HMC619 - Hittite Microwave Corporation

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 apps@hittite.com

BIAS CONTROLLERS - CHIP

HMC980

v00.0312

ACTIVE BIAS CONTROLLER

High Current

General DescriptionFunctional Diagram

Features

Typical Applications

HMC980 is an active bias controller that can

automatically adjust the gate voltage of an external

amplier 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 amplier. It can

be used to bias any enhancement and depletion

type amplier 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.

• Microwave Radio & VSAT

• Military & Space

• Test Instrumentation

• Fiber Optic Modulator Driver Biasing

• CATV Laser Driver Biasing

• Cellular Base Station

• Wireless Infrastructure Equipment

• Automatic Gate voltage adjustment (No Calibra-

tion required)

• Supply Voltage (5V to 16.5V)

• Bias both Enhancement or Depletion type

devices

• 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

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 apps@hittite.com

BIAS CONTROLLERS - CHIP

HMC980

v00.0312

ACTIVE BIAS CONTROLLER

High Current

Electrical Specications, TA = +25°C, VDD=12V, VDIG= 3.3V, Depletion Master

Unless Otherwise Noted

Parameter Symbol Conditions Min. Ty p . Max. Units

Supply Voltage Vdd 5 16.5 V

VDD Quiescent Current IDD

VDD = 5V EN = VDIG 19 mA

EN = GND 7.5 mA

VDD = 12V EN = VDIG 20 mA

EN = GND 9 mA

VDIG Quiescent Current IDIG VDIG= 3.3 V 3.5 mA

VDIG= 5 V 6.5 mA

Charge Pump Oscillator Frequency FOSC 300 kHz

Voltage Reference VREF 1.44 V

ALMTRIG Input Threshold ALMTRIG Vinlow 1 V

Vinhigh 1.4 V

Enable Input Threshold ENTHRS Vinlow 1 V

Vinhigh 1. 4 V

S0, S1 Input Threshold SWTHRS Vinlow 1 V

Vinhigh 1. 4 V

VDRAIN Characteristics

DRAIN Current Adjustment Range IDRAIN

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 A

DRAIN Current Change Over Digital Voltage ∆IDRAINV VDRAIN set to 12V,

IDRAIN set to 400 mA

0.4 %/V

DRAIN Current Change Over Temperature 0.023 %/C

DRAIN Range VDRAIN 516.5 V

VDRAIN Change Over Temperature ∆VDRAIN VDRAIN set to 12V,

IDRAIN set to 400 mA 0.02 %/C

VNEG Characteristics

Negative Voltage Output VNEG -2.46 V

VNEG Current Sink INEG 060 mA

VGATE Characteristics

GATE Current Supply IG -4 4mA

VGATE Low Level VG_MIN VNEG V

VGATE High Level VG_MAX VNEG+4.5 V

VG2 Characteristics

VG2 Current Supply IG2

VG2<2V - 0.1 0.1 mA

6V>VG2>2V -1 1 mA

VG2>6V -5 5 mA

VG2 Adjustment Range VG2 1VDD-1.3 V

VDIG Characteristics

Adjustment Range VDIG 3.3 5 V

VDIG Quiescent Current 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 apps@hittite.com

BIAS CONTROLLERS - CHIP

HMC980

v00.0312

ACTIVE BIAS CONTROLLER

High Current

Bias Current Accuracy[2]

Power Up Waveform

Bias Current Accuracy[1]

370

375

380

385

390

395

400

405

3.3 3.5 3.6 3.8 4.0 4.2 4.3 4.5 4.7 4.8 5.0

+25 C

+85 C

-55 C

IDRAIN (mA)

VDIG (V)

IDrain is set to: 388mA

1300

1325

1350

1375

1400

1425

1450

1475

3.3 3.5 3.6 3.8 4 4.2 4.3 4.5 4.7 4.8 5

+25 C

+85 C

-55 C

IDRAIN (mA)

VDIG (V)

IDrain is set to: 1409mA

Enable Waveform

Shutdown Waveform

-4

-2

0 20 40 60 80 100 120 140 160 180 200

VDD(V)

VDRAIN (V)

VDIG (V)

VG2 (V)

VNEG (V)

VGATE (V)

VOLTAGE (V)

TIME (ms)

-12

-8

-4

0123456

EN(V)

VDRAIN (V)

VG2 (V)

VNEG (V)

VGATE (V)

VOLTAGE (V)

