Volansys Technologies pvt ltd MKW41Z ユーザーズマニュアル
VT-MKW41Z Module Datasheet
Rev 0.4
Confidential
Copyright © 2017 Volansys
Volansys Technologies
Page | 15
5.2 Antenna
The MKW41z Module includes an integrated chip antenna. The MKW41Z Module should be mounted with
the PCB chip antenna overhanging the edge of the host board. To further improve performance, a ground
plane may be placed on the host board under the module up to the antenna keep out area. The installation
of an uninterrupted ground plane on a layer directly beneath the module will also allow you to run traces
under this layer.
the PCB chip antenna overhanging the edge of the host board. To further improve performance, a ground
plane may be placed on the host board under the module up to the antenna keep out area. The installation
of an uninterrupted ground plane on a layer directly beneath the module will also allow you to run traces
under this layer.
The chip antenna is compact and highly efficient. To maximize range, an adequate ground plane must be
provided on the host PCB. Correctly positioned, the ground plane on the host PCB will contribute
significantly to the antenna performance; it should not be directly under the chip antenna. The position
of the module on the host board and overall design of the product enclosure contribute to antenna
performance. Poor design affects radiation patterns and can result in reflection, diffraction and/or
scattering of the transmitted signal.
provided on the host PCB. Correctly positioned, the ground plane on the host PCB will contribute
significantly to the antenna performance; it should not be directly under the chip antenna. The position
of the module on the host board and overall design of the product enclosure contribute to antenna
performance. Poor design affects radiation patterns and can result in reflection, diffraction and/or
scattering of the transmitted signal.
A few design guidelines to help ensure antenna performance:
• Never place the ground plane or route copper traces directly underneath the antenna portion of the
module
• Never place the antenna close to metallic objects
• In the overall design, ensure that wiring and other components are not placed near the antenna
• Do not place the antenna in a metallic or metalized plastic enclosure
• Keep plastic enclosures 1cm or more away from the antenna in any direction
• Never place the ground plane or route copper traces directly underneath the antenna portion of the
module
• Never place the antenna close to metallic objects
• In the overall design, ensure that wiring and other components are not placed near the antenna
• Do not place the antenna in a metallic or metalized plastic enclosure
• Keep plastic enclosures 1cm or more away from the antenna in any direction
5.3 Module Reset
Pin 15 is used as an external reset. The reset pin only contains an active pull down device. This pin can be
used for other functions, such as GPIO, by setting the RESET_PIN_CFG option bit of the FTFA_FPORT
register to 0. This bit is retained through system resets and low power modes. When the RESET pin is
disabled and configured as a GPIO output, it operates as a pseudo open drain output.
used for other functions, such as GPIO, by setting the RESET_PIN_CFG option bit of the FTFA_FPORT
register to 0. This bit is retained through system resets and low power modes. When the RESET pin is
disabled and configured as a GPIO output, it operates as a pseudo open drain output.
5.4 Clock
The MKW41z Module requires two clock system.
On module 32MHz crystal used for RF reference oscillator. The clock is used by the RF, analog and digital
section interfaces. It can be used also by the MCU core and as a clock source for some internal peripherals.
For normal run modes, an internal oscillator can provide the low frequency clock. However, to make full
use of reduced power modes an external crystal must be present.
section interfaces. It can be used also by the MCU core and as a clock source for some internal peripherals.
For normal run modes, an internal oscillator can provide the low frequency clock. However, to make full
use of reduced power modes an external crystal must be present.
The MKW41z Module supports external 32/32.768KHz crystal. This is used as the clock for the RTC and
the deep-sleep clock.
the deep-sleep clock.
Symbol
Parameter
Typ.
Max.
Unit
F
NOM_LFXO
Crystal frequency
32/32.768
-
KHz
F
TOL_LFXO_BLE
Frequency tolerance, BLE applications
±20
±250
ppm
C
L_LFXO
Load Capacitance
7
12.5
pF
Note: External capacitors are not required for 32KHz crystal.