APEX MICROTECHNOLOGY CORPORATION TELEPHONE (520) 690-8600 FAX (520) 888-3329 ORDERS (520) 690-8601 EMAIL prodlit@apexmicrotech.com
1
PRELIMINARY
TYPICAL APPLICATION
The typical application diagram shows a bridge connection
of the two amplifiers inside a dual PA79 and provides output
voltage swing twice that of one amplifier. Two possible situ-
ations where there is an advantage would be in applications
with low supply voltages, or applications that operate amplifiers
near their maximum voltage ratings in which a single amplifier
could not provide sufficient drive. The bridge connection also
effectively doubles the slew rate, and non-linearity becomes
symmetrical reducing second harmonic distortion in compari-
son to a single amplifier circuit.
EXTERNAL CONNECTIONS - DK PACKAGE
FEATURES
A UNIQUE (Patent Pending) TECHNIQUE FOR VERY
LOW QUIESCENT CURRENT < 1 mA
OVER 350 V/S SLEW RATE
WIDE SUPPLY VOLTAGE
Single Supply: 10V to 350V
Split Supplies: +/- 10V to +/- 175V
OUTPUT CURRENT- 150mA cont. ; 200mA Pk
DUAL AMPLIFIER
UP TO TBD WATT DISSIPATION CAPABILITY
OVER 200 kHz POWER BANDWIDTH
APPLICATIONS
PIEZOELECTRIC POSITIONING AND ACTUATION
ELECTROSTATIC DEFLECTION
DEFORMABLE MIRROR ACTUATORS
CHEMICAL AND BIOLOGICAL STIMULATORS
DESCRIPTION
The PA79 is a dual high voltage, high speed Precision IC
power op amp with performance and unique features not
found previously in any commercially available OpAmp. This
approach provides a cost-effective, high density solution to
applications where multiple amplifiers are required.
Novel input stage design of this amplifier provides extremely
high slew rates in pulse applications while maintaining low
quiescent current of under 1mA. This novel input stage also
has the effect of adding variables to the power response and
slew rate characteristics of the amplifier. To a lesser degree,
there are also input related effects on open loop gain and
phase. It is important to note that slew rate for the PA79 is
independent of supply current. However the slew rate is a
strong function of input voltage amplitude.
The output stages are well protected with user defined
current limit although the Safe Operating Area (SOA) must
be observed for reliable protection. Proper heat sinking is
required for maintaining maximum reliability. External phase
compensation provides the user with great flexibility in trading
gain, stability and bandwidth.
M I C R O T E C H N O L O G Y
PA79
20-PIN PSOP
PACKAGE STYLE DK
NOTES:
1. The package heat slug needs to be connected to a stable reference such as gnd
for high slew rates. Please refer to special considerations section for details.
2. Supply bypassing required for Vs and +Vs.
3. For Cc and Rc values refer to power supply biasing section.
4. Dimple and ESD triangle denotes pin 1.
APEX MICROTECHNOLOGY CORPORATION 5980 NORTH SHANNON ROAD TUCSON, ARIZONA 85741 USA APPLICATIONS HOTLINE: 1 (800) 546-2739
2
PRELIMINARY
ABSOLUTE MAXIMUM RATINGS
SPECIFICATIONS
SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS
SUPPLY VOLTAGE, +V
S
to -V
S
350V
OUTPUT CURRENT, peak
200mA, within SOA
POWER DISSIPATION, internal, DC
TBD
INPUT VOLTAGE, Differential
15V
INPUT VOLTAGE, Common Mode
Vs
TEMPERATURE, pin solder, 10s
TBD
TEMPERATURE, junction
2
150C.
TEMPERATURE RANGE, storage
-55 to 125C.
OPERATING TEMPERATURE, case
-40 to 125C
PARAMETER
TESTCONDITIONS
1
MIN
TYP
MAX
UNITS
INPUT
OFFSET VOLTAGE
8
40
mV
OFFSET VOLTAGE vs. temperature
0 to 125C (CaseTemperature)
-63
V/C
OFFSET VOLTAGE vs. supply
32
V/V
BIAS CURRENT, initial
3
8.5
200
pA
BIAS CURRENT vs. supply
pA/V
OFFSET CURRENT, initial
12
400
pA
INPUT RESISTANCE, DC
10
6
INPUT CAPACITANCE
pF
COMMON MODE VOLTAGE RANGE, pos.
+V
S
- 2
V
COMMON MODE VOLTAGE RANGE, neg.
