LTC1345
Single Supply
V.35 Transceiver
U
FEATURES
■
■
■
■
■
■
■
■
■
DESCRIPTIO
Single Chip Provides All V.35 Differential Clock
and Data Signals
Operates From Single 5V Supply
Software Selectable DTE or DCE Configuration
Transmitters and Receivers Will Withstand
Repeated ±10kV ESD Pulses
Shutdown Mode Reduces ICC to 1µA Typ
10MBaud Transmission Rate
Transmitter Maintains High Impedance When
Disabled, Shut Down, or with Power Off
Meets CCITT V.35 Specification
Transmitters are Short-Circuit Protected
U
APPLICATIO S
■
■
■
The LTC®1345 is a single chip transceiver that provides the
differential clock and data signals for a V.35 interface from
a single 5V supply. Combined with an external resistor
termination network and an LT ®1134A RS232 transceiver
for the control signals, the LTC1345 forms a complete low
power DTE or DCE V.35 interface port operating from a
single 5V supply.
The LTC1345 features three current output differential
transmitters, three differential receivers, and a charge
pump. The transceiver can be configured for DTE or DCE
operation or shut down using two Select pins. In the
Shutdown mode, the supply current is reduced to 1µA.
The transceiver operates up to 10Mbaud. All transmitters
feature short-circuit protection and a Receiver Output
Enable pin allows the receiver outputs to be forced into a
high impedance state. Both transmitter outputs and receiver inputs feature ±10kV ESD protection. The charge
pump features a regulated VEE output using three external
1µF capacitors.
Modems
Telecommunications
Data Routers
, LTC and LT are registered trademarks of Linear Technology Corporation.
U
TYPICAL APPLICATIO
Clock and Data Signals for V.35 Interface
1µF
1µF
1µF
DTE
VCC1
5V
2
4
1
28
3
1µF
27
6
7
DX
11
RX
12
RX
13
RX
9
10
VCC1
14
2
26
1
25
2
24
3
23
4
20
14
19
13
18
12
17
11
16
10
15
9
5
7
BI
627T500/1250
BI
627T500/1250
TXD (103)
T
T
SCTE (113)
T
T
TXC (114)
T
T
RXC (115)
T
T
RXD (104)
T
T
8
GND (102)
8
1µF
12
18
11
17
10
16
9
15
1
26
2
25
3
24
4
23
5
22
6
21
7
5
VCC2
5V
4
27
1µF
DX
1
28
LTC1345
1µF
DCE
3
LTC1345
1µF
12
RX
13
RX
6
DX
7
DX
50Ω
8
DX
T
125Ω
=
50Ω
9
VCC2
10
14
BI TECHNOLOGIES
627T500/1250 (SOIC) OR
899TR50/125 (DIP)
LTC1345 • TA01
1
LTC1345
W W
W
AXI U
U
ABSOLUTE
RATI GS
U
U
W
PACKAGE/ORDER I FOR ATIO
(Note 1)
Supply Voltage, VCC .................................................. 6V
Input Voltage
Transmitters ........................... – 0.3V to (VCC + 0.3V)
Receivers ............................................... – 18V to 18V
S1, S2, OE ............................... – 0.3V to (VCC + 0.3V)
Output Voltage
Transmitters .......................................... – 18V to 18V
Receivers ................................ – 0.3V to (VCC + 0.3V)
VEE ........................................................ – 10V to 0.3V
Short-Circuit Duration
Transmitter Output ..................................... Indefinite
Receiver Output .......................................... Indefinite
VEE ................................................................. 30 sec
Operating Temperature Range
Commercial ............................................ 0°C to 70°C
Industrial ........................................... – 40°C to 85°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
ORDER PART
NUMBER
TOP VIEW
C2 +
1
28
C2 –
C1+ 2
27 VEE
VCC 3
26 Y1
C1 – 4
25 Z1
GND 5
24 Y2
T1 6
23 Z2
T2 7
22 Y3
T3 8
21 Z3
S1 9
20 B3
S2 10
19 A3
R3 11
18 B2
R2 12
17 A2
R1 13
16 B1
OE 14
15 A1
NW PACKAGE
28-LEAD PDIP
LTC1345CNW
LTC1345CSW
LTC1345INW
LTC1345ISW
SW PACKAGE
28-LEAD PLASTIC SO
THREE V.35 TRANSMITTERS AND THREE RECEIVERS
TJMAX = 125°C, θJA = 56°C/W (NW)
TJMAX = 125°C, θJA = 65°C/W (SW)
Consult factory for Military grade parts.
