Philips NE5209 Service Manual

INTEGRATED CIRCUITS

NE/SA5209

Wideband variable gain amplifier

Product specification 1990 Aug 20

RF Communications Handbook

Philips Semiconductors

Philips Semiconductors Product specification

NE/SA5209Wideband variable gain amplifier

DESCRIPTION

The NE5209 represents a breakthrough in monolithic amplifier
design featuring several innovations. This unique design has
combined the advantages of a high speed bipolar process with the
proven Gilbert architecture.

The NE5209 is a linear broadband RF amplifier whose gain is
controlled by a single DC voltage. The amplifier runs off a single 5
volt supply and consumes only 40mA. The amplifier has high
impedance (1kΩ) differential inputs. The output is 50Ω differential.
Therefore, the 5209 can simultaneously perform AGC, impedance
transformation, and the balun functions.

The dynamic range is excellent over a wide range of gain setting.
Furthermore, the noise performance degrades at a comparatively
slow rate as the gain is reduced. This is an important feature when
building linear AGC systems.

FEA TURES

•Gain to 1.5GHz

•850MHz bandwidth

•High impedance differential input

•50Ω differential output

•Single 5V power supply

•0 - 1V gain control pin

•>60dB gain control range at 200MHz

•26dB maximum gain differential

•Exceptional V

CONTROL

/ V

GAIN

linearity

•7dB noise figure minimum

•Full ESD protection

•Easily cascadable

PIN CONFIGURA TION

N, D PACKAGES

1

V

CC1

2

GND

1

3

IN

A

4

GND

1

5

IN

B

6

GND

1

7

V

BG

8

V

AGC

Figure 1. Pin Configuration

APPLICATIONS

•Linear AGC systems

•Very linear AM modulator

•RF balun

•Cable TV multi-purpose amplifier

•Fiber optic AGC

•RADAR

•User programmable fixed gain block

•Video

•Satellite receivers

•Cellular communications

16

V

CC2

15

GND

2

14

OUT

A

13

GND

2

12

OUT

B

11

GND

2

10

GND

2

9

GND

2

SR00237

ORDERING INFORMATION

DESCRIPTION TEMPERATURE RANGE ORDER CODE DWG #

16-Pin Plastic Small Outline (SO) package
16-Pin Plastic Dual In-Line Package (DIP) 0 to +70°C NE5209N SOT28-4
16-Pin Plastic Small Outline (SO) package -40 to +85°C SA5209D SOT109-1
16-Pin Plastic Dual In-Line Package (DIP) -40 to +85°C SA5209N SOT28-4

1990 Aug 20 853-1453 00223

2

0 to +70°C

NE5209D SOT109-1

Philips Semiconductors Product specification

SYMBOL

PARAMETER

TEST CONDITIONS

UNIT

ICCS

t

A

AVVolt

t)

dB

AVVolt

/diff

t)

dB

RINInput resistance (single-ended)

kΩ

R

Output resistance (single-ended)

Ω

VOSOutput offset voltage (output referred)

mV

VINDC level on inputs

V

V

DC level on outputs

V

PSRR

dB

BG

gp g

NE/SA5209Wideband variable gain amplifier

ABSOLUTE MAXIMUM RATINGS

SYMBOL PARAMETER RATING UNITS

V

CC

P

D

T

JMAX

T

STG

NOTES:

1. Maximum dissipation is determined by the operating ambient temperature and the thermal resistance, θ
16-Pin DIP: θ
16-Pin SO: θ

RECOMMENDED OPERATING CONDITIONS

SYMBOL PARAMETER RATING UNITS

V

CC

T

A

T

J

Supply voltage -0.5 to +8.0 V
Power dissipation, TA = 25oC (still air)

16-Pin Plastic DIP
16-Pin Plastic SO

1

1450
1100

mW

mW
Maximum operating junction temperature 150
Storage temperature range -65 to +150

:

= 85°C/W

JA

= 110°C/W

JA

Supply voltage V

CC1

JA

= V

= 4.5 to 7.0V V

CC2

Operating ambient temperature range

NE Grade
SA Grade

0 to +70

-40 to +85

Operating junction temperature range

NE Grade
SA Grade

0 to +90

-40 to +105

°C
°C

°C
°C

°C
°C

DC ELECTRICAL CHARACTERISTICS

TA = 25oC, V

OUT

OUT

V

BG

CC1

= V

CC2

= +5V, V

= 1.0V , unless otherwise specified.

