- 您現在的位置：買賣IC網 > PDF目錄382370 > PA19 Voltage-Feedback Operational Amplifier PDF資料下載
參數資料
| 型號： | PA19 |
| 英文描述： | Voltage-Feedback Operational Amplifier |
| 中文描述： | 電壓反饋運算放大器 |
| 文件頁數： | 4/4頁 |
| 文件大小： | 55K |
| 代理商： | PA19 |
APEX MICROTECHNOLOGY CORPORATION
5980 NORTH SHANNON ROAD TUCSON, ARIZONA 85741 USA APPLICATIONS HOTLINE: 1 (800) 546-2739
PA19U REV. H FEBRUARY 1998
1998 Apex Microtechnology Corp.
OPERATING
CONSIDERATIONS
PA19 PA19A
2. Safe short circuit combinations of voltage and current are limited to
a power level of 100W.
3. The output stage is protected against transient flyback. However,
for protection against sustained, high energy flyback, external fast-
recovery diodes should be used.
SUPPLY CURRENT
The PA19 features a class A/B driver stage to charge and discharge
gate capacitance of Q7 and Q19. As these currents approach 0.5A, the
savings of quiescent current over that of a class A driver stage is
considerable. However, supply current drawn by the PA19, even with
no load, varies with slew rate of the output signal as shown below.
OUTPUT LEADS
Keep the output leads as short as possible. In the video frequency
range, even a few inches of wire have significant inductances, raising
the interconnection impedance and limiting the output current slew
rate. Furthermore, the skin effect increases the resistance of heavy
wires at high frequencies. Multistrand Litz Wire is recommended to
carry large video currents with low losses.
THERMAL SHUTDOWN
The thermal protection circuit shuts off the amplifier when the
substrate temperature exceeds approximately 150
°
C. This allows the
heatsink selection to be based on normal operating conditions while
protecting the amplifier against excessive junction temperature during
temporary fault conditions.
Thermal protection is a fairly slow-acting circuit and therefore does
not protect the amplifier against transient SOA violations (areas
outside of the steady state boundary). It is designed to protect against
short-term fault conditions that result in high power dissipation within
the amplifier. If the conditions that cause thermal shutdown are not
removed, the amplifier will oscillate in and out of shutdown. This will
result in high peak power stresses, destroy signal integrity, and reduce
the reliability of the device.
STABILITY
Due to its large bandwidth, the PA19 is more likely to oscillate than
lower bandwidth power operational amplifiers. To prevent oscillations
a reasonable phrase margin must be maintained by:
1. Selection of the proper phase compensation capacitor. Use the
values given in the table under external connections and interpo-
late if necessary. The phase margin can be increased by using a
larger capacitor at the expense of slew rate. Total physical length
(pins of the PA19, capacitor leads plus printed circuit traces) should
be limited to a maximum of 3.5 inches.
2. Keep the external sumpoint stray capacitance to ground at a
minimum and the sumpoint load resistance (input and feedback
resistors in parallel) below 500
. Larger sumpoint load resistances
can be used with increased phase compensation and/or by bypass-
ing the feedback resistor.
3. Connect the case to any AC ground potential.
I
LIM
= .65V
R
CL
R
CL
= .65V
I
CL
– .54A
GENERAL
Please read the “General Operating Considerations” section, which
covers stability, supplies, heatsinking, mounting, current limit, SOA
interpretation, and specification interpretation. Additional information
can be found in the application notes. For information on the package
outline, heatsinks, and mounting hardware, consult the “Accessory
and Package Mechanical Data” section of the handbook.
CURRENT LIMIT
Q2 (and Q25) limit output current by turning on and removing gate
drive when voltage on pin 2 (pin 7) exceeds .65V differential from the
positive (negative) supply rail. With internal resistors equal to 1.2
,
current limits are approximately 0.5A with no external current limit
resistors. With the addition of external resistors current limit will be:
To determine values of external current limit resistors:
PHASE COMPENSATION
At low gain settings, an external compensation capacitor is required
to insure stability. In addition to the resistive feedback network, roll off
or integrating capacitors must also be considered when determining
gain settings. The capacitance values listed in the external connection
diagram, along with good high frequency layout practice, will insure
stability. Interpolate values for intermediate gain settings.
SAFE OPERATING AREA (SOA)
The MOSFET output stage of this power operational amplifier has
two distinct limitations:
1. The current handling capability of the MOSFET geometry and the
wire bonds.
2. The junction temperature of the output MOSFETs.
The SOA curves combine the effect of these limits and allow for
internal thermal delays. For a given application, the direction and
magnitude of the output current should be calculated or measured and
checked against the SOA curves. This is simple for resistive loads but
more complex for reactive and EMF generating loads. The following
guidelines may save extensive analytical efforts:
1. Capacitive and inductive loads up to the following maximums are
safe:
±
V
S
40V
30V
20V
15V
CAPACITIVE LOAD
.1
μ
F
500
μ
F
2500
μ
F
∞
INDUCTIVE LOAD
11mH
24mH
75mH
100mH
2.0
3.0
4.0
3.5
5.0
1.5
2.5
30
50
20
40
25
15
35
70
60
80
O
S
S
(
INTERNAL VOLTAGE DROP SUPPLY TO OUTPUT V
S
–V
O
(V)
STEADYSTATE
t=300ms
t=100ms
T
= 25°C
SUPPLY CURRENT
400
300
200
100
0
30K 100K 300K
FREQUENCY, F (Hz)
1M
3M 10M
S
S
V
OUT
= 60V
SINE
R
L
= 500
相關PDF資料 |
PDF描述 |
|---|---|
| PA19A | Voltage-Feedback Operational Amplifier |
| PA2010 | 200 TO 2000 MHz TO-8 CASCADABLE AMPLIFIER |
| PA2100 | DCS/GSM |
| PA2110 | DCS/PCS/EGSM |
| PA3-1 | Analog IC |
相關代理商/技術參數 |
參數描述 |
|---|---|
| PA-19 | 制造商:Electro Switch Corp 功能描述: 制造商:ELECTROSWITCH 功能描述: 制造商:CENTRALAB 功能描述:1 POLE, 5 POS, NON SHORT, MINIATURE, SEPARATE SECTION |
| PA1900 | 功能描述:TOOL CAN WRENCH 22/4&24/4 CABLE RoHS:是 類別:工具 >> 插口 - 手柄 系列:- 標準包裝:1 系列:- 其它名稱:1900-ND |
| PA-1900-32 | 制造商:Lite-On Semiconductor Corporation 功能描述:PA-1900-32 - Bulk |
| PA-1900-32P1 | 制造商:Lite-On Semiconductor Corporation 功能描述:AC/DC ADAPTER DESKTOP 19V 90W |
| PA1901 | 功能描述:TOOL SPLITTER UNTWIST/SEPARATOR RoHS:是 類別:工具 >> 其它工具 系列:Paladin Tools® 標準包裝:25 系列:* 其它名稱:Q4875803Q6620124A |
發布緊急采購，3分鐘左右您將得到回復。