DC ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCC = 5V ±5% (Notes 2, 3), unless otherwise specified.
SYMBOL
VOD
VOC
IOH
IOL
IOZ
RO
VTH
∆VTH
IIN
RIN
VOH
VOL
IOSR
IOZR
VIH
VIL
IIN
ICC
PARAMETER
Transmitter Differential Output Voltage
Transmitter Common-Mode Output Voltage
Transmitter Output High Current
Transmitter Output Low Current
Transmitter Output Leakage Current
Transmitter Output Impedance
Differential Receiver Input Threshold Voltage
Receiver Input Hysterisis
Receiver Input Current (A, B)
Receiver Input Impedance
Receiver Output High Voltage
Receiver Output Low Voltage
Receiver Output Short-Circuit Current
Receiver Three-State Output Current
Logic Input High Voltage
Logic Input Low Voltage
Logic Input Current
VCC Supply Current
VEE
VEE Voltage
2
CONDITIONS
Figure 1, – 4V ≤ VOS ≤ 4V
Figure 1, VOS = 0V
VY, Z = 0V
VY, Z = 0V
S1 = S2 = 0V, – 5V ≤ VY, Z ≤ 5V
– 2V ≤ VY, Z ≤ 2V
– 7V ≤ (VA + VB)/2 ≤ 7V
– 7V ≤ (VA + VB)/2 ≤ 7V
– 7V ≤ VA, B ≤ 7V
– 7V ≤ VA, B ≤ 7V
IO = 4mA, VB, A = 0.2V
IO = 4mA, VB, A = – 0.2V
0V ≤ VO ≤ VCC
S1 = S2 = 0V, 0V ≤ VO ≤ VCC
T, S1, S2, OE
T, S1, S2, OE
T, S1, S2, OE
Figure 1, VOS = 0, S1 = S2 = HIGH
No Load, S1 = S2 = HIGH
Shutdown, S1 = S2 = 0V
No Load, S1 = S2 = HIGH
●
●
●
●
MIN
0.44
– 0.6
– 12.6
9.4
●
●
TYP
0.55
0
– 11
11
±1
100
25
50
●
17.5
3
●
●
30
4.5
0.2
7
●
●
0.4
85
±10
2
●
●
●
●
●
200
0.4
●
●
MAX
0.66
0.6
– 9.4
12.6
±100
118
19
1
– 5.5
0.8
±10
170
30
100
UNITS
V
V
mA
mA
µA
kΩ
mV
mV
mA
kΩ
V
V
mA
µA
V
V
µA
mA
mA
µA
V
LTC1345
AC ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCC = 5V ±5% (Notes 2, 3), unless otherwise specified.
SYMBOL
tR, tF
tPLH
tPHL
tSKEW
tPLH
tPHL
tSKEW
tZL
tZH
tLZ
tHZ
fOSC
BRMAX
PARAMETER
Transmitter Rise or Fall Time
Transmitter Input to Output
Transmitter Input to Output
Transmitter Output to Output
Receiver Input to Output
Receiver Input to Output
Differential Receiver Skew, tPLH – tPHL
Receiver Enable to Output LOW
Receiver Enable to Output HIGH
Receiver Disable From LOW
Receiver Disable From HIGH
Charge Pump Oscillator Frequency
Maximum Data Rate (Note 4)
CONDITIONS
Figures 1 and 3, VOS = 0V
Figures 1 and 3, VOS = 0V
Figures 1 and 3, VOS = 0V
Figures 1 and 3, VOS = 0V
Figures 1 and 4, VOS = 0V
Figures 1 and 4, VOS = 0V
Figures 1 and 4, VOS = 0V
Figures 2 and 5, CL = 15pF, S1 Closed
Figures 2 and 5, CL = 15pF, S2 Closed
Figures 2 and 5, CL = 15pF, S1 Closed
Figures 2 and 5, CL = 15pF, S2 Closed
MIN
●
●
●
●
●
●
●
●
●
10
●
Note 1: The absolute maximum ratings are those values beyond which the
safety of the device cannot be guaranteed.