AGC

upply curren

age gain (single-ended in/single-ended ou

age gain (single-ended in

-

-

Output offset supply rejection ratio
(output referred)

Bandgap reference voltage

erential ou

LIMITS

MIN TYP MAX

DC tested 38 43 48

Over temperature

1

30 55

DC tested, RL = 10kΩ 17 19 21

Over temperature

1

16 22

DC tested, RL = 10kΩ 23 25 27

Over temperature

1

22 28

DC tested at ±50µA 0.9 1.2 1.5

Over temperature

1

0.8 1.7
DC tested at ±1mA 40 60 75
Over temperature

1

35 90

+20 ±100

Over temperature

1

±250

1.6 2.0 2.4
Over temperature

1

1.4 2.6

1.9 2.4 2.9
Over temperature

1

1.7 3.1

20 45

Over temperature

4.5V<VCC<7V
= 10kΩ

R

BG

Over temperature

1

15

1.2 1.32 1.45

1

1.1 1.55

m

V

1990 Aug 20

3

Philips Semiconductors Product specification

SYMBOL

PARAMETER

TEST CONDITIONS

UNIT

I

AGC pin DC bias current

A

SYMBOL

PARAMETER

TEST CONDITIONS

UNIT

BW-3dB bandwidth

MHz

GF

Gain flatness

dB

V

NE/SA5209Wideband variable gain amplifier

DC ELECTRICAL CHARACTERISTICS

TA = 25oC, V

R

BG

V

AGC

BAGC

NOTES:

1. “Over Temperature Range” testing is as follows:

At the time of this data sheet release, the D package over-temperature data sheet limits are guaranteed via guardbanded room temperature
testing only.

AC ELECTRICAL CHARACTERISTICS

TA = 25oC, V

V

IMAX

OMAX

NF Noise figure (unmatched configuration) RS = 50Ω, f = 50MHz 9.3 dB

V

IN-EQ

S12 Reverse isolation f = 100MHz -60 dB

∆G/∆V

∆G/∆T Gain temperature sensitivity RL = 50Ω 0.013

C

IN

BW

AGC

P

O-1dB

P

I-1dB

IP3

OUT

IP3

IN

∆G

AB

NOTE:

1. “Over Temperature Range” testing is as follows:

At the time of this data sheet release, the D package over-temperature data sheet limits are guaranteed via guardbanded room temperature
testing only.

2. With R
occurs at input for single-ended gain < 6dB and at output for single-ended gain > 6dB.

= V

CC1

= +5.0V, V

CC2

= 1.0V , unless otherwise specified.

AGC

LIMITS

MIN TYP MAX

Bandgap loading Over temperature
AGC DC control voltage range Over temperature

0V<V

AGC

Over temperature

1
1

2 10

0-1.3 V

<1.3V -0.7 -6

1

-10

NE is 0 to +70°C
SA is -40 to +85°C

= V

CC1

= +5.0V, V

CC2

= 1.0V , unless otherwise specified.

AGC

LIMITS

MIN TYP MAX

­Over temperature

1

600 850
500

DC - 500MHz +0.4

Over temperature

Maximum input voltage swing (single-ended) for
linear operation

Maximum output voltage swing (single-ended)
for linear operation

2

RL = 50Ω 400 mV

2

RL = 1kΩ 1.9 V

Equivalent input noise voltage spectral density f = 100MHz 2.5

Gain supply sensitivity (single-ended) 0.3 dB/V

CC

1

+0.6

200 mV

nV/√Hz

dB/°C

Input capacitance (single-ended) 2 pF

-3dB bandwidth of gain control function 20 MHz

1dB gain compression point at output f = 100MHz -3 dBm
1dB gain compression point at input

Third-order intercept point at output

Third-order intercept point at input

f = 100MHz, V

f = 100MHz, V

f = 100MHz, V

Gain match output A to output B f = 100MHz, V

=0.1V

>0.5V

<0.5V

AGC

AGC

AGC

= 1V 0.1 dB

AGC

-10 dBm

+13 dBm

+5 dBm

NE is 0 to +70°C
SA is -40 to +85°C

> 1kΩ, overload occurs at input for single-ended gain < 13dB and at output for single-ended gain > 13dB. With RL = 50Ω, overload

L

kΩ

µ

P-P

P-P

P-P

1990 Aug 20

4

Philips Semiconductors Product specification

NE/SA5209Wideband variable gain amplifier

NE5209 APPLICATIONS

The NE5209 is a wideband variable gain amplifier (VGA) circuit
which finds many applications in the RF, IF and video signal
processing areas. This application note describes the operation of
the circuit and several applications of the VGA. The simplified
equivalent schematic of the VGA is shown in Figure 2. Transistors
Q1-Q6 form the wideband Gilbert multiplier input stage which is
biased by current source I1. The top differential pairs are biased
from a buffered and level-shifted signal derived from the V
and the RF input appears at the lower differential pair. The circuit
topology and layout offer low input noise and wide bandwidth. The
second stage is a differential transimpedance stage with current
feedback which maintains the wide bandwidth of the input stage.
The output stage is a pair of emitter followers with 50Ω output
impedance. There is also an on-chip bandgap reference with
buffered output at 1.3V, which can be used to derive the gain control
voltage.

