VISHAY IRM7001

IRM7001
SIR Modulator/Demodulator
Dimensions in inches (mm)
SOIC Package
A .393 (10.0)
.386 (9.8)
B
.157 (4.0) .244 (6.2)
8 .150 (3.8) .229 (5.8)
16
9
1
.050 (1.27) BSC .068 (1.75)
.054 (1.35)
R x 45°
.009 (.25)
.008 (.19)
T
.019 (.49)
.014 (.35)
FEATURES
• Compliant with IrDA 1.0 Physical Layer Specifications
• Interfaces with IrDA 1.0 Compliant IR Transceivers
• Used in conjunction with Standard 16550 UART
• Transmits/Receives either 1.6µs or 3/16 Pulse Mode
• Internal or External Clock Mode
• Programmable Baud Rate
• 2.7–5.5 V Operation
• 16 Pin SOIC Package
APPLICATIONS
• Interfaces with IR Transceivers in:
- Computer Applications:
PDAs
Dongle or other RS232 Adapter
- Telecom Application:
Modems
Fax Machines
Pagers
- Handheld Data Collection:
Industrial
Medical
Transportation
DESCRIPTION
The IRM7001 SIR-Encoder/Decoder is a CMOS modulator/
demodulator chip that is used to both encode and decode
information as per the IrDA® SIR (Serial InfraRed) signal modulation and demodulation scheme. This chip is designed to
work with Infineon IrDA compatible transceivers and all other
IrDA compatible transceivers. The chip contains a clock
divider circuit used to generate the 16X clock internally. This
makes it very suitable for microcontroller-based embedded
system design.
.049 (1.25)
7° .016 (.40)
.009 (.25)
.004 (0.1)
Notes:
1. Dimensions A and B are datums and T is a datum surface.
2. Dimensioning and tolerancing per ansi Y14.5M, 1982
3. Controlling dimension: millimeter.
4. Dimension A and B do not include mold protrusion.
5. Maximum mold protrusion 0.15 (0.005) per side.
Figure 1. IRM7001 pin out
IRM - 7001
16XCLK
1
16
VCC
TXD
2
15
OSCIN
3
14
4
13
OSCOUT
PWR DN
5
12
6
1
11
7
10
8
9
RCV
A0
A1
A2
CLK_SEL
GND
PLS MOD
IR_TXD
IR_RCV
NRST
Figure 2. IRM7001 Block Diagram
TXD
SIR
ENCODE
IR_TXD
SIR
DECODE
IR_RCV
/NRST
RCV
INT_CLOCK
A0
A1
A2
16XCLK
CLOCK
DIVIDE
PULSEMOD
CLK_SEL
Document Number: 82576
Revision 17-August-01
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1
Figure 3. IRM7001 Usage Scenario (with Internal Clock)
IRM7001
OSCIN
IRMS/T6118
IRM5000
3.6864MHz
15
OSCOUT
14
2
TxD
11
IR_TXD
10
TXD
IRM7001
IRMS/T6118
IRM5000
Microprocessor/
Controller
A0
A1
CLK_SEL A2
3
TxD
IR_TXD
IR_RCV RCV
RxD
SIN
3
SIN
1
VCC
IO 1
6
SOUT
TXD
SOUT
4
5
Microprocessor/
Controller
2
11
10
IR_RCV RCV
RxD
Figure 4. IRM7001 Usage Scenario (with External Clock)
IO 2
16XCLK
BAUDOUT
CLK_SEL
IO 3
Table 1. Selection of Internal Clock Rate from Crystal Oscillator
Selected Clock
Rate (bps)
A2
A1
A0
CRYSTAL FREQ.
