HMC980 v00.0312 Active Bias Controller High Current Bias Controllers - Chip Typical Applications Features • Automatic Gate voltage adjustment (No Calibration required) • Microwave Radio & VSAT • Military & Space • Supply Voltage (5V to 16.5V) • Test Instrumentation • Bias both Enhancement or Depletion type devices • Fiber Optic Modulator Driver Biasing • CATV Laser Driver Biasing • Cellular Base Station • Wireless Infrastructure Equipment Functional Diagram • Adjustable Drain Current up to 1.6 A • Sink or source gate current • Internal negative voltage generation • Can be disabled to use external negative rail • Fast Enable/Disable • Trigger-out Output for Daisy Chain • Power-Up and Power-Down Sequencing • Over/Under Current Alarm with built-in hystresis • Die Size: 1.4 x 2.26 x 0.25mm General Description HMC980 is an active bias controller that can automatically adjust the gate voltage of an external amplifier to achieve constant bias current. With an integrated controller, HMC980 achieves safe power on/ off, disable/enable and automatic supply sequencing ensuring the safety of the external amplifier. It can be used to bias any enhancement and depletion type amplifier operating in Class-A regime with drain voltages (VDRAIN) from 5V to 16.5V and drain currents (IDRAIN) up to 1.6 A, offering a complete biasing solution. HMC980 achieves excellent bias stability over supply, temperature and process variations, and eliminates the required calibration procedures usually employed to prevent RF performance degradation due to such variations. All data shown herein is taken with appropriate probes. 1 For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com Application Support: Phone: 978-250-3343 or [email protected] HMC980 v00.0312 Active Bias Controller High Current Electrical Specifications, TA = +25°C, VDD=12V, VDIG= 3.3V, Depletion Master Unless Otherwise Noted Symbol Conditions Vdd IDIG Charge Pump Oscillator Frequency FOSC Voltage Reference VREF ALMTRIG Input Threshold Enable Input Threshold S0, S1 Input Threshold ALMTRIG ENTHRS SWTHRS Max. 16.5 Units V EN = VDIG 19 mA EN = GND 7.5 mA EN = VDIG 20 mA EN = GND 9 mA VDIG= 3.3 V 3.5 mA VDIG= 5 V 6.5 mA 300 kHz IDD VDD = 12V VDIG Quiescent Current Typ. 5 VDD = 5V VDD Quiescent Current Min. 1.44 Vinlow Vinhigh V 1 V 1 V 1.4 V Vinlow Vinhigh V 1 1.4 V Vinlow Vinhigh 1.4 V VDRAIN Characteristics DRAIN Current Adjustment Range DRAIN Current Change Over Digital Voltage DRAIN Current Change Over Temperature DRAIN Range VDRAIN Change Over Temperature IDRAIN ΔIDRAINV S1=S0=GND 0.05 0.3 A S1=GND, S0=VDIG 0.3 0.6 A S1=VDIG, S0=GND 0.6 1.2 A S1=VDIG, S0=VDIG 1.2 1.6 VDRAIN set to 12V, IDRAIN set to 400 mA VDRAIN ΔVDRAIN %/V 0.023 %/C 5 VDRAIN set to 12V, IDRAIN set to 400 mA A 0.4 16.5 0.02 Bias Controllers - Chip Parameter Supply Voltage V %/C VNEG Characteristics Negative Voltage Output VNEG VNEG Current Sink INEG 0 -2.46 IG -4 V 60 mA 4 mA VGATE Characteristics GATE Current Supply VGATE Low Level VG_MIN VNEG V VGATE High Level VG_MAX VNEG+4.5 V VG2 Characteristics VG2 Current Supply VG2 Adjustment Range IG2 VG2<2V -0.1 0.1 mA 6V>VG2>2V -1 1 mA VG2>6V -5 5 mA 1 VDD-1.3 V 3.3 5 V VG2 VDIG Characteristics Adjustment Range VDIG Quiescent Current VDIG IDIG VDD= 12V, VDIG=EN =3.3 V 3.5 mA SW Characteristics Internal Switch Resistance RDS_ON S1=S0=GND 2.8 Ohm S1=GND, S0=VDIG 1.55 Ohm S1=VDIG, S0=GND 0.85 Ohm S1=VDIG, S0=VDIG 0.7 Ohm For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com Application Support: Phone: 978-250-3343 or [email protected] 2 HMC980 v00.0312 Active Bias Controller High Current Bias Current Accuracy[1] Bias Current Accuracy[2] 1475 IDrain is set to: 388mA 400 1425 IDRAIN (mA) IDRAIN (mA) IDrain is set to: 1409mA 1450 395 390 385 1400 1375 1350 380 +25 C +85 C -55 C 375 +25 C +85 C -55 C 1325 1300 370 3.3 3.5 3.6 3.8 4.0 4.2 4.3 4.5 4.7 4.8 3.3 5.0 3.5 3.6 3.8 4 4.3 4.5 4.7 4.8 5 Shutdown Waveform Power Up Waveform 14 14 12 12 VDD (V) VDRAIN (V) VDIG(V) VG2 (V) VNEG (V) VGATE (V) 8 VDD(V) VDRAIN (V) VDIG (V) VG2 (V) VNEG (V) VGATE (V) 10 VOLTAGE (V) 10 6 4 2 8 6 4 2 0 0 -2 -2 -4 -4 0 10 20 30 40 50 60 TIME (ms) 70 80 90 100 Enable Waveform 0 20 40 60 80 100 120 TIME (ms) 140 160 180 200 Disable Waveform 14 16 12 12 EN(V) VDRAIN (V) VG2 (V) VNEG (V) VGATE (V) 10 VOLTAGE (V) 8 VOLTAGE (V) 4.2 VDIG (V) VDIG (V) VOLTAGE (V) Bias Controllers - Chip 405 4 0 8 6 4 2 0 -4 EN(V) VDRAIN (V) VG2 (V) VNEG (V) VGATE (V) -8 -2 -4 -6 -12 0 1 2 3 4 5 TIME (ms) 6 4 5 6 7 8 9 10 TIME (ms) [1] HMC637LP5 is used as external amplifier [2] HMC591LP5 is used as external amplifier 3 For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com Application Support: Phone: 978-250-3343 or [email protected] HMC980 v00.0312 Active Bias Controller High Current 6 6 5 5 4 3 2 100 150 200 +25C +85C -55C 3 +25C +85C -55C 50 4 250 2 300 300 350 400 Load Regulation @ VDD=16.5V, VDIG=5.0V, SW0=GND, SW1=VDIG 500 550 17 17 16 16 15 15 +25C +85C -55C 14 14 +25C +85C -55C 13 600 700 800 900 1000 1100 13 1200 1200 1300 1400 1500 1600 IDRAIN (mA) IDRAIN (mA) VNEG Load Regulation @ VDD=5V VNEG Load Regulation @ VDD=16.5V -2 -2 -2.1 -2.1 -2.2 -2.2 VNEG (V) VNEG (V) 600 Load Regulation @ VDD=16.5V, VDIG=5.0V, SW0=VDIG, SW1=VDIG VDRAIN (V) VDRAIN (V) 450 IDRAIN (mA) IDRAIN (mA) Bias Controllers - Chip Load Regulation @ VDD=5V, VDIG=3.3V, SW0=3.3V, SW1=GND VDRAIN (V) VDRAIN (V) Load Regulation @ VDD=5V, VDIG=3.3V, SW0=GND, SW1=GND -2.3 -2.4 +25 C +85 C -55 C -2.3 -2.4 +25 C +85 C -55 C -2.5 -2.5 0 5 10 15 INEG (mA) 20 25 30 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 INEG (mA) For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com Application Support: Phone: 978-250-3343 or [email protected] 4 HMC980 v00.0312 Active Bias Controller High Current 40 -2.2 40 -2.25 30 -2.25 30 20 -2.3 20 10 -2.35 10 -2.4 0 -2.4 0 VNEG (V) -2.3 -2.35 -2.45 -10 -20 -2.5 -20 -2.55 -30 -2.55 -30 -2.6 -40 -2.6 -2.45 -10 -2.5 0 1 2 3 4 5 6 7 8 9 10 -40 0 1 2 3 4 TIME (ms) 6 7 8 9 10 VG2 Load Regulation @ VDD=12V [1] 0 10 9 -0.25 IDrain is set to : 388mA VG2=0.97V VG2=1.81V VG2=3.73V VG2=6.68V 8 7 VG2 (V) -0.5 -0.75 -1 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 IDrain is set to : 388mA 6 5 4 3 +25C +85C -55C -1.25 -1.5 5 TIME (ms) VGATE Load Regulation @ VDD=12V [1] VGATE (V) INEG (mA) VNEG (V) VNEG Load Transient VDD=16.5V -2.2 INEG (mA) Bias Controllers - Chip VNEG Load Transient VDD=5V 2 1 6 7 0 -8 -6 -4 -2 0 2 4 6 8 IG2 (mA) IG (mA) VNEG Line Regulation vs. Supply Voltage -2.44 No load condition VNEG (V) -2.46 -2.48 +25C +85C -55C -2.5 5 7 9 11 13 15 17 SUPPLY VOLTAGE (V) [1] HMC637LP5 is used as external amplifier 5 For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com Application Support: Phone: 978-250-3343 or [email protected] HMC980 v00.0312 Active Bias Controller High Current VDD 18V S0, S1, EN, ALM,ALMTRG, VREF, VNEGFB, VGATEFB, TRIG_OUT, ISENSE, ALML, ISET, ALMH, FIXBIAS -0.5V to VDIG + 0.5V CP_VDD VDD-0.5V to VDD+0.5V CP_OUT, VG2_CONT, VG2, VDRAIN -0.5V to VDD + 0.5V VDIG 5.5V VNEG -4V to GND VGATE VNEG to GND Junction Temperature 125 °C Continuous Pdiss (T = 85 °C) (Derate 94.79 mW/°C above 85 °C) 3.8 Watt Thermal Resistance (RTH) (Junction to package bottom) 10.6 °C/W Storage Temperature -65 to +150 °C Operating Temperature -55 to +85 °C ESD Sensitivity (HBM) Class 1A Note that there are two different voltage domains on HMC980; a high voltage domain Vdd, and a low voltage domain VDIG. Take necessary precautions not to violate ABS MAX ratings of each subdomains. ELECTROSTATIC SENSITIVE DEVICE OBSERVE HANDLING PRECAUTIONS Outline Drawing Bias Controllers - Chip Absolute Maximum Ratings NOTES: 1. ALL DIMENSIONS ARE IN INCHES [MM] 2. DIE THICKNESS IS .010” 3. BOND PAD PER TABLE 4. BOND PAD METALIZATION: ALUMINUM 5. NO BACKSIDE METAL 6. OVERALL DIE SIZE ±.002” For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com Application Support: Phone: 978-250-3343 or [email protected] 6 HMC980 v00.0312 Active Bias Controller High Current Bias Controllers - Chip Pad Descriptions 7 Pad Number Function Description 1,12,13,20,21, 35 GND These pads and the die bottom must be connected to a high quality RF/DC ground. 