MC68HC908LB8CPE Freescale Semiconductor, MC68HC908LB8CPE Datasheet - Page 91

• Manufacturer Part Number: MC68HC908LB8CPE
• Description: IC MCU 8K FLASH 8MHZ 20DIP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68HC908LB8CPE

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Peripherals: LVR, POR, PWM
• Number Of I /o: 18
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 7x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 20-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Connectivity: -

Chapter 10
High Resolution PWM (HRP)
10.1 Introduction
The High Resolution PWM (HRP) provides two complementary outputs that can be used to control
half-bridge systems in, for example, light ballast applications. It uses a dithering control method to provide
a high step resolution (3.906 ns from an 8 MHz input clock). It also provides a shutdown input that can be
used to disable the outputs when a fault condition is detected in the application.
The pins supporting the HRP can be seen in
shown in
10.2 Features
Features of the HRP include:
10.3 Pin Name Conventions
The HRP shares two output pins with two port B input/output (I/O) pins and one input pin with one port C
input pin.
Freescale Semiconductor
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One complementary output pair for driving a half bridge
Dithering between two frequencies or duty cycles, for increased output resolution
Automatic calculation of second frequency or duty cycle for output dithering
Variable frequency mode with automatic 50% duty cycle calculation
Variable duty cycle mode
Programmable deadtime insertion
Shutdown input for fast disabling of outputs
Figure
10-3.
HRP Generic Pin Name
Table 10-1. Pin Naming Conventions
SHTDWN
MC68HC908LB8 Data Sheet, Rev. 1
TOP
BOT
Figure
10-1, and a block diagram of the HRP module is
PTC2/SHTDWN/IRQ
Full HRP Pin Name
PTB0/TOP
PTB1/BOT
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