AD1315 [ADI]
High Speed Active Load with Inhibit Mode; 高速有源负载与禁止模式型号: | AD1315 |
厂家: | ADI |
描述: | High Speed Active Load with Inhibit Mode |
文件: | 总8页 (文件大小:249K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
High Speed Active Load
with Inhibit Mode
a
AD1315
FUNCTIONAL BLOCK DIAGRAM
FEATURES
+50 mA Voltage Programmable Current Range
1.5 ns Propagation Delay
Inhibit Mode Function
High Speed Differential Inputs for Maximum Flexibility
Hermetically Sealed Small Gull Wing Package
Compatible with AD1321, AD1324 Pin Drivers
APPLICATIONS
Automatic Test Equipment
Semiconductor Test System
Board Level Test System
PRODUCT DESCRIPTION
tion voltage is programmable from 2 V to +7 V, covering the
large spectrum of logic devices while able to support the large
current specifications (48 mA) typically associated with line
drivers. To test I/O devices, the active load can be switched into
a high impedance state (Inhibit mode) electrically removing the
active load from the path through the Inhibit mode feature. The
active load leakage current in Inhibit is typically 20 nA.
The AD1315 is a complete, high speed, current switching load
designed for use in linear, digital or mixed signal test systems.
By combining a high speed monolithic process with a unique
surface mount package, this product attains superb electrical
performance while preserving optimum packaging densities in
an ultrasmall 16-lead, hermetically sealed gull wing package.
Featuring current programmability of up to +50 mA, the
AD1315 is designed to force the device under test to source or
sink the programmed IOHPROG and IOLPROG currents. The IOH
and IOL currents are determined by applying a corresponding
voltage (5 V = 50 mA) to the IOH and IOL pins. The voltage-
to-current conversion is performed within the AD1315 thus
allowing the current levels to be set by a standard voltage out
digital-to-analog converter.
The Inhibit input circuitry is implemented utilizing high speed
differential inputs with a common-mode voltage range of 7 volts
and a maximum differential voltage of 4 volts. This allows for
the direct interface to the precision of differential ECL timing or
the simplicity of switching the Active Load from a single ended
TTL or CMOS logic source. With switching speeds from IOH
or Io~ into Inhibit of less than 1.5 ns, the AD1315 can be
electrically removed from the signal path “on-the-fly.”
The AD1315’s transition from IOH to IOL occurs when the
output voltage of the device under test slews above or below the
programmed threshold, or commutation voltage. The commuta-
The AD1315 is available in a 16-lead, hermetically sealed gull
wing package and is specified to operate over the ambient com-
mercial temperature range from 0°C to +70°C.
REV. A
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703
World Wide Web Site: http://www.analog.com
© Analog Devices, Inc., 1997
(All measurements made in free air at +25؇C. +VS = +10 V, –VS = –5.2 V, unless
otherwise noted.)
AD1315–SPECIFICATIONS
AD1315KZ
Parameter
Min
Typ
Max
Units
Comments
DIFFERENTIAL INPUT CHARACTERISTICS
INH to INH
Input Voltage, Any One Input
Differential Input Range
Bias Current
–3.0
0.4
–2.0
4.0
4.0
2.0
Volts
Volts
mA
ECL
1.0
Current Program Voltage Range
I
I
OH, 0 mA to +50 mA (Sink)1
0
0
+5.0
+5.0
Volts
Volts
kΩ
Volts
Volts
Volts
Volts
OL, 0 mA to –50 mA (Source)1
Input Resistance
50
I
V
OHRTN, IOCRTN Range2
–2.0
–2.0
0.5
+7.0
+7.0
+7.0
+4.0
COM, VDUT Range
OH, 0 mA to +50 mA
IOL, 0 mA to –50 mA
I
VDUT – VCOM >1 V
VCOM – VDUT >1 V
–2.0
OUTPUT CHARACTERISTICS3
Active (Sink/Source) Mode
Transfer Function
Accuracy
10
mA/V
See Figure 1
See Figure 1
Linearity Error
Gain Error
Offset Error
–0.12
–2.0
–1.0
+0.12
+2.0
+1.0
% FSR
% FSR
mA
Output Current TC
Inhibit Mode
Output Capacitance
Inhibit Leakage
10
20
µA/°C
3.0
200
pF
nA
–200
DYNAMIC PERFORMANCE3
Propagation Delay
±IMAX to INHIBIT (tPD1
INHIBIT to ±IMAX (tPD2
See Figure 2
4
)
)
0.5
1.5
1.5
3.0
ns
ns
4
POWER SUPPLIES
–VS to +VS Difference
Supply Range
15.2
15.4
Volts
Positive Supply
Negative Supply
Current
+9.5
–5.45
+10
–5.2
+10.5
–4.95
Volts
Volts
Positive Supply5
Negative Supply5
Power Dissipation6
PSRR7
+705
+85
–85
1.3
+100
–70
1.54
0.05
mA
mA
–1005
%/%
NOTES
1IOHPROG/IOLPROG voltage range may be extended to –100 mV due to a possible 1 mA offset current.