2 ALM Over/under current alarm. Provides an active high signal (VDIG) if the quiescent bias exceed the upper threshold or drops below the lower threshold. 19 TRIGOUT Trigger out signal. Generates a HIGH (3.3V) signal when the active bias system stabilizes. This signal can be used to trigger next device (ENABLE) if more than one HMC980 is used in a daisy chain. 3 ALMTRG Dummy alarm trigger signal to create test alarm when taken HIGH (3.3V). Defaults to LOW (GND) when left floating. 4 EN Enable pad. Bias control loop is enabled when Ven is HIGH(VDIG). If left floating, Ven defaults to HIGH (enabled). 5,6 S1,S0 Control pads for internal switch resistance. If left floating, default to HIGH. Refer to Table-1 in Application Notes for recommended settings. 7,8,9,10,11 VDD Bias supply Pad. Connect supply voltage to this pad with appropriate filtering. 14 FIXBIAS A high precision (e.g. 0.5%, ±25 ppm TCR) 10K resistor to ground is recommended for good bias accuracy. Interface Schematic For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com Application Support: Phone: 978-250-3343 or [email protected] HMC980 v00.0312 Active Bias Controller High Current Pad Descriptions (Continued) Function Description 15 ALMH A high precision resistor (e.g. 0.5%, ±25 ppm TCR) to ISet pad is recommended for good bias accuracy. The value of the resistor sets the threshold. If alarm feature is not used ALMH can be shorted to ISet. ISET A high precision resistor (e.g. 0.5%, ±25 ppm TCR) between ALML and ISet is recommended for good bias accuracy. The total external resistance from ISet pad to GND should always be equal to 5 k Ω. ALML A high precision resistor (e.g. 0.5%, ±25 ppm TCR) to GND is recommended for good bias accuracy. The value of the resistor sets the threshold value for under current alarm. If alarm feature is not used ALML can be shorted to ISet. ISENSE Drain current adjustment pad. To adjust the bias current of the external amplifier connect a resistor (Rsense) from ISENSE pad to GND according to eqn(2) on page 13-15. A high precision resistor (e.g. 0.5%, ±25 ppm TCR) is recommended for good bias accuracy. 16 17 18 Interface Schematic For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com Application Support: Phone: 978-250-3343 or [email protected] Bias Controllers - Chip Pad Number 8 HMC980 v00.0312 Active Bias Controller High Current Bias Controllers - Chip Pad Descriptions (Continued) 9 Pad Number Function Description 22,23,24,25 26 VDRAIN Drain voltage. Should be connected to the supply terminal of the external amplifier. A minimum 10 nF capacitor has to be placed close to the external amplifier to improve load regulation. VGATE Gate Control pad for external amplifier. Connect to the gate (base) of the external amplifier. In order to guarantee stability, a 2.2μF capacitor should be connected between the gate (base) terminal of the external amplifier and GND as close to the amplifier as possible. 28 VNEG Negative input to the chip. Should be supplied with CPOUT when negative voltage generator is enabled, or connect to external VSS when negative voltage generator is enabled. Defaults to -2.5V. If a value different than -2.5V required, please contact factory. 29 VG2 Second gate control. 30 VG2_CONT Control voltage of the second gate pad VG2. Use a resistor divider between VDD and GND to set the voltage. VG2 is typically 1.3V lower than the VG2CONT. 27 Interface Schematic For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com Application Support: Phone: 978-250-3343 or [email protected] HMC980 v00.0312 Active Bias Controller High Current Pad Descriptions (Continued) Function Description 31 VGATEFB Control pad for VGATEFB. Float VGATEFB when a depletion mode transistor is biased. Selects the mode of operation along with VNEGFB pad. 32 VNEGFB Feedback (Control) pad for Negative Voltage Generator Charge Pump. Float to activate the negative voltage generator / Short to GND to disable the negative voltage generator. 33 VREF 1.44V reference voltage. 34 VDIG 3.3V-5V Digital Bias supply Pad. Connect supply voltage to this pad with appropriate filtering. 