FEATURES
Final Electrical Specifications
LTC1756
Smart Card Interface
February 2000
U
DESCRIPTION
■
Fully ISO 7816-3 and EMV Compliant
■
Buck-Boost Charge Pump Generates 3V or 5V
■
2.7V to 5.5V Input Voltage Range
■
3V↔ 5V Signal Level Translator
■
>10kV ESD on All Smart Card Pins
■
Dynamic Pull-Ups Deliver Fast Signal Rise Times
■
Soft Start Limits Inrush Current at Turn On
■
Very Low Operating Current: 75µA
■
Shutdown Current: <2.5µA
■
Short-Circuit and Overtemperature Protected
■
Available in 16-Pin SSOP Package
U
APPLICATIONS
■
Handheld Payment Terminals
■
Pay Telephones
■
ATMs
■
Key Chain Readers
■
Smart Card Readers
The LTC®1756 universal Smart Card interface is fully
compliant with ISO 7816-3 and EMV specifications. It
provides the smallest and simplest interface circuit between a host microcontroller and general purpose Smart
Cards.
An internal charge pump DC/DC converter delivers regulated 3V or 5V to the Smart Card, while an on-chip level
shifter allows a connection to a low voltage controller. All
Smart Card contacts are rated for 10kV ESD, eliminating
the need for external ESD protection devices.
Input voltage may range from 2.7V to 5.5V, allowing direct
connection to a battery. Automatic DC/DC converter soft
start mitigates start-up problems that may result when the
input power is provided by another regulator.
Battery life is maximized by 75µA operating current and
2µA shutdown current. The 16-pin SSOP package mini-
mizes PCB area for compact portable systems.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATION
SMART CARD
PRESENT SWITCH
N.O.
GND
SMART CARD
V
I/O
RST
CLK
U
CC
10µF
3.3V
1
PRES
2
PWR
3
C3
C2
10µF
GND
4
V
IN
LTC1756
5
V
CC
6
I/O
7
RST
8
CLK
5V/3V
CARD
READY
DATA
RIN
CIN
16
15
14
13
–
C
12
+
C
11
10
9
C1
0.68µF
µCONTROLLER
1756 TA01
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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
1
LTC1756
GN PACKAGE
16-LEAD NARROW PLASTIC SSOP
1
2
3
4
5
6
7
8
TOP VIEW
16
15
14
13
12
11
10
9
PRES
PWR
GND
V
IN
V
CC
I/O
RST
CLK
5V/3V
CARD
READY
C
–
C
+
DATA
RIN
CIN
WW
W
ABSOLUTE MAXIMUM RATINGS
U
PACKAGE
/
O
RDER I FOR ATIO
(Note 1)
VIN to GND............................................... –0.3V to 6.0V
VCC to GND .............................................. –0.3V to 5.5V
Digital Inputs to GND..................... –0.3V to VIN + 0.3V
CLK, RST, I/O to GND .....................–0.3V to VCC + 0.3V
VCC Short-Circuit Duration............................... Indefinite
Operating Temperature Range (Note 2) .. –40°C to 85°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
T
= 125°C, θJA = 135°C/W
JMAX
Consult factory for Industrial and Military grade parts.
ELECTRICAL CHARACTERISTICS
temperature range, otherwise specificatons are at TA = 25°C. VIN = 2.7V to 5.5V, unless otherwise noted.