Note 2: All currents into device pins are termed positive; all currents out of
device pins are termed negative. All voltages are referenced to device
ground unless otherwise specified.
TYP
7
25
25
0
49
52
3
40
35
30
35
200
15
MAX
40
70
70
100
100
70
70
70
70
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
kHz
Mbaud
Note 3: All typicals are given for VCC = 5V, C1 = C2 = C3 = 1µF ceramic
capacitors and TA = 25°C.
Note 4: Maximum data rate is specified for NRZ data encoding scheme.
The maximum data rate may be different for other data encoding schemes.
Data rate is guaranteed by correlation and is not tested.
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Transmitter Output Current
vs Output Voltage
Transmitter Output Current
vs Temperature
13
VCC = 5V
TA = 25°C
VCC = 5V
12
11
10
75
50
25
TEMPERATURE (˚C)
0
100
125
LTC1345 • TPC01
15
12
TIME (ns)
OUTPUT CURRENT (mA)
OUTPUT CURRENT (mA)
20
13
VCC = 5V
9
–50 –25
Transmitter Output Skew
vs Temperature
11
10
5
10
9
–2.0 –1.5 –1.0 –0.5 0 0.5 1.0
OUTPUT VOLTAGE (V)
1.5
2.0
LTC1345 • TPC02
0
–50 –25
75
50
25
TEMPERATURE (˚C)
0
100
125
LTC1345 • TPC03
3
LTC1345
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Receiver tPLH – tPHL
vs Temperature
Supply Current vs Temperature
20
VEE Voltage vs Temperature
140
VCC = 5V
30
–4.5
VCC = 5V
VCC = 5V
LOADED
10
5
0
–50 –25
75
50
25
TEMPERATURE (˚C)
0
100
125
25
NO LOAD
100
20
80
15
60
–50 –25
75
50
25
TEMPERATURE (˚C)
0
LTC1345 • TPC04
100
10
125
–5.0
VOLTAGE (V)
CURRENT (mA)
120
CURRENT (mA)
TIME (ns)
15
–5.5
–6.0
–6.5
–50 –25
75
50
25
TEMPERATURE (˚C)
0
LTC1345 • TPC05
Transmitter Output Waveforms
INPUT
5V/DIV
Receiver Output Waveforms
OUTPUT
5V/DIV
LTC1345 • TPC07
LTC1345 • TPC08
U
U
U
PI FU CTIO S
C2+ (Pin 1): Capacitor C2 Positive Terminal.
R3 (Pin 11): Receiver 3 Output.
C1+ (Pin 2): Capacitor C1 Positive Terminal.
R2 (Pin 12): Receiver 2 Output.
VCC (Pin 3): Positive Supply, 4.75 ≤ VCC ≤ 5.25V.
R1 (Pin 13): Receiver 1 Output.
C1– (Pin 4): Capacitor C1 Negative Terminal.
OE (Pin 14): Receiver Output Enable.
GND (Pin 5): Ground. The positive terminal of C3 is
connected to ground.
A1 (Pin 15): Receiver 1 Inverting Input.
T1 (Pin 6): Transmitter 1 Input.
T2 (Pin 7): Transmitter 2 Input.
T3 (Pin 8): Transmitter 3 Input.
S1 (Pin 9): Select Input 1.
S2 (Pin 10): Select Input 2.
4
125
LTC1345 • TPC06
INPUT
0.2/DIV
OUTPUT
0.2V/DIV
100
B1 (Pin 16): Receiver 1 Noninverting Input.
A2 (Pin 17): Receiver 2 Inverting Input.
B2 (Pin 18): Receiver 2 Noninverting Input.
A3 (Pin 19): Receiver 3 Inverting Input.
