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CC3135 Datasheet(PDF) 29 Page - Texas Instruments |
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CC3135 Datasheet(HTML) 29 Page - Texas Instruments |
29 / 78 page ![]() POWER OFF HW INIT FW INIT Device Ready to serve API calls VBAT VIO nRESET STATE 32-kHz XTAL T1 T2 T3 nHIB RESET 29 CC3135 www.ti.com SWAS037 – JANUARY 2019 Submit Documentation Feedback Product Folder Links: CC3135 Specifications Copyright © 2019, Texas Instruments Incorporated 5.17 Timing and Switching Characteristics 5.17.1 Power Supply Sequencing For proper operation of the CC3135 device, perform the recommended power-up sequencing as follows: 1. Tie the following pins together on the board: – VBAT (pins 37, 39, and 44) – VIO (pins 54 and 10) 2. Hold the RESET pin low while the supplies are ramping up. TI recommends using a simple RC circuit (100 K ||, 0.01 µF, RC = 1 ms). 3. For an external RTC, ensure that the clock is stable before RESET is deasserted (high). For timing diagrams, see Section 5.17.3. 5.17.2 Device Reset When a device restart is required, the user may issue a negative pulse to the nRESET pin. The user must follow one of the following alternatives to ensure the reset is properly applied: • A negative reset pulse (on pin 32) of at least 200-ms duration • If the 200-ms pulse duration cannot be ensured, a pulldown resistor of 2 MΩ must be connected to pin 52 (RTC_XTAL_N). If implemented, a shorter pulse of at least 100 µs can be used. To ensure a proper reset sequence, the user must call the sl_stop function prior to toggling the reset. When a reset is required, it is preferable to use the software reset instead of an external trigger. 5.17.3 Reset Timing 5.17.3.1 nRESET (32-kHz Crystal) Figure 5-6 shows the reset timing diagram for the 32-kHz crystal first-time power-up and reset removal. Figure 5-6. First-Time Power-Up and Reset Removal Timing Diagram (32-kHz Crystal) Table 5-11 describes the timing requirements for the 32-kHz crystal first-time power-up and reset removal. Table 5-11. First-Time Power-Up and Reset Removal Timing Requirements (32-kHz Crystal) ITEM NAME DESCRIPTION MIN TYP MAX UNIT T1 nReset time nReset timing after VBAT and VIO supply are stable 1 ms T2 Hardware wake-up time 25 ms T3 Initialization time 32-kHz crystal settling plus firmware initialization time plus radio calibration 1.35 s |
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