TIME (ms)

Disable Waveform

-6

-4

-2

45678910

EN(V)

VDRAIN (V)

VG2 (V)

VNEG (V)

VGATE (V)

VOLTAGE (V)

TIME (ms)

-4

-2

0 10 20 30 40 50 60 70 80 90 100

VDD (V)

VDRAIN (V)

VDIG(V)

VG2 (V)

VNEG (V)

VGATE (V)

VOLTAGE (V)

TIME (ms)

[1] HMC637LP5 is used as external amplier

[2] HMC591LP5 is used as external amplier

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 apps@hittite.com

BIAS CONTROLLERS - CHIP

HMC980

v00.0312

ACTIVE BIAS CONTROLLER

High Current

Load Regulation @ VDD=5V, VDIG=3.3V,

SW0=GND, SW1=GND

50 100 150 200 250 300

+25C

+85C

-55C

IDRAIN (mA)

VDRAIN (V)

Load Regulation @ VDD=5V, VDIG=3.3V,

SW0=3.3V, SW1=GND

300 350 400 450 500 550 600

+25C

+85C

-55C

IDRAIN (mA)

VDRAIN (V)

Load Regulation @ VDD=16.5V,

VDIG=5.0V, SW0=GND, SW1=VDIG

600 700 800 900 1000 1100 1200

+25C

+85C

-55C

IDRAIN (mA)

VDRAIN (V)

Load Regulation @ VDD=16.5V,

VDIG=5.0V, SW0=VDIG, SW1=VDIG

-2.5

-2.4

-2.3

-2.2

-2.1

-2

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70

+25 C

+85 C

-55 C

VNEG (V)

INEG (mA)

VNEG Load Regulation @ VDD=5V VNEG Load Regulation @ VDD=16.5V

-2.5

-2.4

-2.3

-2.2

-2.1

-2

0 5 10 15 20 25 30

+25 C

+85 C

-55 C

VNEG (V)

INEG (mA)

1200 1300 1400 1500 1600

+25C

+85C

-55C

IDRAIN (mA)

VDRAIN (V)

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 apps@hittite.com

BIAS CONTROLLERS - CHIP

HMC980

v00.0312

ACTIVE BIAS CONTROLLER

High Current

VNEG Load Transient VDD=5V

-2.6

-2.55

-2.5

-2.45

-2.4

-2.35

-2.3

-2.25

-2.2

-40

-30

-20

-10

012345678910

VNEG (V)

INEG (mA)

TIME (ms)

VNEG Load Transient VDD=16.5V

-2.6

-2.55

-2.5

-2.45

-2.4

-2.35

-2.3

-2.25

-2.2

-40

-30

-20

-10

012345678910

VNEG (V)

INEG (mA)

TIME (ms)

VGATE Load Regulation @ VDD=12V [1]

-1.5

-1.25

-1

-0.75

-0.5

-0.25

-7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7

+25C

+85C

-55C

IG (mA)

VGATE (V)

IDrain is set to : 388mA

VG2 Load Regulation @ VDD=12V [1]

-8 -6 -4 -2 0 2 4 6 8

VG2=0.97V

VG2=1.81V

VG2=3.73V

VG2=6.68V

IG2 (mA)

VG2 (V)

IDrain is set to : 388mA

-2.5

-2.48

-2.46

-2.44

5 7 9 11 13 15 17

+25C

+85C

-55C

SUPPLY VOLTAGE (V)

VNEG (V)

No load condition

VNEG Line Regulation vs. Supply Voltage

[1] HMC637LP5 is used as external amplier

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 apps@hittite.com

BIAS CONTROLLERS - CHIP

HMC980

v00.0312

ACTIVE BIAS CONTROLLER

High Current

Outline Drawing

Absolute Maximum Ratings

VDD 18V

S0, S1, EN, ALM,ALMTRG, VREF,

VNEGFB, VGATEFB, TRIG_OUT,

ISENSE, ALML, ISET, ALMH, FIX-

BIAS

-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

ELECTROSTATIC SENSITIVE DEVICE

OBSERVE HANDLING PRECAUTIONS

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.

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 apps@hittite.com

BIAS CONTROLLERS - CHIP

HMC980

v00.0312

ACTIVE BIAS CONTROLLER

High Current

Pad Descriptions

Pad Number Function Description Interface Schematic

1,12,13,20,21,

35 GND These pads and the die bottom must be connected to a

high quality RF/DC ground.