B3 (Pin 20): Receiver 3 Noninverting Input.
Z3 (Pin 21): Transmitter 3 Inverting Output.
LTC1345
U
U
U
PI FU CTIO S
Y3 (Pin 22): Transmitter 3 Noninverting Output.
Y1 (Pin 26): Transmitter 1 Noninverting Output.
Z2 (Pin 23): Transmitter 2 Inverting Output.
Y2 (Pin 24): Transmitter 2 Noninverting Output
VEE (Pin 27): Charge Pump Output. Connected to negative
terminal of capacitor C3.
Z1 (Pin 25): Transmitter 1 Inverting Output.
C2 – (Pin 28): Capacitor C2 Negative Terminal.
U
U
FU CTIO TABLES
Receiver
Transmitter and Receiver Configuration
S1
S2
TX#
RX#
INPUTS
REMARKS
OUTPUTS
0
0
—
—
Shutdown
CONFIGURATION S1 S2 OE
1
0
1, 2, 3
1, 2
DCE Mode, RX3 Shut Down
DTE or All ON
X
1
0
≥ 0.2V
1
1
0
1
1, 2
1, 2, 3
DTE Mode, TX3 Shut Down
DTE or All ON
X
1
0
≤ – 0.2V
0
0
1
1
1, 2, 3
1, 2, 3
All Active
DCE
1
0
0
≥ 0.2V
1
Z
DCE
1
0
0
≤ – 0.2V
0
Z
Disabled
X
X
1
X
Z
Z
Shutdown
0
0
X
X
Z
Z
Transmitter
INPUTS
OUTPUTS
CONFIGURATION S1 S2
T
Y1 AND Y2
Z1 AND Z2
Y3
Z3
DTE
0
1
0
0
1
Z
Z
DTE
0
1
1
1
0
Z
Z
DCE or All ON
1
X
0
0
1
0
1
DCE or All ON
1
X
1
1
0
1
0
Shutdown
0
0
X
Z
Z
Z
Z
B–A
R1 AND R2
R3
TEST CIRCUITS
VCC
Y
S1
50Ω
T
Y
125Ω
VOS
50Ω
B
125Ω
VOD
A
Z
50Ω
VOC = (VY + VZ)/2
50Ω
RECEIVER
OUTPUT
R
OE
Z
Figure 1. V.35 Transmitter/Receiver Test Circuit
1k
15pF
CL
S2
LTC1345 • F02
LTC1345 • F01
Figure 2. Receiver Output Enable/Disable Timing Test Load
5
LTC1345
U
W
W
SWITCHI G TI E WAVEFOR S
3V
f = 1MHz: t r ≤ 10ns: t f ≤ 10ns
1.5V
T
1.5V
0V
t PLH
t PHL
VO
90%
Y–Z
VDIFF = V(Y) – V(Z)
50%
10%
–VO
90%
50%
10%
1/2 VO
tr
tf
Z
VO
Y
tSKEW
tSKEW
LTC1345 • F03
Figure 3. V.35 Transmitter Propagation Delays
VID
f = 1MHz: t r ≤ 10ns: t f ≤ 10ns
0V
B–A
INPUT
0V
–VID
t PLH
t PHL
VOH
R
1.5V
OUTPUT
1.5V
VOL
LTC1345 • F04
Figure 4. V.35 Receiver Propagation Delays
3V
1.5V
OE
0V
f = 1MHz: t r ≤ 10ns: t f ≤ 10ns
t ZL
1.5V
t LZ
5V
R
1.5V
OUTPUT NORMALLY LOW
VOL
t ZH
OUTPUT NORMALLY HIGH
VOH
0.5V
t HZ
0.5V
1.5V
R
0V
LTC1345 • F05
Figure 5. Receiver Enable and Disable Times
6
LTC1345
U
W
U U
APPLICATIO S I FOR ATIO
Review of CCITT Recommendation V.35
Electrical Specifications
V.35 is a CCITT recommendation for synchronous data
transmission via modems. Appendix 2 of the recommendation describes the electrical specifications which are
summarized below:
1. The interface cable is balanced twisted-pair with 80Ω to
120Ω impedance.