37 CP_OUT Negative voltage generator charge pump output. Negative voltage generator requires a flying capacitor, a reservoir capacitor and two diodes to operate. 38 CP_VDD Bias supply for negative voltage generator. Connect supply voltage with appropriate filtering. CP_VDD supply voltage should be same as VDD. Interface Schematic For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com Application Support: Phone: 978-250-3343 or [email protected] Bias Controllers - Chip Pad Number 10 HMC980 v00.0312 Active Bias Controller High Current Bias Controllers - Chip Application Circuit Notes: [1] A variable resistor is assembled on RSENSE slot to adjust bias current for evaluating various different amplifiers without soldering. 11 For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com Application Support: Phone: 978-250-3343 or [email protected] HMC980 v00.0312 Active Bias Controller High Current Detailed Description All amplifiers require stable quiescent current to operate at their specifications. Many amplifiers in the market require external biasing to achieve stable quiscent current. HMC980 is a fully integrated biasing solution for such amplifiers. With an internal feedback, the automatic gate voltage control achieves constant quiescent bias through the amplifier under bias, independent of temperature and amplifier threshold variations. The quiescent current is adjusted with a resistor connected externally. The HMC980 employs an integrated control circuitry to manage safe power-up and power-down sequencing of the targeted amplifier. The HMC980 can provide auto-bias solution to virtually any amplifier in the market (both enhancement and depletion type) with a quiescent current of up to 1.6A and a supply voltage of up to 16.5V. The HMC980 has an integrated negative voltage generator to create negative voltages required to drive depletion mode amplifiers. If an external negative supply is already available or an enhancement mode device is targeted, the negative voltage generator can be disabled. The HMC980 achieves excellent bias stability over supply and temperature variations. The gate control can both sink and source current (±4 mA) which is required to compensate for charging gate current of the amplifier over input power variations. The HMC980 also generates a second gate voltage VG2. VG2 can be adjusted through a resistor divider connected to VDD for the amplifiers which require second gate voltage. The HMC980 ensures safety of the external amplifier during turn on/off by automatically adjusting the sequence of VDRAIN, VGATE and VG2 outputs. Bias Controllers - Chip Application Notes The HMC980 has a built-in over-under current alarm feature. If a fault conditions arises (either under or over current) an alarm signal is generated (ALM, active HIGH). The current alarm signal provided in HMC980 does not affect the operation of the controller. It is included for monitoring purposes where a system level protection can be implemented with external control circuitry. The HMC980 employs S0, S1 pads to control RDS_ON resistance of the internal switch between VDD and VDRAIN. Refer to the section under the “Supply and Drain Voltage” section for details. The HMC980 has a built-in self protection feature to protect itself against short circuit conditions at the VDRAIN output. The HMC980 has also a built-in VNEG fault protection feature to protect both itself and the amplifier under bias against short circuit conditions at the VNEG pad. Digital Power Supply (VDIG) The HMC980 requires an external low voltage bias rail (3.3V to 5.0V). VDIG powers the internal logic circuitry. VDIG draws and average of 3.5 mA from a 3.3V. VDIG can accept voltages up to 5.0V. Supply and Drain Voltage (VDD and VDRAIN) The VDD supply to the HMC980 is directly connected to the VDRAIN output through an internal MOSFET switch. This internal MOSFET is controlled through power-up sequencing which ensures that no voltage is applied to the drain of the external amplifier until the gate voltage is pulled down to VNEG (ensuring external amplifier is pinched-off). The VDRAIN