LT5520 datasheet(5/12 Pages) LINER

5 / 12 page

LT5520

5520f

PI FU CTIO S

GND (Pins 1, 4, 9, 12, 13, 16): Internal Grounds. These

pins are used to improve isolation and are not intended as

DC or RF grounds for the IC. Connect these pins to low

impedance grounds for best performance.

IF+, IF– (Pins 2, 3): Differential IF Signal Inputs. A differ-

ential signal must be applied to these pins through DC

blocking capacitors. The pins must be connected to ground

with 100

Ω resistors (the grounds must each be capable of

sinking about 18mA). For best LO leakage performance,

these pins should be DC isolated from each other. An

impedance transformation is required to match the IF

input to the desired source impedance (typically 50

Ω or

Ω).

EN (Pin 5): Enable Pin. When the applied voltage is greater

than 3V, the IC is enabled. When the applied voltage is less

than 0.5V, the IC is disabled and the DC current drops to

about 1

µA.

VCC1 (Pin 6): Power Supply Pin for the Bias Circuits.

Typical current consumption is about 2mA. This pin

should be externally connected to VCC and have appropri-

ate RF bypass capacitors.

VCC2 (Pin 7): Power Supply Pin for the LO Buffer Circuits.

Typical current consumption is about 22mA. This pin

should have appropriate RF bypass capacitors as shown

in Figure 2. The 1000pF capacitor should be located as

close to the pins as possible.

VCC3 (Pin 8): Power Supply Pin for the Internal Mixer.

Typical current consumption is about 36mA. This pin

should be externally connected to VCC through an induc-

tor. A 39nH inductor is used in Figure 2, though the value

is not critical.

RF–, RF+ (Pins 10, 11): Differential RF Outputs. One pin

may be DC connected to a low impedance ground to realize

a 50

Ω single-ended output. No external matching compo-

nents are required. A DC voltage should not be applied

across these pins, as they are internally connected through

a transformer winding.

LO+, LO– (Pins 14, 15): Differential Local Oscillator In-

puts. The LT5520 works well with a single-ended source

driving the LO+ pin and the LO– pin connected to a low

impedance ground. No external matching components are

required. An internal resistor is connected across these

pins; therefore, a DC voltage should not be applied across

the inputs.

GROUND (Pin 17, Exposed Pad): DC and RF ground

return for the entire IC. This must be soldered to the

printed circuit board low impedance ground plane.

BLOCK DIAGRA

IF+

IF –

LO–

LO+

RF+

RF –

BIAS

VCC1

VCC2

VCC3

5520 BD

GND

DOUBLE-

BALANCED

MIXER

HIGH SPEED

LO BUFFER

BACKSIDE

GROUND

10pF

5pF

Ω

LT5520 Datasheet(PDF) 5 Page - Linear Technology

LT5520 Datasheet(HTML) 5 Page - Linear Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12

Datasheet Download

Link URL