A Product Line of Diodes Incorporated ZNBG3118 LNA GaAs FET BIAS CONTROLLER WITH POLARIZATION AND BAND SELECT Summary The ZNBG3118 is a bias and control solution designed for Satellite Low Noise Blocks (LNB’s). Providing three bias stages to power control and protect the GaAs or HEMT FET low noise amplifier’s (LNA’s). The ZNBG3118 integrates an accurate voltage detector to select the LNB polarisation channel and an advanced tone detector to select the local oscillator (LO) for band switching. Pin Assignments • Drain current set by external resistor G1 LB • Regulated negative rail generator requires only 2 external capacitors GND HB CNB1 Accurate voltage detector and polarisation switch for LNB’s VCC CNB2 LOV • Band switch supports both Discrete, MIMIC and PLL local oscillators • Compliant with ASTRA control specifications • Low current for power efficient systems • Wide operating supply range of 3.3V to 8V Top View CSUB Application • Single Output LNB’s • Two single type twin LNB’s • Low power LNB’s • PLL Single LNB’s VPOL 22kHz tone detection for band switching with rejection of unwanted signals FIN G2 • RCAL • G3 Dynamic FET protection and temperature compensation D3 Provides bias for up to three GaAs and HEMT FETs • D12 • CSUB NEW PRODUCT Features Bottom View Single Universal LNB System Diagram ZNBG3118 Document number: DS32049 Rev. 2 - 2 1 of 10 www.diodes.com February 2010 © Diodes Incorporated A Product Line of Diodes Incorporated ZNBG3118 Device Description NEW PRODUCT The ZNBG series of devices are designed to meet the bias requirements of GaAs and HEMT FETs commonly used in satellite receiver LNBs 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 -2.5 volts, can also be used to supply other external circuits. The ZNBG3118 includes bias circuits to drive up to three external FETs. The voltage applied to the VPOL pin determines which one of first two FETs is operational, the third FET is permanently active. This feature is normally used as an LNB polarisation switch to select the required polarisation. Specific to Universal LNB applications is the oscillator band select. This is achieved by detecting a 22kHz tone which enables or disables the relevant local oscillator. The ZNBG3118 has been designed to control various oscillators and down converter designs including Discrete (Bi-polar or MOSFET), MIMIC oscillators and IF amplifier / down-converters IC’s with logic enabled phase lock loop (PLL) oscillators. The ZNBG3118 has been designed to cope with DiSEqC™ ready set top boxes and rejects transients from channel switching. ZNBG3118 Document number: DS32049 Rev. 2 - 2 Drain current setting of the ZNBG3118 is user selectable over the range 0 to 15mA, achieved with addition of a single resistor. The drain voltage for all the FET’s is set internally to 2 volts. To minimise the pin out and package size FET 1 and FET 2 share a common drain pin. 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. 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 -3V. Additionally each stage has its own individual current limiter. 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. To minimise PCB space ZNBG3118 is packaged in the 16 pin 3mm x 3mm QFN package. Device operating temperature is -40 to 85°C to suit a wide range of environmental conditions. 