pin 11.
Ground connection for both LO buffer amplifiers. Keep traces physically
short and connect immediately to ground plane for best performance.
Open-collector IF Output pin. This is a balanced output. The output
impedance is set by an internal 1000Ω resistor to pin 16. Thus the differential IF output impedance is 1000Ω. The resistor sets the operating
impedance, but an external choke or matching inductor to VCC must be
supplied in order to bias this output. This inductor is typically incorporated in the matching network between the output and IF filter. Because
this pin is biased to VCC, a DC blocking capacitor must be used if the IF
filter input has a DC path to ground.
Same as pin 15, except complementary output.
LO
BUFF
EN
U F
pg O
ra R
de
d
P
3
Supply Voltage for the Mixer and RF Buffer Amplifier. External RF
bypassing is required. The trace length between the pin and the bypass
capacitor should be minimized. The ground side of the bypass capacitor should connect immediately to ground plane.
Supply Voltage for the LNAs and associated select logic. External RF
bypassing is required. The trace length between the pin and the bypass
capacitor should be minimized. The ground side of the bypass capacitor should connect immediately to ground plane.
Ground connection for LNA2. Keep traces physically short and connect
immediately to ground plane for best performance.
RF Input pin for LNA2. This pin is internally DC blocked and internally
matched for minimum noise figure (NOT for minimum VSWR), given a
50Ω source impedance.
Same as pin 4.
LNA
SEL
D
R ES
F9
98 IG
6 N
S
VCC1
Interface Schematic
Selects which LNA (LNA1 or LNA2) is active. This is a digitally controlled input. A logic "high" (≥3.1V.) selects LNA2. A logic "low" (≤0.5V.)
selects LNA1.
uc
t
2
Description
N
E
ro W
d
Function
LNA SEL
N
S O
ee T
FRONT-ENDS
8
Pin
1
7.5 kΩ
IF-
IF+
1 kΩ
See pin 15.
Ground connection for the Mixer. Keep traces physically short and connect immediately to ground plane for best performance.
Mixer RF Input Pin. This pin is internally DC blocked and matched to
50Ω.
Same as pin 17.
Rev A8 000822
RF9936
21
22
GND8
VCC4
23
24
GND9
GC
Description
Interface Schematic
LNA Output pin. This is an open-collector output. This pin is typically
connected to pin 22 through a bias/matching inductor. This inductor, in
conjunction with a series blocking/matching capacitor, forms a matching network to the 50Ω image filter and provides bias (see Application
Example). The LNA’s IP3 may be increased 10dB by connecting pin 20
to VCC through the inductor. The LNA’s current then increases by
10mA. Other in-between IP3 vs. ICC trade-offs may be made by connecting resistance values between VCC and the matching inductor. The
two reference points for consideration are with 150Ω used, which is
what connection to pin 22 achieves, the Input IP3 is +2dBm and the
LNA ICC is 5mA. Using no resistance, the Input IP3 is +12 dBm and the
LNA ICC is 15 mA. Desired operating points in between these values
may be interpolated, roughly.
Same as pin 17.
LNA
OUT
D
R ES
F9
98 IG
6 N
S
Function
LNA OUT
Output supply voltage for the LNA Output (pin 20). This pin should NOT
be connected to a voltage supply. This pin should be connected to pin
20 through a bias/matching inductor (see Application Example). External RF bypassing is required. The trace length between the pin and the
bypass capacitor should be minimized. The ground side of the bypass
capacitor should connect immediately to ground plane.
Same as pin 17.
Analog gain adjustment for RF buffer amplifier. Minimum gain is
selected with 2.5V to 3.0V. Maximum gain is selected with 0V to 0.5 V.
When operating the RF9936 at fixed maximum gain, this pin may be
grounded.
See pin 2.
150 Ω
GC
8
350 Ω
N
S O
ee T
U F
pg O
ra R
de
d
P
uc
t
FRONT-ENDS
N
E
ro W
d
Pin
20
Rev A8 000822
8-125
RF9936
Application Schematic
LNA SEL
1
GC
(Min Gain: ≥3.1V, Max Gain: ≤0.5V)
24
VCC
2
GAIN
ADJUST
23
68 pF
3
22
4
21
5
20
68 pF
RF2 IN
2.7 nH
SEL.
