ML13175-5P View Datasheet(PDF) - LANSDALE Semiconductor Inc.
Part Name
Description
View to exact match
ML13175-5P Datasheet PDF : 16 Pages
| |||
ML13175/ML13176
LANSDALE Semiconductor, Inc.
Pin Symbol
8
Xtale
9
Xtalb
10 Reg. Gnd
11
Enable
12
VCC
13 & 14 Out 1 and
Out 2
15
Out_Gnd
16
Imod
Xtalb
9
8
Xtale
PIN FUNCTION DESCRIPTIONS
Internal Equivalent
Circuit
Description/External
Circuit Requirements
VCC
8.0k
12k
4.0k
Crystal Oscillator Inputs
The internal reference oscillator is configured as a common
emitter Colpitts. It may be operated with either a fundamental
or overtone crystal depending on the carrier frequency and the
internal prescaler. Crystal oscillator circuits and specifications
of crystals are discussed in detail in the applications section.
With VCC = 3.0 Vdc, the voltage at Pin 8 is approximately 1.8
Vdc and at Pin 9 is approximately 2.3 Vdc. 500 to 1000 mVp–p
should be present at Pin 9. The Colpitts is biased at 200 µA;
additional drive may be acquired by increasing the bias to
approximately 500 µA. Use 6.2 k from Pin 8 to ground.
VCC
11
Enable
Subcon
8.0k
10
Reg. Gnd
VCC
12
VCC
Reg
5.0p
2.4k
Regulator Ground
An additional ground pin is provided to enhance the stability of
the system. Decoupling to the VCC (RF ground) is essential; it
should be done at the ground return for Pin 10.
Device Enable
The potential at Pin 11 is approximately 1.25 Vdc. When Pin 11
is open, the transmitter is disabled in a power down mode and
draws less than 1.0 µA ICC if the MOD at Pin 16 is also open
(i.e., it has no current driving it). To enable the transmitter a
current source of 10 µA to 90 µA is provided. Figures 3 and 4
show the relationship between ICC, VCC and Ireg. enable. Note
that ICC is flat at approximately 10 mA for Ireg. enable = 5.0 to
100 µA (Imod = 0).
Supply Voltage (VCC)
The operating supply voltage range is from 1.8 Vdc to 5.0 Vdc.
In the PCB layout, the VCC trace must be kept as wide as
possible to minimize inductive reactances along the trace; it is
best to have it completely fill around the surface mount
components and traces on the circuit side of the PCB.
13
Out 1
VCC
14
Out 2
16
Imod
15
Out_Gnd
Differential Output
The output is configured differentially to easily drive a loop
antenna. By using a transformer or balun, as shown in the
application schematic, the device may then drive an unbalanced
low impedance load. Figure 6 shows how much the Output
Power and Free–Running Oscillator Frequency change with
temperature at 3.0 Vdc; Imod = 2.0 mA.
Output Ground
This additional ground pin provides direct access for the output
ground to the circuit board VEE.
AM Modulation/Power Output Level
The DC voltage at this pin is 0.8 Vdc with the current source
active. An external resistor is chosen to provide a source
current of 1.0 to 3.0 mA, depending on the desired output power
level at a given VCC. Figure 23 shows the relationship of Power
Output to Modulation Current, Imod. At VCC = 3.0 Vdc, 3.5 dBm
power output can be acquired with about 35 mA ICC.
For FM modulation, Pin 16 is used to set the desired output
power level as described above.
For AM modulation, the modulation signal must ride on a
positive DC bias offset which sets a static (modulation off)
modulation current. External circuitry for various schemes is
further discussed in the Applications Information section.
Page 4 of 16
www.lansdale.com
Issue c
|
|
Share Link: 