2. The transmitter’s source impedance is between 50Ω and
150Ω.
Cable Termination
Each end of the cable connected to an LTC1345 must be
terminated by either one of two electrically equivalent
external Y or ∆ resistor networks for proper operation. The
Y-termination has two series connected 50Ω resistors and
a 125Ω resistor connected between ground and the center
tap of the two 50Ω resistors as shown in Figure 6A.
50Ω
125Ω
50Ω
3. The transmitter’s resistance between shorted terminals
and ground is 150Ω ±15Ω.
4. When terminated by a 100Ω resistive load, the terminalto-terminal voltage should be 0.55V ±20%.
A
300Ω
120Ω
5. The transmitter’s rise time should be less than 1% of the
signal pulse or 40ns, whichever is greater.
300Ω
B
6. The common-mode voltage at the transmitter output
should not exceed 0.6V.
7. The receiver impedance is 100Ω ±10Ω.
8. The receiver impedance to ground is 150Ω ±15Ω.
9. The transmitter or receiver should not be damaged by
connection to earth ground, short-circuiting, or cross
connection to other lines.
10. No data errors should occur with ±2V common-mode
change at either the transmitter or receiver, or ±4V ground
potential difference between transmitter and receiver.
LTC1345 • F06
Figure 6. Y and ∆ Termination Networks
The alternative ∆-termination has a 120Ω resistor across
the twisted wires and two 300Ω resistors between each
wire and ground as shown in Figure 6B. Standard 1/8W,
5% surface mount resistors can be used for the termination
network. To maintain the proper differential output swing,
the resistor tolerance must be 5% or less. A termination
network that combines all the resistors into an SO-14
package is available from:
BI Technologies (Formerly Beckman Industrial)
Resistor Networks
4200 Bonita Place
Fullerton, CA 92635
Phone: (714) 447-2357
FAX: (714) 447-2500
Part #: BI Technologies 627T500/1250 (SOIC)
899TR50/125 (DIP)
7
LTC1345
U
W
U U
APPLICATIO S I FOR ATIO
Theory of Operation
The transmitter output consists of complementary
switched-current sources as shown in Figure 7.
VCC
A charge pump generates the regulated negative supply
voltage (VEE) with three 1µF capacitors. Commutating
capacitors C1 and C2 form a voltage doubler and inverter
while C3 acts as a reservoir capacitor. To insure proper
operation, the capacitors must have an ESR less than 1Ω.
Monolithic ceramic or solid tantalum capacitors are good
choices. Under light loads, regulation at about – 5.2V is
provided by a pulse-skipping scheme. Under heavy loads
the charge pump is on continuously. A small ripple of about
500mV will be present on VEE.
CHIP
BOUNDARY
11mA
Y
50Ω
125Ω
T
50Ω
Z
11mA
VEE
may be forced into a high impedance state by pulling the
output enable (OE) pin high. For normal operation OE
should be pulled low.
LTC1345 • F07
Two Select pins, S1 and S2, configure the chip for DTE,
DCE, all transmitters and receivers on, or Shutdown. In
Shutdown mode, ICC drops to 1µA. The outputs of the
transmitters and receivers are in high impedance states,
the charge pump stops and VEE is clamped to ground.
Figure 7. Simplified Transmitter Schematic
ESD Protection
With a logic zero at the transmitter input, the inverting
output Z sources 11mA and the noninverting output Y
sinks 11mA. The differential transmitter output voltage is
then set by the termination resistors. With two differential
50Ω resistors at each end of the cable, the voltage is set to
(50Ω × 11mA) = 0.55V. With a logic 1 at the transmitter
input, output Z sinks 11mA and Y sources 11mA. The
common-mode voltage of Y and Z is 0V when both current
sources are matched and there is no ground potential
difference between the cable terminations. The transmitter
current sources have a common-mode range of ±2V,
which allows for a ground difference between cable terminations of ±4V.
