Datasheet ADL5519 (Analog Devices) - 20

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ADL5519 Data Sheet USING THE ADL5519 BASIC CONNECTIONS VPSA CURRENT
The ADL5519 is specified for operation up to 10 GHz. As a result,
5pF 5pF
low impedance supply pins with adequate isolation between functions are essential. A power supply voltage between 3.3 V
FIRST 18.7kΩ 18.7kΩ GAIN
and 5.5 V should be applied to VPSA, VPSB, and VPSR. Power
STAGE INHA
supply decoupling capacitors of 100 pF and 0.1 μF should be
2kΩ A = 9dB
connected close to these power supply pins (see Figure 53).
INLA
The paddle of the LFCSP package is internally connected to
Gm OFFSET
044
STAGE COMP
8- COMR. For optimum thermal and electrical performance, the 0619 paddle should be soldered to a low impedance ground plane. Figure 52. Single-Channel Input Interface
INPUT SIGNAL COUPLING
Although the input can be reactively matched, in general this reactive matching is not necessary. An external 52.3 Ω shunt The ADL5519 inputs are differential but were characterized resistor (connected on the signal side of the input coupling capaci- and are generally used single ended. When using the ADL5519 tors, as shown in Figure 53) combines with the relatively high in single-ended mode, the INHA, INHB pins must be ac-coupled, input impedance to give an adequate broadband match of 50 Ω. and INLA, INLB must be ac-coupled to ground. Suggested coupling capacitors are 47 nF, ceramic 0402-style capacitors for The coupling time constant, 50 × CC/2, forms a high-pass corner input frequencies of 1 MHz to 10 GHz. The coupling capacitors with a 3 dB attenuation at fHP = 1/(2π × 50 × CC ), where C1 = should be mounted close to the INHA, INHB and INLA, INLB C2 = C3 = C4 = CC. Using the typical value of 47 nF, this high- pins. The coupling capacitor values can be increased to lower pass corner is ~68 kHz. In high frequency applications, fHP should the input stage high-pass cutoff frequency. be as large as possible to minimize the coupling of unwanted low frequency signals. In low frequency applications, a simple RC The high-pass corner is set by the input coupling capacitors and network forming a low-pass filter should be added at the input the internal 10 pF high-pass capacitor. The dc voltage on INHA, for similar reasons. This low-pass filter should generally be placed INHB and INLA, INLB is approximately one diode voltage at the generator side of the coupling capacitors, thereby lowering drop below the supply voltage. the required capacitance value for a given high-pass corner frequency. Rev. C | Page 20 of 39 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 USING THE ADL5519 BASIC CONNECTIONS INPUT SIGNAL COUPLING TEMPERATURE SENSOR INTERFACE VREF INTERFACE POWER-DOWN INTERFACE SETPOINT INTERFACE—VSTA, VSTB OUTPUT INTERFACE—OUTA, OUTB DIFFERENCE OUTPUT—OUTP, OUTN DESCRIPTION OF CHARACTERIZATION BASIS FOR ERROR CALCULATIONS DEVICE CALIBRATION ADJUSTING ACCURACY THROUGH CHOICE OF CALIBRATION POINTS TEMPERATURE COMPENSATION ADJUSTMENT ALTERING THE SLOPE CHANNEL ISOLATION OUTPUT FILTERING PACKAGE CONSIDERATIONS OPERATION ABOVE 8 GHz APPLICATIONS INFORMATION MEASUREMENT MODE CONTROLLER MODE AUTOMATIC GAIN CONTROL GAIN-STABLE TRANSMITTER/RECEIVER MEASURING VSWR EVALUATION BOARD CONFIGURATION OPTIONS EVALUATION BOARD SCHEMATIC AND ARTWORK OUTLINE DIMENSIONS ORDERING GUIDE