User's Guide

ATOP3.5G Product Description
80447ST10636A rev.10 – 2015-03-03
Reproduction forbidden without written authorization from Telit Communications S.p.A. - All Rights
Reserved. Page 37 of 66
Mod. 0808 2011-07 Rev.2
13.3 Voltage references
Table 16 VIO_REF voltage reference
To be used as a reference for connecting BB digital interfaces. Parameters mentioned in this table are indicative and taken
from supplier data sheets.
Symbol Parameter Conditions Min Typ Max Unit
Pin: VIO_REF
V
o
output voltage 1.74 1.80 1.86 V
∆V
o
/V
o
relative output voltage
variation
for V
BAT (VBAT_SNK)
variation - - 3 %/V
Table 17 VADC_REF voltage reference
Used as power supply reference for internal ADCs.
Symbol Parameter Conditions Min Typ Max Unit
Pin: VADC_REF
V
o
output voltage
for T
amb
= 40 °C to +85 °C
2.9 3.0 3.1 V
I
o
output current
for T
amb
= 40 °C to +85 °C [1]
- - 1 mA
∆V
o
/(V
o
x∆V
i
) relative output voltage
variation with input
voltage
for V
BAT (VBAT_MC_SNK)
variation [2]
0.1
- 0.1 %/V
[1] To be used only as a reference voltage.
[2] Parameter is indicative and taken from supplier data sheet.
13.4 Clocks
Table 18 1PPS
This pulse is synchronized with GPS system clock.
Symbol Parameter Conditions Min Typ Max Unit
t
w
pulse width - 100 -
s
t
jit
jitter time RMS stationary and receiving 4 or more satellites - 4.1 - ms
V
OH
HIGH-level output voltage 1.35 - 1.80 V
V
OL
LOW-level output voltage - - 0.1 V
Table 19 BB_EXT_CLK
Symbol Parameter Conditions Min Typ Max Unit
f
xtal
reference oscillator
frequency
- 19.2 - MHz
f
xtal
/f
xtal
reference oscillator
frequency accuracy
(40°C to +85°C)
- 2 5 ppm
V
OH
HIGH-level output voltage at 6 mA 2.15 2.60 - V
V
OL
LOW-level output voltage at 6 mA - - 0.45 V