AAHS298B
Radiation Tolerant 8-channel Source Driver
Description
Features
The AAHS298B is part of Microsemi’s new family of
Radiation Tolerant products aimed at the aerospace
and defense markets. The AAHS298B is a RadiationTolerant source driver with eight non-inverting
channels, with internal thermal shutdown.
700mA Output Source Current
Zero Quiescent Off Current
Full Channel Isolation to Prevent Fault
Propagation
Internal Ground Clamp Diodes
75V Output Breakdown Voltage
TTL, 5V and 12V Logic Compatible
Internal Thermal Shutdown
Radiation tolerant to 100kRad(Si) Total Dose,
50kRad (Si) ELDRS
-55°C to +125°C Temperature Range
Available in 20-pin Ceramic SOIC with formed
and flat Leads
QML-V and QML-Q Qualified
Capable of providing an interface from TTL, 5V or 12V
logic systems to relays, motors, solenoids, and other
loads, this device adds the additional benefit of an
internal thermal shutdown and output transient
protection/clamp diodes with sustaining voltages to
75V.
Each output is capable of sourcing 700mA with a
withstand voltage of 75V over the full military
temperature range. The thermal shutdown is intended
to protect against over-current and soft-start
occurrences.
The AAHS298B is offered in 20-pin ceramic SOIC
package with formed and flat leads. The AAHS298B
has demonstrated tolerance to 100kRad (Si) total dose
(min), 50kRad (Si) ELDRS (min), as well as immunity
to latch-up and SEE tolerance. Available standard
screening includes Level “S” or Level “B,” Other
screening or processing in line with our capabilities can
be supported to meet customers’ requirements.
Applications
Relay/Solenoid Drivers
Lamp/LED Drivers
Stepper and/or Servo Motor Drivers
Redundant Power Distribution
Product Highlight
VS2
VS1
AAHS298B
20
1
20
11
10
11
10
2
19
2
19
12
9
12
9
3
18
3
18
13
8
13
8
4
17
4
17
14
7
14
7
5
16
5
16
15
6
15
6
6
15
6
15
16
5
16
5
7
14
7
14
17
4
17
4
8
13
8
13
18
3
18
3
9
1
0
12
9
12
19
2
19
11
10
11
20
1
20
1
IN1
IN2
IN3
IN4
IN5
IN6
IN7
IN8
VS1
LX7710
LX7710
2
AAHS298B
IN8
IN7
IN6
IN5
IN4
IN3
IN2
IN1
1
VS2
CH1 Power Bus
CH2 Power Bus
CH3 Power Bus
CH4 Power Bus
CH5 Power Bus
CH6 Power Bus
CH7 Power Bus
CH8 Power Bus
Figure 1 · Redundant Switchable Power Bus
March 2016 Rev. 1.4
www.microsemi.com
© 2015 Microsemi Corporation- Analog Mixed Signal
1
Pin Configuration and Pinout
Pin Configuration and Pinout
1
20
2
19
3
18
4
5
6
7
8
MSC-S
AAHS298B
1MN37
YYWW XXX
VS
IN1
IN2
IN3
IN4
IN5
IN6
IN7
IN8
VS
17
16
15
14
13
9
12
10
11
GND
OUT1
OUT2
OUT3
OUT4
OUT5
OUT6
OUT7
OUT8
GND
S20 PACKAGE
(Top View)
YYWW XXX = Year/Week/Serial Number
S Flow marking shown i.e. MSC-S
Ordering Information
Ambient
Temperature
-55°C to
125°C
Type
Package
Hermetic
CSOIC 20L
Flat Lead
Part Number
Flow
AAHS298B-07-4020A-EV
Equivalent to
Class V
AAHS298B-06-4020A-EQ
Equivalent to
Class Q
Tray
AAHS298B-S-S20B-S
SMD 5962-1523101VXA
-55°C to
125°C
Hermetic
0°C to 70°C
AAHS298B Rev. 1.4
CSOIC 20L
Packaging
Type
AAHS298B-S-S20B-B
SMD 5962-1523101QXA
AAHS298B-S-S20B-ENGR
QML-V
QML- Q
Tray
Commercial
2
Pin Description
Pin Description
Pin Number
Pin Designator
1, 10
Supply Voltage
2-9
IN[1:8]
11, 20
GND
12-19
OUT[1:8]
Description
Input Supply Voltage, both pins should be externally connected on the PCB
to improve the internal current distribution and allow the device to safely
provide the maximum 2800mA of continuous supply current.
8 Logic Inputs, TTL, CMOS & High Voltage (12V) compatible. With all
inputs low the device is in sleep mode.