2 of 10 www.diodes.com February 2010 © Diodes Incorporated A Product Line of Diodes Incorporated ZNBG3118 Maximum Ratings NEW PRODUCT Parameter Supply Voltage Supply Current Power Dissipation VPOL Input Voltage Operating Temperature Range Storage Temperature Range Electrical Characteristics Rating -0.6 to +12 100 500 25 Continuous -40 to +85 -40 to +150 Measured at Tamb = 25°C, Vcc = 5V, Rcal = 39k (setting Id to 10mA) unless otherwise specified. Parameter Supply Voltage Operating Range Supply Current Substrate Voltage Conditions +/-5% Supply tolerance permitted Id1 = Id2 = Id3 = 0 Id1 = 0, Id2 = Id3 = 10mA, Vpol = 15.5V Id2 = 0, Id1 = Id3 = 10mA, Vpol = 14V Id1 = Id2 = Id3 = 0, Ilb = 10mA Id1 = Id2 = Id3 = 0, Ihb = 10mA (Internally generated), Isub=0 Isub = -200uA Gate characteristics Gate 1 Output Voltage Off Voltage Low Voltage High Gate 2 Output Voltage Off Voltage Low Voltage High Gate 3 Output Voltage Low Voltage High Drain characteristics Drain 12 Output Voltage High 1 Voltage High 2 Drain 3 Output Voltage High Drains 12 and 3 delta Vd vs Vcc delta Vd vs Tj D1,2 and 3 Current Range Current delta Id vs Vcc delta Id vs Tj Min 3.3 Limits Typ. Max 8.0 Units V -3.0 1.5 22 22 12 12 -2.5 150 270 Vpol = 14.75V (Applied via a 10k resistor) (Applied via a 10k resistor) 30 14.0 42 14.75 52.5 15.5 100 uA V us Id12 = 0, Vpol = 14V, Ig1 = 0 Id12 = 12mA, Vpol = 15.5V, Ig1 = -10uA Id12 = 8mA, Vpol = 15.5V, Ig1 = 0 -3.0 -3.0 0.4 -2.5 -2.5 0.75 -2.0 -2.0 1.0 V V V Id12 = 0, Vpol = 15.5V, Ig2 = 0 Id12 = 12mA, Vpol = 14V, Ig2 = -10uA Id12 = 8mA, Vpol = 14V, Ig2 = 0 -3.0 -3.0 0.4 -2.5 -2.5 0.75 -2.0 -2.0 1.0 V V V Id3 = 12mA, Ig3 = -10uA Id3 = 8mA, Ig3 = 0 -3.0 0.4 -2.5 0.75 -2.0 1.0 V V Id12 = 10mA, Vpol = 15.5V Id12 = 10mA, Vpol = 14V 1.8 1.8 2.0 2.0 2.2 2.2 V V Id3 = 10mA 1.8 2.0 2.2 V Oscillator Freq. Vpol Input Current V Threshold Switching Speed Unit V mA mW V °C °C Vcc = 3.3 to 8V Tj = -40 to +85°C 0 8 Vcc = 3.3 to 8V Tj = -40 to +85°C Document number: DS32049 Rev. 2 - 2 mA mA mA mA mA V V kHz 0.5 50 (Set by Rcal) ZNBG3118 2.5 24 24 14 14 -2.0 -2.0 800 3 of 10 www.diodes.com 10 2.5 0.05 %/V ppm 15 12 mA mA %/V %/°C February 2010 © Diodes Incorporated A Product Line of Diodes Incorporated ZNBG3118 Electrical Characteristics (Continued) NEW PRODUCT Parameter Measured at Tamb = 25°C, Vcc = 5V, Rcal = 39k (setting Id to 10mA) unless otherwise specified. Conditions Output Noise Drain Voltage Gate Voltage Cgate-gnd = 4.7nF, Cdrain-gnd = 10nF ICgate-gnd = 4.7nF, Cdrain-gnd = 10nF Tone Detector Threshold 22kHz sq.wave, trise = tfall = 10us Noise Rejection LO Output Stage Lov Voltage Rng. Lov Bias Cur. I_LB/HB Max I_LB/HB Max Min Limits Typ. Units Max 0.02 0.005 100 150 Square wave signal, 1Vpk-pk 1.0 5.0 Note 1 Vlov = 0 Vlov = -0.5V to Vcc – 1.0V Vlov = Vcc – 1.0V to Vcc -0.5 0 0.25 Vpk-pk Vpk-pk mV pk-pk kHz 300 Vcc 1.0 35 V uA mA uA 100 LB Vout Low LB Vout High HB Vout Low HB Vout High Vlov = 0, Il = 0, Rlb-csub = 1MΩ, Tone enabled Vlov = 0, Il = 10mA, Tone disabled Vlov = 0, Il = 0, Rhb-csub = 1MΩ, Tone disabled Vlov = 0, Il = 10mA, Tone enabled -3.0 -0.025 -3.0 -0.025 -2.5 0 -2.5 0 -2.0 0.025 -2.0 0.025 V V V V LB Vout Low LB Vout High HB Vout Low HB Vout High Vlov = 4.0, Il = 0, Rlb-gnd = 1MΩ, Tone enabled Vlov = 4.0, Il = 35mA, Tone disabled Vlov = 4.0, Il = 0, Rhb-gnd = 1MΩ, Tone disabled Vlov = 4.0, Il = 35mA, Tone enabled -0.1 3.9 -0.1 3.9 0 4.0 0 4.0 0.1 4.1 0.1 4.1 V V V V LB Vout Low LB Vout High HB Vout Low HB Vout High Vlov = Vcc, Il = 0, Rlb-gnd = 1MΩ, Tone enabled Vlov = Vcc, Il = 100uA, Tone disabled Vlov = Vcc, Il = 0, Rhb-gnd = 1MΩ, Tone disabled Vlov = Vcc, Il = 100uA, Tone enabled -0.1 Vcc-0.1 -0.1 Vcc-0.1 0 Vcc 0 Vcc 0.1 Vcc+0.1 0.1 Vcc+0.1 V V V V Notes: 1. V_Lov – V_LB or V_HB should not be allowed to exceed 6.0V. Care should be taken concerning the Off-state voltages of outputs LB and HB if V_Lov is set to greater than 6.0V. Similarly, Vcc – V_LB or V_HB should not be allowed to exceed 8.5V. 2. ESD sensitive, handling precautions are recommended. ZNBG3118 Document number: DS32049 Rev. 2 - 2 4 of 10 www.diodes.com February 2010 © Diodes Incorporated A Product Line of Diodes Incorporated ZNBG3118 Typical Characteristics (Measured at TAMB = 25°C, VCC = 5V, RCAL = 39k (setting ID to 10mA) unless otherwise stated) 2.5 16 2.4 14 NEW PRODUCT Drain Voltage (V) Drain Current (mA) 2.3 12 10 8 6 4 2.2 2.1 2 1.9 1.8 1.7 2 1.6 1.5 0 0 20 40 60 80 100 120 140 160 180 200 0 2 4 6 8 10 12 14 16 Drain Current (mA) RCAL Value (kΩ ) Drain Current vs RCAL Value Drain Voltage vs Drain Current Single Universal Block Diagram Figure 1 shows the main elements of a typical single universal LNB. The ZNBG3118 is compliant with virtually all markets including the fleet of Astra satellites. The simple but flexible solution provides the negative rail, FET bias control, polarisation switch control, tone detection and band switching with the minimum of external components. The ZNBG3118 can be also used in other DBS applications such a twin output, mono-block and Low power LNB’s. Figure 1 Typical single universal LNB system diagram Polarization and band switching on the ZNBG3118 uses the standard 13V-17V and 22kHz as defined by Astra. The exception is that the devices voltage detector has a much tighter tolerance than defined to increase field reliability. The tone detector has been designed to cope with distorted 22kHz tones so reliability is maintained with regional differences and variations on set-top box designs. Tone detection and band switching has been designed to meet various different system architectures. The following diagrams (figures 2 to 4) show how this feature operates in an LNB and the external components required. The presence or absence of a 22kHz tone applied to pin FIN enables one of two outputs, LB and HB. A tone present enables HB and tone absent enables LB. The LB and HB outputs are designed to be compatible with MMIC, Discrete (bipolar or FET) and PLL based local oscillator applications and are easily configured by the LOV pin. Bi-polar or FET local oscillators Referring to Figure 2 wiring pin LOV to a positive voltage source (e.g. a potential divider across VCC and ground set to the required oscillator supply voltage, VOSC) will force the LB and HB outputs to provide the required oscillator supply. VOSC when enabled and 0V when disabled. Driving loads of up to 35mA, the maximum allowed programmed output voltage of LB and HB is VCC -1V. If a greater supply