LOGIC
7
RF1 IN
8
D
R ES
F9
98 IG
6 N
S
1.8 pF
6
18
VCC
68 pF
17
LO IN
8
C1
L1
C2
ZFILTER = 1 kΩ
Filter
16
IF-
C2
10
LO BUFF EN
(On: ≥3.1v, Off: ≤0.5V)
VCC
1 nF
68 pF
9
RF Image
Filter, 50 Ω
19
15
68 pF
11
12
14
13
C1
L1
VCC
1 nF
ZOUT = 1 kΩ
IF+
Measurement
Reference Plane
LO BUFF OUT
N
S O
ee T
U F
pg O
ra R
de
d
P
uc
t
FRONT-ENDS
N
E
ro W
d
L1 and C2 serve dual purposes. L1 serves as an output bias choke, and C2 serves as a
series DC block. In addition, the values of L1 and C2 may be chosen to form an
impedance matching network if the IF filter's input impedance is not 100 Ω. Otherwise,
the values of L1 and C1 are chosen to form a parallel-resonant tank circuit at the IF
when the IF filter's input impedance is 100 Ω.
8-126
Rev A8 000822
RF9936
Evaluation Board Schematic
IF 210MHz
(Download Bill of Materials from www.rfmd.com.)
R1
1 kΩ
1
C15
1 nF
24
2
P1-1
C17
1 nF
LNA2 IN
J2
C16
22 pF
22
4
21
50 Ω µstrip
5
LNA1 IN
J1
50 Ω µstrip
SEL.
LOGIC
P1-1
C18
22 pF
8
9
R2
1 kΩ
P1-3
C23
1 nF
C20
22 pF
10
11
50 Ω µstrip
J3
12
19
2
C1
22 pF
see notes
P1-3
1
3
C5
22 pF
see notes
6
FL1 (SAW Filter)
4
5
50 Ω µstrip
J6
L6
39 nH
C21
1 pF
C6
100 pF
C3
22 pF
see notes
16
15
L7
39 nH
14
13
C22
1 pF
C7
100 pF
L2
470 nH
L3
470 nH
C13
22 pF
C9
1 nF
L5
180 nH
C12
1 nF
C8
5.1 pF
T1
5.5:1
C11
1.5 pF
1
VCC
2
GND
3
BUFFER
ENABLE
P2
P2-1
MIXER IN
18
17
P1-1
P2-3
1
LNA
SELECT
2
GND
3
GC
IF OUT
50 Ω µstrip
J4
L4
47 nH
C24
4.7 µF
50 Ω µstrip
8
LO OUT
J5
N
S O
ee T
U F
pg O
ra R
de
d
P
uc
t
FRONT-ENDS
N
E
ro W
d
Note: 1) For cascaded LNA/MIXER applications, install C1 and C5
and remove C2 and C3 (default configuration).
2) For LNA only and/or MIXER only characterization, install C2
and remove C1 and C5.
3) L5 select value 180 nH to 220 nH.
4) Do not install C2, C3 in normal cascade operation.
50 Ω µstrip
LNA OUT
J7
L1
2.7 nH
C4
3.9 pF
Drawing 9936401 Rev A
P1
C2
22 pF
see notes
C10
22 pF
20
7
C19
1 nF
23
3
6
LO IN
GAIN
ADJUST
P2-3
C14
1 nF
D
R ES
F9
98 IG
6 N
S
P2-1
Rev A8 000822
8-127
RF9936
Evaluation Board Layout
D
R ES
F9
98 IG
6 N
S
(Assembly, Top layer, Mid-signal layer, Internal Ground layer)
N
S O
ee T
U F
pg O
ra R
de
d
P
uc
t
FRONT-ENDS
N
E
ro W
d
8
8-128
Rev A8 000822
U F
pg O
ra R
de
d
P
N
S O
ee T
Rev A8 000822
D
R ES
F9
98 IG
6 N
S
FRONT-ENDS
uc
t
N
E
ro W
d
RF9936
Evaluation Board Layout cont’d
8
8-129
U F
pg O
ra R
de
d
P
N
S O
ee T
uc
t
8
D
R ES
F9
98 IG
6 N
S
N
E
ro W
d
FRONT-ENDS
RF9936
8-130
Rev A8 000822