ZLF645E0H2864G Zilog, ZLF645E0H2864G Datasheet - Page 137

• Manufacturer Part Number: ZLF645E0H2864G
• Description: IC MCU 64K FLASH 1K RAM 28-SSOP
• Manufacturer: Zilog
• Series: Crimzon™ ZLFr

Specifications of ZLF645E0H2864G

• Core Processor: Z8 LXMC
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: UART/USART
• Peripherals: Brown-out Detect/Reset, HLVD, POR, WDT
• Number Of I /o: 24
• Program Memory Size: 64KB (64K x 8)
• Program Memory Type: FLASH
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 1.9 V ~ 3.6 V
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 28-SSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Oscillator Type: -
• Other names: 269-4719

Clock
PS026407-0408
ZLF645 MCUs on-chip oscillator has a high-gain, parallel-resonant amplifier for
connecting to a crystal, ceramic resonator, or any suitable external clock source
(XTAL1 = Input, XTAL2 = Output).
Crystal Specification
The crystal must be AT cut, 1 MHz to 8 MHz (maximum), with a series resistance (RS)
less than or equal to 100
clock source.
The crystal must be connected across XTAL1 and XTAL2 pins using the recommended
capacitors from each pin to ground. The typical capacitor value is 10 pF for 8 MHz. Check
with the crystal supplier for the optimum capacitance.
Zilog’s IR MCU supports crystal, resonator, and oscillator. Most resonators have a
frequency tolerance of less than ±0.5%, which is enough for a remote control application.
Resonator has a very fast startup time, which is around few hundred microseconds. Most
crystals have a frequency tolerance of less than 50 ppm (±0.005%). However, crystal
needs longer startup time than the resonator. The large loading capacitance slows down the
oscillation startup time. Clock oscillation must be stable before the CPU begins instruction
execution. If oscillation is not present or not stable before the chip completes timeout of its
Power-On Reset (POR) period, the chip’s behavior could be indeterminate.
C1
C2
Ceramic Resonator or Crystal
C1, C2 = 10 pF *
f = 8 MHz
*Note: preliminary value, including pin parasitics.
XTAL1
XTAL2
Ω
Figure 41. Oscillator Configuration
. The on-chip oscillator can be driven with a suitable external
External Clock
XTAL1
XTAL2
ZLF645 Series Flash MCUs
Ceramic Resonator f = 8 MHz
Product Specification
XTAL1
XTAL2
Clock
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