LTC1349 5V Low Power RS232 3-Driver/5-Receiver Transceiver with 2 Receivers Active in Shutdown
FEATURES
■ ■ ■ ■ ■ ■ ■ ■
DESCRIPTIO
■
■ ■
Low Supply Current: 300µA Two Receivers Kept Alive in Shutdown ESD Protection Over ±10kV Operates from a Single 5V Supply Uses Small Capacitors: 0.1µF Operates to 120k Baud Three-State Outputs Are High Impedance When Off Output Overvoltage Does Not Force Current Back into Supplies RS232 I/O Lines Can Be Forced to ± 25V Without Damage Pin Compatible with LT1137A and LT1237 Flowthrough Architecture
The LTC®1349 is a 3-driver/5-receiver RS232 transceiver with very low supply current. In the no load condition, the supply current is only 300µA. The charge pump only requires four 0.1µF capacitors. In Shutdown mode, two receivers are kept alive and the supply current is 35µA. All RS232 outputs assume a high impedance state in Shutdown and with the power off. The LTC1349 is fully compliant with all data rate and overvoltage RS232 specifications. The transceiver can operate up to 120k baud with a 2500pF, 3kΩ load. Both driver outputs and receiver inputs can be forced to ± 25V without damage, and can survive multiple ± 10kV ESD strikes.
APPLICATIO S
■ ■
Notebook Computers Palmtop Computers
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
3-Drivers/5-Receivers with Shutdown
V+ C1 0.1µF C2 0.1µF DRIVER 1 OUT RX1 IN DRIVER 2 OUT RX2 IN RX3 IN RX4 IN DRIVER 3 OUT RX5 IN ON/OFF NC VCC 1 2 3 4 5 6 7 8 9 10 11 12 13 14 LTC1349 28 27 26 25 24 23 22 21 20 19 18 17 16 15 C3 0.1µF DRIVER 1 IN RX1 OUT DRIVER 2 IN RX2 OUT RX3 OUT RX4 OUT DRIVER 3 IN RX5 OUT GND NC NC
LTC1349 • TA01
Quiescent and Shutdown Supply Current vs Temperature
1200
C4 0.1µF
V–
1000
QUIESCENT CURRENT (µA)
800 600 400 200 0 –40
0 0 80 100 20 60 40 TEMPERATURE (°C) TEST CONDITION: VCC = 5V, ALL DRIVER INPUTS TIED TO VCC. –20
LTC1349 • TA02
U
60 50
SHUTDOWN CURRENT (µA)
U
U
SHUTDOWN CURRENT
40 30
QUIESCENT CURRENT
20 10
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LTC1349
ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO
TOP VIEW V+ 1 VCC 2 C1+ 3 C1– 4 DR1 OUT 5 RX1 IN 6 DR2 OUT 7 RX2 IN 8 RX3 IN 9 RX4 IN 10 DR3 OUT 11 RX5 IN 12 ON/OFF 13 NC 14 G PACKAGE 28-LEAD SSOP 28 V– 27 C2+ 26 C2– 25 DR1 IN 24 RX1 OUT 23 DR2 IN 22 RX2 OUT 21 RX3 OUT 20 RX4 OUT 19 DR3 IN 18 RX5 OUT 17 GND 16 NC 15 NC NW PACKAGE 28-LEAD PDIP
Supply Voltage (VCC) ................................................ 6V Input Voltage Driver ....................................... – 0.3V to V CC + 0.3V Receiver ............................................... – 25V to 25V On/Off Pin .................................. – 0.3V to VCC + 0.3V Output Voltage Driver .................................................... – 25V to 25V Receiver .................................... – 0.3V to VCC + 0.3V Short Circuit Duration V + ................................................................... 30 sec V – ................................................................... 30 sec Driver Output .............................................. Indefinite Receiver Output .......................................... Indefinite Operating Temperature Range Commercial (LTC1349C) ........................ 0°C to 70°C Industrial (LTC1349I) ........................ – 40°C to 85°C Storage Temperature Range ................ – 65°C to 150°C Lead Temperature (Soldering, 10 sec)................. 300°C
ORDER PART NUMBER LTC1349CG LTC1349CNW LTC1349CSW LTC1349IG LTC1349INW LTC1349ISW
SW PACKAGE 28-LEAD PLASTIC SO
TJMAX = 125°C, θJA = 96°C/W (G) TJMAX = 125°C, θJA = 56°C/W (NW) TJMAX = 125°C, θJA = 85°C/W (SW)
Consult LTC Marketing for parts specified with wider operating temperature ranges.