Ground, both pins should be externally connected externally on the PCB to
improve the internal current distribution and improve forward voltage of the
flyback clamping diodes.
700mA Source Outputs.
Block Diagram
VS
1
20
GND
IN1
2
19
OUT1
IN2
3
18
OUT2
IN3
4
17
OUT3
IN4
5
16
OUT4
IN5
6
15
OUT5
IN6
7
14
OUT6
IN7
8
13
OUT7
IN8
9
12
OUT8
VS
10
11
GND
Input
Level
Shift
Bias &
Controls
Figure 2 · AAHS298B Simplified Block Diagram
AAHS298B Rev. 1.4
3
Absolute Maximum Ratings
Absolute Maximum Ratings
Parameter
Supply Voltage (VS, Max voltage between VS and GND)
Digital Inputs (IN[1:8], Max voltage between INPUT & GND)
Output Voltage (OUT[1:8], Maximum voltage between OUT[1:8]
and GND)
Single Output Continuous Current (OUT[1:8])
Single Output Peak Current (OUT[1:8], ≤ 1 second)
Multiple Output Simultaneously Continuous Current (OUT[1:8])
ESD (all pins, HBM)
Operating Junction Range
Storage Temperature Range
Lead Temperature (Soldering, 10 Seconds)
Peak Package Solder Reflow Temp. (40 sec. max. exp.)
Lead Temperature. (Soldering 10 seconds)
Value
-0.5 to 75
-0.5 to 15
Units
V
V
75
V
-700
-1200
-2800
2000
-55 to 150
-65 to 150
300
mA
mA
mA
V
°C
°C
°C
260 (+0, -5)
°C
300
°C
Exceeding these ratings could cause damage to the device. All voltages are with respect to GND. Currents are positive into,
negative out of specified terminal. These are stress ratings only and functional operation of the device at these or any other
conditions beyond those indicated under “Recommended Operating Conditions” are not implied. Exposure to “Absolute Maximum
Ratings” for extended periods may affect device reliability.
Thermal Data
Parameter
S20 Package:
Thermal Resistance-Junction to Case, θJC
Value
Units
2.24
°C/W
Note: The θJC number is for conduction only to the ceramic base of the package. It assumes that the ceramic base has a thermal
epoxy underneath the ceramic package to exhaust the heat from the package into the PCB, or other mounting surface.
AAHS298B Rev. 1.4
4
Electrical Characteristics
Electrical Characteristics
°
Unless otherwise stated the following specifications apply over operating ambient temperature of -55 C <
°
Temp < 125 C, VS = 50V, 100kRad (Si) TID (min), 50kRad (Si) ELDRS (min)
Symbol
Parameter
Test Condition
Test
Setup
Min
Typ
Max
1
20
5
25
7
25
Units
Operating Supply Current
ISLEEP
Standby Supply Current
IN[1:8] = 0.0V, No Output Load
IVS2.5
Active Supply Current
IN[1:8] = 2.5V, No Output Load
IVS5
Active Supply Current
IN[1:8] = 5.0V, No Output Load
1
2
µA
mA
AC Characteristics
ton
toff
tR
tF
Output Turn On Delay
Time
Output Turn Off Delay
Time
Output Rise Time (10% to
90%)
Output Fall Time (90% to
10%)
2
10
Load = 470Ω, 100pF, VS = 45V
VIL = 0.8; VIH = 2.5V
µs
2
10
DC Characteristics
VS
THSDTRIP
THSDRST
Thermal Shutdown Trip
Temperature
Thermal Shutdown Reset
Temperature
VIH
Input High Level
VIL
Input Low Level
VCESAT
VCESAT
10
Supply Voltage Range
135
50
155
V
175
ºC
Restarts at 125ºC
125
2.5
3
Output Saturation at
350mA
Output Saturation at
500mA
VCESAT
Output Saturation at
700mA
IIH
Input High Leakage
0.8
IN[1:8] = 2.5V
4
IN[1:8] = 5.0V
1.7
2.2
1.8
2.3
2.1
2.7
60
100
0.1
10
2
50
V
5
IIL
Input Low Leakage
IN[1:8] = 0.0V
IOL
Output Low Leakage
Output OFF, VOUTX = 0.0V
Clamp Diode Forward
Voltage
IF = 200mA
VF
IR
Clamp Diode Leakage
Current
AAHS298B Rev. 1.4
6
2.5
7
IF = 700mA
VR = 50V
µA
V
3.0
8
50
µA
5
Parameter Test Configurations
Parameter Test Configurations
(See test setup numbers in Electrical Characteristics Table)
VS
VS
ISLEEP µ A
IVSx m A
VIN
VS
VIN
VIN
OPEN
VOUT
OPEN
V
V
Test Setup 1
Standby Supply Current
Test Setup 2
Active Supply Current
Test Setup 3
Input Threshold Voltage
VS
VS
VS
VSAT
V
VIN
VIN
mA
IOUT
µA
VIN
VOUT
IC
VOUT
µA
ICEX
Test Setup 4
VCE(sat) Test Circuit
Test Setup 5
Input Bias Current
Test Setup 6
Output Leakage Current
OPEN
VS
µA
OPEN
VIN
VOUT
VF V
VIN
VOUT
IF
Test Setup 7
Clamp Diode Forward Voltage
AAHS298B Rev. 1.4
IR
Test Setup 8
Clamp Diode Leakage Current
6
Single Channel Block Diagram
Single Channel Block Diagram
VS
Bias & Controls
2k
Input
ESD
Diode
60k
TTL, CMOS &
High-Level
Compatible
300
60k
