SA601 Datasheet, PDF (4/11 Pages) NXP Semiconductors – Low voltage LNA and mixer - 1GHz

Philips Semiconductors RF Communications Products
Low voltage LNA and mixer - 1GHz
Product specification
SA601
J1
LNA IN
C15
1µF
C1
100pF
C2
2.7pF
** ^{w = 10 mils}
L = 535 mils
w = 15 mils
L = 110 mils
J2
EXT LO
C3
100pF
(-7dBm, 964MHz)
L1
56nH
U1
1 _Vcc
2 _GND
3 _{LNA IN}
4 _GND
5 _GND
6 _GND
7 _{MIXER PD}
8 _GND
9 _{LO IN}
10 _{LO IN}
SA601
C4
100pF
V_CC
C13
100pF
Vcc ²⁰
GND ¹⁹
LNA OUT ¹⁸
GND ¹⁷
MIXER IN ¹⁶
GND ¹⁵
MIXER OUT ¹⁴
MIXER OUT ¹³
GND ¹²
Vcc ¹¹
C14
100nF
V_CC
** ^C11
100pF
w = 10 mils
L = 535 mils
J5
LNA OUT
w = 15 mils
L = 95 mils
C12
2.2pF
J4
C10 ^{MIXER IN}
C9
4.7pF
w = 15 mils
L = 190 mils
100pF
L3
270nH
C7
33pF
C5
V_CC
C8
100nF
L2
18pF
470nH
R2 _*
2.2k
C6
8.2pF
J3
MIXER OUT _{** *}
(50Ω, 83MHz)
*SEE MIXER POWER GAIN NOTE BELOW
** SPIRAL INDUCTORS ON NATURAL FR-4, 62 MILS THICK
** * ^{SEE MIXER FILTER INTERFACE NOTE BELOW}
Figure 1. Application Circuit
CIRCUIT TECHNOLOGY
LNA
Impedance Match: Intrinsic return loss at the input and output ports
is 7dB and 9dB, respectively. With no external matching, the
associated LNA gain is ≈10dB and the noise figure is ≈1.4dB.
However, the return loss can be improved at 881MHz using
suggested L/C elements (Figure 1) as the LNA is unconditionally
stable.
Noise Match: The LNA achieves 1.6dB noise figure at 881MHz
when S₁₁ = -10dB. Further improvements in S₁₁ will slightly
decrease the NF and increase S₂₁.
Temperature Compensation: The LNA has a built-in temperature
compensation scheme to reduce the gain drift to 0.003dB/°C from
–40°C to +85°C.
Supply Voltage Compensation: Unique circuitry provides gain
stabilization over wide supply voltage range. The gain changes no
more than 0.5dB when V_CC increases from 3V to 5V.
LO Drive Level: Resistor R1 can be replaced by an inductor of
4.7nH and C13 should be adjusted to achieve a good return loss at
the LO port. Under this condition, the mixer will operate with less
than -10dBm LO drive.
IP3 Performance: C9 between Pin 16 and ground can be removed
to introduce 3dB mismatch loss, while improving the IP3 to +3dBm.
The associated noise figure is 11dB.
Mixer
Input Match: The mixer is configured for maximum gain and best
noise figure. The user needs to supply L/C elements to achieve this
performance.
Power Gain: The gain can be increased by approximately 1.5dB by
placing R2 across C7, instead of C5.
Power Down: The mixer can be disabled by connecting Pin 7 to
ground. When the mixer is disabled, 3mA is saved.
Power Combining: The mixer output circuit features passive
power combining (patent pending) to optimize conversion gain and
noise figure performance without using extra DC current or
degrading the IP3. For IF frequencies significantly different than
83MHz, the component values must be altered accordingly.
Filter Interface: For system integration where a high impedance
filter of 1kΩ is to be cascaded at the mixer IF output, capacitors C5
and C6 need to be changed to 27pF and 1000pF, respectively.
December 15, 1994
4