output of the HMC980 should be connected to the drain (collector) of the amplifier under bias for the active bias control feedback and power-up/down sequencing to operate properly. There will be a voltage drop from VDD to VDRAIN due to finite RDS_ON resistance of the internal switch. To compensate for this voltage drop choose the VDD value as shown in equation (1). VDD = VDRAIN + IDRAIN x RDS_ON (1) For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com Application Support: Phone: 978-250-3343 or [email protected] 12 HMC980 v00.0312 Active Bias Controller High Current Bias Controllers - Chip where VDRAIN is the supply voltage of the external amplifier and IDRAIN is the desired constant bias current through the external amplifier. Note that RDS_ON resistance of the internal FET switch can be adjusted through S0, S1 pads based on the DRAIN current requirement as shown in table-1. RDS_ON is typically equal to 0.7 Ohm when S0 and S1 are pulled up to VDIG, and is typically equal to 2.8 Ohm when S0 and S1 are pulled down to GND. If S0 and S1 pads are left floating, it is pulled up to VDIG through an internal weak pull-up. Recommended settings for the S0 and S1 positions are given in Table-1. Not using the HMC980 in the recommended settings may increase the power dissipation of the part and the part-to-part variation. Table 1. Recomended Current Range Configuration Current Range (A) Condition RD_ON Value (Ohm) 0.05 to 0.3 S1=S0=GND 2.8 0.3 to 0.6 S1=GND, S0=VDIG 1.55 0.6 to 1.2 S1=VDIG, S0=GND 0.85 1.2 to 1.6 S1=VDIG, S0=VDIG 0.7 Negative Voltage Generator (VNEGOUT) The HMC980 has internal regulated charge pump circuitry to generate the negative voltage (VNEGOUT) required for depletion mode devices. The HMC980 generates -2.5V at the VNEGOUT output in default configuration. It requires two diodes and two capacitors connected externally as shown in the sample application schematics. It can be disabled through the VGATEFB and VNEGFB pads, if an enhancement device is targeted or a negative supply is already available in the system. In this configuration, simply connect the available negative supply to the VNEG pad. See Table-2 for the operation mode selection. The HMC980 is designed to reject the ripple on the VNEGOUT pad by isolating VNEGOUT from the VGATE. Thus, switching noise of the charge-pump is effectively isolated from the external amplifier. Enable/Disable (EN) The active bias control loop is enabled when EN is pulled up to VDIG, and it is disabled when it is pulled down to GND. If EN is left floating HMC980 is enabled through an internal weak pull-up. Note that VNEG operation is independent of EN condition. EN signal controls the operation of only VGATE, VG2 and VDRAIN outputs. When EN pulled down to GND, the HMC980 discharges VDRAIN and VG2 down to GND and it pulls the VGATE down to VNEG. When EN pulled high to VDIG, HM980 enables, VDRAIN and VG2, and enables the bias control loop to automatically adjust the VGATE voltage. Please see the “Active Bias Control Loop” section for detailed explanation and refer to the Enable and Disable waveforms for transient characteristics. Active Bias Control Loop The HMC980 regulates the bias current (IDRAIN) of the amplifier under bias through VGATE output connected to the gate of the external amplifier. In this closed loop operation the current passing through the amplifier under bias is sampled and is used to automatically adjust VGATE to achieve constant quiescent bias through the external amplifier. The HMC980 continuously adjusts VGATE voltage to achieve constant DRAIN current over any supply, temperature, process variations and threshold drifts due to aging. The part-to-part, temperature, and supply variation of the HMC980 is excellent. Thus, by using an accurate sense resistor connected to the ISENSE pad, expensive calibration procedures in high volume production could be avoided. The gate control of the HMC980 is designed to both sink and source current in to the gate of the targeted amplifier (at least ±4 mA). This unique feature is important to achieve nearly constant quiescent bias through the amplifier under varying gate current at different input power values. 