1
DEMO MANUAL DC094
DESIGN READY SWITCHER
LTC1435 Constant Frequency
Synchronous DC/DC Converter
DESCRIPTIO
U
, LTC and LT are registered trademarks of Linear Technology Corporation.
This results in a power supply that has very high
efficiency, low ripple and fast transient response. At
low output currents the LTC1435 automatically switches
to Burst Mode
TM
operation to reduce switching losses
and maintain high operating efficiencies. Additionally,
the supply current can be shut down to less than
20µA with an input voltage of 10V. This feature is an
absolute necessity to maximize battery life in portable
applications. Gerber files for this circuit board are avail-
able. Call the LTC factory.
Burst Mode is a trademark of Linear Technology Corporation.
TYPICAL PERFOR A CE CHARACTERISTICS A D BOARD PHOTO
UU
W
Efficiency
LOAD CURRENT (mA)
1
EFFICIENCY (%)
100
90
80
70
60
50
10 100
DM094 TPC01
1000 4000
V
IN
= 10V
SFB = INT V
CC
V
OUT
= 5V
V
OUT
= 2.5V
V
OUT
= 3.3V
PERFOR A CE SU ARY
UWWW
Operating Temperature Range 0
°
C to 50
°
C
Input Voltage Range
Maximum Input Voltage (Limited by External MOSFET and Input Capacitor) 4.5V to 28V
Output Output Voltage (Jumper Selectable) 1.8V, 2.5V, 2.9V, 3.3V, 5V
Maximum Output Current (Continuous) 3A
Maximum Output Current (Peak) 3.5A
Typical Output Ripple at 10MHz Bandwidth (Burst Mode Operation) IO = 100mA 50mVP-P
Typical Output Ripple at 10MHz Bandwidth (Continuous) IO = 1A 35mVP-P
VIN Line Regulation, 6V to 20V 0.002%/V
IOUT Load Regulation, No Load to Full Rated Output –1%
IQSupply Current with No Load at 10V Input (Typical), SFB = INT VCC, EXT VCC = 5V 50µA
Supply Current in Shutdown (Typical), VIN = 10V 15µA
IEXTVCC EXT VCC Pin Current, VEXTVCC = 5V, VIN = 10V, No Load 650µA
VRUN Run Pin Threshold (Typical) 1.3V
Frequency Operating Frequency (Typical), COSC = 68pF
170kHz
DM094 BP
Demonstration Circuit 094 is a constant frequency step-
down (buck) regulator implemented entirely in surface
mount using the LTC
®
1435 switching regulator controller.
The output voltage is programmable from 1.8V to 5V via
a jumper. The input voltage can range from 4.5V to 28V
(limited by the external MOSFETs). The circuit highlights
the capabilities of the LTC1435 which uses a current
mode, constant frequency architecture to switch a pair of
N-channel power MOSFETs while providing 99% maxi-
mum duty cycle. Operating efficiencies exceeding 90%
are obtained.
2
DEMO MANUAL DC094
DESIGN READY SWITCHER
PACKAGE A D SCHE ATIC DIAGRA SM
W UW
TOP VIEW
S PACKAGE
16-LEAD PLASTIC SO
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
C
OSC
RUN/SS
I
TH
SFB
SGND
V
OSENSE
SENSE
–
SENSE
+
TG
BOOST
SW
V
IN
INT V
CC
BG
PGND
EXT V
CC
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
+
+
C
OSC
RUN/SS
I
TH
SFB
SGND
V
OSENSE
SENSE
–
SENSE
+
TG
BOOST
SW
V
IN
INT V
CC
BG
PGND
EXT V
CC
C
OSC
68pF
E3
RUN E4
SFB
E5
EXT V
CC
C
OUT
100µF
10V
× 2
+
C
IN
22µF
35V
× 2
C
C
330pF
Q2
Si4412DY
Q1
Si4412DY
D2
