MAX1472_10 Datasheet, PDF (8/9 Pages) Maxim Integrated Products – 300MHz-to-450MHz Low-Power, Crystal-Based ASK Transmitter

300MHz-to-450MHz Low-Power,
Crystal-Based ASK Transmitter
Layout Considerations
A properly designed PC board is an essential part of
any RF/microwave circuit. On the PA output, use con-
trolled-impedance lines and keep them as short as
possible to minimize losses and radiation. At high fre-
quencies, trace lengths that are on the order of λ/10 or
longer can act as antennas.
Keeping the traces short also reduces parasitic induc-
tance. Generally, 1in of PC board trace adds about
20nH of parasitic inductance. The parasitic inductance
can have a dramatic effect on the effective inductance.
For example, a 0.5in trace connecting a 100nH induc-
tor adds an extra 10nH of inductance, or 10%.
To reduce the parasitic inductance, use wider traces
and a solid ground or power plane below the signal
traces. Using a solid ground plane can reduce the par-
asitic inductance from approximately 20nH/in to 7nH/in.
Also, use low-inductance connections to ground on all
GND pins, and place decoupling capacitors close to all
V_DD connections.
PROCESS: CMOS
Chip Information
Functional Diagram
DATA
ENABLE
AND
GATE
MAX1472
PA
XTAL1
XTAL2
LOCK DETECT
32 x PLL
CRYSTAL-
OSCILLATOR
DRIVER
V_DD
PAOUT
PAGND
GND
Package Information
For the latest package outline information and land patterns,
go to www.maxim-ic.com/packages. Note that a “+”, “#”, or
“-” in the package code indicates RoHS status only. Package
drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
PACKAGE
TYPE
8 SOT23
PACKAGE
CODE
K8SN+1
LAND
OUTLINE NO. _{PATTERN NO.}
21-0078
90-0176
8 _______________________________________________________________________________________