8

LT5557

5557fa

TEST CIRCUITS

REF DES

VALUE

SIZE

PART NUMBER

REF DES

VALUE

SIZE

PART NUMBER

C1

1000pF

0402

AVX 04025C102JAT

L4, C4, C5

0402

See Applications Information

C2

1

μF

0603

AVX 0603ZD105KAT

L1

82nH

0603

Toko LLQ1608-F82NG

C3

2.2pF

0402

AVX 04025A2R2BAT

T1

8:1

Mini-Circuits TC8-1+

Figure 1. Standard Downmixer Test Schematic—Transformer-Based Bandpass IF Matching (240MHz IF)

REF DES

VALUE

SIZE

PART NUMBER

REF DES

VALUE

SIZE

PART NUMBER

C1, C3

1000pF

0402

AVX 04025C102JAT

L4, C4, C5

0402

See Applications Information

C2

1

μF

0603

AVX 0603ZD105KAT

L1, L2

100nH

0603

Toko LL1608-FSLR10J

C6, C7

4.7pF

0402

AVX 04025A4R7CAT

L3

150nH

0603

Toko LL1608-FSLR15J

Figure 2. Downmixer Test Schematic—Discrete IF Balun Matching (240MHz IF)

240MHz

5557 F02

16

15

14

13

56

7

8

12

11

10

9

NC

NC

GND

GND

EN

EN

NC

RF

LO

NC

NC

1

2

3

4

EXTERNAL MATCHING

FOR LO BELOW 1GHz

NC

NC

IF

+

IF–

L1

L2

L3

C4

50

Ω

C1

C2

C6

C3

C7

DISCRETE

IF BALUN

LT5557

L4

C5

L (mm)

LOW-PASS MATCH

FOR 450MHz, 900MHz

AND 3.6GHz RF

RF

GND

GND

BIAS

0.018"

0.018"

0.062"

DC910A

BOARD

STACK-UP

(FR-4)

240MHz

5557 F01

16

15

14

13

56

7

8

12

11

10

9

NC

NC

GND

GND

EN

EN

NC

RF

LO

NC

NC

1

2

3

4

NC

NC

IF

+

IF–

T1

C4

50

Ω

C1

C2

C3

3

LT5557

L4

C5

C5

3.9pF

L5

3.6nH

L (mm)

LOW-PASS MATCH

FOR 450MHz, 900MHz

AND 3.6GHz RF

EXTERNAL MATCHING

FOR LO BELOW 1GHz

*HIGH-PASS MATCH

FOR 2.6GHz RF

RF

GND

GND

BIAS

0.015"

0.015"

0.062"

2

1

4

6

••

APPLICATION

RF MATCH

LO MATCH

IF MATCH

RF

LO

IF

L

C5

L4

C4

L1

C3

450MHz High Side

70MHz

6.5mm

12pF

10nH

8.2pF

270nH

15pF

900MHz

Low Side 140MHz

1.7mm

3.9pF

2.7nH

3.9pF

180nH

3.9pF

2.6GHz

360MHz

HIGH-PASS*

–

–

47nH

1.2pF

3.6GHz

450MHz

2.9mm

1pF

–

–

39nH

–

L1

DC1131A

BOARD

STACK-UP

(NELCO N4000-13)