MBRS140T3
SGND
DM 094 F01
L1
10µH
R1
35.7k
1%
R
SENSE
0.033Ω
V
IN
4.5V TO 28V
C3
4.7µF
16V
R2
69.8k
1%
C4
0.1µF
C6
100pF
C2
0.1µF
JP1
INT V
CC
GND
D1
CMDSH-3
U1
LTC1435
C5
1000pF
R
C
, 10k
C
C2
, 51pF
C1, 100pF
C
SS
, 0.1µF
E1
E6
V
OUT
E7
V
OSENSE
E8
GND
E2
JP2A
1.8V
R3
32.4k
1%
JP2B
2.5V
R4
24.9k
1%
JP2C
2.9V
R5
20k
1%
JP2D
3.3V
R6
11k
1%
JP2E
5V
Figure 1. LTC1435 Constant Frequency, High Efficiency Converter
PARTS LIST
REFERENCE
DESIGNATOR QUANTITY PART NUMBER DESCRIPTION VENDOR TELEPHONE
C
C
1 08055A331KAT1A 330pF 50V 10% NPO Chip Capacitor AVX (803) 448-9411
C
C2
1 08055A510KAT1A 51pF 50V 10% NPO Chip Capacitor AVX (803) 448-9411
C
IN1
, C
IN2
2 TPSE226M035 22µF 35V 20% Tantalum Capacitor AVX (803) 448-9411
C
OSC
1 08055A680JAT1A 68pF 50V 5% NPO Chip Capacitor AVX (803) 448-9411
C
OUT1
, C
OUT2
2 TPSD107M010R0080 100µF 10V 20% Tantalum Capacitor AVX (803) 448-9411
C1, C6 2 08055A101KAT1A 100pF 50V 10% NPO Chip Capacitor AVX (803) 448-9411
C2, C4, C
SS
3 08055G104KAT1A 0.1µF 50V 10% Y5V Chip Capacitor AVX (803) 448-9411
C3 1 TAJB475M016 4.7µF 16V 20% Tantalum Capacitor AVX (803) 448-9411
C5 1 08055C102KAT1A 1000pF 50V 10% X7R Chip Capacitor AVX (803) 448-9411
D1 1 CMDSH-3 BVR = 30V Schottky Diode Central (516) 435-1110
D2 1 MBRS140T3 BVR = 40V Schottky Diode Motorola (602) 244-3576
E1 to E8 8 1502-2 Turret Terminal Keystone (718) 956-8900
LTC1435CS
3
DEMO MANUAL DC094
DESIGN READY SWITCHER
PARTS LIST
REFERENCE
DESIGNATOR QUANTITY PART NUMBER DESCRIPTION VENDOR TELEPHONE
JP1 1 2802S-03-G2 2mm Pin Header Comm Con (818) 301-4200
JP2 1 2802S-10-G2 2mm Pin Header Comm Con (818) 301-4200
L1 1 CDRH125-10 10µH Inductor Sumida (708) 956-0666
CDRH127-10 10µH Inductor (Alternate) Sumida
Q1, Q2 2 Si4412DY N-Channel MOSFET Siliconix (800) 554-5565
R1 1 CR21-3572F-T 35.7k 1/10W 1% Chip Resistor AVX (803) 448-9411
R2 1 CR21-6982F-T 69.8k 1/10W 1% Chip Resistor AVX (803) 448-9411
R3 1 CR21-3242F-T 32.4k 1/10W 1% Chip Resistor AVX (803) 448-9411
R4 1 CR21-2492F-T 24.9k 1/10W 1% Chip Resistor AVX (803) 448-9411
R5 1 CR21-2002F-T 20k 1/10W 1% Chip Resistor AVX (803) 448-9411
R6 1 CR21-1102F-T 11k 1/10W 1% Chip Resistor AVX (803) 448-9411
R
C
1 CR21-103J-T 10k 1/10W 5% Chip Resistor AVX (803) 448-9411
R
SENSE
1 LR2010-01-R033-F 0.033Ω 1/2W 1% Resistor IRC (512) 992-7900
U1 1 LTC1435CS 16-Lead Narrow Small Outline IC LTC (408) 432-1900
2 CCIJ2mm-138-G Jumper Comm Con (818) 301-4200
QUICK START GUIDE
This demonstration board is easy to set up to evaluate the
performance of the LTC1435. Please follow the procedure
outlined below for proper operation.
1. Refer to Figure 3 for proper arrangement of monitoring
equipment for correct measurement equipment setup.
2. Connect the input power supply to the V
IN
and GND
terminals on the left-hand side of the board. Do not
increase V
IN
over 28V or the MOSFET(s)
will be dam-
aged
. At lower output voltages (V
OUT
< 2.5V) the maxi-
mum input voltage must be decreased. See Table 1.