The ● denotes specifications which apply over the full specified
WU
ORDER PART
NUMBER
LTC1756EGN
U
PARAMETER CONDITIONS MIN TYP MAX UNITS
Power Supply
VIN Operating Voltage ● 2.7 5.5 V
I
Operating Current ACTIVE State, I
VIN
I
Shutdown Current IDLE State, VIN ≤ 3.6V ● 2.5 µA
VIN
VCC Output Voltage 5V/3V = V
I
Output Current 5V/3V = 0V 3V ≤ VIN ≤ 5.5V ● 55 mA
VCC
VCC Turn-On Time C
VCC Discharge Time to 0.4V I
Controller Input/Output DATA
High Input Voltage Threshold (VIH) ● VIN – 0.6 0.5 • V
Low Input Voltage Threshold (VIL) ● 0.5 • V
High Level Output Voltage (VOH) Source Current = 20µA ● 0.7 • V
Low Level Output Voltage (VOL) Sink Current = –500µA (Note 3) ● 0.3 V
Output Rise/Fall Time Loaded with 30pF, 10% to 90% ● 0.5 µs
Input Current (IIH/IIL) PWR = V
2
= 0 ● 75 150 µA
VCC
IDLE State, 3.6V ≤ V
5V/3V = 0V
5V/3V = V
5V/3V = 0V 2.7V ≤ VIN ≤ 5.5V ● 55 mA
5V/3V = V
VCC
IN
IN
IN
= 10µF, PWR to READY ● 2.7 12 ms
OUT
= 0mA, VCC = 5V, C
IN
≤ 5.5V ● 10 µA
IN
● 4.75 5.00 5.25 V
● 2.80 3.00 3.20 V
3V ≤ VIN ≤ 5.5V ● 65 mA
2.7V ≤ VIN ≤ 5.5V ● 40 mA
= 10µF ● 100 250 µs
OUT
IN
0.3 V
IN
IN
● –1 1 µA
V
V
LTC1756
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full specified
temperature range, otherwise specificatons are at TA = 25°C. VIN = 2.7V to 5.5V, unless otherwise noted.
PARAMETER CONDITIONS MIN TYP MAX UNITS
RIN, CIN, PWR, 5V/3V
High Input Voltage Threshold (VIH) ● 0.7 • VIN0.5 • V
Low Input Voltage Threshold (VIL) ● 0.5 • VIN0.2 • V
Input Current (IIH/IIL) ● –1 1 µA
READY, CARD
Pull-Up Current (IOH) ● 250 nA
Low Level Output Voltage (VOL) Sink Current = –20µA ● 0.3 V
Smart Card Input/Output I/O, VCC = 3V or 5V
High Input Voltage Threshold (VIH)I
Low Input Voltage Threshold (VIL)I
High Level Output Voltage (VOH) Source Current = 20µA, DATA = V
Low Level Output Voltage (VOL) Sink Current = –1mA, DATA = 0V (Note 3) ● 0.3 V
Rise/ Fall Time Loaded with 30pF, 10% to 90% ● 0.5 µs
Short-Circuit Current Shorted to V
CLK
High Level Output Voltage (VOH) Source Current = 100µA ● VCC – 0.5 V
Low Level Output Voltage (VOL) Sink Current = –200µA ● 0.3 V
CLK Rise/Fall Time CLK Loaded with 30pF ● 16 ns
CLK Frequency CLK Loaded with 30pF ● 5 MHz
RST
High Level Output Voltage (VOH) Source Current = 200µA ● 0.8 • V
Low Level Output Voltage (VOL) Sink Current = –200µA ● 0.3 V
RST Rise/Fall Time Loaded with 30pF ● 0.5 µs
PRES
High Input Voltage Threshold (VIH) ● 0.7 • VIN0.5 • V
Low Input Voltage Threshold (VIL) ● 0.5 • VIN0.2 • V
PRES Pull-Up Current V
PRES Debounce Time Proportional to the 0.68µF Charge Pump Capacitor ● 40 80 ms
= ±20µA ● 0.6 • VCC0.5 • V
IH(MAX)
= 1mA ● 0.5 • V
IL(MAX)
IN
CC
= 0V ● 0.5 1 µA
PRES
● 0.8 • V
● 3.5 5 mA
CC
CC
IN
CC
CC
IN
IN
0.8 V
IN
V
V
V
V
V
V
V
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LTC1756 is guaranteed to meet performance specifications
from 0°C to 70°C. Specifications over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 3: The DATA and I/O pull-down drivers must sink up to 250µA
sourced by the internal current sources.
3
LTC1756
UUU
PIN FUNCTIONS
PRES (Pin 1): (Input) Connects to the Smart Card acceptor’s
PRESENT indicator switch to detect if a card is inserted.
This pin has a pull-up current source so that a normally
open grounded switch can be detected with no external
components. The pull-up current source is nonlinear,
delivering higher current when the PRES pin is above 1V
but very little current below 1V. This helps resist false card
indications due to leakage current.
