Datasheet

www.microchip.com/lighting LED Lighting Solutions Design Guide 7
LED Lighting Solutions
Adding Intelligence – PIC10F Solutions
LED lighting applications can benefit from the intelligence of
a MCU. The MCU can be used for a variety of tasks, including
the user interface, communication, battery status monitoring
and temperature measurement.
The addition of a MCU to a design does not have to be
complicated, space consuming, or expensive. Microchip offers the
PIC10F family of MCUs with devices that have 6 pins in a space
saving SOT-23 or 2 x 3 mm DFN style package. The oscillator and
reset circuitry are inside the device. Connect power, ground, and
you get four I/O pins that can be programmed to do anything you
want. It’s as simple as that.
The PIC10F pins can be used as analog or digital pins. Two
devices in the PIC10F family have analog comparator modules.
Two PIC10F devices are available with an 8-bit analog to digital
converter (ADC). There are only 33 assembly instructions to learn
in order to write code for the PIC10F. There are also C compilers
are available for the PIC10F family, if you prefer to write in a
high-level language.
PIC10F 6-Pin Microcontroller Family
Device
Flash Program Memory
Words
Data
RAM Bytes
8-Bit
Timer
Analog Comparator
Module
8-bit
ADC Module
PIC10F200 256 16 Yes – –
PIC10F202 512 24 Yes – –
PIC10F204 256 16 Yes Yes –
PIC10F206 512 24 Yes Yes –
PIC10F220 256 16 Yes – Yes
PIC10F222 512 24 Yes – Yes
Provide Simple Dimming Control
One application for a MCU in LED lighting is brightness
control. A power LED can be dimmed by reducing the drive
current. However, this is not the most efficient way to
control the brightness of a LED. A power LED provides the
best efficiency at the maximum rated drive current. Better
efficiency can be obtained by turning the LED on and off
using a low frequency PWM signal. The PWM signal is
connected to the enable input of the SMPS control IC. The
LED is always driven at the maximum current level when it is
on.
The MCP1650 Multiple White LED Demo Board and the
MCP1650 3W White LED Demo Board both take advantage
of the 6-pin PIC10F206 MCU (see pages 5-7 for more
information). The PIC10F206 device provides the user button
interface and generates the PWM control signal for the
SMPS IC. The PIC10F206 has an internal oscillator and reset
circuit, so no external circuitry is required. The PIC10F206
device could also be used to linearize the brightness control
or monitor battery status in these applications.
Shown approximate size.
Package Comparison
SOT-23 vs. MSOP and SOIC
6-SOT (OT)
3 x 3 mm
PIC10F2XX
8-MSOP (MS)
3 x 5 mm
8-SOIC (SN)
5 x 6 mm
8-TDFN
(MC/MNY)
2 x 3 mm