ZNBG3211中文资料switched-bias-generators数据手册Diodes规格书

描述 Description

The ZNBG series of devices are designed to meet the bias requirements of GaAs and HEMT FETs commonly used in satellite receiver LNBs, PMR cellular telephones etc. with a minimum of external components.
With the addition of two capacitors and a resistor the devices provide drain voltage and current control for three external grounded source FETs, generating the regulated negative rail required for FET gate biasing whilst operating from a single supply. This negative bias, at -3 volts, can also be used to supply other external circuits.
The ZNBG3210/11 includes bias circuits to drive up to three external FETs. A control input to the device selects either one of two FETs as operational using 0V gate switching methodology, the third FET is permanently active. This feature is particularly used as an LNB polarisation switch. Also specific to LNB applications is the enhanced 22kHz tone detection and logic output feature which is used to enable high and low band frequency switching. The detector has been specifically designed to reject inerference such as low frequency signals and DiSEqC tone bursts - without the use of additional external components.
Drain current setting of the ZNBG3210/11 is user selectable over the range 0 to 15mA, this is achieved with the addition of a single resistor. The series also offers the choice of FET drain voltage, the 3210 gives 2.2 volts drain whilst the 3211 gives 2 volts.
These devices are unconditionally stable over the full working temperature with the FETs in place, subject to the inclusion of the recommended gate and drain capacitors. These ensure RF stability and minimal injected noise.
It is possible to use less than the devices full complement of FET bias controls, unused drain and gate connections can be left open circuit without affecting operation of the remaining bias circuits.
In order to protect the external FETs the circuits have been designed to ensure that, under any conditions including power up/down transients, the gate drive from the bias circuits cannot exceed the range -3.5V to 1V. Furthermore if the negative rail experiences a fault condition, such as overload or short circuit, the drain supply to the FETs will shut down avoiding excessive current flow.
The ZNBG3210/11 are available in QSOP20 for the minimum in device size. Device operating temperature is -40 to 70°C to suit a wide range of environmental conditions.

特性 Features

Provides bias for GaAs and HEMT FETsDrives up to three FETsDynamic FET protectionDrain current set by external resistorRegulated negative rail generator requires only 2 external capacitorsChoice in drain voltageWide supply voltage rangePolarisation switch for LNBs -supporting zero volt gate switching topology.22kHz tone detection for band switchingCompliant with ASTRA control specificationsQSOP surface mount package

应用 Application

Satellite receiver LNBsPrivate mobile radio (PMR)Cellular telephones

简介

ZNBG3211属于集成电路（IC）的电源管理-专用。由制造生产的ZNBG3211电源管理 - 专用专用型电源管理集成电路 (PMIC) 用于电源的控制或操作，适合特定或小范围的目标应用，例如汽车气囊管理、电容器组平衡、AC 公共电力监控、存储器总线端接、接地故障检测、能量收集、小型引擎管理、处理器或芯片集专用电压调节、负载突降保护、触觉驱动器、热电制冷器控制等。