Each receiver input has a 30k resistance to ground and
requires external termination to meet the V.35 input impedance specification. The receivers have an input hysteresis
of 50mV to improve noise immunity. The receiver output
8
LTC1345 transmitter outputs and receiver inputs have onchip protection from multiple ±10kV ESD transients. ESD
testing is done using the Human Body ESD Model. ESD
testing must be done with an AC ground on the VCC and VEE
supply pins. The low ESR supply decoupling and VEE
reservoir capacitors provide this AC ground during normal
operation.
Complete V.35 Port
Figure 8 shows the schematic of a complete surface
mounted, single 5V DTE and DCE V.35 port using only
three ICs and eight capacitors per port. The LTC1345 is
used to transmit the clock and data signals, and the
LT1134A to transmit the control signals. If test signals
140, 141, and 142 are not used, the transmitter inputs
should be tied to VCC.
LTC1345
U
U
W
U
APPLICATIONS INFORMATION
1µF
1µF
50Ω
DTE
T
VCC1
5V
2
4
1
50Ω
28
3
27
1µF
LTC1345
1µF
6
DX
7
DX
11
RX
12
RX
13
RX
10
9
26
1
25
2
24
3
23
4
20
14
19
13
18
12
17
11
16
10
15
9
5
7
4
T
P
TXD (103)
S
U
T
W
AA
T
TXC (114)
T
V
T
T
R
T
T
X
V
RXD (104)
T
AA
Y
RXC (115)
BI
627T500/
1250
(SOIC)
U
W
Y
X
P
S
SCTE (113)
3
22
1µF
1
28
T
T
R
B
GND (102)
B
A
CABLE SHIELD
A
T
12
18
11
17
10
16
9
15
1
26
2
25
3
24
4
23
5
22
6
21
7
5
3
12
13
RX
6
DX
7
DX
8
DX
9
10
14
VCC2
23
4
0.2µF
3
22
1
0.1µF
1µF
RX
0.2µF
LT1134A
VCC2
5V
4
LTC1345
8
24
2
27
1µF
0.2µF
1
0.1µF
BI
627T500/
1250
(SOIC)
8
14
VCC1
0.2µF
1µF
DCE
125Ω
=
0.1µF
23
24
LT1134A
0.1µF
2
21
19
20
18
OPTIONAL SIGNALS
16
14
17
15
DX
DX
RX
RX
RX
RX
DX
DX
13
5
H
DTR (108)
7
C
RTS (105)
6
E
DSR (107)
8
D
CTS (106)
10
F
DCD (109)
12
NN
TM (142)
9
N
RDL (140)
11
L
LLB (141)
H
6
C
8
E
5
D
7
F
9
NN
11
N
10
L
12
ISO 2593
ISO 2593
34-PIN DTE/DCE
34-PIN DTE/DCE
INTERFACE CONNECTOR INTERFACE CONNECTOR
20
RX
18
RX
DX
DX
DX
DX
21
19
17
15
16
RX
14
RX
13
LTC1345 • TA08
Figure 8. Complete Single 5V V.35 Interface
9
LTC1345
U
W
U
U
APPLICATIONS INFORMATION
RS422/RS485 Applications
The receivers on the LTC1345 are ideal for RS422 and
RS485 applications. Using the test circuit in Figure 9, the
LTC1345 receivers are able to successfully reconstruct
the data stream with the common-mode voltage meeting
RS422 and RS485 requirements (12V to – 7V).
RECEIVER
OUTPUT
5V/DIV
Figures 10 and 11 show that the LTC1345 receivers are
very capable of reconstructing data at rates up to 10Mbaud.
RECEIVER
INPUT A
B
5V/DIV
A
GND
TTL
IN
–5V
100Ω
100Ω
B
AX
Figure 10. – 7V Common Mode
LTC1345
GND
–+
12V TO – 7V
COMMON-MODE VOLTAGE
–10V
LTC1345 • F10
BX
LTC485
0
0V
VCC2
5V
VCC1
5V
5
TTL
OUT
RECEIVER
B
INPUT A
5V/DIV
15V
10V
LTC1345 • F09
5V
Figure 9 RS422/RS485 Receiver Interface
0V
5
RECEIVER
OUTPUT
5V/DIV
0
LTC1345 • F11
Figure 11. 12V Common Mode
10
LTC1345
U
PACKAGE DESCRIPTION
Dimensions in inches (millimeters) unless otherwise noted.