DIVISION
115200
0
0
0
Divided by 2
57600
0
0
1
Divided by 4
19200
0
1
0
Divided by 12
9600
0
1
1
Divided by 24
38400
1
0
0
Divided by 6
4800
1
0
1
Divided by 48
2400
1
1
0
Divided by 96
TEST PURPOSE
1
1
1
No Division
Figure 5. Transceivers IRMS/T6118 and IRM5000
IRMS/T6118
IRM5000
0=L, 1=H
IRM7001 SIR Modulator/Demodulator functions extremely well
with Infineon IRMS6118/IRMT6118 and IRM5000 SIR (115 Kb/
s) Infrared Data transceivers. These products provide the user
with a low component count and cost effective way of implementing an IrDA port on their products where the microcontroller does not have a built-in IrDA port support
Document Number: 82576
Revision 17-August-01
Figures 12, 13, and 14 show the schematic, PCB front side and
back side for an IRM5000/7001 based port. Table 7 provides
the Bill of Materials list to implement the port. Figures 15, 16,
and 17 show the schematic, PCB front and the back side for an
IRMS6118/IRM7001 based port. Table 8 provides the Bill of
Materials list to implement the port.
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2
Table 2. Pin Out and Signal Description
Signal
Pin
Type
Description
16X CLK
1
DIGIN
Positive edge triggered input clock signal that is set to 16 times the data transmission baudrate. This
clock is used to drive the Encoder/Decoder state machine. Depending on the application, the
16XCLK can be provided by the application circuitry, or the internal clock divider circuitry can be
used. Selection of operating mode (Internal or External clock) is selected by the CLK_SEL line. If
External clock mode is selected, the application circuitry need not provide an oscillator.
TXD
2
DIGIN
Negative edge triggered input signal that is normally tied to the SOUT signal of a UART (serial data
to be transmitted). Data is modulated and output as IR_TXD.
RCV
3
DIGOUT
Output signal normally tied to SIN signal of a UART (received serial data). RCV is the demodulated
output of IR_RCV.
A0-A2
4-6
DIGIN
Clock multiplex signals. These signals are asserted to select the appropriate clock rate to support
the following baudrate: 115200, 57600, 38400, 19200, 9600, 4800 and 2400 bps.
CLK_SEL
7
DIGIN
Active high signal, used to activate either the Internal or External clock. A high on this line activates
the External clock (16XCLK), or if it is pulled low, the Internal clock is used.
GND
8
NRST
9
DIGIN
Active low signal used to reset the IrDA-SIR Decode state machine. Normally this line is tied to the
POR (power on reset) line of the circuit or simply to Vcc. In addition to resetting the circuitry, this
signal can be asserted to disable any data reception.
IR_RCV
10
DIGIN
Input is from the SIR optoelectronics. Input signal is a 3/16th pulse which is demodulated (pulse
stretched) to generate the RCV (3) output signal.
IR_TXD
11
DIGOUT
This signal is the modulated TXD signal.
PULSEMOD
12
DIGIN (with
pulldown)
A level high on this input puts the chip into the monoshot transmit mode. In this mode, when there
is a negative transition on the TXD input, a rising edge on the internal transmit modulation state machine will activate a high pulse on IR_TXD for 6 crystal clock cycles. With a 3.6864MHz crystal, this
corresponds to 1.63us. This mode cannot be used in conjunction with the 16XCLK clock. It is meant
to be used with the external crystal clock. By default, this input pin is pulled to GND.
POWER-DN
13
DIGIN (with
pulldown)
A high on this input puts the internal oscillator in POWERDOWN MODE. The internal oscillator normally is not powered down.
Chip ground
OSCOUT
14
ANAOUT
Crystal Oscillator input
OSCIN
15
ANAIN
Crystal Oscillator input
VCC
16
Power (see Electrical Specifications for detail)
Function
The IRM7001 can be used in conjunction with a microcontroller/microprocessor that has a serial communication interface
(UART). Prior to communication the processor selects the
transmission baudrate by selecting appropriate levels on the
A0-A2 lines. This process sets up the communication system
to operate at the prescribed data rate. After this initial step,
serial data can be transmitted or received at the prescribed
data rate.
The SIR Encode block is driven by TXD (negative edge triggered signal), which initiates the modulation state machine,
resulting in the modulated IR_TXD signal (which drives the SIR
compatible electronics).
The IRM7001 consists of two state machines–the SIR Encode
and SIR Decode blocks, and a sequential block Clock Divide,
which synthesizes the required internal signal INT-CLOCK,
based on the inputs A0-A2 and the CLK_ SEL line. The
IRM7001 can be placed into Internal Clock Mode (CLK_SEL
set to low) or External Clock Mode (CLK_ SEL set to high).
