---
title: Electrical Specifications
description: Absolute maximum ratings, recommended operating conditions, and electrical characteristics for Horizon's power, digital, and RF interfaces.
url: "https://docs.somewear.app/unmanned/installer/specifications/electrical-specifications/"
updated: "2026-06-24"
requires: {}
facets:
  hardware:
    - horizon:
        since: baseline
  client: []
  satcom: []
---

## Absolute Maximum Ratings

> **Warning**
>
> Exceeding these ratings may result in permanent damage to the device.

### Power

| **Parameter** | **Description**                          | **Value** | **Units** |
| ------------- | ---------------------------------------- | --------- | --------- |
| VSUPP         | Supply Voltage (max)                     | 16        | V         |
| V5V\_ACC      | Voltage applied to 5V accessory output   | 5.5       | V         |
| I5V\_ACC      | Maximum current from 5V accessory output | 1500      | mA        |
| VUSB\_VBUS    | Maximum voltage on USB connector 5V rail | 5.5       | V         |

### Digital Interfaces

| **Parameter** | **Description**                           | **Value** | **Units** |
| ------------- | ----------------------------------------- | --------- | --------- |
| VUART\_MAX    | Voltage on any UART pin                   | 5.5       | V         |
| VIMAX         | Voltage on any general-purpose input pin  | 5.5       | V         |
| VOMAX         | Voltage on any general-purpose output pin | 5.5       | V         |

### RF Interfaces

| **Parameter**   | **Description**                                 | **Value** | **Units** |
| --------------- | ----------------------------------------------- | --------- | --------- |
| PIN\_LOSMAX     | Maximum RF power applied to LOS radio connector | +10       | dBm       |
| VSWRLOSMAX\_IN  | Maximum in-band VSWR at LOS radio connectors    | 6:1       | —         |
| VSWRBLOSMAX\_IN | Maximum in-band VSWR at BLOS radio connector    | 2:1       | —         |

## Recommended Operating Conditions

### Power

| **Parameter** | **Description**                       | **Min** | **Typ** | **Max** | **Units** |
| ------------- | ------------------------------------- | ------- | ------- | ------- | --------- |
| VSUPP         | Supply Voltage                        | 6       | —       | 13      | V         |
| I5V\_ACC      | Current draw from 5V accessory output | —       | —       | 250     | mA        |

### RF Interfaces

| **Parameter** | **Description**                          | **Min** | **Typ** | **Max** | **Units** |
| ------------- | ---------------------------------------- | ------- | ------- | ------- | --------- |
| VSWRLOS       | In-band VSWR at LOS radio connectors     | —       | —       | 2:1     | —         |
| VSWRBLOS      | In-band VSWR at BLOS radio connector     | —       | —       | 1.5:1   | —         |
| ILBLOS\_FEED  | BLOS antenna maximum feedline loss       | —       | —       | 3       | dB        |
| S21\_LOS      | Isolation between LOS1 and LOS2 antennas | 40      | —       | —       | dB        |

## Electrical Characteristics

> **Note**
>
> All values measured at 25°C ambient unless otherwise specified.

### Power Input (VSUPP)

| **Parameter** | **Description**               | **Min** | **Typ** | **Max** | **Units** |
| ------------- | ----------------------------- | ------- | ------- | ------- | --------- |
| I6V\_IN       | Input current at VSUPP = 6V¹  | 350     | —       | 925     | mA        |
| I9V\_IN       | Input current at VSUPP = 9V¹  | 250     | —       | 650     | mA        |
| I12V\_IN      | Input current at VSUPP = 12V¹ | 190     | —       | 500     | mA        |
| I13V\_IN      | Input current at VSUPP = 13V¹ | 175     | —       | 465     | mA        |
| IINRUSH       | VSUPP inrush current          | —       | —       | 1.7     | A         |
| TINRUSH       | VSUPP inrush duration         | —       | —       | 6.0     | ms        |

¹ Measured without any devices connected to 5V\_ACC output.

### 5V Accessory Output

| **Parameter** | **Description**                    | **Min** | **Typ** | **Max** | **Units** |
| ------------- | ---------------------------------- | ------- | ------- | ------- | --------- |
| V5V\_ACC      | Output voltage                     | 4.90    | 5.04    | 5.2     | V         |
| IOC\_TRIP     | Overcurrent protection trip point¹ | —       | —       | 1.5     | A         |

¹ OCP is provided to protect the device from faulty accessories. Do not exceed the recommended 250 mA limit (see **Recommended Operating Conditions** above).

### Digital Interfaces

| **Parameter** | **Description**                   | **Min** | **Typ** | **Max** | **Units** |
| ------------- | --------------------------------- | ------- | ------- | ------- | --------- |
| VIO           | Digital I/O voltage range         | 0       | —       | 3.6     | V         |
| IOH           | Digital output high-level current | —       | —       | -24     | mA        |
| IOL           | Digital output low-level current  | —       | —       | 24      | mA        |
| UARTDMAX      | Maximum UART baud rate            | —       | —       | 115200  | bps       |

> **Note**
>
> UART lines and the digital input pin may tolerate 5V logic levels without damage, but performance is not guaranteed at 5V.