DatasheetQ Logo
Electronic component search and free download site.
Transistors,MosFET ,Diode,Integrated circuits

ML13176-5P View Datasheet(PDF) - LANSDALE Semiconductor Inc.

Part Name
Description
Manufacturer
ML13176-5P
LANSDALE
LANSDALE Semiconductor Inc. LANSDALE
ML13176-5P Datasheet PDF : 16 Pages
1 2 3 4 5 6 7 8 9 10 Next Last
ML13175/ML13176
LANSDALE Semiconductor, Inc.
Figure 9. Change in Oscillator Frequency
versus Oscillator Control Current
20
10
VCC = 3.0 Vdc
0
Imod = 2.0 mA
TA = 25 °C
fosc (ICont @ 0) 320 MHz
–10
– 20
– 30
– 40
–100
0
100 200 300 400 500 600
ICont, OSCILLATOR CONTROL CURRENT (µA)
Figure 10. Change in Oscillator Frequency
versus Oscillator Control Current
20
10
VCC = 3.0 Vdc
0
Imod = 2.0 mA
TA = 25 °C
fosc (ICont @ 0) 450 MHz
–10
– 20
– 30
– 40
–100 0
100 200 300 400 500 600
ICont, OSCILLATOR CONTROL CURRENT (µA)
Legacy Applications Information
APPLICATIONS INFORMATION
EVALUATION PC BOARD
The evaluation PCB, shown in Figures 26 and 27, is very versatile
and is intended to be used across the entire useful frequency range
of this device. The center section of the board provides an area for
attaching all SMT components to the component ground side of the
PCB (see Figures 28 and 29). Additionally, the peripheral area sur-
rounding the RF core provides pads to add supporting and interface
circuitry as a particular application requires. This evaluation board
will be discussed and referenced in this section.
CURRENT CONTROLLED OSCILLATOR (Pins 1 to 4)
It is critical to keep the interconnect leads from the CCO (Pins 1
and 4) to the external inductor symmetrical and equal in length.
With a minimum inductor, the maximum free running frequency
is greater than 1.0 GHz. Since this inductor will be small, it may
be either a microstrip inductor, an air wound inductor or a tune-
able RF coil. An air wound inductor may be tuned by spreading
the windings, whereas tunable RF coils are tuned by adjusting
the position of an aluminum core in a threaded coilform. As the
aluminum core coupling to the windings is increased, the induc-
tance is decreased. The temperature coefficient using an alu-
minum core is better than a ferrite core. The UniCoil™ induc-
tors made by Coilcraft may be obtained with aluminum cores
(Part No. 51–129–169).
GROUND (Pins 5, 10 and 15)
GROUND RETURNS: It is best to take the grounds to a back-
side ground plane via plated through holes or eyelets at the pins.
The application PCB layout implements this technique. Note
that the grounds are located at or less than 100 mils from the
device pins.
DECOUPLING: Decoupling each ground pin to VCC isolates
each section of the device by reducing interaction between sec-
tions and by localizing circulating currents.
LOOP CHARACTERISTICS (Pins 6 and 7)
Figure 11 is the component block diagram of the ML1317x PLL
system where the loop characteristics are described by the gain
constants. Access to individual components of this PLL system
is limited, inasmuch as the loop is only pinned out at the phase
detector output and the frequency control input for the CCO.
However, this allows for characterization of the gain constants
of these loop components. The gain constants Kp, Ko and Kn
are well defined in the ML13175 and ML13176.
PHASE DETECTOR (Pin 7)
With the loop in lock, the difference frequency output of the
phase detector is DC voltage that is a function of the phase dif-
ference. The sinusoidal type detector used in the IC has the fol-
lowing transfer characteristic:
le = A Sin θe
The gain factor of the phase detector, Kp (with the loop in lock)
is specified as the ratio of DC output current, le to phase error,
θe:
Kp = le/θe (Amps/radians)
Kp = A Sin θe/θe
Sin θe ~ θe for θe 0.2 radians;
thus Kp = A (Amps/radians)
Figures 7 and 8 show that the detector DC current is approxi-
mately 30 µA where the loop loses lock at θe = ±π/2 radians;
therefore Kp is 30 µA/radians.
CURRENT CONTROLLED OSCILLATOR, CCO (Pin 6)
Figures 9 and 10 show the non–linear change in frequency of
the oscillator over an extended range of control current for 320
and 450 MHz applications. Ko ranges from approximately
6.3x105 rad/sec/µA or 100 kHz/µA (Figure 9) to 8.8x105
rad/sec/µA or 140 kHz/µA (Figure 10) over a relatively linear
response of control current (0 to 100 µA). The oscillator gain
factor depends on the operating range of the control current
(i.e., the slope is not constant). Included in the CCO gain factor
is the internal amplifier which can sink and source at least
30µA of input current from the phase detector. The internal cir-
cuitry at Pin 6 limits the CCO control current to 50 µA of
source capability while its sink capability exceeds 200 µA as
shown in Figures 9 and 10. Further information to follow shows
how to use the full capabilities of the CCO by addition of an
external loop amplifier and filter (see Figure 15). This addition-
al circuitry yields at Ko = 0.145 MHz/µA or 9.1x105
rad/sec/µA.
Page 6 of 16
www.lansdale.com
Issue c
 

Share Link: 

datasheetq.com  [ Privacy Policy ]Request Datasheet ] [ Contact Us ]