PWR (Pin 2): (Input) A low on the PWR pin places the
LTC1756 in the ACTIVE state enabling the charge pump.
The READY pin indicates when the card supply voltage
(VCC) has reached its final value and communication with
the Smart Card is possible. The reset and clock channels
are enabled after READY goes low. The I/O channel is also
enabled only after READY goes low.
The falling edge of PWR latches the state of the 5V/3V pin.
After PWR is low, changes on the 5V/3V pin are ignored.
GND (Pin 3): Ground Reference for the IC. This pin should
be connected to a low impedance ground plane. Bypass
capacitors for VIN and VCC should be in close proximity to
the GND pin.
VIN (Pin 4): Supply Voltage. May be between 2.7V and 5.5V.
A 10µF low ESR ceramic bypass capacitor is required on
this pin for optimum performance.
VCC (Pin 5): Regulated Smart Card Supply Voltage. This
pin should be connected to the Smart Card VCC contact.
The 5V/3V pin determines the VCC output voltage.
The VCC pin is protected against short circuits by comparing the actual output voltage with an internal reference
voltage. If VCC is below its correct level (for as little as 5µs)
the LTC1756 switches to the Alarm state (see the State
Diagram). The VCC pin requires a 10µF charge storage
capacitor to ground. For optimum performance a low ESR
ceramic capacitor should be used.
to the Smart Card I/O contact. The Smart Card I/O pin must
be able to sink up to 250µA when driving the I/O pin low
due to the pull-up current source. The I/O pin becomes a
low impedance to ground during the Idle state. It does not
become active until READY goes low indicating that VCC is
stable.
Once READY is low, the I/O pin is protected against short
circuits to VCC by current limiting to 5mA maximum.
The DATA-I/O channel is bidirectional for half-duplex
transmissions. Its idle state is H-H. Once an L is detected
on one side of the channel the direction of transmission is
established. Specifically, the side which received an L first
is now the input, and the opposite side is the output.
Transmission from the output side back to the input side
is inhibited, thereby preventing a latch condition. Once the
input side releases its L, both sides return to H, and the
channel is now ready for a new L to be transmitted in either
direction. If an L is forced externally on the output side, and
it persists until after the L on the input side is released, this
illegal input will not be transmitted to the input side
because the transmission direction will not have changed.
The direction of transmission can only be established from
the idle (H-H) state and is determined by the first receipt
of an L on either side.
RST (Pin 7): (Output) Level-Shifted Reset Output Pin. This
pin should be connected to the Smart Card RST contact.
The RST pin becomes a low impedance to ground during
the Idle state (see the State Diagram). The reset channel
does not become active until the READY signal goes low
indicating that VCC is stable.
Short-circuit protection is provided on the RST pin by
comparing RST with RIN. If these signals differ for several
microseconds then the LTC1756 switches to the Alarm
state. This fault checking is only performed after the VCC pin
has reached its final value (as indicated by the READY pin).
During the Idle and Alarm states the VCC pin is rapidly
discharged to ground to comply with the deactivation
requirements of the EMV and ISO-7816 specifications.
I/O (Pin 6): (Input/Output) Smart Card Side Data I/O Pin.
This pin is used for bidirectional data transfer between the
microcontroller and the Smart Card. It should be connected
4
CLK (Pin 8): (Output) Level-Shifted Clock Output Pin. This
pin should be connected to the Smart Card CLK contact.
The CLK pin becomes a low impedance to ground during
the Idle state (see the State Diagram). The clock channel
does not become active until the READY signal goes low
indicating that VCC is stable.
UUU
PIN FUNCTIONS
LTC1756
Short-circuit protection is provided on the CLK pin by comparing CLK with CIN. If these signals differ for several microseconds then the LTC1756 switches to the Alarm state.
This fault checking is only performed after the VCC pin has
reached its final value (as indicated by the READY pin).
The clock channel is optimized for signal integrity in order
to meet the stringent duty cycle requirements of the EMV
specification. Therefore, to reduce power in low power
applications, clock stop mode is recommended when data
is not being exchanged.
CIN (Pin 9): (Input) Clock Input Pin from the Microcontroller. During the Active state this signal appears on the CLK
pin after being level-shifted and buffered.
