MC13155

3

MOTOROLA ANALOG IC DEVICE DATA

CIRCUIT DESCRIPTION

The MC13155 consists of a wideband three–stage limiting

amplifier, a wideband quadrature detector which may be

operated up to 200 MHz, and a received signal strength

indicator (RSSI) circuit which provides a current output

linearly proportional to the IF input signal level for

approximately 35 dB range of input level.

+

10

µ

Figure 2. Test Circuit

Limiter 2

Output

Limiter 1

Output

Video

Output

Vin

330

1.0n

49.9

1.0n

27

1.0k

100n

330

L1 – Coilcraft part number 146–09J08S

L1

260n

20p

499

VEE

VEE

VEE

+

10n

1.0n

1.0n

1.0n

1.0n

100n

1.0n

IN2

DEC2

VEE1

RSSI

Buffer

RSSI

VEE2

LIMO2

QUAD2

QUAD1

LIMO1

VCC2

DETO2

DETO1

VCC1

DEC1

IN1

9

10

11

12

13

14

15

16

8

7

6

5

4

3

2

1

10

µ

APPLICATIONS INFORMATION

Evaluation PC Board

The evaluation PCB shown in Figures 19 and 20 is very

versatile and is designed to cascade two ICs. The center

section of the board provides an area for attaching all surface

mount components to the circuit side and radial leaded

components to the component ground side of the PCB (see

Figures 17 and 18). Additionally, the peripheral area

surrounding the RF core provides pads to add supporting

and interface circuitry as a particular application dictates.

This evaluation board will be discussed and referenced in

this section.

Limiting Amplifier

Differential input and output ports interfacing the three

stage limiting amplifier provide a differential power gain of

typically 46 dB and useable frequency range of 300 MHz.

The IF gain flatness may be controlled by decoupling of the

internal feedback network at Pins 2 and 15.

Scattering parameter (S–parameter) characterization of

the IF as a two port linear amplifier is useful to implement

maximum stable power gain, input matching, and stability

over a desired bandpass response and to ensure stable

operation outside the bandpass as well. The MC13155 is

unconditionally stable over most of its useful operating

frequency range; however, it can be made unconditionally

stable over its entire operating range with the proper

decoupling of Pins 2 and 15. Relatively small decoupling

capacitors of about 100 pF have a significant effect on the

wideband response and stability. This is shown in the

scattering parameter tables where S–parameters are shown

for various values of C2 and C15 and at VEE of – 3.0 and

– 5.0 Vdc.

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com