3. Connect the load between the V
OUT
and GND terminals
on the right side of the board.
4. The RUN pin can be left unconnected. To shut down the
LTC1435 tie this pin to ground.
5. When the 5V output voltage option is selected externally
connect EXT V
CC
to V
OUT
.
6. Set the jumper JP1 so that SFB is connected to
INT V
CC
.
7. Set the desired output voltage with jumper JP2 shown
in Figure 2 and Table 1.
Table 1. Maximum Allowable Input Voltage vs Selected
Output Voltage
MAXIMUM INPUT
POSITION OUTPUT VOLTAGE VOLTAGE
A 1.8V 18V
B 2.5V 24V
C 2.9V 28V
D 3.3V 28V
E 5V 28V
Figure 2. Output Voltage Selection (JP2)
(3.3V Position Shown)
JP2
ABCDE
2.5V
1.8V 2.9V 3.3V 5V
DM094 F02
4
DEMO MANUAL DC094
DESIGN READY SWITCHER
I TRODUCTIO
U U
The circuit in Figure 1 highlights the capabilities of the
LTC1435. The application circuit is set up for a variety of
output voltages. Output voltages from 1.8V to 5V are
available by selecting the appropriate jumper position.
The LTC1435 is a synchronous step-down switching
regulator controller which drives external N-channel power
MOSFETs using a fixed frequency architecture. Burst
Mode operation provides high efficiency at low load cur-
rents. Operating efficiencies typically exceed 90% over
three decades of load current range. A maximum high duty
cycle limit of 99% provides low dropout operation which
extends operating time in battery-operated systems.
The use of small spring-clip leads are very convenient for
small-signal bench testing and voltage measurements,
but should not be used with the high currents associated
with this circuit. Soldered wire connections are required to
properly ascertain the performance of the PC board.
This demonstration unit is intended for the evaluation of
the LTC1435 switching regulator IC and was not designed
for any other purpose.
OPERATIO
U
The operating frequency is set by an external capacitor
C
OSC
, allowing maximum flexibility in optimizing effi-
ciency. In this application the frequency is set to 170kHz.
A secondary winding feedback control pin SFB inhibits
Burst Mode which reduces noise and RF interference.
Soft start is provided by an external capacitor C
SS
which
can be used to properly sequence supplies. The operating
current level is user-programmable via an external current
sense resistor and is set to 3A. Short-circuit current limit
is set approximately to 4A.
This demo board is optimized for 3.3V outputs. A wide
input supply range allows operation from 4.5V to 28V for
V
OUT
voltages of 3.3V and 5V. Because this board allows
for a wide output voltage range (1.8V to 5V) and the
operating frequency remains constant at 170kHz, there is
a duty cycle induced limit on the maximum input voltage
when low output voltages are selected (V
OUT
< 2.9V). This
is necessary for an adequate turn-on time for the top
MOSFET with the required duty cycle at a given frequency.
If a higher input supply voltage is required together with
low output voltage, the operating frequency can be de-
creased by increasing C
OSC
.
Main Control Loop
The LTC1435 uses a constant frequency, current mode
step-down architecture. Current mode operation was
judged to be mandatory for its well-known advantages of
clean start-up, accurate current limit and excellent line and
load regulation.
During normal operation, the top MOSFET is turned on
each cycle when the oscillator sets a latch and turned off
when the main current comparator resets the latch. The
peak inductor current is controlled by the voltage on the
I
TH
pin, which is the output of error amplifier EA.
The V
OSENSE
pin allows EA to receive an output feedback
voltage V
FB
from an external resistive divider. When the
load current increases, it causes a slight decrease in V
FB
relative to the 1.19V reference, which in turn causes the I
TH
voltage to increase until the average inductor current
matches the new load current. While the top MOSFET is
off, the bottom MOSFET is turned on until either the
inductor current starts to reverse or the beginning of the
next cycle.
The top MOSFET driver is biased from floating bootstrap
capacitor C4, which normally is recharged during each off
cycle. However, when V
IN
decreases to a voltage close to
V
OUT
, the loop may enter dropout and attempt to turn on
the top MOSFET continuously. The dropout detector counts
the number of oscillator cycles that the top MOSFET
remains on and periodically forces a brief off period to
allow C4 to recharge.