voltage is required for the oscillators then it may be possible to use an oscillator circuit. ZNBG3118 Document number: DS32049 Rev. 2 - 2 5 of 10 www.diodes.com February 2010 © Diodes Incorporated A Product Line of Diodes Incorporated ZNBG3118 MIMIC local oscillators Referring to Figure 3 wiring pin LOV to ground will force LB and HB to switch between -2.5V (disabled) and 0V (enabled). Note that Vcc(max) should not exceed 6.0V when using this configuration. Logic enabled PLL local oscillators Referring to Figure 4 connecting the LOV pin to Vcc will pull the LB and HB to VCC when enabled and 0V when disabled. Using the same supply voltage for the ZNBG3118 and the PLL local oscillator block, the LB and HB outputs will provide a suitable logic signal of up to 100uA to drive the LO select pin of a PLL system. D3 G3 D12 NEW PRODUCT G2 Local Oscillator Configurations G1 RLB1 LB ZNBG3118 Gnd RHB1 HB Cnb1 Vcc Cnb2 Lov RLB2 Q2 CHB Vpol Fin Rcal Csub CSUB 47nF CLB RHB2 RLV1 CNB 47nF Q1 RLV2 RCAL 39k 9.75GHz Local Osc. CFIN 330pF 10.6GHz Local Osc. Vcc RPOL 10k LNB Downf eed Vcc D3 G3 D12 G2 Figure 2 Applications circuit for the ZNBG3118 using Bi-polar oscillators G1 LB ZNBG3118 Gnd RLB1 Cnb1 Vcc Cnb2 Lov G1 RHB1 HB Local Osc. MMIC G2 RHB2 240k Vpol Fin CSUB 47nF Rcal Csub CNB 47nF RLB2 240k CLB CHB RCAL 39k CFIN 330pF RPOL 10k LNB Downf eed Figure 3 Applications circuit for the ZNBG3118 using MIMIC local oscillators ZNBG3118 Document number: DS32049 Rev. 2 - 2 6 of 10 www.diodes.com February 2010 © Diodes Incorporated A Product Line of Diodes Incorporated Vcc D3 G3 D12 G2 ZNBG3118 G1 LB ZNBG3118 Gnd HB HB Cnb1 Vcc Cnb2 Lov CNB 47nF Vpol Fin Rcal Csub RHB CSUB 47nF NEW PRODUCT Local Osc. PLL RCAL 39k CFIN 330pF RPOL 10k LNB Downf eed Figure 4 Applications circuit for the ZNBG3118 using logic controlled PLL local oscillators at 3.3V Functional Tables ZNBG3118 System Function Inputs Vin (V) <14.0 >15.5 <14.0 >15.5 Fin (kHz) 0 0 22 22 FET 1 Disabled Active Disabled Active Outputs FET 3 Active Active Active Active FET 2 Active Disabled Active Disabled LB(1) Active Active Disabled Disabled HB(1) Disabled Disabled Active Active Note 1: See LO description above and the table below for explanation of Active and Disabled. Tone Detection Function Lov Gnd Vosc Vcc Fin (kHz) 0 22 0 22 0 22 LB HB Enabled Disabled Enabled Disabled Enabled Disabled Disabled Enabled Disabled Enabled Disabled Enabled LB Gnd -2.5V Vosc Note (2) Vcc – 0.1V Note (2) HB -2.5V Gnd Note (2) Vosc Note (2) Vcc – 0.1V Note 2: 0 Volts in a typical LNB application but dependant on the external circuits ZNBG3118 Document number: DS32049 Rev. 2 - 2 7 of 10 www.diodes.com February 2010 © Diodes Incorporated A Product Line of Diodes Incorporated ZNBG3118 Applications Information * L1 * L3 C2 10nF * C1 J1 J3 * L2 G1 RLB1 LB ZNBG3118 Gnd RHB1 HB Cnb1 Vcc Cnb2 Lov RLB2 * Stripline Elements RLV1 CLB RHB2 Q5 CHB Vpol Fin Rcal CNB 47nF CSUB 47nF * C10 D3 C9 10nF G3 C4 10nF * C3 G2 * C5 * L4 Csub NEW PRODUCT C6 10nF * C8 J2 D12 * L3 C7 10nF RLV2 Q4 RCAL 39k 9.75GHz Local Osc. CFIN 330pF 10.6GHz Local Osc. RPOL 10k Vcc LNB Downf eed Figure 5 Applications circuit for the ZNBG3118 using Bi-polar local oscillators Figure 5 is a typical applications circuit for the ZNBG3118, showing