In addition, there is a pin provided to the user, called the
PULSEMOD. A high level input on this pin activates the 1.6us
mode on the IR_TXD. In this mode, whenever there is a negative edge on the TXD, the rising edge on the modulation state
machine will set the IR_TXD signal high for 6 crystal clock
cycles no matter what the selection on A2, A1 and A0 lines is.
With a crystal frequency of 3.6864MHz, this corresponds to a
high pulse of 1.63us.
The internal clock signal INT_CLOCK source is then gated
appropriately through to the INT_CLOCK signal. In application
where the external 16XCLK signal is provided, there is no need
to provide an oscillator.
Document Number: 82576
Revision 17-August-01
The SIR Decode block is driven by the IR_RCV signal (negative edge triggered signal, derived from the optoelectronics).
IR_RCV is demodulated by the SIR Decode block resulting in
the RCV signal, which represents the stretched input pulse.
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ELECTRICAL SPECIFICATIONS
Table 3. Absolute Maximum Ratings
Parameter
Symbol
Min.
Max.
Unit
Power Supply Voltage
VCC
–0.5
+7.0
V
Input/Output Voltage
VI/VO
–0.5
VCC +0.5
V
Power Dissipation
Pmax
0.46
W
Output Current
IO
-100
100
mA
Operating Temperature
TA
–40
+85
°C
Storage Temperature
TS
–65
+150
°C
Table 4. AC Characteristics VCC=5 V ±10%, TA=–20 to +85°C
Parameter
Symbol
Conditions
Propagation Delay Time
tpd
VCC=5.5 V, CL=50 pF
Output Rise Time
tr
Output Fall Time
Output Capacitance
tf
Min.
Typ.
Max.
Unit
80
ns
VCC=5.5 V, CL=50 pF
4.0
7.0
12
ns
VCC=2.7 V, CL=50 pF
10
16
24
ns
VCC=5.5 V, CL=50 pF
4.0
8.0
11
ns
VCC=2.7 V, CL=50 pF
11
16
26
ns
50
PF
COUT
Operating conditions
Operating conditions are specified with respect to GND unless
otherwise specified.
All the parameters below have been specified for VCC in the
range of 2.7 V(min) and 5.5 V(max) and for a temperature
range of –20°C to 85°C.
Document Number: 82576
Revision 17-August-01
Propagation Delay Time in the output buffer is the time taken
from the input passing VCC/2 to the time of the output reaching
VCC/2 with 50pF as the output load.
The output rise time is the time taken for the output (RCV,
IRTXD) to rise from 10% to 90% of final value.
The output fall time is the time taken for the outputs (RCV,
IR_TXD) to fall from 90% of original value to 10% of final value.
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Table 5. Operating Conditions at VCC=2.7 V
Parameter
Symbol
Min
Typ
Max
Unit
Supply voltage
VCC
2.7
5
5.5
V
Input voltage
VIN
0
VCC
V
Ambient temperature
Ta
–20
+85
°C
High-Level Input Voltage
VIH
0.7 VCC
VCC
V
Low-Level Input Voltage
VIL
0
0.3 VCC
V
Output High Voltage
VOH
2.2
Output Low Voltage
VOL
Static Power Dissipation
PSTAT
Dynamic Power Dissipation
Conditions
V
IOH=2.0 mA
0.5
V
IOL=2.0 mA
0.11
0.15
mW
PDYN
5.4
8.1
mW
Static Current Consumption
ISTAT
40
54
µA
Dynamic Power Dissipation
IDYN
2
3
mA
Max Clk Frequency(16XCLK)
f16xclk
2
MHz
Minimum Pulse Width(IR_TXD)
tmpw
1630
Pulse Width on monoshot (IR_TXD)
tmpw
1630
Output Capacitance on Output Pads
used for simulation
COUT
Value of pulldown resistor used on
POWERDN & PULSEMOD input pins
RDWN
114
Trigger Low Level Input Voltage
(For /NRST input pin)
VIL_TRIG
Trigger High Level Input Voltage
(For /NRST input pin)
VIH_TRIG
Document Number: 82576
Revision 17-August-01
ns
1710
1730
ns
50
pF
152
256
KOhms
0.7
0.8
0.9
V
1.7
1.85
1.9
V
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Table 6. Operating Conditions at VCC=5.5 V
Parameter
Symbol
Min
Typ
Max
Unit
Supply voltage
