View PA94_1293453.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

FEATURES
* * * * HIGH VOLTAGE -- 900V (450V) HIGH SLEW RATE -- 500V/S HIGH OUTPUT CURRENT -- 100mA PROGRAMMABLE CURRENT LIMIT
PATENTED
APPLICATIONS
* * * * HIGH VOLTAGE INSTRUMENTATION PROGRAMMABLE POWER SUPPLIES UP TO 430V MASS SPECTROMETERS SEMICONDUCTOR MEASUREMENT EQUIPMENT
8-PIN SIP PACKAGE STYLE DQ
Formed leads available See package styles EC & EP
DESCRIPTION
The PA94 is a high voltage, MOSFET operational amplifier designed as a low cost solution for driving continuous output currents up to 100mA and pulse currents up to 200mA into capacitive loads. The safe operating area (SOA) has no second breakdown limitations and can be observed for all load types by choosing an appropriate current limiting resistor. The MOSFET output stage is biased AB for linear operation. External compensation provides flexibility in choosing bandwidth and slew rate for the application. APEX's Power SIP package uses a minimum of board space allowing for high density circuit boards.. The Power SIP package is electrically isolated. Isolating thermal washers (TW13) prevent arcing from pins to heatsink.
TYPICAL APPLICATION
Piezo positioning may be applied to the focusing of segmented mirror systems. The composite mirror may be composed of hundreds of elements, each requiring focusing under computer control. In such complex systems the PA94 reduces the costs of power supplies and cooling with its advantages of low cost and low quiescent power consumption while increasing circuit density with the SIP package.

EQUIVALENT SCHEMATIC

EXTERNAL CONNECTIONS

PHASE COMPENSATION
GAIN CC 100 2.2pF 50 4.7pF 10 22pF CC rated for full supply voltage. RLIM = .7 ILIM

APEX MICROTECHNOLOGY CORPORATION * TELEPHONE (520) 690-8600 * FAX (520) 888-3329 * ORDERS (520) 690-8601 * EMAIL prodlit@apexmicrotech.com
1
ABSOLUTE MAXIMUM RATINGS SPECIFICATIONS
PA94
SUPPLY VOLTAGE, +VS to -VS OUTPUT CURRENT, source, sink POWER DISSIPATION, continuous @ TC = 25C INPUT VOLTAGE, differential INPUT VOLTAGE, common mode3 TEMPERATURE, pin solder - 10s max. TEMPERATURE, junction2 TEMPERATURE RANGE, storage OPERATING TEMPERATURE RANGE, case 900V 200mA, within SOA 30W 20V VS 260C 150C -40 to +85C -25 to +85C
ABSOLUTE MAXIMUM RATINGS
SPECIFICATIONS
PARAMETER INPUT OFFSET VOLTAGE, initial OFFSET VOLTAGE, vs. temperature OFFSET VOLTAGE, vs. supply OFFSET VOLTAGE, vs. time BIAS CURRENT, initial BIAS CURRENT, vs. supply OFFSET CURRENT, initial INPUT IMPEDANCE, DC INPUT CAPACITANCE COMMON MODE VOLTAGE RANGE3 COMMON MODE REJECTION, DC NOISE GAIN OPEN LOOP, @ 15Hz GAIN BANDWIDTH PRODUCT at 1MHz POWER BANDWIDTH PHASE MARGIN, Av=100 OUTPUT VOLTAGE SWING CURRENT, continuous SLEW RATE, AV = 100 SETTLING TIME to .1% RESISTANCE POWER SUPPLY VOLTAGE 5 CURRENT, quiescent total CURRENT, quiescent output stage only THERMAL RESISTANCE, AC, junction to case 4 RESISTANCE, DC, junction to case RESISTANCE, junction to air TEMPERATURE RANGE, case TEST CONDITIONS 1 MIN TYP .5 15 10 75 200 4 50 1011 4 VS 30 80 MAX 5 50 25 2000 500 UNITS mV V/C V/V V/kh pA pA/V pA pF V dB Vrms dB MHz kHz V mA V/s s 450 24 120 2.5 4.2 30 -25 +85 V mA A C/W C/W C/W C
Full temperature range
RL = 5K RL = 5K RL = 5K Full temperature range IO = 70mA CC =2.2pF 2V step no load See note 5
94
700 1 100 300 17
50
Full temperature range, F > 60Hz Full temperature range, F < 60Hz Full temperature range Meets full range specifications
NOTES: 1. Unless otherwise noted: TC = 25C, DC input specifications are value given. Power supply voltage is typical rating. Cc= 4.7pF. 2. Long term operation at the maximum junction temperature will result in reduced product life. Derate internal power dissipation to achieve high MTTF. 3. Although supply voltages can range up to 450V the input pins cannot swing over this range. The input pins must be at least 30V from either supply rail but not more than 450V from either supply rail. See text for a more complete description of the common mode voltage range. 4. Rating applies if the output current alternates between both output transistors at a rate faster than 60Hz. 5. Derate max supply rating .625 V/C below 25C case. No derating needed above 25C case. The PA94 is constructed from MOSFET transistors. ESD handling procedures must be observed. The exposed substrate contains beryllia (BeO). Do not crush, machine, or subject to temperatures in excess of 850C to avoid toxic fumes.
CAUTION
APEX MICROTECHNOLOGY CORPORATION * 5980 NORTH SHANNON ROAD * TUCSON, ARIZONA 85741 * USA * APPLICATIONS HOTLINE: 1 (800) 546-2739
2
VS 24 100 500
Vs = 450V3 VCM = 90V 10KHz BW, RS = 1K
98 2 115 140 300 60 VS 20
PA94
TYPICAL PERFORMANCE GRAPHS