A built-in comparator guards against transient overshoots
> 7.5% by turning off the top MOSFET and keeping it off
until the fault is removed.
5
DEMO MANUAL DC094
DESIGN READY SWITCHER
OPERATIO
U
Low Current Operation
The LTC1435 is capable of Burst Mode operation in which
the external MOSFETs operate intermittently based on
load demand. If the voltage across R
SENSE
does not exceed
approximately 20mV for one full cycle, then on following
cycles the top and bottom drives are disabled. This contin-
ues until the I
TH
voltage exceeds 0.6V, which causes drive
to be returned to the top MOSFET on the next cycle.
Two conditions can force continuous synchronous opera-
tion, even when the load current would otherwise dictate
low current operation. One is when the common mode
voltage of the Sense
+
and Sense
–
pins is below 1.4V, and
the other is when the SFB pin is below 1.19V. See the SFB
pin function description.
INT V
CC
/EXT V
CC
Power
Power for the top and bottom MOSFET drivers and most
of the other LTC1435 circuitry is derived from INT V
CC
pin.
When the EXT V
CC
pin is left open, an internal 5V low
dropout regulator supplies INT V
CC
power. If EXT V
CC
is
taken above 4.7V, the 5V regulator is turned off and an
internal switch is turned on to connect EXT V
CC
to INT V
CC
.
This allows the INT V
CC
power to be derived from a high
efficiency external source such as the output of the regu-
lator itself or a secondary winding, as described in the
LTC1435 data sheet.
When the 5V output voltage option is selected (JP2E
installed) the EXT V
CC
pin should be externally connected
to V
OUT
.
HOW TO MEASURE VOLTAGE REGULATION
When trying to measure voltage regulation, remember
that all measurements must be taken at the point of
regulation. This point is where the LTC1435’s control loop
looks for the information to keep the output voltage
constant. In this demonstration board this information
point occurs between Pin 5 of the LTC1435, the signal
ground, and the output side of R1. These points corre-
spond to the V
OSENSE
(E7) terminal of the board. Output
voltage test leads should be attached directly to this
terminal. The load should be placed across V
OUT
(E6) to
GND (E8). Measurements
should not
be taken at the end
of test leads at the load. Refer to Figure 3 for the proper
monitoring equipment configuration.
This applies to line regulation (input to output voltage
regulation) as well as load regulation tests. In doing line
regulation tests always look at the input voltage across the
input terminals.
For the purposes of these tests the demonstration circuit
should be fed from a regulated DC bench supply so
additional variation on the DC input does not add an error
to the regulation measurements.
Figure 3. Proper Measurement Setup
REMOTE OUTPUT VOLTAGE SENSING
Remote output voltage sensing can be accomplished by
modifying the PC board. A small PC trace connecting V
OUT
to V
OSENSE
must be cut as shown in Figure 4. An external
connection from V
OSENSE
directly across the load must be
made. To prevent uncertainty, solder a 10Ω resistor
across the V
OUT
and V
OSENSE
terminals. Never, under any
circumstance, allow V
OSENSE
to float!
JP1
V
IN
V
IN
GND
RUN
OPEN
OFF
RUN
SFB
LINEAR TECHNOLOGY
(408) 432-1900 DEMO CIRCUIT 094A
CONSTANT FREQUENCY
HIGH EFFICIENCY CONVERTER
LTC1435
EXT V
CC
V
OUT
I
OUT
V
OUT
V
OSENSE
GND
BURST MODE ENABLED
BURST MODE DISABLED
EXTERNAL
SOURCE
JP2
ABCDE
DM094 F03
+
+
A
I
IN
+
A
+
V
+
VV ≤ 10V
LOAD
6
DEMO MANUAL DC094
DESIGN READY SWITCHER
OPERATIO
U
However, for 3.3V and other lower voltage regulators,
additional circuitry is required to derive INT V
CC
power
from the output.
The following list summarizes the four possible connec-
tions for EXT V
CC:
1. EXT V
CC
Left Open (or Grounded). This will cause
INT V
CC
to be powered from the internal 5V regulator
resulting in an efficiency penalty of up to 10% at high
input voltages.