DC ELECTRICAL CHARACTERISTICS
PARAMETER Any Driver Output Voltage Swing Logic Input Voltage Level Logic Input Current Output Short-Circuit Current Output Leakage Current Any Receiver Input Voltage Thresholds Hysteresis Input Resistance Output Voltage Output Short-Circuit Current Output Leakage Current Power Supply Generator V + Output Voltage V – Output Voltage Supply Rise Time CONDITIONS 3k to GND
The ● denotes specifications which apply over the full operating temperature range. VCC = 5V, C1 = C2 = C3 = C4 = 0.1µF, unless noted.
MIN Positive Negative
● ● ● ● ● ●
TYP 7.0 – 6.5 1.4 1.4
MAX
UNITS V V V V µA µA mA µA V V V kΩ V V mA µA V V V V ms
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5.0 – 5.0 2.0
Input Low Level (VOUT = High) Input High Level (VOUT = Low) VIN = 5V VIN = 0V VOUT = 0V Shutdown, VOUT = ±20V (Note 3) Input Low Threshold Input High Threshold – 10V ≤ VIN ≤ 10V Output Low, IOUT = – 1.6mA (VCC = 5V) Output High, IOUT = 160µA (VCC = 5V) Sinking Current, VOUT = VCC Shutdown, 0 ≤ VOUT ≤ VCC (Note 3) IOUT = 0mA IOUT = 12mA IOUT = 0mA IOUT = – 12mA Shutdown to Turn-On
0.8 5 –5
±9
● ● ● ● ● ● ●
±12 ± 10 ± 500
0.8 0.1 3 3.5 – 15
1.3 1.7 0.4 5 0.2 4.8 – 40 1 8.0 7.5 – 8.0 – 7.0 0.2
2.4 1.0 7 0.4
10
2
U
W
U
U
WW
W
LTC1349
DC ELECTRICAL CHARACTERISTICS
PARAMETER Power Supply VCC Supply Current CONDITIONS
The ● denotes specifications which apply over the full operating temperature range. VCC = 5V, C1 = C2 = C3 = C4 = 0.1µF, unless noted.
MIN
● ● ● ● ● ● ● ●
TYP 0.3 0.5 0.3 0.3 0.5 35 1.4 1.4
MAX 0.8 1.0 1.0 1.5 1.5 50 0.8
UNITS mA mA mA mA mA µA V V
Supply Leakage Current (VCC) On/Off Threshold Low On/Off Threshold High
No Load (All Drivers VIN = VCC)(Note 2), 0°C ≤ TA ≤ 70°C No Load (All Drivers VIN = 0V)(Note 2), 0°C ≤ TA ≤ 70°C No Load (All Drivers VIN = VCC)(Note 2), 0°C ≤ TA ≤ 85°C No Load (All Drivers VIN = VCC)(Note 2), – 40°C ≤ TA ≤ 0°C No Load (All Drivers VIN = 0V)(Note 2), – 40°C ≤ TA ≤ 85°C Shutdown (Note 3)
2.0
AC CHARACTERISTICS
PARAMETER Slew Rate Driver Propagation Delay (TTL to RS232) Receiver Propagation Delay (RS232 to TTL)
The ● denotes specifications which apply over the full operating temperature range. VCC = 5V, C1 = C2 = C3 = C4 = 0.1µF, unless noted.
CONDITIONS RL = 3k, CL = 51pF RL = 3k, CL = 2500pF t HLD (Figure 1) t LHD (Figure 1) t HLR (Figure 2) t LHR (Figure 2)
● ● ● ●
MIN 3
TYP 8 5 2 2 0.3 0.2
MAX 30 3.5 3.5 0.8 0.8
UNITS V/µs V/µs µs µs µs µs
Note 1: Absolute Maximum Ratings are those values beyond which the life of the device may be impaired. Note 2: Supply current is measured with driver and receiver outputs unloaded.
Note 3: Supply current and leakage current measurements in Shutdown are performed with VON/OFF = 0V.