VCC
2.7
5
5.5
V
Input voltage
VIN
0
VCC
V
Ambient temperature
Ta
–20
+85
°C
High-Level Input Voltage
VIH
0.7 VCC
VCC
V
Low-Level Input Voltage
VIL
0
0.3 VCC
V
Output High Voltage
VOH
4.5
Output Low Voltage
VOL
Static Power Dissipation
PSTAT
Dynamic Power Dissipation
Conditions
V
IOH=2.0 mA
0.5
V
IOL=2.0 mA
0.44
0.61
mW
PDYN
11
16.5
mW
Static Current Consumption
ISTAT
80
110
µA
Dynamic Power Dissipation
IDYN
2
3
mA
Max Clk Frequency(16XCLK)
f16xclk
2
MHz
Minimum Pulse Width(IR_TXD)
tmpw
1630
Pulse Width on monoshot (IR_TXD)
tmpw
1630
Output Capacitance on Output Pads
used for simulation
COUT
Value of pulldown resistor used on
POWERDN & PULSEMOD input pins
RDWN
114
Trigger Low Level Input Voltage
(For /NRST input pin)
VIL_TRIG
Trigger High Level Input Voltage
(For /NRST input pin)
VIH_TRIG
ns
1710
1730
ns
50
pF
152
256
KOhms
0.7
0.8
0.9
V
1.7
1.85
1.9
V
IRDA Parameters
1. The Max Clk Frequency (f16xClk) represents the maximum
clock frequency that the IRM7001 internal state machine
should be driven at. Under normal circumstances, this clock
input should not exceed 16*115200(bps) =1.8432 MHz.
This is the maximum transmission rate under the IRDA Physical layer 1.0 specification. The IRM7001 can handle higher
clock rates, but the recommended maximum is as specified
above.
Document Number: 82576
Revision 17-August-01
2. The Minimum Pulse Width (tmpw), represents the minimum
pulse width of the encoded IR_TXD pulse as well as the minimum pulse width for the IR_RCV pulse. As per the IRDA
specification, the minimum pulse width of the IR_TXD and
IR_RCV pulses should be 3*(1/1.8432 MHz) = 1.63 µS. The
minimum pulse width that can be handled by the IRM7001 is
250ns, which is within the IRDA SIR specifications. Under
normal circumstances using a 16XCLK clock that does not
exceed 2 MHz, the minimum pulse width of IR_TXD should
not be shorter than 1.63 µs.
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IRDA-SIR Encoding and Decoding Scheme
Figure 6. Encoding Scheme—Macro Perspective
Overview of Encoding Scheme
Figures 5 and 6 outline the IRDA-SIR encoding
scheme. The encoding scheme relies on a clock
being present, which is set to 16 times the data
transmission baud rate (16XCLK).
The encoder sends a pulse for every space (0) that
is sent. On a high to low transition of the TXD line,
the generation of the pulse is delayed for 7 clock
cycles of the 16XCLK clock before the pulse is set
high for 3 clock cycles (or 3/16 of a bit time) and
subsequently pulled low. This in essence generates
a 3/16th bit time pulse centered around the bit of
information (0) that is being transmitted.
For consecutive spaces, pulses with a 1 bit time
delay are generated in series. If a logic 1 (mark) is
sent, then the encoder does not generate a pulse.
16 Cycles
16 Cycles
16 Cycles
16 Cycles
16 XCLK
TXD
7 CS
IRTXD
3 CS
Figure 7. IrDA-SIR Encoding Scheme—Detailed Timing Diagram
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
16XCLK
TXD
IRTXD
Overview of the Decoding Scheme
Figure 8. Decoding Scheme—Macro Perspective
The IRDA-SIR decoding modulation method can be
thought of as a pulse stretching scheme:
Every high to low transition of the IR-RXD line signifies the arrival of a 3/16th pulse. This pulse needs to
be stretched to accommodate 1 bit time (or 16
16XCLK cycles). Every pulse that is received is
translated into a'O' or space on the RXD line. If a
series of pulses separated by 1 bit time are
received, then the net result is a I bit time low pulse
for every 3/16th pulse received (see figure 9).