all the external components required for appropriate biasing. The bias circuits are unconditionally stable over the full temperature range with the associated FETs and gate and drain capacitors in circuit. Capacitors C2, C4, C6, C7 and C9 ensure that residual power supply and substrate generator noise is not allowed to affect external circuits which may be sensitive to interference. They also serve to suppress any potential RF feed through between stages via the ZNBG3118. These capacitors are required for all stages used. Values around 10nF are recommended however this is design dependent and any value between 1nF and 100nF could be used. The capacitor CSUB is an integral part of the ZNBG3118 negative supply generator. The negative bias voltage is generated on-chip using an internal oscillator. The required value of capacitor CSUB is 47nF. This generator produces a low current supply of approximately -2.5V. Although this generator is intended purely to bias the external FETs, it can be used to power other external low current circuits via the CSUB pin. Note that the exposed pad of the package must be either left floating or connected to Csub. Resistor RCAL sets the drain current at which all external amplifier FETs are operated. To minimize the pin-count and package size Drain 1 (D1) and Drain 2 (D2) share a common pin. If any bias control circuit is not required, its related drain and gate connections may be left open circuit without affecting the operation of the remaining bias circuits. The ZNBG3118 has been designed to protect the external FETs from adverse operating conditions. With a JFET connected to any bias circuit, the gate output voltage of the bias circuit can not exceed the range -3V under any conditions, including power up and power down transients. Should the negative bias generator be shorted or overloaded so that the drain current of the external FETs can no longer be controlled, the drain supply to FETs is shut down to avoid damage to the FETs by excessive drain current. ZNBG3118 Document number: DS32049 Rev. 2 - 2 8 of 10 www.diodes.com February 2010 © Diodes Incorporated A Product Line of Diodes Incorporated ZNBG3118 Package Outline Dimensions E A1 QFN16 3x3 Dim Min Max A 0.55 0.65 A1 0.00 0.05 A3 0.15 Typ b 0.18 0.28 D 2.95 3.05 D2 1.40 1.60 e 0.50 BSC E 2.95 3.05 E2 1.40 1.60 L 0.35 0.45 Z 0.625 Typ All Dimensions in mm D A3 E2 Pin #1 ID NEW PRODUCT A L D2 e b Z Note: Controlling dimensions are in millimetres. Approximate dimensions are provided in inches. The package appearance may vary as shown, for further details please contact your local Diodes sales office. Ordering Information (Note x) Device Package ZNBG3118JA16TC QFN1633 Reel Size (inches) 13 Tape Width (mm) 8 Quantity (per reel) 3000 Marking Information Pin 1 ZNBG 3118 YYWW ZNBG3118 Document number: DS32049 Rev. 2 - 2 Part Name Date Code Year/Week 9 of 10 www.diodes.com February 2010 © Diodes Incorporated A Product Line of Diodes Incorporated ZNBG3118 IMPORTANT NOTICE NEW PRODUCT DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION). Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes without further notice to this document and any product described herein. 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