Hardware Guide

© SAMSUNG Electronics Co., Ltd. Confidential & Proprietary
32 / 82
3.1.2 Input Power Supply Interface
Input power supply interfaces are VPH_PWR.
When the module works normally, power is supplied through the VPH_PWR pins and the voltage ranges from 4.0 V
to 4.4 V (typical value is 4.2 V).
When the module works at GSM mode and transmits signals at the maximum power, the transient peak current
may reach 2.75A due to the differences in actual network environments. In this case, the input power voltage will
drop. If you want goo d wireless performance, please make sure that the voltage does not drop below 3.8 V in any
case. Otherwise, exceptions such as restart of the module may occur.
A LDO (Low Dropout Regulator) or switch power with current output of more than 3 A is recommended for
external power supply. Furthermore, four 220 µF or above energy storage capacitors are connected in parallel at the
power interface of the module. In addition, to reduce the impact of channel impedance on voltage drop, it is
recommended to try to shorten the power supply circuit of the VPH_PWR interface.
Figure 3-1 Recommended power circuit
The UVLO circuit for the NAD prevents the device from malfunctioning at low-input voltages and from
excessive discharge of the power. As VPH_PWR voltage is under UVLO threshold, the NAD enters into
UVLO state, which forces the device to an inactive state until the VPH_PWR is high enough to allow the
device to operate normal function.
The UVLO voltage level are 2.9 V rising and 2.0 V falling (hysteresis 900 mV), respectively. In case the
VPH_PWR voltage rises over 2.9 V, NAD including all regulators starts to operate from lockout state and if
the VPH_PWR voltage falls under 2.0 V, NAD is turned off.
3.1.3 Output Power Supply Interface
Output power supply interfaces are VLDO2_CP_VDD180 and VLDO10_CP_USIM0.
Table 3-2 Output power supply interface signals
Pin Name
Typ. (V)
Typ. (mA)
VLDO2_CP_VDD180
1.8
10
VLDO10_CP_USIM0
1.8/2.85
150
VLDO11_CP_USIM1
1.8/2.85
150
Through the VLDO2_CP_VDD180, the module can supply 1.8 V power externally with an output current of 10
mA (typical value) for external level conversion. This power is shared with CP GPIO. Be aware to affect CP stable.
Through the VLDO10_CP_USIM0, the module can supply 1.8 V or 2.85 V power for the USIM card.