INTERNAL POWER DISSIPATION AND HEATSINK SELECTION
With the unique combination of high voltage and speed of the PA94, traditional formulas for heatsink selection will falsely lower the apparent power handling capability of this amplifier. To more accurately predict operating temperatures use Power Design1 revision 10 or higher, or use the following procedure: Find internal dissipation (PD) resulting from driving the load. Use Power Design or refer to Apex Applications Note 1, General Operating Considertaions, paragraph 7. Find total quiescent power (PDQ) by multiplying 0.024A by VSS (total supply voltage). Find output stage quiescent power (PDQOUT) by multiplying 0.00012 by VSS. Calculate a heatsink rating which will maintain the case at 85C or lower.
ROSA =
Where: TC = maximum case temperature allowed TA = maximum ambient temperature encountered Calculate a heatsink rating which will maintain output transistor junctions at 150C or lower.
ROSA = TJ - Ta - (PD + PDQOUT) *ROJC -0.1C/W PD + PDQ
Tc - Ta -0.1C/W PD + PDQ
Where: TJ = maximum junction temperature allowed. ROJC = AC or DC thermal resistance from the specification table. Use the larger heatsink of these two calculations. Power Design is an Excel spreadsheet available free from www.apexmicrotech.com
APEX MICROTECHNOLOGY CORPORATION * TELEPHONE (520) 690-8600 * FAX (520) 888-3329 * ORDERS (520) 690-8601 * EMAIL prodlit@apexmicrotech.com
3
OPERATING CONSIDERATIONS
PA94
mended as protection on the supply pins. The zeners clamp transients to voltages within the power supply rating and also clamp power supply reversals to ground. Whether the zeners are used or not, the system power supply should be evaluated for transient performance including power-on overshoot and power-off polarity reversal as well as line regulation. Conditions which can cause open circuits or polarity reversals on either power supply rail should be avoided or protected against. Reversals or opens on the negative supply rail is known to induce input stage failure. Unidirectional transzorbs prevent this, and it is desirable that they be both electrically and physically as close to the amplifier as possible.
GENERAL
Please read Application Note 1 "General Operating Considerations" which covers stability, supplies, heat sinking, mounting, current limit, SOA interpretation, and specification interpretation. Visit www.apexmicrotech.com for design tools that help automate tasks such as calculations for stability, internal power dissipation, current limit; heat sink selection; Apex's complete Application Notes library; Technical Seminar Workbook; and Evaluation Kits.
CURRENT LIMIT
For proper operation, the current limit resistor (RLIM) must be connected as shown in the external connection diagram. The minimum value is 3.5 ohm, however for optimum reliability the resistor value should be set as high as possible. The value is calculated as follows; with the maximum practical value of 30 ohms. .7 RLIM = ILIM
STABILITY
The PA94 is stable at gains of 100 or more with a NPO (COG) compensation capacitor of 2.2pF. The compensation capacitor, Cc, in the external connections diagram must be rated at 1000V working voltage and mounted closely to pins 4 and 6 to prevent spurious oscillation. A compensation capacitor less than 2.2pF is not recommended.