2IOHRTN/IOLRTN should be connected to VCOM to minimize power dissipation.
3VDUT = –2 V to +7 V, CTOTAL = 10 pF, RDUT = 10 Ω. For inhibit leakage tests, VDUT = 0 V to +5.9 V, IOH = –4 mA, IOL = +4 mA, TCASE = +36°C.
4Measured from the ECL crossing to the 10% change in the output current.
5IPROGRAM = ±50 mA.
6Maximum power dissipation with +VS = +10 V, –VS = 5.2 V, IPROGRAM 50 mA, VCOM = VDUT = 0 V.
7For a 1% change in +VS or VS, the output current may change a maximum of 0.05% of Full Scale Range (FSR).
Specifications subject to change without notice.
REV. A
–2–
AD1315
ABSOLUTE MAXIMUM RATINGS1
CONNECTION DIAGRAM
Power Supply Voltage
+VS to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +12 V
–VS to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –11 V
Difference from +VS to –VS . . . . . . . . . . . . . . . . . . . . . 16 V
Inputs
Difference from INH to INH . . . . . . . . . . . . . . . . . . . . . 5 V
INH, INH . . . . . . . . . . . . . . . . . . +VS – 13.4 V, –VS + 11 V
V
COM, VDUT . . . . . . . . . . . . . . . +VS – 13.1 V, –VS + 13.2 V
I
OL, IOH Program Voltage . . . . . . . . +VS – 15 V, –VS + 15 V
Operating Temperature Range . . . . . . . . . . . . . . . 0 to +70°C
Storage Temperature Range . . . . . . . . . . . . –65°C to +125°C
Lead Temperature Range (Soldering 20 sec)2 . . . . . . .+300°C
SUGGESTED PAD LOCATION
Dimensions shown in inches and (mm).
Pin
No.
Symbol
Function
1
2
3
4
IOLRTN
VCOM
VDUT
–VS
Logic Low Current Return
Communication Voltage
Load/Dot Connection
Negative Supply
5
6
7
8
IOHRTN
IOLPROG
LID
GND
IOHPROG
N/C
N/C
N/C
+VS
INH
Logic High Current Return
Logic Low Current Program Voltage
Lid Connection (Internal)
Ground
Logic High Current Program Voltage
No Connection
No Connection
No Connection
Positive Supply
Inhibit
9
10
11
12
13
14
15
16
INH
N/C
Inhibit
No Connection
ORDERING GUIDE
Temperature Package
Package
Option*
1Stresses above those listed under Absolute Maximum Ratings may cause perma-
nent damage to the device. This is a stress rating only; functional operation of the
device at these or any other conditions above those indicated in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.
Model
Range
Description
AD1315KZ 0 to +70°C
16-Lead Gull Wing Z-16B
*Z = Leaded Chip Carrier (Ceramic).
2To ensure lead coplanarity (±0.002 inches) and solderability, handling with bare
hands should be avoided and the device should be stored in an environment at
24°C, ±5°C (75°F, ±10°F) with relative humidity not to exceed 65%.
REV. A
–3–
AD1315
DEFINITION OF TERMS
Gain
The measured transconductance.
outputs are unipolar, this small initial offset of 2 mA must be set
to allow for measurement of possible negative offset. With a gain
of 10 mA/V, a 0.2 V input should yield an output of ±2 mA. The
difference between the observed output and the ideal ±2 mA
output is the offset error.