RIN (Pin 10): (Input) Reset Input Pin from the Microcontroller. During the Active state this signal appears on the
RST pin after being level-shifted and buffered.
DATA (Pin 11): (Input/Output) Microcontroller Side Data
I/O Pin. This pin is used for bidirectional data transfer
between the microcontroller and the Smart Card. The
microcontroller data pin must be open drain and must be
able to sink up to 250µA when driving the DATA pin low
due to the pull-up current source. The DATA pin becomes
high impedance during the Idle state (see the State Diagram). It does not become active until the READY signal
goes low indicating that VCC is stable.
C+, C– (Pins 12, 13): Charge Pump Flying Capacitor
Terminals. Optimum values for the flying capacitor range
from 0.68µF to 1µF. Best performance is achieved with a
low ESR X7R ceramic capacitor.
READY (Pin 14): (Output) Readiness Indicator of the
Smart Card Supply Voltage (VCC). When the LTC1756 is
placed in the Active state the soft start feature slowly
ramps the VCC voltage. A low on the READY pin indicates
that VCC has reached its final value.
The READY pin is configured as an open-drain pull-down
with a weak pull-up current source.
The READY pin also indicates if the LTC1756 is in Alarm
mode. The LTC1756 detects faults such as VCC underrange
for at least 5µs, overtemperature shutdown, CLK or RST
invalid output levels and card removal during Active
state. CLK or RST invalid and overtemperature faults are
detected only after VCC has reached its final value. V
underrange and card removal during Active faults are
detected at any time during the Active period (i.e., once
PWR = 0V).
If the LTC1756 has been activated normally and VCC, the
card voltage, has reached its final value then READY will
go low indicating normal operation. If, following this, a
fault occurs and the LTC1756 enters the Alarm state, the
READY pin will return high.
In the event that a fault precedes the activation of VCC,
such as a direct short circuit from VCC to GND, the
LTC1756 will attempt to operate until the fault is detected
and then automatically shut down and enter the Alarm
state. In this case the READY pin will never go low after the
command to start the smart card is given (i.e., PWR = 0V).
If the LTC1756 enters the Alarm state it can only be
cleared by returning the PWR pin high.
CARD (Pin 15): (Output) Level-Shifted and Debounced
PRES Signal from the Smart Card Acceptor Switch. When
a valid card indication appears, this pin communicates the
presence of the Smart Card to the microcontroller. The
CARD pin has an open-drain active pull-down with a weak
pull-up current source. The debounce circuit ensures that
a card has been present for a continuous period of at least
40ms before asserting CARD low. The CARD pin returns
high within 50µs of card removal.
5V/3V (Pin 16):(Input) Controls the output voltage (VCC)
of the DC/DC converter during the Active state. A valid high
sets VCC to 5V. A valid low sets VCC to 3V. The 5V/3V pin
is latched on the falling edge of the PWR pin. When PWR
is low, changes on the 5V/3V pin are ignored. To change
the voltage on VCC the LTC1756 must first be returned to
the Idle state by bringing the PWR pin high.
CC
5
LTC1756
BLOCK DIAGRA
W
V
IN
PRES 1
PWR 2
GND 3
V
IN
V
CC
I/O 6
τ
DC/DC CONVERTER
AND
CONTROL LOGIC
4
5
*
*
16
5V/3V
CARD
15
READY
14
–
C
13
+
C
12
DATA11
6
RST 7
CLK
8
DYNAMIC PULL-UP CURRENT SOURCE
*
1756 BD
RIN
10
CIN
9
LTC1756
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WUU
APPLICATIONS INFORMATION
10kV ESD Protection
All Smart Card pins (CLK, RST, I/O, VCC and GND) can
withstand over 10kV of human body model ESD in situ. In
order to ensure proper ESD protection, careful board
layout is required. The GND pin should be tied directly to
a ground plane. The VCC capacitor should be located very
close to the VCC pin and tied immediately to the ground
plane.
Capacitor Selection
The style and value of capacitors used with the LTC1756
determine several parameters such as output ripple voltage, charge pump strength, Smart Card switch debounce
time and VCC discharge rate.
