Linear Technology 2429A Demo Manual

Description
Demonstration Circuit 2429A is a PLL/VCO Supply and
Reference Board that features the
noise and ultrahigh PSRR RF linear regulator. When
powered from any lab or wall wart supply, the DC2429A
produces four ultralow noise supplies and an ultralow
noise 100MHz reference that ensures PLL/VCO evaluation
meets data sheet performance.
Functionally, this circuit produces four separate ultralow
noise supplies from a single 6V to 20V supply input.
These supplies provide a fixed 3.3V/800mA supply, a fixed
5V/200mA supply, a variable voltage/200mA supply and a
fixed 3.3V/200mA supply that powers an onboard 100MHz
reference. The variable supply is ideal for powering external
OUTPUT SUPPLY
VARIABLE V, 200mA
BANANA JACK OR TURRET
DEFAULT VOLTAGE: 5V
JUMPER SELECTABLE (JP5)
OUTPUT SUPPLY
5V, 200mA
BANANA JACK OR TURRET
Arrow.com.
Downloaded from
VCOs, by providing a jumper option that selects between
LT 3042, an ultralow seven common VCO power supply voltages.
®
The onboard 100MHz reference is capable of providing a
signal which is clean enough to produce data sheet per-
formance from a PLL/VCO. The default reference output
mates directly with the LTC
LTC6948 demo board reference inputs. For evaluation of
PLL/VCOs with other references, the DC2429A can be
modified to accommodate different onboard reference
frequencies, signal types and package footprints.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2429A
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
INPUT SUPPLY
6V TO 29V, MAX 1.4A
WALL WART, BANANA JACK OR TURRET
FOR BEST PERFORMANCE, USE SHIELDED CABLES
REF+ OUTPUT
100MHz, CMOS
MALE SMA
Figure 1. DC2429A Connections
DEMO MANUAL DC2429A
PLL/VCO Supply and
Reference Board
6945, LTC6946, LTC6947 and
®
SUPPLY OPTIONS
ON/OFF CONTROL VIA JP1, JP2, JP3, JP4
REFERENCE OPTIONS
SUPPORTS A VARIETY OF FOOTPRINTS (U7),
FREQUENCIES AND SE/DIFF OUTPUT TYPES
LT3042
OUTPUT SUPPLY
3.3V, 800mA
BANANA JACK OR TURRET
dc2429af
1