To be correctly received and interpreted by a UART,
the stretched pulse must be at least 3/4 of a bit time
in duration.
16 Cycles
16 Cycles
16 Cycles
16 Cycles
16 XCLK
IRRXD
3 CS
RXD
Figure 9. IrDA-SIR Decoding Scheme—Detailed Timing Diagram
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
16XCLK
IRRXD
RXD
16 Clock Cycles = 1 Bit Time
Document Number: 82576
Revision 17-August-01
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7
Figure 10. Monoshot Operation
1 2 3 4 5 6 7 8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
CRYSTAL CLK
INT CLK
(DIVBY2)
TXD
INTERNAL
IRTXD
OUTPUT
6 CRYSTAL CYCLES
IRTXD
(MONOSHOT)
clock, this corresponds to a pulse of 1.63us. The duration of
this pulse is independent of the code A2, A1, A0 and is always
6 clock cycles of the crystal, corresponding to the monoshot
operation.
Fig 7 illustrates the operation of the monoshot when the internal
clock is set to divide by 2 mode, i.e. when A2=0, A1=0 and
A0=0. A rising edge on the internal modulation state machine
(here called IRTXD OUTPUT), will cause the output on the
IRTXD to go up for 6 crystal clock cycles. With a 3.6864MHz
Figure 11. IRM5000/7001 Schematic with External Clock
5.2
1 - LED Anode
2 - Vcc
5V Power
Supply
C2
22µF
C3 R1
0.1µF 10K
SOUT
3–Tx
2
UART
16550
9
16
/NRST
Vcc
TxD
IR_TxD
C1
0.1µF
11 2
TxD
IRM7001
BAUDOUT
SIN
1 5
LED Vcc
ANODE
IRM5000
16XCLK
4–Tx
3
7
RCV
CLK_SEL
IR_RCV
GND
8
10 3
RxD
SD GND
4
6
12–GND
Document Number: 82576
Revision 17-August-01
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8
Figure 12. IRM5000/7001 Schematic using Internal Clock
VCC
RLED
Watt
2.7 V
0Ω
1/
4
W
5.1Ω
1/
4
W
5.0 V
RLED
1 - LED Anode
2 - Vcc
11-PLSMD
Power
Supply
C3
0.1µF
O5
O6
µP/
Controller
13
9-POWERDWN
4 - Tx
2
SOUT
IO1
5 - A0
4
IO2
8 - A1
5
7 - A2
6
IO3
SIN
O4
Data Rate A2 A1 A0
115.2K
0 0 0
57.6K
0 0 1
19.2K
0 1 0
9.6K
0 1 1
38.4K
1 0 0
4.8K
1 0 1
2.4K
1 1 0
10-CLK_SEL
15
R2 10MΩ
C5
15pF C4
Description
Quantity
U1
IRM7001-Encoder/
Decoder IC
(Infineon)
1 EA
U2
IRMS5000-IR Data
Transceiver
(Infineon)
1 EA
Y1
HC49
3.6864MHz Crystal
Oscillator
1 EA
R1
1206
10KΩ Resistor
1 EA
R2
1206
10MΩ Resistor
1 EA
C1
1210
0.1µF Capacitor
1 EA
C2
C
22µF Capacitor
1 EA
C3
1210
0.1µF Capacitor
1 EA
C4
1206
15pF Capacitor
1 EA
C5
1206
15pF Capacitor
1 EA
DO2436-2 (Infineon)
1 EA
PCB
Document Number: 82576
Revision 17-August-01
12
16
1
5
Vcc LED
ANODE
Vcc
9-POWERDWN
TxD
C1
0.1µF
IR_TxD
11
2
A0
A1
IRM5000
IRM7001
IR_RCV
OSCIN OCSOUT GND
XTL
8
14
3.6864MHz
TxD
10
3
RxD
SD GND
6
4
15pF
12- GND
Table 7. IRM5000/7001 Eval Board Bill of Materials
Case
type
9
/NRST PLSMD
A2
3 RCV
7
CLK_SEL
1
16XCLK
6 - Rx
3-16XCLK
Component
R1
10K
C2
22µF
Figure 13. IRM5000/7001 Eval Board Looking from Front Side
Figure 14. IRM5000/7001 Eval Board Looking from Back Side
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9
