Overview
The LNBH25SPQR, produced by STMicroelectronics, is a monolithic voltage regulator and interface IC designed specifically for analog and digital satellite receivers, including Sat-TV and Sat-PC cards. This IC provides a complete solution for powering and controlling Low Noise Block (LNB) down-converters in antenna dishes or multi-switch boxes. It integrates a DC-DC step-up converter, an LDO post-regulator, and a 22 kHz tone generator, ensuring high efficiency and compliance with main satellite receiver output voltage specifications.
Key Specifications
| Parameter | Description |
|---|---|
| Package | QFN24L (4x4 mm) |
| Supply Voltage Range | 8 V to 16 V |
| Output Voltage Levels | 13 V and 18 V (programmable via I²C bus) |
| Output Current Limit | Selectable by external resistor up to 1 A |
| Efficiency | Typically 93% @ 0.5 A |
| 22 kHz Tone Generator | Accurate, factory-trimmed, and compliant with DiSEqC standards |
| I²C Interface | Standard I²C bus interface for control and diagnostics |
| Protection Features | Overload, overtemperature, and short-circuit protection |
| Low Power Mode | LPM function to reduce power dissipation when 22 kHz tone is disabled |
Key Features
- Complete Interface: Provides a complete interface between the LNB and the I²C bus.
- DC-DC Converter: Built-in DC-DC step-up converter for single 12 V supply operation with high efficiency.
- Programmable Output Voltage: Output voltage levels can be programmed via the I²C bus to 15 different levels.
- 22 kHz Tone Generator: Accurate built-in 22 kHz tone generator compliant with DiSEqC standards.
- Low Power Mode: LPM function to reduce power dissipation when the 22 kHz tone is disabled.
- Protection Features: Includes overload, overtemperature, and short-circuit protection with diagnostic bits.
- I²C Interface: Standard I²C bus interface for control and diagnostics.
Applications
- Satellite Receivers: Suitable for STB (Set-Top Box) satellite receivers, TV satellite receivers, and PC card satellite receivers.
- Sat-TV and Sat-PC Cards: Designed for use in analog and digital satellite receivers and Sat-PC cards.
- Multi-switch Boxes: Can be used in multi-switch boxes to control and power LNB down-converters.
Q & A
- What is the primary function of the LNBH25SPQR?
The LNBH25SPQR is a monolithic voltage regulator and interface IC designed to provide power and control for Low Noise Block (LNB) down-converters in satellite receivers and multi-switch boxes.
- What are the output voltage levels supported by the LNBH25SPQR?
The IC supports programmable output voltage levels of 13 V and 18 V, with 15 different programmable levels via the I²C bus.
- How does the 22 kHz tone generator work?
The 22 kHz tone generator is accurate and factory-trimmed, compliant with DiSEqC standards. It can be controlled via the I²C bus and activated by external signals or envelope control.
- What protection features are included in the LNBH25SPQR?
The IC includes overload, overtemperature, and short-circuit protection with diagnostic bits available via the I²C interface.
- How does the low power mode (LPM) function work?
The LPM function reduces power dissipation by disabling the 22 kHz tone output and reducing the drop voltage across the integrated LDO regulator when the tone is not needed.
- What is the role of the I²C interface in the LNBH25SPQR?
The I²C interface allows for control and diagnostics of the IC, including setting output voltage levels, controlling the 22 kHz tone, and monitoring diagnostic status.
- What is the typical efficiency of the DC-DC converter in the LNBH25SPQR?
The DC-DC converter has a typical efficiency of 93% at 0.5 A load.
- How is the output current limit set in the LNBH25SPQR?
The output current limit can be set by an external resistor connected to the ISEL pin, allowing for a current limit up to 1 A.
- What is the purpose of the fault flag (FLT) pin in the LNBH25SPQR?
The FLT pin provides an immediate feedback on diagnostic status, indicating faults such as overload, overtemperature, or power issues.
- What are the typical application circuits for the LNBH25SPQR?
The IC is typically used in satellite receivers, multi-switch boxes, and other applications requiring LNB power and control, with detailed application circuits provided in the datasheet.
