AN1777 End Circuits Datasheet

AN1777 Datasheet, PDF, Equivalent


Part Number

AN1777

Description

Low Voltage Front End Circuits

Manufacture

Philips

Total Page 30 Pages
Datasheet
Download AN1777 Datasheet


AN1777
INTEGRATED CIRCUITS
www.DataSheet4U.com
AN1777
Low voltage front-end circuits:
SA601, SA620
M. B. Judson
1997 Aug 20
Philips
Semiconductors

AN1777
Philips Semiconductors
Low voltage front-end circuits: SA601, SA620
Application note
AN1777
Author: M. B. Judson
CONTENTS
I. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
II. Key Attributes of the SA601 and SA620
2
III. Power Consumption . . . . . . . . . . . . . . . . . .
IV. Low Noise Amplifiers . . . . . . . . . . . . . . . . .
V. SA620 Mixer . . . . . . . . . . . . . . . . . . . . . . . . .
Open-Collector Output Basics . . . . . . . . . . . . . . . . . . . . .
Why RC Acts Like A Source Resistor . . . . . . . . . . . . . . .
Open-collector with RLOAD . . . . . . . . . . . . . . . . . . . . . . . .
www.DataSheet4U.coOmpen-collector with inductor (LC) . . . . . . . . . . . . . . . . . .
Open-collector with Inductor (LC) and RLOAD . . . . . . . .
VI. Flexible Matching Circuit . . . . . . . . . . . . .
2
3
3
4-46
4-46
4-46
4-48
4-51
9
VII. SA601 MIXER . . . . . . . . . . . . . . . . . . . . . . . .
VIII. Matching the Open-Collector Differential
Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inductor L2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Capacitors C5 and C7 . . . . . . . . . . . . . . . . . . . . . . . . .
Inductor L3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Capacitor C6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Resistor R2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Method of Achieving High Impedance Matching with a
Network Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Non-Ideal Current-Combiner Ckt Considerations . . . . .
IX. Matching Examples . . . . . . . . . . . . . . . . . .
83MHz, 1 kMatch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
45MHz, 1 kMatch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
110.592MHz, 50Match . . . . . . . . . . . . . . . . . . . . . . . . .
SA601 IP3IN Considerations . . . . . . . . . . . . . . . . . . . . . .
Summary of Mixer Open-Collector Output Concepts . .
X. SA601 Mixer Characterization . . . . . . . . .
SA601 System SINAD Performance . . . . . . . . . . . . . . .
XI. SA620 VCO . . . . . . . . . . . . . . . . . . . . . . . . . .
XII. µ-Strip Inductor Oscillator
Resonant Circuit . . . . . . . . . . . . . . . . . . . . .
10
11
4-54
4-54
4-54
4-54
4-54
4-54
4-55
14
4-56
4-58
4-59
4-61
4-62
20
4-62
20
21
General Theoretical Background . . . . . . . . . . . . . . . . . . . 4-63
Increasing Loaded-Q . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-64
High-Q Short Microstrip Inductor . . . . . . . . . . . . . . . . . . . 4-64
UHF VCO Using the SA620 at 900MHz . . . . . . . . . . . . . 4-65
XIII. Application Boards . . . . . . . . . . . . . . . . . . . 26
SA601 Applications Board . . . . . . . . . . . . . . . . . . . . . . . . 4-68
SA601 Application Board Modification For Increasing Mixer
Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-68
SA620 Applications Board . . . . . . . . . . . . . . . . . . . . . . . . 4-69
XIV. Test and Measurement Tips . . . . . . . . . . . 29
Noise Figure and Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-71
1dB Compression Point . . . . . . . . . . . . . . . . . . . . . . . . . . 4-72
Input Third-Order Intercept Point . . . . . . . . . . . . . . . . . . . 4-73
Phase Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-73
XV. Common Questions and Answers . . . . . 31
XVI. References . . . . . . . . . . . . . . . . . . . . . . . . . . 31
I. INTRODUCTION
The objectives of this application note are to highlight key features
and distinguish key differences between the SA601 and SA620.
The power, gain, noise figure, and third-order intercept point of the
LNA and mixer will be characterized. A resonant circuit
implementing a high loaded-Q µ-strip inductor and an extensive
discussion of open-collector mixer outputs and how to match them
will also be presented.
The SA601 and SA620 are products designed for high performance
low power RF communication applications from 800 to 1200MHz.
These chips offer the system designer an alternative to discrete
front-end designs which characteristically introduce a great deal of
end-product variation, require external biasing components, and
require a substantial amount of LO drive. The SA601 and SA620
contain a low noise amplifier and mixer, offering an increase in
manufacturability and a minimum of external biasing components
due to integration. The LO drive requirements for active mixers are
less stringent than passive mixers, thus minimizing LO isolation
problems associated with high LO drive-levels. These chips also
contain power down circuitry for turning off all or portions of the chip
while not in use. This minimizes the average power consumed by
the front-end circuitry. The SA620 features an internal VCO that
eliminates additional cost and space needed for an external VCO.
The SA601 and SA620 fit within a 20-pin surface mount plastic
shrink small outline package (SSOP), thus saving a considerable
amount of space.
II. KEY ATTRIBUTES OF THE SA601 AND SA620
The primary differences between the SA601 and SA620 are the LNA
power down capability, the implementation of the mixer output
circuitry, and the incorporation of an integrated VCO.
Table 1 below summarizes the attributes of both parts.
Table 1. Showing SA601 and SA602 Attributes
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁProduct
Diff. Mixer LNA Thru
Output
Mode
Mixer
Power
Down
Int. VCO
and VCO
Pwr Down
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁSA601
Yes
No Yes No
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁSA620
No
Yes Yes Yes
III. POWER CONSUMPTION
As mentioned above, the average power consumed by the front-end
circuitry can be decreased by selectively turning off circuitry that is
not in use. The supply current at a given voltage will decrease more
than 3mA for each LNA, mixer, or VCO disabled. When the LNA is
disabled on the SA620 it is replaced by a 9dB attenuator. This is
useful for extending the dynamic range of the receiver when an
overload condition exists. Tables 2 and 3 below contain averaged
data taken on the SA601 and SA620 while in an application board
environment.
Table 2. Showing SA601 Supply Current
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁVCC
ICC (mA)
3.0 8.4
ICC (mA) Mixer Disabled
4.9
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ4.0 8.4
4.7
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ5.0 8.3
4.5
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁTable 3. Showing SA620 Supply Current
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁVCC
ICC
(mA)
ICC (mA)
LNA
Disabled
ICC (mA)
Mixer
Disabled
ICC (mA)
VCO
Disabled
ICC (mA)
Chip Fully
Powered
Down
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ3.0 11.4
8.0
8.1
8.2
1.4
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ4.0 11.6
8.5
8.0
8.2
1.6
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ5.0 11.7
8.9
8.0
8.2
1.7
1995 Aug 10
2


