User's Manual

Chapter 1 - Product Overview Landis+Gyr
8 98-1546 Rev AA UtiliNet SCADA Single Board Radio
Pin 1 (VIN)
This pin must be supplied with DC voltage between 4.0 and 7.0 VDC with 5.0 VDC considered
nominal.
The input voltage of 5.0 VDC is linearly regulated on the board to 3.4 VDC. While the linear
regulation can remove some noise, its PSRR (Power Supply Rejection Ratio) varies with frequency.
If the power source is particularly noisy, filtering may be required. Landis+Gyr engineering can
assist in defining radio tests to determine if power supply noise is affecting radio performance.
The input voltage must be maintained between 4.0 VDC and 7.0 VDC during operation. The on-
board electronics include fast-acting reset circuitry. If the voltage drops below 4.0 VDC, even
transiently, the system will reboot once the voltage returns to normal range. If the voltage rises above
7.0 VDC, even transiently, the voltage-sensitive components could be damaged.
Upon power up, the on board processor and voltage regulator requires the supply voltage to have a
minimum of 0.05 V/msec slew rate - which implies rising from 0 to 3.4 VDC in 68 msec max.
During normal receive mode, current consumption is 25 mA.
During the first 30 minutes and after an extended outage or initial power on, the on-board super-
capacitor will be charging to prepare for outage notification (an RF function of the UtiliNet system).
During this time, the total input current to the device will increase to 55 mA.
During RF transmission at 100 mW, the UtiliNet SBR current consumption is 200 mA maximum.
The UtiliNet SBR uses a frequency hopping sequence transmission and, while typically rare,
transmissions can be as long as 400 mS in duration, and can theoretically sustained at a 45% duty
cycle.
The worst-case consumption profile, for a UtiliNet SBR that has just booted-up, charging its super-
capacitor, and transmitting packets at the max possible rate would be approximately 255 mA.
Typical current consumption is approximately 175 mA, drawn occasionally, for about 250 msec in
duration, and 25 mA when not transmitting.
Figure 1 - 5. Worst-Case Current Consumption Profile
Figure 1 - 6. Typical Current Consumption Profile
Time [mS]
55
255
~ 400[mS]~ 500[mS]
Iin [mA]
Time [mS]
25
175
~ 250[mS]
Occasional
Packets
Iin [mA]