Thermal
Shutdown
ESD
Diode
1k
OUTPUT
Inductive Kickback
Clamp Diode
200mA DC, 700mA
10ms
GND
Figure 3 · AAHS298B Single Channel Simplified Block Diagram
Application Information
VS Pins
The AAHS298B has two VS (Input Supply) pins (pins 1, 10). The maximum 2800mA total supply current limit
for the AAHS298B comes from the supply bond wires current capability, these bond wires will fuse open
around 2A each. By externally connecting these two pins on the printed-circuit board the utilization of two
pins one at each end of the package improves the internal current distribution. With only one VS pin
connected, the saturation voltage would progressively increase from the near to the far channel due to
internal IR losses in the die metallization, and the part will not be capable of the full 2800mA, only 1400mA.
IN Pins
The IN (Inputs) pins are compatible with TTL (5V), CMOS (3V) & High-Level (12V) logic levels and not only
turn on their respective output but also provide bias to the device activating for instance the thermal
shutdown circuitry. Conversely if all IN pins are low the device is off with no quiescent current, and the
device is in sleep mode.
AAHS298B Rev. 1.4
7
Application Information
OUT Pins
The OUT (Output) pins are switched high-side drivers designed to output 700mA continuous current with a
typical saturation voltage drop of 2.1V. See figure 4 for the typical saturation voltages with changes in
output current and temperature. At the rated maximum continuous operating current which is 700mA, the
saturation voltage still has a negative temperature coefficient as indicated in the chart. This is advantageous
since it reduces the power dissipation when the device operates at elevated temperatures.
Above 700mA the saturation increases more rapidly and due to the design of the output transistors the
output current self-limits itself around 1.4A, but could reach the bond-wire fusing current of 2A on a "dead"
short-circuit condition in a matter of milliseconds. This is a protection feature designed to isolate a shorted
output under overstress while allowing the remaining outputs to function normally. The 700mA per channel
current was therefore determined to be around 50% of the drive maximum capability of the output
transistors.
Thermal Shutdown
The thermal shut-down circuitry is located in the center of the die between channels 4 & 5. The die being
relatively thick, and the silicon being a good conductor of heat, the temperature gradient at the surface of the
die, say between channel #1 and #4 cannot exceed a few degrees centigrade.
When all channels are dissipating power, the Junction to Case Thermal Resistance is less than 3°C/W when
measured between the junctions at the surface of the silicon and the bottom of the ceramic package. The
Junction to Case thermal resistance for one channel only is less than 20°C/W.
When the package is mounted with a heat pad under it on a PCB equipped with an integral heat-sink, the
Junction to PCB thermal resistance could be of the order of 10°C/W, and in this condition which we have
verified, it is almost impossible for the thermal shut-down circuitry to trip.
On the contrary, if the part is simply mounted on the PCB with no heat sinking we have been able to make
the thermal shutdown trip with the PCB at room temperature with 4 channels ON at full load (2800mA total
creating approximately 6W of power dissipation).
There is a time constant associated with the thermal shut-down circuitry which measures in seconds and
this is why we cannot rely on it to protect the part against "dead" short-circuits during which the current could
exceed 2A and blow the bond wire in 10 to 20mS.
Clamp Diodes
Each output channel includes an integrated clamp diode to protect against possible inductive kick-backs.
These diodes are rated for 200mA DC current at a maximum of 2.5V, and can withstand 700mA for about
10ms. Like the VS pins by externally connecting the two GND pins together on the printed-circuit board the
utilization of both pins one at each end of the package improves the internal current distribution and losses.