13 For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com Application Support: Phone: 978-250-3343 or [email protected] HMC980 v00.0312 Active Bias Controller High Current IDRAIN=150/Rsense (A) (2) VG2 Voltage Adjustment The HMC980 generates a second gate voltage (VG2). VG2 can be adjusted through a resistor divider connected to VG2_CONT for the amplifiers which require second gate voltage. Eqn. (3) gives the formula to adjust VG2 : VG2(V)= VDD*R4/(R3+R4) - 1.3 (3) For instance, choosing 5.1k Ohm as R3 and 3.3k Ohm as R4 sets VG2 voltage to 3.4V when VDD=12V. For improved accuracy, choose resistor values below 5k Ohm on R3. Self Protection Feature Due to the small resistance of the internal switch FET between VDD and VDRAIN, a large amount of current may flow through the HMC980. HMC980 limits the maximum current to self protect itself under such fault conditions, by turning off VDRAIN and VGATE. The HMC980 will remain in this protection mode until a full power-cycle or enable/disable cycle is applied. VNEG Fault Detection Feature In depletion mode operation VNEG is continuously monitored against short circuit fault to GND. If VNEG rises above a preset value (typically -0.6V) the system and the external amplifier are disabled by pulling VDRAIN and VG2 to GND and VGATE to VNEG. The system will stay in this stand-by mode until short fault at VNEG is fixed. Bias Controllers - Chip The bias current passing through the external amplifier can be adjusted with RSENSE, where RSENSE is the R10 connected from ISENSE to GND. Use the relation given in equation (2) to set the desired bias current through the external amplifier. Over/Under Current Alarm The HMC980 provides over and under current alarm indicator ALM (pad#2) signal. The ALM is pulled up to VDIG when the IDRAIN current exceeds ± 6% (With the given R11, R12, and R13 values in application circuit) of IDRAIN regulation target value as shown in Figure 1. The alarm threshold level is user adjustable through R11,R12, and R13 according to the following equations: Over current ALM Threshold = Iocth = IDRAIN (1+R11/(R12+R13)), Under current ALM Threshold = Iucth = IDRAIN (1-R12/(R12+R13)) , where R12+R13 should always be equal to 5 kΩ (%1 accuracy) Threshold values possess a small built-in hysterisis. The condition of ALM signal does not effect the operation of HMC980. It is provided only for monitoring purposes. For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com Application Support: Phone: 978-250-3343 or [email protected] 14 HMC980 v00.0312 Bias Controllers - Chip Active Bias Controller High Current Over current Set current Under current ALARM Figure 1. Current Alarm Behavior Power-up and Enable Sequencing To ensure the safety of the external amplifier, the HMC980 provides an automatic power-up sequence for enabling the active bias control loop. During start-up VDRAIN and VG2 are kept at GND while VGATE is taken to the most negative supply available (VGATE=VNEG). This ensures that external amplifier is completely pinched-off before VDRAIN is applied. When EN signal is received, VDRAIN is applied and the active bias loop is enabled. After the VDRAIN is applied, VG2 is generated. The power-up sequence is completed by increasing the VGATE linearly until the set IDRAIN value is reached. For power-down and disabling, the same sequencing is applied in the reverse order. Daisy-Chain Operation HMC980 produces a trigger out signal (TRIGOUT pad#19) when the quiscent current is in regulation. This trigger signal can be used to enable additional HMC980 chips in a chain of amplifiers. The triggering sequence can be routed in any way, from input to output, or from output to input depending on the use. Figure-2 shows a sample use of three HMC980s in an amplification chain. Please note that, only one of the HMC980 (in master mode) is used to generate the negative voltage and the remaining HMC980 (in slave mode) is set to receive external negative voltage (which is provided from the master depletion mode HMC980). Generating negative voltage from a single HMC980 reduces the number of the components in the system, and decreases the over all current consumption. Please note that, to ensure proper start-up, the system enable signal should be applied to the depletion master mode device that has the negative voltage generator. 