2ALM

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.

3ALMTRG

Dummy alarm trigger signal to create test alarm when

taken HIGH (3.3V). Defaults to LOW (GND) when left

oating.

4EN

Enable pad. Bias control loop is enabled when Ven

is HIGH(VDIG). If left oating, Ven defaults to HIGH

(enabled).

5,6 S1,S0

Control pads for internal switch resistance. If left oat-

ing, 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 ltering.

14 FIXBIAS A high precision (e.g. 0.5%, ±25 ppm TCR) 10K resistor

to ground is recommended for good bias accuracy.

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 apps@hittite.com

BIAS CONTROLLERS - CHIP

HMC980

v00.0312

ACTIVE BIAS CONTROLLER

High Current

Pad Descriptions (Continued)

Pad Number Function Description Interface Schematic

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.

16 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.

17 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.

18 ISENSE

Drain current adjustment pad. To adjust the bias current

of the external amplier 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.

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 apps@hittite.com

BIAS CONTROLLERS - CHIP

HMC980

v00.0312

ACTIVE BIAS CONTROLLER

High Current

Pad Number Function Description Interface Schematic

22,23,24,25

26 VDRAIN

Drain voltage. Should be connected to the supply termi-

nal of the external amplier. A minimum 10 nF capacitor

has to be placed close to the external amplier to

improve load regulation.

27 VGATE

Gate Control pad for external amplier. Connect to the

gate (base) of the external amplier. In order to guar-

antee stability, a 2.2F capacitor should be connected

between the gate (base) terminal of the external ampli-

er and GND as close to the amplier 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 genera-

tor 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 volt-

age. VG2 is typically 1.3V lower than the VG2CONT.

Pad Descriptions (Continued)

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 apps@hittite.com

BIAS CONTROLLERS - CHIP

HMC980

v00.0312

ACTIVE BIAS CONTROLLER

High Current

Pad Number Function Description Interface Schematic

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 Genera-

tor 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 volt-

age to this pad with appropriate ltering.

37 CP_OUT

Negative voltage generator charge pump output. Nega-

tive voltage generator requires a ying capacitor, a

reservoir capacitor and two diodes to operate.

38 CP_VDD

Bias supply for negative voltage generator. Connect

supply voltage with appropriate ltering. CP_VDD

supply voltage should be same as VDD.

Pad Descriptions (Continued)

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 apps@hittite.com

BIAS CONTROLLERS - CHIP

HMC980

v00.0312

ACTIVE BIAS CONTROLLER

High Current

Application Circuit

Notes:

[1] A variable resistor is assembled on RSENSE slot to adjust bias current for evaluating various different ampliers

without soldering.

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 apps@hittite.com

BIAS CONTROLLERS - CHIP

HMC980

v00.0312

ACTIVE BIAS CONTROLLER

High Current

Application Notes

Detailed Description

All ampliers require stable quiescent current to operate at their specications. Many ampliers in the market require

external biasing to achieve stable quiscent current. HMC980 is a fully integrated biasing solution for such ampliers.

With an internal feedback, the automatic gate voltage control achieves constant quiescent bias through the amplier

under bias, independent of temperature and amplier 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 amplier. The HMC980 can provide auto-bias solution to virtually any

amplier 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 ampliers. 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 amplier 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 ampliers which require second gate voltage.

The HMC980 ensures safety of the external amplier during turn on/off by automatically adjusting the sequence of

VDRAIN, VGATE and VG2 outputs.

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 amplier 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 amplier until the gate voltage is pulled down to VNEG (ensuring external amplier is pinched-off). The

VDRAIN output of the HMC980 should be connected to the drain (collector) of the amplier 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 nite 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 apps@hittite.com

BIAS CONTROLLERS - CHIP

HMC980

v00.0312

ACTIVE BIAS CONTROLLER

High Current

where VDRAIN is the supply voltage of the external amplier and IDRAIN is the desired constant bias current through

the external amplier.

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 oating,

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 Conguration

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 conguration. It requires

two diodes and two capacitors connected externally as shown in the sample application schematics. It can be dis-

abled through the VGATEFB and VNEGFB pads, if an enhancement device is targeted or a negative supply is already

available in the system. In this conguration, 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 iso-

lating VNEGOUT from the VGATE. Thus, switching noise of the charge-pump is effectively isolated from the external

amplier.

