Avnet AES-ATT-M18QWG-SK-G, Руководство пользователя по оборудованию

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Page 34
3.5 Power Regulation
Table 16
– Summary of LTE System Board Voltages
3.5.1 VIN
Unregulated DC input power (in range of 4.5V to 16V) can be supplied to the LTE System
board via one of three different input interfaces:

the “PWR IN” MicroUSB connector (J6)

the 60-pin Expansion Connector (J1)

the 2-pin VIN and GND aux connector (J10, unpopulated)
In the IoT Starter Kit, the provided 5V 2.5A AC/DC power adaptor applies power to the LTE
System board via
the “PWR IN” MicroUSB (J6) connector
The input supply voltage can be measured by placing voltmeter test leads across the
unpopulated DC aux input connector pads (J10)
3.5.2 3V8 (VCC)
3.8V @ 3 A max , An onboard ON Semi NCP3170 buck switching regulator supplies the WNC
module’s VCC input requirement. Regulators on the WNC module then convert this voltage
down to the lower core voltages required
The REG_EN regulator enable input:

is pulled high following power-up via an RC delay circuit (enables the 3V8 output)

can be pulled low from the 60-pin Expansion Connector (to disable the 3V8 output)
Power Good status of the 3V8 output supply rail can be verified in two places

LED1 - illuminates green when the circuit is correctly powered and REG_EN is high

PG test point - this should be high (when circuit is powered and REG_EN = high)
An unpopulated 2-pin header site (JP1) is provided for 3V8 current measurement.
To use this feature, the following board modification is required:

Zero-ohm resistor R47 must be removed

A 2-pin header connector JP1 must be added

The meter test leads must be placed across the pins of JP1

After completion of current measurements, a shorting link (JPR1) must be fitted
across these JP1 header pins
Voltage Rail Voltage Current max (A)
VIN 5.0V (nominal) 1.8 A (MicroUSB)
4.0 A (Exp. Connector)
3V8 (VCC) 3.8V 3.0 A
1V8_VREF (VREF) 1.8V 0.1 A
VCC_UIM_SIM 1.8V / 3.3V 0.15 A
3V3 3.3V 0.3 A