unicore UM981 User Manual

UM981 User Manual
16 Hardware Design UC-00-M33 EN R1.0
4. It is not recommended to take VCC_RF as ANT_BIAS to feed the antenna (VCC_RF is
not optimized for anti-lightning strike, anti-surge and over current protection due to
the compact size of the module)
5. D1: ESD diode, choose the ESD protection device that supports high frequency
signals (above 2000 MHz)
6. D2: TVS diode, choose a TVS diode with appropriate clamping specification
according to the requirement of feed voltage and the antenna withstand voltage
3.3 Power-on and Power-off
VCC
 The VCC initial level when power-on should be less than 0.4 V.
 The VCC ramp when power-on should be monotonic, without plateaus.
 The voltages of undershoot and ringing should be within 5% VCC.
 VCC power-on waveform: The time interval from 10% rising to 90% must be within
100 μs ~1 ms.
 Power-on time interval: The time interval between the power-off (VCC < 0.4 V) to
the next power-on must be larger than 500 ms.
V_BCKP
 The V_BCKP initial level when power-on should be less than 0.4 V.
 The V_BCKP ramp when power-on should be monotonic, without plateaus.
 The voltages of undershoot and ringing should be within 5% V_BCKP.
 V_BCKP power-on waveform: The time interval from 10% rising to 90% must be
within 100 us ~1 ms.
 Power-on time interval: The time interval between the power-off (V_BCKP < 0.4 V)
to the next power-on must be larger than 500 ms.

unicore UM981 Specifications

General

Brand	unicore
Model	UM981
Category	Control Unit
Language	English