I
OUT (@ 5V Input ) − IOUT (@ 0.2V Input )
Gain =
V
PROG(@ 5V ) −VPROG(@ 0.2V )
Offset Error = IOUT (@ 0.2 V) – Gain ϫ VPROG (@ 0.2 V)
where:
PROG values are measured at IOL/IOH PROG
Linearity Error
The deviation of the transfer function from a straight line de-
fined by Offset and Gain expressed as a % of FSR.
V
Gain Error
The difference between the measured transconductance and the
ideal expressed as a % of full-scale range.
I
OUT (calc) = Gain ϫ VPROG (@ set point) + Offset
where:
Ideal Gain = 10 mA/V
Ideal Gain − Actual Gain
set point = VPROG (from 0.2 V to 5 V)
IOUT (FSR) = Gain ϫ VPROG (@ 5 V) + Offset
Gain Error =
×100
Ideal Gain
I
OUT (measured ) − IOUT (calc)
Linearity Error
×100
Offset Error
I
OUT (FSR)
Offset Error is measured by setting the IOHPROG or IOLPROG
inputs to 0.2 V and measuring IOUT. Since both IOH and IOL
Figure 2. Timing Diagram for Inhibit Transition
Figure 1. Definition of Terms
Figure 5. IOL, IOH Linearity Error vs.
Current Program Voltage
Figure 3. IOL, IOH Offset Current vs.
Temperature
Figure 4. IOL, IOH Gain Error vs.
Temperature
REV. A
–4–
AD1315
Figure 7. Inhibit to +IMAX, –IMAX
Propagation Delay vs. Temperature
Figure 6. +IMAX, –IMAX to Inhibit
Propagation Delay vs. Temperature
Figure 8. Inhibit Mode Leakage Current vs. Case Temperature
Figure 9. AD1315 DC Test Circuit
Figure 10. AD1315 Propagation Delay Test Circuit
–5–
REV. A
AD1315
FUNCTIONAL DESCRIPTION
The AD1315 is a complete high speed active load designed for
use in general purpose instrumentation and digital functional
test equipment. The function of the active load is to provide
independently variable source and sink currents for the device to
be tested.
The equivalent circuit for the AD1315 is shown in Figure 11.
An active load performs the function of loading the output of
the device under test with a programmed IOH or IOL. These
currents are independently programmable. VCOM is the commu-
tation voltage point at which the load switches from source to
sink mode. The active load may also be inhibited, steering cur-
rent to the IOLRTN and IOHRTN pins, effectively disconnecting it
from the test pin.
Figure 12. Allowable Current Range for IOH, IOL vs. VDUT
The AD1315 accepts differential digital signals at its inhibit
inputs ensuring precise timing control and high noise immunity.
The wide inhibit input voltage range allows for ECL power
supplies of –5.2 V and 0 V, –3.2 V and +2 V, and 0 V and +5 V.
Where speed and timing accuracy are less important, TTL or
CMOS logic levels may be used to toggle the Inhibit inputs of
the AD1315. Single ended operation is possible by biasing one
of the inputs to approximately +1.3 V for TTL or VCC/2 for
CMOS. Care should be taken to observe the 4 V maximum
allowable input voltage.
Ideally, the commutation point set at VCOM would provide in-
stantaneous current sink/source switching. Because of I/V
characteristics of the internal bridge diodes, this is not the case.
To guarantee full current switching at the DUT, at least a 1 volt
difference between VCOM and VDUT must be maintained in
steady state conditions. Because of the relatively fast edge rates
exhibited by typical logic device outputs, this should not be a
problem in normal ATE applications.
INHIBIT MODE LEAKAGE
The AD1315’s inhibit-mode leakage current changes with both
temperature and bias levels. There are two major contributing
effects: transistor reverse-bias collector-base leakage and reverse
leakage in the Schottky-diode bridge. Leakage variations with
The IOH and IOL programming inputs accept 0 V to +5 V analog
inputs, corresponding to 0 to 50 mA output currents. The VCOM
input, which sets the IOH/IOL switch point, may be set anywhere
within the input range of –2 V to +7 V.