Both the inputs and outputs should be capacitor coupled or DC
isolated from the signal sources and loads. Furthermore, the two
inputs should be DC isolated from each other and the two outputs
should likewise be DC isolated from each other. The NE5209 was
designed to provide optimum performance from a 5V power source.
However, there is some range around this value (4.5 - 7V) that can
be used.

The input impedance is about 1kΩ. The main advantage to a
differential input configuration is to provide the balun function.
Otherwise, there is an advantage to common mode rejection, a
specification that is not normally important to RF designs. The
source impedance can be chosen for two different performance
characteristics: Gain, or noise performance. Gain optimization will
be realized if the input impedance is matched to about 1kΩ. A 4:1
balun will provide such a broadband match from a 50Ω source.
Noise performance will be optimized if the input impedance is
matched to about 200Ω. A 2:1 balun will provide such a broadband
match from a 50Ω source. The minimum noise figure can then be
expected to be about 7dB. Maximum gain will be about 23dB for a
single-ended output. If the differential output is used and properly
matched, nearly 30dB can be realized. With gain optimization, the
noise figure will degrade to about 8dB. With no matching unit at the
input, a 9dB noise figure can be expected from a 50Ω source. If the
source is terminated, the noise figure will increase to about 15dB.
All these noise figures will occur at maximum gain.

The NE5209 has an excellent noise figure vs gain relationship. With
any VGA circuit, the noise performance will degrade with decreasing

AGC

input

gain. The 5209 has about a 1.2dB noise figure degradation for
each 2dB gain reduction. With the input matched for optimum gain,
the 8dB noise figure at 23dB gain will degrade to about a 20dB
noise figure at 0dB gain.

The NE5209 also displays excellent linearity between voltage gain
and control voltage. Indeed, the relationship is of sufficient linearity
that high fidelity AM modulation is possible using the NE5209. A
maximum control voltage frequency of about 20MHz permits video
baseband sources for AM.

A stabilized bandgap reference voltage is made available on the
NE5209 (Pin 7). For fixed gain applications this voltage can be
resistor divided, and then fed to the gain control terminal (Pin 8).
Using the bandgap voltage reference for gain control produces very
stable gain characteristics over wide temperature ranges. The gain
setting resistors are not part of the RF signal path, and thus stray
capacitance here is not important.

The wide bandwidth and excellent gain control linearity make the
NE5209 VGA ideally suited for the automatic gain control (AGC)
function in RF and IF processing in cellular radio base stations,
Direct Broadcast Satellite (DBS) decoders, cable TV systems, fiber
optic receivers for wideband data and video, and other radio
communication applications. A typical AGC configuration using the
NE5209 is shown in Figure 3. Three NE5209s are cascaded with
appropriate AC coupling capacitors. The output of the final stage
drives the full-wave rectifier composed of two UHF Schottky diodes
BAT17 as shown. The diodes are biased by R1 and R2 to V

CC

such
that a quiescent current of about 2mA in each leg is achieved. An
NE5230 low voltage op amp is used as an integrator which drives
the V

pin on all three NE5209s. R3 and C3 filter the high

AGC

frequency ripple from the full-wave rectified signal. A voltage
divider is used to generate the reference for the non-inverting input
of the op amp at about 1.7V. Keeping D3 the same type as D1 and
D2 will provide a first order compensation for the change in Schottky
voltage over the operating temperature range and improve the AGC
performance. R6 is a variable resistor for adjustments to the op
amp reference voltage. In low cost and large volume applications
this could be replaced with a fixed resistor, which would result in a
slight loss of the AGC dynamic range. Cascading three NE5209s
will give a dynamic range in excess of 60dB.

The NE5209 is a very user-friendly part and will not oscillate in most
applications. However, in an application such as with gains in
excess of 60dB and bandwidth beyond 100MHz, good PC board
layout with proper supply decoupling is strongly recommended.

V

0–1V

1990 Aug 20

AGC

V

CC

R

1

Q

Q

1

2

+

–

IN

Q

5

B

IN

A

I

1

Q

3

R

2

Q

4

Q

6

R

3

A1

R

4

BANDGAP

REFERENCE

Q

7

Q

8

I

2

OUT

B

Ω

50

I

3

V

BG

OUT

A

Ω

50

SR00238

Figure 2. Equivalent Schematic of the VGA

5