Data Sheet
Table Of Contents
- Contents
- Tables
- Figures
- 1 Product Overview
- 2 Functional Description
- 3 FM17520 Register Set
- 4 Host Interfaces
- 5 Analog Interface And Contactless UART
- 6 CRC Coprocessor
- 7 FIFO Buffer
- 8 Interrupt Request System
- 9 Timer
- 10 Power Reduction Modes
- 11 Low Voltage Detection
- 12 Oscillator Circuitry
- 13 Reset And Oscillator Start-Up Time
- 14 Command Set
- 15 Testsignals
- 16 Typical Application Diagram
- 17 Characteristics
- 18 Ordering Information
- 19 Package Information
- Revision History
- Sales and Service
13 Reset And Oscillator Start-Up Time
Datasheet
FM17520 Contactless Transceiver IC Ver 1.0 57
13 Reset And Oscillator Start-Up Time
13.1 Reset Timing Requirements
The reset signal is filtered bya spike filter before it enters thedigital circuit. The spike filter rejects signals
shorter than 10 ns. In order to perform a reset,the signal must be LOW for at least 100 ns.
13.2 Oscillator Start-Up Time
If the FM17520 has been set to a Power-down mode or is powered by a V
DDX
supply, the start-up time for
the FM17520 depends on the oscillatoruesd and is shown in Fig 13-1.
Fig13-1 Oscillator start-up time
The time（tstartup） is the start-up time of the crystal oscillator circuit. The crystal oscillator start-uptime is
defined by the crystal.
The time（td） is the internal delay time of the FM17520 when the clock signal is stable before the
FM17520 can be addressed.
The delay time is：
td = 1024/(27.12MHz) = 37.76μs
The time（tOSC） is the sum of td and tstartup.