TYPICAL PERFOR A CE CHARACTERISTICS
Driver Output Voltage
10 8 RL = 3k OUTPUT HIGH VCC = 5V
DRIVER OUTPUT VOLTAGE (V)
THRESHOLD VOLTAGE (V)
4 2 0 –2 –4 –6 VCC = 5V –8 –40 –20 20 0 40 60 TEMPERATURE (°C) 80 100 OUTPUT LOW VCC = 4.5V
1.8 VTH 1.6 VTL 1.4 1.2
SUPPLY CURRENT (mA)
6
VCC = 4.5V
LTC1349 • TPC01
UW
Receiver Input Thresholds
2.2 2.0
35 30 25 20 15 10 5 45 40
Supply Current vs Data Rate
VCC = 5V RL = 3k CL = 2500pF 3 DRIVERS ACTIVE
1.0 –40 –20
40 20 60 0 TEMPERATURE (˚C)
80
100
0 0 25 75 100 125 50 DATA RATE (k BAUD) 150 175
LTC1349 • TPC02
LTC1349 • TPC03
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LTC1349 TYPICAL PERFOR A CE CHARACTERISTICS
VCC Supply Current
20 16 3 DRIVERS LOADED RL = 3k
LEAKAGE CURRENT (µA) SUPPLY CURRENT (mA) 45 40 35 30 25 20 15 10 5 0 VOUT = 20V VOUT = – 20V
14 12 10 8 6 4 2 0 0 10
SHORT-CIRCUIT CURRENT (mA)
1 DRIVER LOADED RL = 3k
30 20 40 50 TEMPERATURE (°C)
LTC1349 • TPC04
Receiver Short-Circuit Current
60
SHORT-CIRCUIT CURRENT (mA)
DRIVER OUTPUT RL = 3k CL = 2500pF
50
40
ISC–
30
INPUT
ISC+ 20
LTC1349 • TPC08 LTC1349 • TPC09
10 –40 –20
40 20 0 60 TEMPERATURE (°C)
PI FU CTIO S
VCC: 5V Input Supply Pin. Supply current is typically 35µA in the Shutdown mode. This pin should be decoupled with a 0.1µF ceramic capacitor. GND: Ground Pin. ON/OFF: TTL/CMOS Compatible Shutdown Pin. A logic low puts the device in Shutdown mode, with receivers 4 and 5 kept alive and the supply current equal to 35µA. All driver outputs and other receiver outputs are in high impedance state. This pin can not float. V +: Positive Supply Output (RS232 Drivers). V + ≅ 2VCC – 1V. This pin requires an external capacitor C = 0.1µF for charge storage. The capacitor may be tied to ground or 5V. With multiple devices, the V + and V – pins may be paralleled into common capacitors. For large numbers of devices, increasing the size of the shared common storage capacitors is recommended to reduce ripple. V –: Negative Supply Output (RS232 Drivers). V – ≅ 2VCC – 1.5V. This pin requires an external capacitor C = 0.1µF for charge storage. C1+, C1–, C2+, C2–: Commutating Capacitor Inputs. These pins require two external capacitors C = 0.1µF: one from C1+ to C1–, and another from C2+ to C2–. To maintain charge pump efficiency, the capacitor’s effective series resistance should be less than 20Ω.
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UW
60 80
LTC1349 • TPC07
Driver Leakage in Shutdown
20 18 16 14 12 10 8 6 4
60 70
Driver Short-Circuit Current
ISC– ISC+
70
0
10
30 20 40 50 TEMPERATURE (°C)
0 –40
–20
20 0 40 60 TEMPERATURE (°C)
80
100
LTC1349 • TPC05
LTC1349 • TPC06
Driver Output Waveforms
Receiver Output Waveforms
DRIVER OUTPUT RL = 3k
RECEIVER OUTPUT CL = 2500pF
INPUT
100
U
U
U
LTC1349
PI FU CTIO S
DRIVER IN: RS232 Driver Input Pins. Inputs are TTL/ CMOS compatible. Inputs should not be allowed to float. Tie unused inputs to VCC. DRIVER OUT: Driver Outputs at RS232 Voltage Levels. Outputs are in a high impedance state when in Shutdown mode or VCC = 0V. The driver outputs are protected against ESD to ±10kV for human body model discharges. RX IN: Receiver Inputs. These pins can be forced to ± 25V without damage. The receiver inputs are protected against ESD to ±10kV for human body model discharges. Each receiver provides 0.4V of hysteresis for noise immunity. RX OUT: Receiver Outputs with TTL/CMOS Voltage Levels. Receiver 1, 2 and 3 outputs are in a high impedance state when in Shutdown mode to allow data line sharing. Receivers 4 and 5 are kept alive in Shutdown.