Due to the switching nature of a capacitive charge pump,
low equivalent series resistance (ESR) capacitors are
recommended for the capacitors at VIN and VCC. Whenever the flying capacitor is switched to the VCC charge
storage capacitor, considerable current flows. The product of this high current and the ESR of the output capacitor
can generate substantial voltage spikes on the VCC output.
These spikes may cause problems with the Smart Card or
may interfere with the regulation loop of the LTC1756.
Therefore, ceramic or tantalum capacitors are recommended rather than higher ESR aluminum capacitors.
Between ceramic and tantalum, ceramic capacitors generally have the lowest ESR. Some manufacturers have
developed low ESR tantalum capacitors but they can be
expensive and may still have higher ESR than ceramic
types. Thus, while they cannot be avoided, ESR spikes will
typically be lowest when using ceramic capacitors.
For ceramic capacitors there are several different materials available to choose from. The choice of ceramic
material is generally based on factors such as available
capacitance, case size, voltage rating, electrical performance and cost. For example, capacitors made of Y5V
material have high packing density, which provides high
capacitance for a given case size. However, Y5V capacitors tend to lose considerable capacitance over the – 40°C
to 85°C temperature range. X7R ceramic capacitors are
more stable over temperature but don’t provide the high
packing density. Therefore, large capacitance values are
generally not available in X7R ceramic.
The value and style of the flying capacitor are important
not only for the charge pump but also because they
provide the large debounce time for the Smart Card
detection channel. A 0.68µF X7R capacitor is a good
choice for the flying capacitor because it provides fairly
constant capacitance over temperature and its value is not
prohibitively large.
The charge storage capacitor on the VCC pin determines
the ripple voltage magnitude and the discharge time of the
Smart Card voltage. To minimize ripple, generally, a large
value is needed. However, to meet the VCC discharge rate
specification, the value should not exceed 20µF. A 10µF
capacitor can be used but the ripple magnitude will be
higher leading to worse apparent DC load regulation.
Typically a 15µF to 18µF Y5V ceramic capacitor is the best
choice for the VCC charge storage capacitor. For best
performance, this capacitor should be connected as close
as possible to the VCC and GND pins. Note that most of the
electrostatic discharge (ESD) current on the Smart Card
pins is absorbed by this capacitor.
7
LTC1756
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WUU
APPLICATIONS INFORMATION
The bypass capacitor at VIN is also important. Large dips
on the input supply due to ESR may cause problems with
the internal circuitry of the LTC1756. A good choice for the
input bypass capacitor is a 10µF Y5V style ceramic
Dynamic Pull-Up Current Sources
The current sources on the bidirectional pins (DATA and
I/O) are dynamically activated to achieve a fast rise time
with a relatively small static current (Figure 1). Once a
bidirectional pin is relinquished, a small start-up current
begins to charge the node. An edge rate detector determines if the pin is released by comparing its slew rate with
an internal reference value. If a valid transition is detected,
a large pull-up current enhances the edge rate on the node.
The higher slew rate corroborates the decision to charge
the node thereby effecting a dynamic form of hysteresis.
Once the node has reached the power supply voltage the
internal comparator requires several hundred nanoseconds to reset. Pulling down on the pin before the reset
delay expires will result in a momentary contention and a
higher current flow. Therefore, the comparator delay sets
the upper limit on the maximum data rate of the bidirectional channels to about 500kHz.
Low Power Operation
The LTC1756 is inherently a low power device. When there
is no Smart Card present the supply current is less than
2.5µA. When a Smart Card is present the LTC1756 oper-
ates with a quiescent current of only 75µA, thus the
majority of power is consumed by charge pump losses
and the card itself. If the card can be made to consume less
power during idle times a significant power savings will be
achieved. Whenever possible Clock Stop Mode should be
used (or alternatively a very low “idling” clock speed).
Furthermore, in the Active state, the bidirectional pins
should all be relinquished whenever possible since there
is some static current flow when a bidirectional pin is
pulled down.
Overtemperature Fault Protection
An overtemperature circuit disables the chip and places
the LTC1765 in the Alarm state if the IC’s junction temperature exceeds 150°C.
