Rainbow Electronics MAX2055 - Manual (Page 9)

MAX2055
Digitally Controlled, Variable-Gain, Differential
ADC Driver/Amplifier
_______________________________________________________________________________________ 9
Pin Description
PIN NAME FUNCTION
1, 9 V CC
Power Supply. Bypass to GND with capacitors as close to the pin as possible as shown in the typical
application circuits (Figures 1 and 2).
2 RF_IN
Signal Input. Internally matched to 50 Ω over the operating frequency. See the typical application
circuit for recommended component values.
3, 18, 20, EP GND
Ground. Use low-inductance layout techniques on the PC board. Solder the exposed paddle to the
board ground plane.
4–8 B4–B0 Attenuation Control Bits. Digital input for attenuation control. See Table 3 for attenuation setting.
10 RF_OUT-
Inverted Differential Signal Output. Requires an external pullup choke inductor (120mA typical
current) to V
CC along with a DC-blocking capacitor; see Figures 1 and 2.
11 RF_OUT+
Noninverted Differential Signal Output. Requires an external pullup choke inductor (120mA typical
current) to V
CC along with a DC-blocking capacitor; see Figures 1 and 2.
12 I BIAS Amplifier Bias Input. See Figures 1 and 2 for detailed connection.
13 C BP Bypass Capacitor. See Figures 1 and 2 for detailed connection.
14 L
E
Amplifier DC Ground. Requires choke inductor that can handle supply current. DC resistance of
inductor should be less than 0.2
Ω.
15 AMP IN Amplifier Input. Requires DC-coupling to allow biasing.
16 C
C
Compensation Capacitor. Requires connection to AMP
IN
(pin 15) for stability.
17 I
SET
Connect R1 from I
SET
to GND (see Table 1 or Table 2 for values).
19 ATTN OUT Attenuator Output. Requires external DC-blocking capacitor.
COMPONENT VALUE SIZE
C1, C3–C6, C8, C9, C10, C12 1nF 0603
C2, C11 100pF 0603
L1, L3 330nH 0603
L2 100nH 0603
L4, L5 680nH 1008
R1 1.13k Ω 0603
R7 10 Ω 0603
T1, T2 1:1 —
Table 1. Suggested Components of
Circuit of Figure 1
COMPONENT VALUE SIZE
C1, C3, C4, C5, C7–C10, C12 1nF 0603
C2, C11 100pF 0603
L1, L2, L3 330nH 0603
L4, L5 680nH 1008
R1 909 Ω 0603
R7 10 Ω 0603
T2 1:1 —
Table 2. Suggested Components of
Circuit of Figure 2