NW Package
28-Lead PDIP (Wide 0.600)
(LTC DWG # 05-08-1520)
1.455*
(36.957)
MAX
28
27
26
25
24
23
22
21
20
19
18
17
16
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
0.505 – 0.560*
(12.827 – 14.224)
0.600 – 0.625
(15.240 – 15.875)
0.009 – 0.015
(0.229 – 0.381)
(
+0.035
0.625 –0.015
+0.889
15.87
–0.381
)
0.150 ± 0.005
(3.810 ± 0.127)
0.045 – 0.065
(1.143 – 1.651)
0.015
(0.381)
MIN
0.070
(1.778)
TYP
0.125
(3.175)
MIN
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
0.035 – 0.080
(0.889 – 2.032)
0.018 ± 0.003
(0.457 ± 0.076)
0.100
(2.54)
BSC
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.
N28 1098
11
LTC1345
U
PACKAGE DESCRIPTION
Dimensions in inches (millimeters) unless otherwise noted.
SW Package
28-Lead Plastic Small Outline (Wide 0.300)
(LTC DWG # 05-08-1620)
0.697 – 0.712*
(17.70 – 18.08)
28
27
26
25
24
23
22
21
20
19
18
17
16
15
0.394 – 0.419
(10.007 – 10.643)
NOTE 1
0.291 – 0.299**
(7.391 – 7.595)
1
2
3
4
5
6
7
8
9
10
11
12
13
0.037 – 0.045
(0.940 – 1.143)
0.093 – 0.104
(2.362 – 2.642)
0.010 – 0.029 × 45°
(0.254 – 0.737)
14
0° – 8° TYP
0.009 – 0.013
(0.229 – 0.330)
NOTE 1
0.050
(1.270)
BSC
0.016 – 0.050
(0.406 – 1.270)
0.004 – 0.012
(0.102 – 0.305)
0.014 – 0.019
(0.356 – 0.482)
TYP
NOTE:
1. PIN 1 IDENT, NOTCH ON TOP AND CAVITIES ON THE BOTTOM OF PACKAGES ARE THE MANUFACTURING OPTIONS.
THE PART MAY BE SUPPLIED WITH OR WITHOUT ANY OF THE OPTIONS
S28 (WIDE) 1098
*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
RELATED PARTS
PART NUMBER
DESCRIPTION
LTC1334
Single 5V RS232/RS485 Multiprotocol Transceiver
Two RS485 Driver/Receiver or Four RS232 Driver/Receiver Pairs
LTC1343
Software-Selectable Multiprotocol Transceiver
4-Driver/4-Receiver for Data and Clock Signals
LTC1344/LTC1344A
Software-Selectable Cable Terminator
Perfect for Terminating the LTC1543 (Not Needed with LTC1546)
LTC1346
Dual Supply V.35 Transceiver
3-Driver/3-Receiver for Data and Clock Signals
LTC1387
RS232/RS485 Multiprotocol Transceiver
One RS485 Driver/Receiver or Two RS232 Driver/Receiver Pairs
LTC1543
Software-Selectable Multiprotocol Transceiver
Terminated with LTC1344A for Data and Clock Signals, Companion to
LTC1544 or LTC1545 for Control Signals
LTC1544
Software-Selectable Multiprotocol Transceiver
Companion to LTC1546 or LTC1543 for Control Signals Including LL
LTC1545
Software-Selectable Multiprotocol Transceiver
5-Driver/5-Receiver Companion to LTC1546 or LTC1543
for Control Signals Including LL, TM and RL
LTC1546
Multiprotocol Transceiver with Termination
Combines LTC1543 and LTC1344A Functions for Data and Clock Signals
12
Linear Technology Corporation
COMMENTS
1345fa LT/TP 0400 2K REV A • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408)432-1900 ● FAX: (408) 434-0507 ● www.linear-tech.com
LINEAR TECHNOLOGY CORPORATION 1995
工商网监
湘ICP备2023018690号
