Philips Semiconductors

Product specification

NE/SA5209

Wideband variable gain amplifier

1990 Aug 20

8

50

Ω

50

Ω

50

Ω

+5V

SOURCE

OUTPUT

5209

R

2

R

V

BG

VBG

VAGC

R1

R2

SR00247

Figure 11. User-Programmable Fixed Gain Block

All harmonic distortion products will be

at least -50dBc over the audio spectrum.

50

Ω

50

Ω

50

Ω

+5V

SOURCE

OUTPUT

5209

+5V

RF INPUT

FULL CARRIER

AM (DSB)

MODULATING

SIGNAL

.5V

R9R

VAGC

SR00248

Figure 12. AM Modulator

The high input impedance to the NE5209 makes matching

to crystal filters relatively easy. The total delta gain of this

system will approach 80dB. IF frequencies well into the UHF

region can be configured with this type of architecture.

50

Ω

5209

CRYSTAL

GAIN CONTROL

SIGNAL

FILTER

50

Ω

OUTPUT

5209

5209

VAGC

VAGC

VAGC

SR00249

Figure 13. Receiver AGC IF Gain

RL

5209

RL

±

±

VS

RS

RT

RT

VAGC

VCC (+5V, unless otherwise noted)

SR00250

Figure 14. Test Set-up 1 (Used for all Graphs)