ZLF645E0H2864G00TR Maxim Integrated, ZLF645E0H2864G00TR Datasheet - Page 92

• Manufacturer Part Number: ZLF645E0H2864G00TR
• Description: 8-bit Microcontrollers - MCU Crimzon Flash Infrared MCU
• Manufacturer: Maxim Integrated

Specifications of ZLF645E0H2864G00TR

• Core: Z8
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 8 MHz
• Program Memory Size: 64 KB
• Data Ram Size: 1 KB
• Operating Supply Voltage: 2 V to 3.6 V
• Package / Case: SSOP-28
• Mounting Style: SMD/SMT
• Interface Type: UART
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Number Of Programmable I/os: 5
• Number Of Timers: 2 x 8 bit, 1 x 16 bit
• Processor Series: ZLF645
• Program Memory Type: Flash

Infrared Learning Amplifier
19-4572; Rev 0; 4/09
The ZLF645 MCU’s infrared learning amplifier allows you to detect and decode infrared
transmissions directly from the output of the receiving diode without the need for external
circuitry (see
An IR diode can be connected to the IR amplifier as displayed in
amplifier is enabled and an input current is detected on Port 3, Pin 1 (P31), the IR ampli-
fier outputs a logical High value. When the input current is below the switching threshold
of the IR amplifier, the amplifier outputs a logical Low value.
Within the MCU, the IR amp output goes to the capture/timer logic, which can be 
programmed to demodulate the IR signal. The IR amplifier output can also be read by the
CPU, or drive the Port 3, Pin 4 (P34) output if write-only register bit PCON[0] is set to 1.
For the maximum current input that is clearly recognized by the ZLF645 as a 0 and the
minimum current input that is clearly recognized as a 1, see I
parameters, respectively, in
The IR learning amplifier can demodulate signals up to a frequency of 500 kHz. A special
mode exists that allows you to capture the third, fourth, and fifth edges of the IR amplifier
output and generate an interrupt.
For details on programming the timers to demodulate a received signal, see
page 99.
Figure 21. Learning Amplification Circuitry within the ZLF645 Flash MCU
Port 3
on page 23).
Table 80
V
DD
on page 165.
D1
Photodiode
P31 of MCU
ZLF645 Series Flash MCUs
DETLO
Product Specification
Infrared Learning Amplifier
Figure
and I
21. When the IR
DETHI
Timers

on
84