Datasheet LT5570 (Analog Devices) - 8

LT5570
PIN FUNCTIONS VCC (Pin 1):
Power Supply Pin for the Bias Circuits. Typi-
OUT (Pin 6):
DC Output Pin. The output impedance is cal current consumption is 26.5mA. This pin should be mainly determined by an internal 100Ω series resistance externally bypassed with 1nF and 1μF chip capacitors. that provides output circuit protection if the output is shorted to ground.
IN+, IN– (Pins 2, 4):
Differential Input Signal Pins. These pins are preferably driven with a differential signal for
DNC (Pins 7, 8):
Do Not Connect. Don’t connect any optimum performance. The pins are internally biased to external component at these pins. Avoid a long wire or VCC – 1.224V and should be DC blocked externally. The metal trace on the PCB. differential impedance is about 200Ω.
EN (Pin 9):
Enable Pin. An applied voltage above 2V will
DEC (Pin 3):
Input Common Mode Decoupling Pin. This activate the bias for the IC. For an applied voltage below pin is internally biased to VCC – 1.224V. The input imped- 1V, the circuits will be shut down (disabled) with a corre- ance is about 1.75KΩ in parallel with a 10pF internal sponding reduction in power supply current. If the enable shunt capacitor to ground. The impedance between DEC function is not required, then this pin should be con- and IN+ (or IN–) is about 100Ω. The pin can be connected nected to VCC. Typical enable pin input current is 68μA for to the center tap of an external balun. An ac-decoupling EN = 5V. Note that at no time should the Enable pin voltage capacitor may be connected to ground to maintain the IC be allowed to exceed VCC by more than 0.3V. performance if necessary.
FLTR (Pin 10):
Connection for an External Filtering Capaci-
GND (Pin 5, Exposed Pad):
Circuit Ground Return for tor C1. A minimum 22nF capacitor is required for stable the Entire IC. This must be soldered to the printed circuit ac average power measurement. This capacitor should be board ground plane. connected between Pin 10 and VCC. 5570f 8