It is very important to recirculate any flyback current close to the source to minimize noise issues. When
using the AAHS298B’s built-in output transient suppression diodes for this purpose the PCB layout or wiring
should insure that the digital input side and output power sides do not share ground paths, and the
conductors and/or traces are sized accordingly. When the proximity of the inductive load is some distance
from the driver then an additional ‘freewheel diode’, or snubber circuit may be required to minimize noise
and clamp voltage excursions. If using the internal diode causes other complications (delay times, etc.) a
varistor or transorb may be used instead. Keeping the power and digital grounds separate and only
connecting them at the one star ground point should minimize and ground loop or bounce issues.
AAHS298B Rev. 1.4
8
Characteristic Curves
Characteristic Curves
2.4
TYPICAL AAHS298B OUTPUT VCE SATURATION VOLTAGE VS
TEMPERATURE
2.2
VCESat (V)
2.0
1.8
1.6
1.4
10mA
100mA
300mA
350mA
500mA
700mA
1.2
1.0
0.8
-55
-35
-15
5
25
45
65
85
105
125
Temperature (°C)
Figure 4 · Typical Output VCE vs Saturation Voltage
MAXIMUM CHANNEL OUTPUT CURRENT VS DUTY CYCLE
Maximum Peak Output Current (mA)
800
750
Maximum Continous Output Current
700
650
600
5
550
500
8
450
6
7
400
Number of Outputs
Conducting Simltaneously
VS = 50V
350
300
250
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Duty Cycle (%)
Figure 5 · Maximum Channel Output vs Duty Cycle
(≤ 4 channels may be operated continuously at maximum current within package power limitations)
AAHS298B Rev. 1.4
9
Package Outline Dimensions
Package Outline Dimensions
Controlling dimensions are in inches, metric equivalents are shown for general information.
Dim
A
2.28
A1
D
20
11
E2
E1
E
1
10
e
MILLIME
ERS
MIN
MAX
2.92
INCHES
MIN
MAX
0.090
0.115
0.38
0.015
A2
1.78
2.41
0.070
0.095
b
0.36
0.48
.0140
.0190
c
0.15
0.25
0.006
0.010
D
12.45
13.08
0.490
0.515
E
10.16
11.18
0.400
0.440
E1
7.24
7.62
0.285
0.300
1
L
b
A
c
A2
A1
E2
4.70 BSC
0.185 BSC
e
1.27 BSC
0.050 BSC
L
0.50
0.76
0.020
0.030
Figure 6 · S20 20-Lead Ceramic SOIC Package Dimensions
Dim
MIN
MAX
MIN
MAX
A
2.28
2.92
0.090
0.115
A2
1.78
2.41
0.070
0.095
b
0.36
0.48
.0140
.0190
c
0.15
0.25
0.006
0.010
D
12.45
13.08
0.490
0.515
E
21.00
23.00
0.827
0.906
E1
7.24
7.62
0.285
0.300
D
20
11
E
E2
E1
1
e
10
1
b
A
INCHES
MILLIMETERS
A2
c
E2
4.70 BSC
0.185 BSC
e
1.27 BSC
0.050 BSC
Figure 7 · S20 20-Lead Ceramic SOIC Package with Flat Leads Dimensions
AAHS298B Rev. 1.4
10
Microsemi Corporation (Nasdaq: MSCC) offers a comprehensive portfolio of semiconductor
and system solutions for communications, defense & security, aerospace and industrial
markets. Products include high-performance and radiation-hardened analog mixed-signal
integrated circuits, FPGAs, SoCs and ASICs; power management products; timing and
synchronization devices and precise time solutions, setting the world’s standard for time; voice
processing devices; RF solutions; discrete components; security technologies and scalable
anti-tamper products; Power-over-Ethernet ICs and midspans; as well as custom design
capabilities and services. Microsemi is headquartered in Aliso Viejo, Calif., and has
approximately 3,400 employees globally. Learn more at www.microsemi.com.
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property of their respective owners.
Microsemi makes no warranty, representation, or guarantee regarding the information contained herein or
the suitability of its products and services for any particular purpose, nor does Microsemi assume any
liability whatsoever arising out of the application or use of any product or circuit. The products sold
hereunder and any other products sold by Microsemi have been subject to limited testing and should not
be used in conjunction with mission-critical equipment or applications. Any performance specifications are
believed to be reliable but are not verified, and Buyer must conduct and complete all performance and
other testing of the products, alone and together with, or installed in, any end-products. Buyer shall not
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AAHS298B.1.4/1.16