2. EXT V
CC
Connected Directly to V
OUT
. This is the normal
connection for a 5V regulator and provides the highest
efficiency.
3. EXT V
CC
Connected to an Output-Derived Boost Net-
work. For 3.3V and other low voltage regulators, effi-
ciency gains can still be realized by connecting EXT V
CC
to an output-derived voltage which has been boosted to
greater than 4.7V. See the LTC1435 data sheet for
further details.
4. EXT V
CC
Connected to an External Supply. If an external
supply is available in the 5V to 10V range (EXT V
CC
<
V
IN
), it may be used to power EXT V
CC
providing an
efficiency boost.
SFB Pin Function (Burst Mode Disable)
When the SFB (E4) pin drops below its ground-referenced
1.19V threshold, continuous mode operation is forced
(Burst Mode is inhibited). In continuous mode the
N-channel main and synchronous switches are continu-
ously switched irrelevant of the load on the main output.
This reduces noise and interference but impacts effi-
ciency. Jumper JP1 sets the voltage on SFB and is set as
follows:
SFB Condition
GND Burst Mode Inhibited
INT V
CC
Burst Mode Enabled
In addition to providing a logic input to force continuous
synchronous operation, the SFB pin provides a means to
regulate a flyback winding output. See the LTC1435 data
sheet for additional information.
INT V
CC
Regulator
An internal P-channel low dropout regulator produces the
5V supply which powers the drivers and internal circuitry
within the LTC1435. The INT V
CC
pin can supply up to
15mA (this includes the gate drive currents). External
loading of the INT V
CC
pin may be up to 10mA. At high
input voltages the maximum junction temperature rating
for the LTC1435 may be exceeded if too large an external
load is placed on INT V
CC
. See the LTC1435 data sheet for
further details.
EXT V
CC
Connection
The LTC1435 contains an internal P-channel MOSFET
switch connected between the EXT V
CC
and INT V
CC
pins.
The switch closes and supplies the INT V
CC
power when-
ever the EXT V
CC
pin is above 4.7V and remains closed
until EXT V
CC
drops below 4.5V. This allows the MOSFET
driver and control power to be derived from the output
during normal operation (4.7V < V
OUT
< 9V) and from the
internal regulator when the output is out of regulation
(start-up, short circuit). Do not apply greater than 10V to
the EXT V
CC
pin and ensure that EXT V
CC
< V
IN
.
Significant efficiency gains can be realized by powering
INT V
CC
from the output, since the V
IN
current resulting
from the driver and control currents will be scaled by a
factor of (Duty Cycle)/(Efficiency). For 5V regulators this
simply means connecting the EXT V
CC
pin directly to V
OUT
.
JP1
V
IN
V
IN
GND
RUN
OPEN
OFF
RUN
SFB
LINEAR TECHNOLOGY
(408) 432-1900 DEMO CIRCUIT 094A
CONSTANT FREQUENCY
HIGH EFFICIENCY CONVERTER
LTC1435
EXT V
CC
V
OUT
I
OUT
V
OUT
CUT THIS
TRACE
ADD THIS
RESISTOR 10Ω
V
OSENSE
GND
BURST MODE ENABLED
BURST MODE DISABLED
EXTERNAL
SOURCE
JP2
ABCDE
DM094 F04
+
+
A
I
IN
+
A
+
V
+
VV ≤ 10V
LOAD
Figure 4. Remote Output Voltage Sense
7
DEMO MANUAL DC094
DESIGN READY SWITCHER
OPERATIO
U
2.7V). The output current thus ramps up slowly, charging
the output capacitor. If Run/SS has been pulled all the way
to ground there is a delay before starting of approximately
500ms/µF, followed by an additional 500ms/µF to reach
full current. C
SS
= 0.1µF on this PC board.
Pulling the Run/SS pin below 1.3V puts the LTC1435 into
a low quiescent current shutdown (I
Q
< 20µA). The
Run/SS pin has an internal 6V Zener clamp (see the data
sheet for further information).
Component Manufacturers
Following is a partial list of component manufacturers
which can be used in LTC1435 applications. Using com-
ponents other than the ones supplied on the demonstra-
tion board will require careful analysis to verify that all
component specifications are not exceeded. Finally, re-
characterizing the circuit for efficiency is necessary.
