Datasheet AD8310 (Analog Devices) - 22

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AD8310 Table 6. Evaluation Board Setup Options Component Function Default Condition
TP1, TP2 Supply and Ground Vector Pins. Not applicable SW1 Device Enable. When in Position A, the ENBL pin is connected to +VS, and the AD8310 is in normal SW1 = A operating mode. When in Position B, the ENBL pin is connected to ground, putting the device into sleep mode. R1/R4 SMA Connector Grounds. Connects common of INHI and INLO SMA connectors to ground. They R1 = R4 = 0 Ω can be used to isolate the generator ground from the evaluation board ground. See Figure 28. C1, C2, R3 Input Interface. R3 (52.3 Ω) combines with the AD8310’s 1 kΩ input impedance to give an overall R3 = 52.3 Ω, broadband input impedance of 50 Ω. C1, C2, and the AD8310’s input impedance combine to set a C1 = C2 = 0.01 μF high-pass input corner of 32 kHz. Alternatively, R3, C1, and C2 can be replaced by an inductor and matching capacitors to form an input matching network. See the Input Matching section for details. C3 RSSI (Video) Bandwidth Adjust. The addition of C3 (farads) lowers the RSSI bandwidth of the C3 = open AD8310’s output according to the following equation: CFILT = 1/(2π × 3 kΩ Video Bandwidth) − 2.1 pF C4, C5, R5 Supply Decoupling. The normal supply decoupling of 0.01 μF (C4) can be augmented by a larger C4 = 0.01 μF, capacitor in C5. An inductor or small resistor can be placed in R5 for additional decoupling. C5 = open, R5 = 0 Ω R6 Output Source Impedance. In cable-driving applications, a resistor (typically 50 Ω or 75 Ω) can be R6 = 0 Ω placed in R6 to give the circuit a back-terminated output impedance. W1, W2, C6, R7 Output Loading. Resistors and capacitors can be placed in C6 and R7 to load-test VOUT. Jumper W1 C6 = R7 = open, and Jumper W2 are used to connect or disconnect the loads. W1 = W2 = installed C7 Offset Compensation Loop. A capacitor in C7 reduces the corner frequency of the offset control C7 = open loop in low frequency applications. Rev. F | Page 21 of 24 Document Outline FEATURES APPLICATIONS FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION PROGRESSIVE COMPRESSION SLOPE AND INTERCEPT CALIBRATION OFFSET CONTROL PRODUCT OVERVIEW ENABLE INTERFACE INPUT INTERFACE OFFSET INTERFACE OUTPUT INTERFACE USING THE AD8310 BASIC CONNECTIONS TRANSFER FUNCTION IN TERMS OF SLOPE AND INTERCEPT dBV vs. dBm INPUT MATCHING NARROW-BAND MATCHING GENERAL MATCHING PROCEDURE Step 1: Tune Out CIN Step 2: Calculate CO and LO Step 3: Split CO into Two Parts Step 4: Calculate LM SLOPE AND INTERCEPT ADJUSTMENTS INCREASING THE SLOPE TO A FIXED VALUE OUTPUT FILTERING LOWERING THE HIGH-PASS CORNER FREQUENCY OF THE OFFSET COMPENSATION LOOP APPLICATIONS INFORMATION CABLE-DRIVING DC-COUPLED INPUT EVALUATION BOARD DIE INFORMATION OUTLINE DIMENSIONS ORDERING GUIDE