LTC6948-4 View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
LTC6948-4
Linear Technology
'LTC6948-4' PDF : 36 Pages View PDF
LTC6948
Pin Functions
TB (Pin 16): VCO Bypass. This output has a 2k resistance
and must be bypassed with a 2.2µF ceramic capacitor to
GND. It is normally connected to CMA, CMB, and CMC with
a short trace. Do not couple this pin to any other signal.
CMA, CMB, CMC (Pins 18, 19, 20): VCO Bias Inputs. These
inputs are normally connected to TB with a short trace
and bypassed with a 2.2µF ceramic capacitor to GND. Do
not couple these pins to any other signal. For best phase
noise performance, DO NOT place a trace between these
pads underneath the package.
BVCO (Pin 22): VCO Bypass Pin. This output must be
bypassed with a 1µF ceramic capacitor to GND. Do not
couple this pin to any other signal.
VVCO+ (Pin 23): 4.75V to 5.25V Positive Supply Pin for
VCO Circuitry. This pin should be bypassed directly to the
ground plane using a 0.01µF ceramic capacitor as close
to the pin as possible.
GND (24): Negative Power Supply (Ground). This pin is
attached directly to the die attach paddle (DAP) and should
be tied directly to the ground plane.
VCP+ (Pin 25): 4V to 5.25V Positive Supply Pin for Charge
Pump Circuitry. This pin should be bypassed directly to
the ground plane using a 0.1µF ceramic capacitor as close
to the pin as possible.
CP (Pin 26): Charge Pump Output. This bidirectional current
output is normally connected to the external loop filter.
See the Applications Information section for more details.
VREF+ (Pin 27): 3.15V to 3.45V Positive Supply Pin for
Reference Input Circuitry. This pin should be bypassed
directly to the ground plane using a 0.1µF ceramic capaci-
tor as close to the pin as possible.
6948f
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For more information www.linear.com/LTC6948
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