SWITCHI G TI E WAVEFOR S
DRIVER INPUT DRIVER OUTPUT t LHD VCC 1.4V 1.4V 0V V+ 0V t HLD
LTC1349 • F01
Figure 1. Driver Propagation Delay Timing
RX INPUT RX OUTPUT t LHR
1.7V
Figure 2. Receiver Propagation Delay Timing
TEST CIRCUITS
Driver Timing Test Load
DRIVER OUTPUT DRIVER 51pF 3k
DRIVER INPUT
LTC1349 • TA03
W
W
U
U
U
U
0V
V–
VCC 1.3V 0V 2.4V 0.8V t HLR VCC 0V
LTC1349 • F02
Receiver Timing Test Load
RX OUTPUT RX INPUT RX 51pF
LTC1349 • TA04
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LTC1349
TEST CIRCUITS
ESD Test Circuit
V+ C1 0.1µF C2 0.1µF DRIVER 1 OUT RX1 IN RS232 LINE PINS PROTECTED TO ±10kV DRIVER 2 OUT RX2 IN RX3 IN RX4 IN DRIVER 3 OUT RX5 IN ON/OFF NC VCC 1 2 3 4 5 6 7 8 9 10 11 12 13 14 LTC1349 28 27 26 25 24 23 22 21 20 19 18 17 16 15 C3 0.1µF DRIVER 1 IN RX1 OUT DRIVER 2 IN RX2 OUT RX3 OUT RX4 OUT DRIVER 3 IN RX5 OUT GND NC NC
LTC1349 • TC
V– C4 0.1µF
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LTC1349
PACKAGE DESCRIPTIO U
G Package 28-Lead Plastic SSOP (5.3mm)
(Reference LTC DWG # 05-08-1640)
9.90 – 10.50* (.390 – .413) 1.25 ± 0.12 28 27 26 25 24 23 22 21 20 19 18 17 16 15 5.3 – 5.7 7.40 – 8.20 (.291 – .323) 0.65 BSC 1 2 3 4 5 6 7 8 9 10 11 12 13 14 2.0 (.079)
0° – 8°
7.8 – 8.2
0.42 ± 0.03 RECOMMENDED SOLDER PAD LAYOUT 5.00 – 5.60** (.197 – .221)
0.09 – 0.25 (.0035 – .010)
0.55 – 0.95 (.022 – .037)
0.65 (.0256) BSC
NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS MILLIMETERS 2. DIMENSIONS ARE IN (INCHES) 3. DRAWING NOT TO SCALE *DIMENSIONS DO NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED .152mm (.006") PER SIDE **DIMENSIONS DO NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED .254mm (.010") PER SIDE
0.22 – 0.38 (.009 – .015)
0.05 (.002)
G28 SSOP 0802
NW Package 28-Lead PDIP (Wide .600 Inch)
(Reference LTC DWG # 05-08-1520)
1.467* (36.957) MAX 28 27 26 25 24 23 22 21 20 19 18 17 16 15
.505 – .560* (12.827 – 14.224)
1 .600 – .625 (15.240 – 15.875) .150 ± .005 (3.810 ± 0.127) .015 (0.381) MIN
2
3
4
5
6
7
8
9
10
11
12
13
14
.045 – .065 (1.143 – 1.651)
.008 – .015 (0.203 – 0.381) +.035 .625 –.015
.070 (1.778) TYP .120 (3.175) MIN .035 – .080 (0.889 – 2.032) .100 (2.54) BSC .018 ± .003 (0.457 ± 0.076)
INCHES MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)
NOTE: 1. DIMENSIONS ARE
(
15.87
+0.889 –0.381
)
NW28 1002
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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.
7
LTC1349
PACKAGE DESCRIPTIO
.030 ±.005 TYP N
.050 BSC .045 ±.005 .697 – .712 (17.70 – 18.08) NOTE 4 28 27 26 25 24 23 22 21 20 19 18 17 16 15
.420 MIN
1
2
3
N/2 N/2
RECOMMENDED SOLDER PAD LAYOUT .291 – .299 (7.391 – 7.595) NOTE 4 .010 – .029 × 45° (0.254 – 0.737)
0° – 8° TYP
.005 (0.127) RAD MIN
.009 – .013 (0.229 – 0.330)
NOTE 3 .016 – .050 (0.406 – 1.270)
NOTE: 1. DIMENSIONS IN
INCHES (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. 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 4. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
RELATED PARTS
PART NUMBER LT ®1137A LTC1327 LTC1337 LTC1348 DESCRIPTION 5V, 3 Driver, 5 Receiver RS232 Transceiver 3.3V, 3 Driver, 5 Receiver RS562 Transceiver 5V, 3 Driver, 5 Receiver RS232 Transceiver 3.3V to 5V, 3 Driver, 5 Receiver RS232 Transceiver COMMENTS ± 15kV ESD per IEC 1000-4 300µA Supply Current, 0.2µA in Shutdown 300µA Supply Current, 1µA in Shutdown True RS232 on 3.3V, 5 Receivers Active in Shutdown
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Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7487
(408) 432-1900 ● FAX: (408) 434-0507
●
WWW.linear.com
U
SW Package 28-Lead Plastic Small Outline (Wide .300 Inch)
(Reference LTC DWG # 05-08-1620)
N .325 ±.005 NOTE 3 .394 – .419 (10.007 – 10.643) 1 .093 – .104 (2.362 – 2.642) 2 3 4 5 6 7 8 9 10 11 12 13 14 .037 – .045 (0.940 – 1.143) .050 (1.270) BSC .014 – .019 (0.356 – 0.482) TYP .004 – .012 (0.102 – 0.305)
S28 (WIDE) 0502
1349fa LW/TP 1102 1K REV A • PRINTED IN USA
LINEAR TECHNOLOGY CORPORATION 1993