-V
S
+ 5.5
V
COMMON MODE REJECTION, DC
90
TBD
dB
NOISE
1MHz bandwidth, 1kR
S
V RMS
GAIN
OPEN LOOP @ 15Hz
89
120
dB
GAIN BANDWIDTH PRODUCT @ 1MHz
1
MHz
PHASE MARGIN
Full temperature range
50
OUTPUT
VOLTAGE SWING
I
O
= 10mA
|V
S
| - 2
V
VOLTAGE SWING
I
O
= 100mA
TBD
|V
S
| - 12
V
VOLTAGE SWING
I
O
= 150mA
|V
S
| - 10
V
CURRENT, continuous, DC
150
mA
SLEW RATE
PackageTabConnectedtoGND
100
350
V/S
SETTLING TIME, to 0.1%
2V Step
TBD
S
POWER BANDWIDTH, 300V
P-P
+V
S
= 160V, -V
S
= -160V
200
kHz
POWERSUPPLY
VOLTAGE
10
150
175
V
CURRENT, quiescent
150V Supply
0.2
0.7
2.5
mA
THERMAL
RESISTANCE, AC, junction to case
5
Full temperature range, f 60Hz
C/W
RESISTANCE, DC, junction to case
Full temperature range, f < 60Hz
TBD
C/W
RESISTANCE, junction to air
Full temperature range
C/W
TEMPERATURE RANGE, case
-40
85
C
PA79
NOTES: 1. Unless otherwise noted: TC = 25C, DC input specifications are value given, power supply voltage is typical rating. Ratings
apply to one amplifier.
2. Long term operation at the maximum junction temperature will result in reduced product life. Derate power dissipation to achieve
high MTTF.
3. Doubles for every 10
o
C of temperature increase.
4. +V
S
and V
S
denote the positive and negative supply voltages of the output stage.
5. Rating applies if output current alternates between both output transistors at a rate faster than 60Hz.
APEX MICROTECHNOLOGY CORPORATION TELEPHONE (520) 690-8600 FAX (520) 888-3329 ORDERS (520) 690-8601 EMAIL prodlit@apexmicrotech.com
3
PRELIMINARY
TYPICAL PERFORMANCE
GRAPHS
PA79
APEX MICROTECHNOLOGY CORPORATION 5980 NORTH SHANNON ROAD TUCSON, ARIZONA 85741 USA APPLICATIONS HOTLINE: 1 (800) 546-2739
4
PRELIMINARY
POWER SUPPLY BYPASSING
Bypass capacitors to power supply terminals +Vs and Vs
must be connected physically close to the pins to prevent lo-
cal parasitic oscillation in the output stage of the PA79. Use
electrolytic capacitors at least 1F. Bypass the electrolytic
capacitors with high quality ceramic capacitors (X7R) 0.1F
or greater.
SUPPLY CURRENT
The PA79 features a class A/B driver stage to drive the output
MOSFETs and an innovative input stage to achieve very high
slew rates. The supply current drawn by the PA79, even with
no load, varies with the slew rate of the output signal.
HEATSINKING
TBD
STABILITY
The PA79 is externally compensated and performance
can be tailored to the application. Use the graphs of small
signal response and power response as a guide. Due to the
innovative design of the PA79, two compensation networks
are required. The values of these components should be the
same to provide symmetric slew rate characteristics. The
compensation capacitor Cc must be rated at 500V working
voltage. NPO capacitors are recommended. The compensa-
tion networks CcRc must be mounted closely to the amplifier
pins x & y and z & w to avoid spurious oscillation.
The PA79 may require an external 33 pF capacitor (mini-
mum breakdown of 350V) between Cc- and Vs to prevent
oscillations in the falling edge of the output. This capacitor
is provided with the evaluation kit. Please refer to EK60U
datasheet for details.
GENERAL
Please read Application Note 1 "General Operating Consid-
erations" which covers stability, power 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.
SPECIAL CONSIDERATIONS
Itisveryimportanttorealizethatinordertoachieve
highfrequencyperformancetheheatsinktabhastobe
tiedtoastable,lowimpedancereference,i.e.powersup-
plyorGND.AnACconnectionthrougha0.1Fcapacitor
isalsosufficient.InternaltothePA79,theheatsinktab
iselectricallyisolatedtomorethan350V.Thismayhelp
allaysomeelectricalisolationconcernsintyingtheheat
sinktoVsorGND.
CURRENT LIMIT
For proper operation, the current limit resistor, Rlim, must
be connected as shown in the external connections diagram.
For maximum reliability and protection, the resistor should
be set as high as possible. The value of the resistor is calcu-
lated as follows, with Ilim in A; the maximum practical value
is 1500.
Rlim = 0.7 / Ilim
SAFE OPERATING AREA
The MOSFET output stage of the PA79 is not limited by
second breakdown considerations as in bipolar output stages.
However there are still three distinct limitations:
1. Voltage with stand capability of the transistors.
2. Current handling capability of the die metallization.
3. Temperature of the output MOSFETS.
These limitations can be seen in the SOA (see Safe Operat-
ing Area graphs). Note that each pulse capability line shows
a constant power level (unlike second breakdown limitations
where power varies with voltage stress). These lines are
shown for a case temperature of 25C and correspond to
thermal resistances of TBDC/W for the PA79DK. Pulse stress
levels for other case temperatures can be calculated in the
same manner as DC power levels at different temperatures.
The output stage is protected against transient fly back by
the parasitic diodes of the output stage MOSFET structure.
However, for protection against sustained high energy fly back
external fast-recovery diodes must be used.
OPERATING
CONSIDERATIONS
PA79
This data sheet has been carefully checked and is believed to be reliable, however, no responsibility is assumed for possible inaccuracies or omissions. All specifications are subject to change without notice.
PA79U REV 2 FEBRUARY 2006 2006 Apex Microtechnology Corp.
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