> 5 | Electrical and Environmental Characteristics

> Table 21: | Absolute maximum ratings

> Parameter | Port / Description | Min. | Max. | Unit
> Supply voltage | POWER | -33 | +33 | V
> Input voltage for Ignition | IGT_IN | -30 | +30 | V
> Input voltage for emergency off | EMERGOFF | -25 | +30 | V
> RS-232 input voltage range | TXD0, DTR0, RTS0 | -30 | +30 | V
> | RXD0, CTS0, DSR0, DCD0, RING0 (No DC Input) | -0.3 | +0.3 1 | V
> Digital GPIO, SPI, I2C | GPIO1 – GPIO10, I2CCLK_SPICLK, I2CDAT_SPIDO, SPICS, SPIDI, I2CDAT_SPIDO | -0.3 | +3.05 2 +0.3 1 | V
> Analog Input | ADC1_IN_P, ADC1_IN_N, ADC2_IN_P, ADC2_IN_N | -6 | +6 | V
> Backup battery | BACKUP | -4.7 | +4.7 | V
> On/Off- line | ONOFF (No DC Input) | -0.3 | +0.3 3 | V
> VDD supply voltage | VDD (No DC Input) | -0.3 | +0.3 1 | V
> Microphone input line AC voltage (pins to GND) | MICP1, MICN1 (No DC Input) |  | 0.6 1 3.1 2, 4 | Vpp
> Earpiece voltage (idle, no power) | EPP1, EPN1 (No DC Input) | -0.3 | +0.3 1 | V
> Antenna Connector | No DC input | 0 | 0 | V
> Immunity against air discharge of static electricity | All connectors (lines) | -8 | +8 | kV
> Immunity against contact discharge of static electricity | All connectors (lines) | -4 | +4 | kV
> Protection Class | IP40 (avoid exposing to liquid or moisture, for example do not use it in a shower or bath) |  | IP 40 |
> Mechanical vibrations amplitude | @ 5-200Hz |  | 7.5 | mm
> Mechanical pulse-acceleration | @ 18ms duration |  | 30 | G

> 1
> For Power Down and Power Off.
> 2
> For all operation modes.
> 3
> Only Power Off.
> 4
> A call is established or the AT command “AT^SNFM=,1” was executed.

> Table 22: | Operating conditions

> Parameter | Min | Typ | Max | Unit
> Ambient temperature | -30 | 25 | 65 *) | °C
> Supply voltage V POWER measured at (6-pole) western jack plug (1, 2 to 5,6) | 7.6 lowest voltage (minimum peak) incl. all ripple and drops | 12 | 30 | V

> *) Continuous operation at 65°C environmental temperature is not possible in every operating mode due to intrinsic heating of the TC65 Terminal.
> The level of intrinsic heating depends on several factors depending on the level of the supply voltage, the operating mode (GPRS/GSM) and the network coverage. The maximum possible environmental temperature in GPRS Class 12 operating mode (MS-configuration 1down/4up, PCL5/Gamma3, 12V supply voltage, 900MHz band, with power reduction) is about 45°C. When this temperature is exceeded the TC65 Terminal will send a request to the base station for changing the GPRS-Class (e.g. from GPRS Class 12 to GPRS Class 8). At a successful change of the GPRS class the intrinsic heating of the TC65 Terminal will be reduced. If the board temperature decreases by an amount of 15°C the GPRS Class will be stepped up again.
> Continuous operation in Talk mode is possible up to an environmental temperature of about 67°C (12V, 900MHz, PCL5). With decreasing transmit power of the TC65 Terminal, the maximum possible environmental temperature increases at which a GPRS continuous operation at PCL5/Gamma3 is possible.
> For a short time it is also possible to establish a GPRS Class 12 connection at PCL5/Gamma3 and at an ambient temperature of 65°C. Starting a data download in GPRS Class 12 mode with power reduction at 65°C environmental temperature the request for a change of the GPRS Class will be enabled after 7 minutes. This information applies to 12V supply voltage. At 8V resp. 30V the intrinsic heating is higher, whereby the maximum possible environmental temperature will be lower.
> The following table shows the highest possible ambient temperatures at which the temperature of the NTC will reach a final value of 81°C (GPRS Class 10,12 Temperature of GPRS Class Change) or the final shut down temperature 90°C (GPRS Class 8 and Voice Call).

> Table 23: | Highest temperatures

> Terminal horizontal, normal position | Highest possible ambient temperature
> GPRS Class 8 PCL5/Gamma3 | 67°C
> GPRS Class 10 PCL5/Gamma3 | 48°C
> GPRS Class 12 PCL5/Gamma3 with Power Reduction | 45°C
> GPRS Class 12 PCL5/Gamma3 without Power Reduction | 34°C

> The following table shows the longest possible duration of a connection until 81°C (Temperature of GPRS Class Change) are reached at the NTC when the ambient temperature is 65°C.

> Table 24: | Longest duration until 81°C are reached

> Terminal horizontal, normal position | Longest possible duration of connection
> GPRS Class 10 PCL5/Gamma3 | 11 minutes
> GPRS Class 12 PCL5/Gamma3 with Power Reduction | 7 minutes
> GPRS Class 12 PCL5/Gamma3 without Power Reduction | ---

> The following table shows the longest possible duration of connection when the GPRS Class Change from GPRS Class 12 or 10 to GPRS Class 8 did not work properly and 90°C (Temperature of Hardware shut off) will be reached at the NTC (ambient temperature is 65°C).

> Table 25: | Longest duration when GPRS Class Change does not work properly

> Terminal horizontal, normal position | Longest possible duration of connection
> GPRS Class 8 PCL5/Gamma3 | Continuous operation
> GPRS Class 10 PCL5/Gamma3 | 22 minutes
> GPRS Class 12 PCL5/Gamma3 with Power Reduction | 14 minutes
> GPRS Class 12 PCL5/Gamma3 without Power Reduction | ---