Vbat Interface Compatibility Design; Detailed Interface Differences; Vbat Interface Design Guide - Huawei MU509 Hardware Migration Manual

HUAWEI 30 mm × 30 mm LGA Module
Hardware Migration Guide

2.7 VBAT Interface Compatibility Design

2.7.1 Detailed Interface Differences

The VBAT voltage ranges from 3.3 V to 4.2 V, and it ranges from 3.2 V to 4.2 V for
ME909s, with a typical value being 3.8 V. The 30 mm × 30 mm LGA module provides
two VBAT pads.
When the 30 mm × 30 mm LGA module works in the GSM mode, the peak current
can reach 2.75 A. To ensure that the module works normally, place a large-capacity
capacitor (1.1 mF is the best) near VBAT pads. This ensures that the VBAT voltage is
not lower than 3.3 V, and for ME909s, it is not lower than 3.2 V.
All the 30 mm × 30 mm LGA modules must be installed with a large-capacity
capacitor on the VBAT. Furthermore, five 220 µF or above energy storage capacitors
are connected in parallel at the power interface of the LGA module (VBAT Pin). But
for MC509, a 220 µF or above energy storage capacitors in parallel are enough.
Table 2-14 Differences of capacitors in parallel at the VBAT Pin
Pin Interface Name
No.
12 Power VBAT
and interface
(3.3 V–4.2 V)
13
VBAT
(3.2 V–4.2 V)
is only for
ME909s

2.7.2 VBAT Interface Design Guide

It is recommended that you add ferrite beads and five 220 µF capacitors (a 220 µF
capacitor for MC509) are connected in parallel at VBAT pin to the power circuit. The
diagram of recommended circuit is shown in the following figures.
Issue 08 (2016-12-12)
MC509 MU509
A 220 µF Five 220 µF capacitors needed
capacitor
needed
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LGA Interface Differences
MU609 ME209u ME909u
-526
MU709 ME909s
38