Features INTEGRATED CIRCUITS www.DataSheet4U.com AN1777 Low voltage front-end circuits : SA601, SA620 M. B. Judson 1997 Aug 20 Philips Semiconductors Philips Semic onductors Application note Low voltag e front-end circuits: SA601, SA620 Auth or: M. B. Judson CONTENTS I. Introducti on . . . . . . . . . . . . . . . . . . . . . . . . . II. Key Attributes of the SA601 and SA620 III. Power Consumption . . . . . . . . . . . . . . . . . . IV . Low Noise Amplifiers . . . . . . . . . . . . . . . . . V. SA620 Mixer . . . . . . . . . . . . . . . . . . . . . . . . . Open-Collector Output Basics . . . . . . . . . . . . . . . . . . . . . Wh y RC Acts Like A Source Resistor . . . . . . . . . . . . . . . Open-collector with RLOAD . . . . . . . . . . . . . . . . . . . . . . . . Open-collector with inductor (LC) . . . . . . . . . . . . . . . . . . www.DataSheet4U.com Open-co llector with Inductor (LC) and RLOAD . . . . . . . . AN1777 2 2 2 3 3 4-46 4 -46 4-46 4-48 4-51 implementing a high loaded-Q µ-strip induct.
Keywords AN1777, datasheet, pdf, Philips, Low, Voltage, Front, End, Circuits, N1777, 1777, 777, AN177, AN17, AN1, Equivalent, stock, pinout, distributor, price, schematic, inventory, databook, Electronic, Components, Parameters, parts, cross reference, chip, Semiconductor, circuit, Electric, manual, substitute




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