SM3320-RF-EV/NOPB National Semiconductor, SM3320-RF-EV/NOPB Datasheet - Page 2

• Manufacturer Part Number: SM3320-RF-EV/NOPB
• Description: SOLARMAGIC RF EVAL KIT 2.4GHZ
• Manufacturer: National Semiconductor
• Series: SolarMagic™r
• Type: Power Optimizer, Transceiverr

Specifications of SM3320-RF-EV/NOPB

• Frequency: 2.4GHz
• For Use With/related Products: SM3320-1A1, nRF24LE1
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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SM3320-RF-EV
Design Specification
1) SM3320 RF-EV KIT
Included in the SM3320-RF-EV are the following items:
1.
2.
3.
4.
In order to get started as quickly as possible with this kit, users
are recommended to purchase a Nordic nRF6310 mother-
board. Using the included Central Transmitter sample code
will enable users to test the enable/disable and Panel-Mode
functionality.
2) FEATURES
•
•
•
•
•
•
3) DESIGN DESCRIPTION
The Sirius RF evaluation board shares the same power spec-
ifications as the SolarMagic SM3320-1A1 Power Optimizer.
The controller for the power optimizer consists of an SM72442
programmable MPPT controller for PV panels and a Nordic
nRF24LE1 low power system-on-chip wireless solution. The
nRF24LE1 has a built in 2.4GHz transceiver (250kbps,
1Mbps and 2Mbps air data rates) and an 8051 compatible
microcontroller. Operation at 250kbps is recommended.
Receiver
The nRF24LE1 IC will be located in the SM3320-RF-EV board
and used as a receiver that controls the forced shutdown and
Panel-Mode operation.
By utilizing these two ICs (SM72442 and nRF24LE1),the
evaluation board is capable of tracking the maximum power
point of PV panels during normal operation as well as con-
trolling a shutdown during emergency conditions. Two of the
GPIO outputs (P0.0 and P0.1) from the microcontroller are
used to send a shutdown or Panel-Mode signal into the
SM72442. The shutdown signal will pull the RESET pin low
in order to deactivate the PWM signals that are coming out
from SM72442. Panel-Mode operation can be forced on the
SM72442 by pulling the PM pin of the SM72442 low.
Wireless shutdown for SM3320-1A1
Wireless Panel-Mode operation for SM3320-1A1
MPPT for Photovoltaic Panel
2.4 GHz ISM band operation
Enhanced 8 bit 8051 compatible microcontroller
Power line antenna
SM3320-RF-EV PCB
Software for the Receiver (SM3320-RF-EV) – compiled
and source code
Software for the Central Transmitter (nRF6310) -
compiled and source code
Design files – Schematic, BOM and Gerbers
Symbol
MPP
PM
V
P
V
OVP
OTP
V
I
I
OUT
MPP
MPP
OUT
SC
OC
EFF
EFF
PV Module MPP Voltage
PV Module Power
PV Module Open Circuit Voltage
PV Module Short-Circuit Current
Output Voltage
Output Current
Overvoltage Protection Threshold
Overtemperature Protection Threshold
MPP Efficiency
Panel-Mode Efficiency
Parameter
2
Figure 2
puts of nRF24LE1 are used to force a reset or Panel-Mode
condition on the SM72442. The nRF24LE1 radio uses the
power line as an antenna by coupling into the output wire of
the SM3320-RF-EV. This implementation is shown on
3. In order to not short the output of the radio to ground, an
air wound inductor (L104 in schematic) is placed between the
OUT (-) terminal and the actual string wire. The inductor, to-
gether with the capacitors to ground at the DC power feed
(C116) and the series capacitor between it and the RF
transceiver device (C113), create an LC Network to couple
RF in and out of the string wire terminal without shorting it to
the DC power feed, and at the same time carrying the DC from
the power feed to the string wire. The other string wire has a
capacitor (C117) to ground to provide a return for the RF
through the ground planes to the RF transceiver device. The
dimensions for the air wound inductor are attached in
4. This inductor introduces approximately 10 dB loss at 2.4
GHz. For better manufacturability, the inductor can be re-
designed with a core so it is smaller. It still needs to carry the
full string current
FIGURE 2. Forced Panel-Mode and Reset using
shows one sample application where the GPIO out-
15 Vdc
0 Vdc
10 W
Min
nRF24LE1
125
98.5%
99.5%
Typ
45V
o
C
50 Vdc
43 Vdc
350 W
40Vdc
12.5A
Max
11A
30143802
Figure
Figure