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
MANUFACTURER DEVICE TELEPHONE FAX
AVX Capacitors (803) 448-9411 (803) 448-1943
Central Semiconductor Diodes (516) 435-1110 (516) 435-1824
Coilcraft Inductors (708) 639-6400 (708) 639-1469
Coiltronics Inductors (407) 241-7876 (407) 241-9339
Comm Con Connectors (818) 301-4200 (818) 301-4212
Dale Inductors/Sense Resistors (605) 665-9301 (605) 665-0817
International Rectifiers MOSFETs/Diodes (310) 322-3331 (310) 322-3332
IRC Sense Resistors (512) 992-7900 (512) 992-3377
KRL Sense Resistors (603) 668-3210 (603) 624-0634
Motorola MOSFETs/Diodes (602) 244-3576 (602) 244-4015
Murata-Erie Capacitors (770) 436-1300 (770) 436-3030
Sanyo Capacitors/MOSFETs (619) 661-6835 (619) 661-1055
[81] 0952-82-3959 [81] 0952-82-4655
Siliconix MOSFETs (800) 554-5565 (408) 970-3979
Sprague Capacitors (603) 224-1961 (603) 224-1430
Sumida Inductors (708) 956-0666 (708) 956-0702
[81] 03-3607-5111 [81] 03-3607-5144
TDK Inductors (708) 803-6100 [81] 03-3278-5358
When the SFB pin is left floating (no jumper installed at J1)
Burst Mode is enabled.
Do not apply an external voltage to
SFB (E4) when the jumper JP1 is installed!
Run/Soft Start Function
The Run/SS pin (E3) is a dual purpose pin which provides
the soft start function and a means to shut down the
LTC1435. Soft start reduces surge currents from V
IN
by
gradually increasing the internal current limit. Power
supply sequencing can also be accomplished using
this pin.
An internal 3µA current source charges up an external
capacitor C
SS.
When the voltage on Run/SS reaches 1.3V
the LTC1435 begins operating. As the voltage on Run/SS
continues to ramp from 1.3V to 2.4V, the internal current
limit is also ramped at a proportional linear rate. The
current limit begins at approximately 50mV/R
SENSE
(at
V
RUN/SS
= 1.3V) and ends at 150mV/R
SENSE
(V
RUN/SS
≤
8
DEMO MANUAL DC094
DESIGN READY SWITCHER
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX
: (408) 434-0507
●
TELEX
: 499-3977
LT/GP 0796 500 • PRINTED IN USA
LINEAR TECHNOLO GY CORPORATION 1996
PCB LAYOUT A D FIL
UW
Component Side Silkscreen Component Side Solder MaskComponent Side
Solder Side Solder Side Solder Mask
PC FAB DRAWI G
U
HOLE CHART
SYMBOL DIAMETER # OF HOLES PLATED
A 0.125 3 NO
B 0.030 260 YES
C 0.094 22 NO
D 0.070 40 NO
E 0.094 160 YES
UNMARKED 0.018 440 YES
TOTAL HOLES 945
NOTES:
1. MATERIAL IS FR4, 0.062” WITH 2 OZ COPPER
2. PCB WILL BE DOUBLE SIDED WITH PLATED THROUGH HOLES
3. HOLE SIZES ARE AFTER PLATING. PLATED THROUGH HOLE WALL
THICKNESS MIN 0.0014” (1 OZ)
4. USE PADMASTER PROCESS
5. SOLDER MASK BOTH SIDES WITH PC401 USING FILM PROVIDED
6. SILKSCREEN COMPONENT SIDE USING FILM PROVIDED. USE WHITE,
NONCONDUCTIVE INK
7. ALL DIMENSIONS ARE IN INCHES ±0.005
8. ALL PANELS IN ORDER MUST BE THE SAME DIMENSIONS ± 0.030”
9. DO NOT PLATE TOOLING HOLES – 0.125
10. DO NOT PLATE SCORING HOLES (22 HOLES 0.094 AT PANEL EDGE)
DO NOT PLATE ALIGNMENT HOLES – 40 HOLES 0.070”
11. SCORE BOTH SIDES LEAVING 0.017 – 0.002 + 0.000 THICKNESS
12. ALL HOLE SIZES AFTER PLATING + 0.003/– 0.
D
D
B
B
B
B × 10
EE
E
E
E
E
E
E
2.100
2.000