Output Matching Network

The RF output is taken from pin 8 and is not at 50

Ω

impedance, so a matching network is required. The

matching network consists of a shunt capacitor at the

collector (C3), a DC-blocking capacitor (C7), a 50

Ω

transmission line (T2), and a shunt capacitor (C2).

Evaluating the MAX2602

Without the Biasing Diode

To evaluate the MAX2602 without the biasing diode

(functionally equivalent to the MAX2601), the 0

Ω resis-

tor (R3) must be removed, and the 430

Ω resistor (R1)

must be replaced by a 0

Ω resistor (a short) (Figure 2).

Now an external bias voltage may be connected to the

nected, so the EV kit will not work without an external

biasing voltage. To avoid damage to the MAX2602 in

ranging from 0V to 0.85V are typically used.

_____________Layout Considerations

For best results, use the MAX2602 EV kit as a layout

guide. The most critical connection is the emitter-

ground contact on the MAX2602’s bottom side. On the

EV kit, this contact is made through a large (0.1 inch,

2.5mm diameter) plated through-hole in the board,

located directly under the part. This contact must be

soldered directly to a large ground plane, as it is the

principal path for heat dissipation, as well as the low-

inductance emitter ground. The MAX2602 EV kit uses

its ground plane as the heatsink.

MAX2602 Evaluation Kit

_______________________________________________________________________________________

3

R1

0

Ω

T1

T2

L2

18.5nH

C9

0.1

µF

C1

2pF

IN

C5

1000pF

C10

0.1

µF

C8

1000pF

C11

1000pF

C12

1000pF

C6

1000pF

C7

1000pF

L1

100nH

R2

24

Ω

C4

12pF

1

3

8

2, 6, 7

BACK-SIDE SLUG

4

5

C2

2pF

OUT

C3

10pF

U1

Figure 2. MAX2602 EV Kit Schematic Without the Bias Diode