BUCK 9 CLICK
PID: MIKROE-3057
Weight: 26 g
Buck 9 Click is a high-efficiency step-down converter which provides a highly regulated
output voltage derived from the connected power source, rated from 4V to 36V. The
regulated output voltage can be selected between two values: 3.3V and 5V. These are
voltage values that are most commonly used in many embedded designs. Buck 9 click
is based around an integrated DC-DC converter, labeled as MP9943. Due to its high
efficiency, MP9943 allows the Click board™ to easily deliver up to 3A of current. The
MP9943 is very reliable, offering over-current and under-voltage protection, as well as a
thermal shutdown.
Buck 9 click is supported by a mikroSDK compliant library, which includes functions that
simplify software development. This Click board™ comes as a fully tested product,
ready to be used on a system equipped with the mikroBUS™ socket.
Besides its protection features, MP9943 is also equipped with a soft-start function, and
a sync option, making this Click board™ a very useful solution for the development of
applications that require regulated 3.3V or 5V power supply. It can be used for a range
of different applications: distributed power supply units (PSUs), wall transformer
regulators, single board systems, general points of load, and similar applications that
require regulated 3.3V or 5V power supply.
HOW DOES IT WORK?
Buck 9 click is equipped with the MP9943, a synchronous step-down converter,
from Monolithic Power Systems (MPS). This is an advanced integrated step-down
converter, which requires a minimum number of external components, readily available
on the market. It utilizes a peak-current-mode control architecture, which ensures an
exceptional transient response and feedback loop stabilization. THE MP9943 buck
converter features over
current, under-voltage, and thermal protection, making Buck 9 click a robust and reliable
power supply solution.
The output voltage is determined by the feedback voltage on the FB pin. Buck 9 click is
equipped with a voltage divider and an SMD jumper, labeled as VOUT. This jumper can
be used to connect one of two available voltage divider resistors, allowing the output to
be set to either 3.3V or 5V. These two voltages are the most commonly used in
embedded development.
The over-current protection is based on cycle-by-cycle limiting of the inductor current. If
the output voltage starts to drop during the current limiting interval, causing the FB
voltage to drop under 84% of the internal reference, the device enters the hiccup mode,
shutting down the output. After a fixed period, the device will try to re-enable the output.
If the short-circuit condition still exists, it will shut down the output again, repeating the
whole process, until the short-circuit condition disappears. The hiccup mode greatly
reduces the short-circuit current, protecting the device when the output is shorted to
ground.
Thanks to its ability to work with the high duty cycle of the internal switching PWM
signal, the MP9943 requires the input voltage to be only about 0.7V above the output
voltage, in order to maintain the regulation. However, if the input voltage drops under
3.3V, the device will not be able to operate properly. Therefore, the under-voltage
protection shuts down the device, as a protection measure. The under-voltage
protection is disabled once the input voltage exceeds 3.5V. This small hysteresis of
0.2V prevents erratic behavior in border-cases.
The MP9943 has some other advanced features, including synchronization with the
external clock in the range from 200kHz up to 2.2MHz over the EN/SYNC pin. The
same pin is also used as a Chip Enable for the device. The EN/SYNC pin is routed to
the mikroBUS™ PWM pin, allowing to both synchronize and enable the MP9943 by the
host MCU. The MP9943 operates at high (fixed) switching frequency of 410 kHz, which
allows a good compromise between the efficiency and the size of the external
components.
As mentioned before, the voltage of the power supply at the input terminal should stay
within the range between 4V and 36V. However, if the output voltage is set to 5V, the
voltage at the input should be approximately 5.7V to 6V at least, in order to provide a
good regulation at the output.
SPECIFICATIONS
Type
Buck
Applications
A very reliable regulated power supply for a range of different applications:
distributed power supply units (PSUs), wall transformer regulators, single
board systems, general points of load, and similar applications that require
regulated 3.3V or 5V power supply.
On-board
modules
MP9943, a synchronous step-down converter, from Monolithic Power
Systems (MPS)
Key Features
Low power dissipation due to high efficiency, over-current, under-voltage,
and thermal protection, selection between two most commonly used voltage
values, etc.
Interface
GPIO
Input Voltage
3.3V
Click board
size
M (42.9 x 25.4 mm)
ONBOARD SETTINGS AND INDICATORS
Label
Name
Default
PWR
PWR
-
Power LED indicator
VIN
-
External PSU input connector
VOUT
-
Output connector
VOUT SEL
3.3V
VIN
VOUT
JP1
Description
Output voltage selection: left position 3.3V, right position 5V
BUCK 9 CLICK ELECTRICAL SPECIFICATIONS
Description
Min
Typ
Max
Unit
Input Voltage
VOUT + 0.7
-
36
V
3.3
-
3
V
0
-
3
A
Output voltage (VOUT)
Output current (continuous)
SOFTWARE SUPPORT
We provide a library for the Buck 9 Click on our LibStock page, as well as a demo
application (example), developed using MikroElektronika compilers. The demo can run
on all the main MikroElektronika development boards.
Library Description
Library carries functions related to GPIO pins control of the Buck 9 click board. The
library includes function for enable or disable device.
Key functions:
void buck9_deviceEnable(uint8_t state) - Function for enable or disable device.
Examples description
The application is composed of the three sections :
System Initialization - Sets PWM pin as OUTPUT.
Application Initialization - Initialization driver init and disable device.
Application Task - (code snippet) - Enable and Disable device every 5000 ms.
Application Task - Predefined characters are inputed from the serial port. Depending on
the character sent the signal frequency, waveform or amplitude will be changed.
void applicationTask()
{
buck9_deviceEnable(_BUCK9_DEVICE_ENABLE);
Delay_ms( 5000 );
buck9_deviceEnable(_BUCK9_DEVICE_DISABLE);
Delay_ms( 5000 );
}
The full application code, and ready to use projects can be found on our LibStock page.
Other mikroE Libraries used in the example:
GPIO
Additional notes and informations
Depending on the development board you are using, you may need USB UART
click, USB UART 2 click or RS232 click to connect to your PC, for development systems
with no UART to USB interface available on the board. The terminal available in all
MikroElektronika compilers, or any other terminal application of your choice, can be
used to read the message.
MIKROSDK
This click board is supported with mikroSDK - MikroElektronika Software Development
Kit. To ensure proper operation of mikroSDK compliant click board demo applications,
mikroSDK should be downloaded from the LibStock and installed for the compiler you
are using.
For more information about mikroSDK, visit the official page.
https://www.mikroe.com/buck‐9‐click/3‐5‐19