V
OR V
CC
IN
+
I
START
–
δV
δt
BIDIRECTIONAL PIN
Figure 1. Dynamic Pull-Up Current Sources
1756 F01
V
REF
8
LTC1756
U
WUU
APPLICATIONS INFORMATION
Self-Start Mode
By connecting the CARD pin to the PWR pin the LTC1756
can be made to start up automatically when a Smart Card
is detected (Figure 2). In this mode, the READY pin
becomes an interrupt signal indicating to the microcontroller that a Smart Card is present and that VCC, the charge
pump voltage, is at its final value. The Smart Card remains
powered as long as it is detected by the PRES pin. When
the Smart Card is removed the LTC1756 will automatically
be deactivated by the fault detection circuitry.
CARD
Figure 2. Self-Start Mode
PWR
READY
TO
MICROCONTROLLER
1756 F02
Deactivation Sequence
For maximum flexibility the Smart Card can be deactivated
either manually or automatically. In manual mode the
deactivation is controlled by explicitly manipulating the
LTC1756 input and control pins (DATA, RIN and CIN
followed by PWR). In automatic mode the PWR pin is used
to perform the built-in deactivation sequence. Once PWR
is brought high the built-in deactivation sequence occurs
as follows:
DEACTIVATION DIRECTIVE
V
CC
RST
CLK
I/O
RST = R
CLK = C
I/O = DATA
IN
IN
1755 F03
Figure 3. Deactivation Sequence
In the event of a fault, the LTC1756 automatically
implements the built-in deactivation sequence.
9
LTC1756
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WUU
APPLICATIONS INFORMATION
POWER OFF
State Definitions
IDLE/DEACTIVATION
VCC, RST, CLK, I/O = L
DEACTIVATION
PWR = V
DEACTIVATION
Figure 4. LTC1756 State Diagram
IDLE
IN
ALARM
PWR = 0V
PWR = V
PRES ≠ “0”
FAULT > 5µs
PRES ≠ “0”
IN
or
ACTIVE
NO
FAULT
FAULT
TIMEOUT
FAULT
1756 F04
ACTIVE
VCC = 3V or 5V (as determined by the 5V/3V pin)
READY, DATA = Z
CARD = PRES
Once the LTC1756 enters the Idle/Deactivation state the
deactivation sequence begins. The deactivation sequence
will continue until VCC is discharged to approximately 1V.
An activation command (PWR = 0V) will only be acknowledged once this occurs.
ALARM/DEACTIVATION
The only possible next state is Idle/Deactivation which is
achieved by disabling the LTC1756 via the PWR pin
(i.e., PWR = VIN).
The alarm indication can be cleared by rapidly cycling the
PWR pin. However, a new activation cycle will not begin
until VCC is or has dropped below approximately 1V.
RST = RIN, CLK = C
IN
I/O, DATA = Ready for data (after READY becomes low)
CARD = PRES
FAULT TIMEOUT
Same as Active except:
The duration of a fault is being measured. If the fault
duration exceeds 5µs then the Alarm/Deactivation state
follows. If the fault duration is less than 5µs, then the
device is returned to the Active state.
10
PACKAGE DESCRIPTION
U
Dimensions in inches (millimeters) unless otherwise noted.
GN Package
16-Lead Plastic SSOP (Narrow 0.150)
(LTC DWG # 05-08-1641)
0.189 – 0.196*
(4.801 – 4.978)
16
15
14
12 11 10
13
LTC1756
0.009
(0.229)
9
REF
0.015
± 0.004
(0.38 ± 0.10)
0.007 – 0.0098
(0.178 – 0.249)
0.016 – 0.050
(0.406 – 1.270)
* DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
0° – 8° TYP
× 45°
0.229 – 0.244
(5.817 – 6.198)
0.053 – 0.068
(1.351 – 1.727)
0.008 – 0.012
(0.203 – 0.305)
12
0.150 – 0.157**
(3.810 – 3.988)
5
4
3
678
0.0250
(0.635)
BSC
0.004 – 0.0098
(0.102 – 0.249)
GN16 (SSOP) 1098
11
LTC1756
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Linear T echnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear-tech.com
1756i LT/TP 0200 4K • PRINTED IN USA
LINEAR TECHN OLOGY CORPORATION 2000
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