VDUT arise primarily from transistor collector-base leakage,
while both effects contribute to leakage current temperature
variations. Inhibit-mode leakage is weakly dependent on VCOM
and decreases slightly as the difference between VDUT and VCOM
is reduced. Figure 8 shows typical AD1315 inhibit leakage cur-
rent as a function of VDUT and temperature.
THERMAL CONSIDERATIONS
The AD1315 is provided in a 0.550" ϫ 0.550", 16-lead (bottom
brazed) gull wing, surface mount package with a θJC of 10°C/W
(typ). Thermal resistance (case-to-ambient) vs. air flow for the
AD1315 in this package is shown in Figure 13. The data pre-
sented is for a ZIF socketed device. For PCB mounted devices
(w/30 mils clearance) the thermal resistance should be ~3 to 7%
lower with air flows below 320 lfm(1). Notice that the improve-
ment in thermal resistance vs. air flow starts to flatten out just
above 400 lfm(2)
.
NOTES
1Ifm is air flow in linear feet/minute.
2For convection cooled systems, the minimum recommended airflow is 400 lfm.
Figure 11. Block Diagram
VDUT VOLTAGE RANGE
In Figure 12, VDUT range, IOH and IOL typical current maxi-
mums are plotted versus DUT voltage. In the IOH mode (VDUT
higher than VCOM), the load will sink 50 mA, until its output
starts to saturate at approximately –1.5 V. In the IOL mode
(VDUT lower than VCOM), the load will source 50 mA until its
output starts to saturate at approximately +5.5 V. At +7 V, the
source current will be close to zero.
Figure 13. Case-to-Ambient Thermal Resistance vs.
Air Flow
REV. A
–6–
AD1315
APPLICATIONS
source current (IOL). Like the IOH and IOL return lines, the VCOM
must be able to sink or source 50 mA, therefore a standard op
amp will not suffice. An op amp with an external complemen-
tary output stage or a high power op amp such as the AD842
will work well here. A typical application is shown in Figure 15.
The AD1315 has been optimized to function as an active load
in an ATE test system. Figure 14 shows a block diagram illus-
trating the electronics behind a single pin of a high speed digital
functional test system with the ability to test I/O pins on logic
devices. The AD1315 active load, AD1321 or AD1324 pin
driver, AD1317 high speed dual comparator and the AD664
quad 12-bit voltage DAC would comprise the pin electronic
portion of the test system. Such a system could operate at
100 MHz with the AD1321 (200 MHz with the AD1324) in a
data mode or 50 MHz (100 MHz) in the I/O mode.
LAYOUT CONSIDERATIONS
IOHRTN and IOLRTN may be connected to any potential between
–2 V and +7 V. These return points must be able to source or
sink 50 mA, since the IOH and IOL programmed currents are
diverted here in the inhibit mode. The RTNs may be connected
to a suitable GND. However, to keep transient ground currents
to a minimum, they are typically tied to the VCOM programming
voltage point.
The VCOM input sets the commutation voltage of the active load.
With DUT output voltage above VCOM, the load will sink cur-
rent (IOH). With DUT output voltage below VCOM, the load will
Figure 14. High Speed Digital Test System Block Diagram
Figure 15. Suggested IOHRTN, IOLRTN, VCOM Hookup
REV. A
–7–
AD1315
EVALUATION BOARD
AD1315KZ active load, an ECL input buffer for Inhibit and the
oscilloscope probe jacks necessary to properly analyze the true
performance of the AD1315KZ. An equipment list is provided
in order to minimize variations due to test setups.
The AD1315 Evaluation Board allows the designer to easily
evaluate the performance of the AD1315 and its suitability for
the specific application. The AD1315EB includes a mounted
Figure 16. AD1315EB Evaluation Board Circuit
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
16-Lead Gull Wing
(Z-16B)
–8–
REV. A
相关型号:
AD1322BKZ
IC 0.085 A BUF OR INV BASED PRPHL DRVR, CDSO16, HERMETIC SEALED, GULL WING, CERAMIC, LCC-16, Peripheral Driver
ADI
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