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 oating 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 amplier under bias through VGATE output connected to

the gate of the external amplier. In this closed loop operation the current passing through the amplier under bias is

sampled and is used to automatically adjust VGATE to achieve constant quiescent bias through the external amplier.

The HMC980 continuously adjusts VGATE voltage to achieve constant DRAIN current over any supply, tempera-

ture, 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 amplier (at

least ±4 mA). This unique feature is important to achieve nearly constant quiescent bias through the amplier under

varying gate current at different input power values.

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

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 apps@hittite.com

BIAS CONTROLLERS - CHIP

HMC980

v00.0312

ACTIVE BIAS CONTROLLER

High Current

The bias current passing through the external amplier 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 amplier.

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 ampliers 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 ow

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 amplier 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 xed.

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 apps@hittite.com

BIAS CONTROLLERS - CHIP

HMC980

v00.0312

ACTIVE BIAS CONTROLLER

High Current

Power-up and Enable Sequencing

To ensure the safety of the external amplier, 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 nega-

tive supply available (VGATE=VNEG). This ensures that external amplier 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 ampliers. 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 amplication 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.

Over current

Set current

Under current

ALARM

Figure 1. Current Alarm Behavior

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 apps@hittite.com

BIAS CONTROLLERS - CHIP

HMC980

v00.0312

ACTIVE BIAS CONTROLLER

High Current

Figure 2. Daisy Chain Operation

Operation Modes

HMC980 can be congured to bias both enhancement and depletion mode external ampliers. 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 amplier 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 oating 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 VGATEFB VNEGIN Description

MODE1

(Depletion/Master Mode) FLOAT F L O AT Connected to

VNEGOUT

Depletion mode transistor. Internal negative voltage generator is

active and generates -2.5V. Sample application schematic given

shown in Fig.3a.

MODE2

(Depletion/Slave Mode) GND F L OAT 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.

MODE3

(Enhancement Mode) GND GND Connected to

GND

Enhancement mode transistor. Internal negative voltage generator is

disabled. Sample application schematic given shown in Fig.3c.

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 apps@hittite.com

BIAS CONTROLLERS - CHIP

HMC980

v00.0312

ACTIVE BIAS CONTROLLER

High Current

Figure 3a. Depletion/Master Mode Amplier Typical Application Circuit (Mode 1)

Figure 3b. Depletion/Slave Mode Amplier Typical Application Circuit (Mode 2)

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 apps@hittite.com

BIAS CONTROLLERS - CHIP

HMC980

v00.0312

ACTIVE BIAS CONTROLLER

High Current

Figure 3c. Enhancement Mode Amplier Typical Application Circuit (Mode 3)

Table 3 - List of Bias Settings for Various Hittite Ampliers

Hittite Part Number VDRAIN

(V)

VDD

(V)

IDRAIN

(mA)

RSENSE

(kOhm)

VG2

(V) S1 S0

Gain Blocks & Drivers

HMC-AUH256 5 5.83 295 0.508 open open - GND GND

LNAs

HMC-ALH435 5 5.08 30 5.000 6.13 51. 5 GND GND

HMC-ALH444 5 5.15 55 2.727 5.95 51. 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 biasing Hittite ampliers compatable with HMC980 refer to the Table 3, where values of the external components

are provided on typical application circuit shown in Figure 3a.

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 apps@hittite.com

BIAS CONTROLLERS - CHIP

HMC980

v00.0312

ACTIVE BIAS CONTROLLER

High Current

Hittite Part Number VDRAIN

(V)

VDD

(V)

IDRAIN

(mA)

RSENSE

(kOhm)

VG2

(V) S1 S0

HMC442LM1 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 67. 1 6 750 0.200 open open - GND VDIG

HMC906 6 7.02 1200 0.125 open open - VDIG GND

HMC943LP5E 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

Wideband (Distributed)

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

Table 3 - List of Bias Settings for Various Hittite Ampliers (Continued)

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 apps@hittite.com

BIAS CONTROLLERS - CHIP

HMC980

v00.0312

ACTIVE BIAS CONTROLLER

High Current

Hittite Part Number VDRAIN

(V)

VDD

(V)

IDRAIN

(mA)

RSENSE

(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. 1 2 400 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. 1 2 400 0.375 3.80 5 3.5 GND GND

HMC797LP5E 10 11. 1 2 400 0.375 3.80 5 3.5 GND GND

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

Table 3 - List of Bias Settings for Various Hittite Ampliers (Continued)