Figure 15. IRMS6118/7001 Schematic using Internal Clock
VCC
RLED
Watt
2.7 V
0Ω
1/
4
W
6.8Ω
1/
4
W
5.0 V
RLED
1 - LED Anode
2 - Vcc
Power
Supply
12
9
/NRST PLSMD
SOUT
µP /
Controller
IO1
IO2
IO3
SIN
3 - Tx
2
5 - A0
4
6 - A1
5
7 - A2
6
4 - Rx
3
Data Rate A2 A1
115.2K
0 0
57.6K
0 0
19.2K
0 1
9.6K
0 1
38.4K
1 0
4.8K
1 0
2.4K
1 1
A0
0
1
0
1
0
1
0
3.6864MHz
10MΩ
C4
R2
15pF C5
Description
Quantity
U1
IRM7001-Encoder/
Decoder IC
(Infineon)
1 EA
U2
IRMS6118-IR Data
Transceiver
(Infineon)
1 EA
Y1
HC49
3.6864MHz Crystal
Oscillator
1 EA
R1
1206
10KΩ Resistor
1 EA
R2
1206
10MΩ Resistor
1 EA
C1
1210
0.1µF Capacitor
1 EA
C2
C
22µF Capacitor
1 EA
C3
1210
0.1µF Capacitor
1 EA
C4
1206
15pF Capacitor
1 EA
C5
1206
15pF Capacitor
1 EA
DO2436-(Infineon)
1 EA
PCB
Document Number: 82576
Revision 17-August-01
6
16
Vcc
IR_TxD
1
Vcc LED
ANODE
11
3
TxD
A1
IRMS6118
IRM7001
A2
RCV
IR_RCV
10
4
RxD
OSCIN
OCSOUT GND CLK-SEL
XTL 14
8
7
SD GND
8
5
15pF
8 - GND
Table 8. IRMS6118/7001 Eval Board Bill of Materials
Case
type
TxD
C1
0.1µF
A0
15
Component
C2
22µF
R1
10K
C3
0.1µF
Figure 16. IRMS6118/7001 Eval Board Looking from Front Side
Note:
For proper operation Pin 7 of IRM7001 should be connected to GND.
Figure 17. IRMS6118/7001 Eval Board Looking from Back Side
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Design Notes:
1. When internal is used, CLK_SEL should be held low (connected to GND). In case of external clock CLK_SEL should
be tied high (VCC).
2. If PULSEMOD is held high and the internal clock is used, the
IR_TXD is limited to a duration of 1.6µs irrespective of data
rate. This helps in reducing LED current at lower data rates.
This function cannot be used with external clock (16XCLK).
3. There are two methods of putting the internal oscillator cell in
POWERDN MODE. Firstly, whenever CLKSEL line is
asserted high, the oscillator cell is automatically put in
power down mode. Secondly, the user may also decide to
put the oscillator in power down mode by providing a high
signal on the POWERDN input pin. Normally the POWERDN
pin stays low.
PACKAGING
Production Package
The package is SOIC 16 pins (150 mils) plastic package.
Chips will be available in Tape and Reel (2500 units per reel).
QUALITY AND RELIABILITY
E.S.D. and latch-up
Maximum DC current through any pin thus avoiding latch-up:
+/- 100 mA Electrostatic discharge protection: 4000 V for
mono-supply voltage Electrostatic discharge protection: 2000
V for multi-supplies voltages E.S.D. sensitivity: MIL STD-8833015.7 Class 2
Specific requirements: environmental endurance
A. Permanence of marking: MIL-STD-883 - Method 2015
B. Solderability: MIL-STD-883 - Method 2003
C. Resistance to soldering heat: MIL-STD-883 - Method 200
Document Number: 82576
Revision 17-August-01
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