PIC16C770-I/SO Microchip Technology, PIC16C770-I/SO Datasheet - Page 65

• Manufacturer Part Number: PIC16C770-I/SO
• Description: IC MCU OTP 2KX14 A/D PWM 20-SOIC
• Manufacturer: Microchip Technology
• Series: PIC® 16Cr

Specifications of PIC16C770-I/SO

• Core Size: 8-Bit
• Program Memory Size: 3.5KB (2K x 14)
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Core Processor: PIC
• Speed: 20MHz
• Connectivity: I²C, SPI
• Number Of I /o: 15
• Program Memory Type: OTP
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 6x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 20-SOIC (7.5mm Width)
• Controller Family/series: PIC16C
• No. Of I/o's: 16
• Ram Memory Size: 256Byte
• Cpu Speed: 20MHz
• No. Of Timers: 3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: ISPICR1 - ADAPTER IN-CIRCUIT PROGRAMMINGAC164028 - MODULE SKT PROMATEII 20SOIC/DIP309-1013 - ADAPTER 20-SOIC TO 20-DIP309-1012 - ADAPTER 20-SOIC TO 20-DIP
• Eeprom Size: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: PIC16C770I/SO

Note that in the Full-Bridge Output mode, the ECCP
module does not provide any deadband delay. In gen-
eral, since only one output is modulated at a time,
deadband delay is not required. However, there is a sit-
uation where a deadband delay might be required. This
situation occurs when all of the following conditions are
true:
1.
2.
Figure 8-11 shows an example, where the PWM direc-
tion changes from forward to reverse at a near 100%
duty cycle. At time t1, the output P1A and P1D become
inactive, while output P1C becomes active. In this
FIGURE 8-11: PWM DIRECTION CHANGE AT NEAR 100% DUTY CYCLE
2002 Microchip Technology Inc.
The direction of the PWM output changes when
the duty cycle of the output is at or near 100%.
The turn off time of the power switch, including
the power device and driver circuit, is greater
than turn on time.
Note 1: All signals are shown as active high.
External Switch C
External Switch D
2: t
3: t
Potential
Shoot Through
Current
on
off
is the turn on delay of power switch and driver.
is the turn off delay of power switch and driver.
P1C
P1D
P1A 1 0
P1B
1
0
1
0
1
0
1
0
1
0
1
0
(PWM)
FORWARD PERIOD
example, since the turn off time of the power devices is
longer than the turn on time, a shoot-through current
flows through the power devices, QB and QD, for the
duration of t= t
to power devices, QC and QB, for PWM direction
change from reverse to forward.
If changing PWM direction at high duty cycle is required
for the user’s application, one of the following require-
ments must be met:
1.
2.
PIC16C717/770/771
Avoid changing PWM output direction at or near
100% duty cycle.
Use switch drivers that compensate for the slow
turn off of the power devices. The total turn off
time (t
must be less than the turn on time (t
t
1
off
) of the power device and the driver
(PWM)
off
-t
t
on
on
. The same phenomenon will occur
REVERSE PERIOD
t
t = t
off
off
- t
on
DS41120B-page 63
on
).