COMMON MODE INPUT RANGE
Operational amplifiers are usually designed to have a common mode input voltage range that approximates the power supply voltage range. However, to keep the cost as low as possible and still meet the requirements of most applications the common mode input voltage range of the PA94 is restricted. The input pins must always be a least 30V from either supply voltage but never more than 450V. This means that the PA94 cannot be used in applications where the supply voltages are extremely unbalanced. For example, supply voltages of +800V and -100V would not be allowed in an application where the non-inverting pin is grounded because in normal operation both input pins would be at 0V and the difference voltage between the positive supply and the input pins would be 800V. In this kind of application, however, supply voltages +450V and -100V does meet the input common mode voltage range requirements since the maximum difference voltage between the inputs pins and the supply voltage is 450V (the maximum allowed). The output has no such restrictions on its voltage swing. The output can swing within 24V of either supply voltage regardless of value so long as the total supply voltage does not exceed 900V.
EXTERNAL COMPONENTS
The compensation capacitor Cc must be rated for the total supply voltage. An NPO (COG) capacitor rated a 1kV is recommended. Of equal importance are the voltage rating and voltage coefficient of the gain setting feedback resistor. Typical voltage ratings of low wattage resistors are 150 to 250V. Up to 500 V can appear across the feedback resistor. High voltage rated resistors can be obtained. However a 1 megohm feedback resistor composed of five 200k resistors in series will produce the proper voltage rating.
CAUTIONS
The operating voltages of the PA94 are potentially lethal. During circuit design develop a functioning circuit at the lowest possible voltages. Clip test leads should be used for "hands off" measurements while troubleshooting.

INPUT PROTECTION
Although the PA94 can withstand differential input voltages up to 20V, additional external protection is recommended. In most applications 1N4148 or 1N914 signal diodes are sufficient (D1, D2 in Figure 1a). In more demanding applications where low leakage or low capacitance are of concern 2N4416 or 2N5457-2N5459 JFETs connected as diodes will be required (Q1, Q2 in Figure 1b). In either case the input differential voltage will be clamped to .7V. This is sufficient overdrive to produce maximum power bandwidth. Note that this protection does not automatically protect the amplifier from excessive common mode input voltages.

POWER SUPPLY PROTECTION
Unidirectional zener diode transient suppressors are recom-
FIGURE 1. OVERVOLTAGE PROTECTION
This data sheet has been carefully checked and is believed to be reliable, SHANNON ROAD * is assumed ARIZONA 85741 * USA * APPLICATIONS are subject 1 (800) 546-2739 APEX MICROTECHNOLOGY CORPORATION * 5980 NORTH however, no responsibility TUCSON, for possible inaccuracies or omissions. All specificationsHOTLINE: to change without notice.
4
PA94U REV J APRIL 2005 (c) 2005 Apex Microtechnology Corp.

▲Up To Search▲

Price & Availability of PA94

	To Download PA94 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .