Philips Semiconductors

Objective specification

SA9503

Dual-band, CDMA/AMPS LNA

and downconverter mixers

2

1999 Jul 29

DESCRIPTION

The SA9503 is an integrated CDMA/AMPS low noise amplifier

(LNA) plus a downconverter, for both the 900 MHz Cellular band and

the 1.9 GHz PCS band. The LNA incorporates 5 settings of digitally

selected stepped gain in the Cellular band and in the PCS band.

One of the modes (high linearity mode) in each of the Cellular and

PCS bands, includes a high IP3 setting in order to meet the 1-tone

CDMA desensitization test. The gain, noise figure and IP3 for the

remaining 4 low current modes in the Cellular band, are designed in

order to have sufficient separation between the antenna power

levels at which the LNA gains are changed, based on multi-tone

interference levels. A 3 dB overlap is allowed in the antenna power

levels for the adjacent modes. Table 1 indicates a typical scenario.

The downconverter portion is based on our SA9502 and is designed

to meet all the stringent spurious rejections that are required in the

Cellular and PCS bands. There are three individual mixer blocks,

each optimized for high linearity with low power consumption for

operation in one of the following modes: 1900 MHz PCS CDMA,

800 MHz Cellular CDMA, or 800 MHz analog FM AMPS/TACS

modes.

The circuit has been designed in our advanced QUBiC3 BiCMOS

FEATURES

Versatile step gain LNA

PARAMETER

MODE

PARAMETER

CEL_L

CEL_1

CEL_2

CEL_3

CEL_4

Gain (dB)

17

15.5

9

3

–4

Noise figure (dB)

2

1.6

1.9

4.5

11

Input IP3 (dBm)

5.5

–2

–3.5

2

15

Current (mA)

13.2

4.9

4.9

4.9

3.7

PARAMETER

MODE

PARAMETER

PCS_L

PCS_1

PCS_2

PCS_3

PCS_4

Gain (dB)

15.2

14.3

8

2

–4.5

Noise figure (dB)

2.5

2

2.5

3.7

11.5

Input IP3 (dBm)

4.5

1

–2

–1

16

Current (mA)

13.3

5.9

5.9

5.9

3.7

Downconverter typical performance

PARAMETER

Cellular FM

Cellular CDMA

PCS CDMA

Gain (dB)

7.5

11.5

12.5

Noise Figure (dB)

10

9

9

Input IP3 (dBm)

5

3.5

4

Current (mA)

(Tx) LO output

buffer off

6.8

13

16

– Cellular FM: 16.8 mA

– Cellular CDMA: 23 mA

– PCS: 26 mA

APPLICATIONS

BCC32++ is a trademark of Fujitsu Microelectronics.