15 For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com Application Support: Phone: 978-250-3343 or [email protected] HMC980 v00.0312 Bias Controllers - Chip Active Bias Controller High Current Figure 2. Daisy Chain Operation Operation Modes HMC980 can be configured to bias both enhancement and depletion mode external amplifiers. The mode of operation can be selected by setting two pads (VNEGFB, VGATEFB) as tabulated in Table-2. The connection to the VNEGIN should be adjusted accordingly. In order not to bias external amplifier in a wrong region, please make sure that the correct mode of operation is selected before powering up the HMC980. The HMC980 does not allow the internal negative voltage generator to work if an enhancement mode is selected. Therefore, if VNEGFB is left floating while VGATEFB is grounded, HMC980 will stay in standby mode. Please note that in depletion slave mode the external negative voltage should be between -2.3V to -3.5V for HMC980 to operate. If your application requires negative voltages outside this range please contact Hittite application support. Table 2. Mode Selection VNEGFB MODE1 (Depletion/Master Mode) MODE2 (Depletion/Slave Mode) --MODE3 (Enhancement Mode) VNEGIN Description FLOAT Connected to VNEGOUT Depletion mode transistor. Internal negative voltage generator is active and generates -2.5V. Sample application schematic given shown in Fig.3a. GND FLOAT Connected to External VSS Depletion mode transistor. Internal negative voltage generator is disabled. An external negative voltage less than -2.3V should be connected to VNEGIN. Sample application schematic given shown in Fig.3b. FLOAT GND N/A Not allowed. HMC980 stays in standby. GND Connected to GND Enhancement mode transistor. Internal negative voltage generator is disabled. Sample application schematic given shown in Fig.3c. FLOAT GND VGATEFB For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com Application Support: Phone: 978-250-3343 or [email protected] 16 HMC980 v00.0312 Bias Controllers - Chip Active Bias Controller High Current Figure 3a. Depletion/Master Mode Amplifier Typical Application Circuit (Mode 1) Figure 3b. Depletion/Slave Mode Amplifier Typical Application Circuit (Mode 2) 17 For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com Application Support: Phone: 978-250-3343 or [email protected] HMC980 v00.0312 Bias Controllers - Chip Active Bias Controller High Current Figure 3c. Enhancement Mode Amplifier Typical Application Circuit (Mode 3) For biasing Hittite amplifiers compatable with HMC980 refer to the Table 3, where values of the external components are provided on typical application circuit shown in Figure 3a. Table 3 - List of Bias Settings for Various Hittite Amplifiers Hittite Part Number VDRAIN (V) VDD (V) IDRAIN (mA) 5 5.83 295 RSENSE (kOhm) R4 (kOhm) R3 (kOhm) VG2 (V) S1 S0 open open - GND GND GND Gain Blocks & Drivers HMC-AUH256 0.508 LNAs HMC-ALH435 5 5.08 30 5.000 6.13 5 1.5 GND HMC-ALH444 5 5.15 55 2.727 5.95 5 1.5 GND GND HMC490 5 5.56 200 0.750 open open - GND GND HMC490LP5 5 5.56 200 0.750 open open - GND GND HMC594 6 6.28 100 1.500 open open - GND GND HMC594LC3B 6 6.28 100 1.500 open open - GND GND HMC609 6 6.48 170 0.882 open open - GND GND HMC609LC4 6 6.48 170 0.882 open open - GND GND HMC753LP4E 5 5.15 55 2.727 5.95 5 1.5 GND GND Linear & Power HMC-ABH209 5 5.22 80 1.875 open open - GND GND HMC-ABH264 5 5.34 120 1.250 open open - GND GND HMC442 5 5.24 85 1.765 open open - GND GND HMC442LC3B 5 5.24 84 1.786 open open - GND GND For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com Application Support: Phone: 978-250-3343 or [email protected] 18 HMC980 v00.0312 Active Bias Controller High Current Table 3 - List of Bias Settings for Various Hittite Amplifiers (Continued) Bias Controllers - Chip Hittite Part Number HMC442LM1 VDRAIN (V) VDD (V) IDRAIN (mA) RSENSE (kOhm) R4 (kOhm) R3 (kOhm) VG2 (V) S1 S0 5 5.24 85 1.765 open open - GND GND HMC499 5 5.56 200 0.750 open open - GND GND HMC499LC4 5 5.56 200 0.750 open open - GND GND HMC-ABH241 5 5.62 220 0.682 open open - GND GND HMC-APH403 5 5.74 475 0.316 open open - GND VDIG HMC-APH460 5 5.77 900 0.167 open open - VDIG GND HMC-APH462 5 6.22 1440 0.104 open open - VDIG GND HMC-APH473 5 5.92 1080 0.139 open open - VDIG GND HMC-APH478 5 5.77 900 0.167 open open - VDIG GND HMC-APH510 5 5.99 640 0.234 open open - GND VDIG HMC-APH518 5 5.81 950 0.158 open open - VDIG GND HMC-APH596 5 6.12 400 0.375 open open - GND GND HMC-APH608 5 5.81 950 0.158 open open - VDIG GND HMC486 7 8.11 1300 0.115 open open - VDIG GND HMC486LP5 / HMC486LP5E 7 8.11 1300 0.115 open open - VDIG GND HMC487LP5 / HMC487LP5E 7 8.11 1300 0.115 open open - VDIG GND HMC489LP5 / HMC489LP5E 7 8.11 1300 0.115 open open - VDIG GND HMC498 5 5.70 250 0.600 open open - GND GND HMC498LC4 5 5.70 250 0.600 open open - GND GND HMC590 7 7.70 820 0.183 open open - VDIG GND HMC590LP5 / HMC590LP5E 7 7.70 820 0.183 open open - VDIG GND HMC591 7 8.14 1340 0.112 open open - VDIG GND HMC591LP5 / HMC591LP5E 7 8.14 1340 0.112 open open - VDIG GND HMC592 7 8.16 750 0.200 open open - GND VDIG HMC608LC4 5 5.87 310 0.484 open open - GND GND HMC693 5 6.24 800 0.188 open open - GND VDIG HMC756 7 8.22 790 0.190 open open - GND VDIG HMC757 7 8.11 395 0.380 open open - GND GND HMC757LP4E 5 6.12 400 0.375 open open - GND GND HMC863 6 7.05 375 0.400 open open - GND GND HMC863LP4E 6 7.05 375 0.400 open open - GND GND HMC864 6 7.16 750 0.200 open open - GND VDIG HMC906 6 7.02 1200 0.125 open open - VDIG GND 5.5 6.52 1200 0.125 open open - VDIG GND HMC949 7 8.02 1200 0.125 open open - VDIG GND HMC965LP5E 6 7.02 1200 0.125 open open - VDIG GND HMC968 6 6.77 900 0.167 open open - VDIG GND HMC969 6 6.77 900 0.167 open open - VDIG GND HMC943LP5E Wideband (Distributed) 19 HMC-AUH232 5 5.50 180 0.833 5.18 5 1.5 GND GND HMC-AUH249 5 5.56 200 0.750 5.07 5 1.5 GND GND HMC-AUH312 8 8.17 60 2.500 3.06 5 1.8 GND GND For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com Application Support: Phone: 978-250-3343 or [email protected] HMC980 v00.0312 Active Bias Controller High Current Hittite Part Number VDRAIN (V) VDD (V) IDRAIN (mA) RSENSE (kOhm) R4 (kOhm) R3 (kOhm) VG2 (V) S1 S0 HMC460 8 8.17 60 2.500 open open - GND GND HMC460LC5 8 8.21 75 2.000 open open - GND GND HMC463 5 5.17 60 2.500 open open - GND GND HMC463LH250 5 5.17 60 2.500 open open - GND GND HMC463LP5 5 5.17 60 2.500 open open - GND GND HMC465 8 8.45 160 0.938 2.48 5 1.5 GND GND HMC465LP5 8 8.45 160 0.938 2.48 5 1.5 GND GND HMC562 8 8.22 80 1.875 open open - GND GND HMC633 5 5.50 180 0.833 open open - GND GND HMC633LC4 5 5.50 180 0.833 open open - GND GND HMC634 5 5.50 180 0.833 open open - GND GND HMC634LC4 5 5.50 180 0.833 open open - GND GND HMC-930 10 10.49 175 0.857 4.22 5 3.5 GND GND HMC-459 8 8.81 290 0.517 4.77 5 3 GND GND HMC-464 8 8.81 290 0.517 4.77 5 3 GND GND HMC464LP5 / HMC464LP5E 8 8.81 290 0.517 4.77 5 3 GND GND HMC559 10 11.12 400 0.375 4.55 5 4 GND GND HMC619 12 12.84 300 0.500 4.82 5 5 GND GND HMC619LP5 / HMC619LP5E 12 12.84 300 0.500 4.82 5 5 GND GND HMC635 5 5.78 280 0.536 open open - GND GND HMC635LC4 5 5.78 280 0.536 open open - GND GND HMC637 12 13.12 400 0.375 6.27 5 6 GND GND HMC637LP5 / HMC637LP5E 12 13.12 400 0.375 4.62 5 5 GND GND HMC659 8 8.84 300 0.500 4.74 5 3 GND GND HMC659LC5 8 8.84 300 0.500 4.74 5 3 GND GND HMC797 10 11.12 400 0.375 3.80 5 3.5 GND GND HMC797LP5E 10 11.12 400 0.375 3.80 5 3.5 GND GND Bias Controllers - Chip Table 3 - List of Bias Settings for Various Hittite Amplifiers (Continued) Microwave & Optical Drivers HMC870LC5 7 7.46 165 0.909 open open - GND GND HMC871LC5 8 8.21 75 2.000 open open - GND GND For price, delivery and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824 Phone: 978-250-3343 Fax: 978-250-3373 Order On-line at www.hittite.com Application Support: Phone: 978-250-3343 or [email protected] 20