±15 kV ESD Protected, 3.3 V, RS-232
T
www.BDTIC.com/ADI
FEATURES
Data rate: 460 kbps
2 Tx and 2 Rx
Meets EIA-232E specifications
0.1 μF charge pump capacitors
ESD protection to IEC 1000-4-2 (801.2) on TTL/CMOS and
RS-232 I/Os
Contact discharge: ±8 kV
Air gap discharge: ±15 kV
APPLICATIONS
General-purpose RS-232 data link
Portable instruments
Handsets
Industrial/telecom diagnostic ports
GENERAL DESCRIPTION
The ADM3232E transceiver is a high speed, 2-channel RS-232/V.28
interface device that operates from a single 3.3 V power supply.
Low power consumption makes it ideal for battery-powered
portable instruments. The ADM3232E conforms to the EIA-232E
and ITU-T V.28 specifications and operates at data rates up to
460 kbps.
All RS-232 (Tx
inputs and outputs are protected against electrostatic discharges
(up to ±15 kV ESD protection). This ensures compliance with
IEC 1000-4-2 requirements.
This device is ideally suited for operation in electrically harsh
environments or where RS-232 cables are frequently plugged/
unplugged, with the ±15 kV ESD protection of the ADM3232E
input/output pins.
and RxIN) and TTL/CMOS (TxIN and Rx
OUT
OUT
)
Line Driver/Receiver
ADM3232E
FUNCTIONAL BLOCK DIAGRAM
+3.3V INPU
ADM3232E
C1
+
0.1µF
10V
C2
+
0.1µF
10V
T1
TTL/CMOS
INPUTS
TTL/CMOS
OUTPUTS
IN
T2
IN
R1
OUT
R2
OUT
Emissions are also controlled to within very strict limits. CMOS
technology is used to keep the power dissipation to an absolute
minimum, allowing maximum battery life in portable applications.
Four external 0.1 µF charge pump capacitors are used for the
voltage doubler/inverter, permitting operation from a single
3.3 V supply.
The ADM3232E is available in a 16-lead narrow and wide SOIC
packages, as well as a space-saving 16-lead TSSOP.
+3.3V TO +6.6V
C1+
C1–
+6.6V TO –6.6V
C2+
C2–
GND
V
5kΩ
5kΩ
CC
V+
V–
T1
T2
R1
R2
C3
+
0.1µF
6.3V
C4
+
0.1µF
10V
OUT
OUT
IN
IN
RS-232
OUTPUTS
RS-232
INPUTS*
VOLTAGE
DOUBLER
VOLTAGE
INVERTER
T1
T2
R1
R2
*INTERNAL 5kΩ PULL-DOWN RESISTOR
ON EACH RS-232 INPUT.
Figure 1.
+
C5
0.1µF
06410-001
Rev. A
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700 www.analog.com
Fax: 781.461.3113 ©2006–2008 Analog Devices, Inc. All rights reserved.
ADM3232E
www.BDTIC.com/ADI
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications ....................................................................................... 1
Functional Block Diagram .............................................................. 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications ..................................................................................... 3
Absolute Maximum Ratings ............................................................ 4
ESD Caution .................................................................................. 4
REVISION HISTORY
7/08—Rev. 0 to Rev. A
Added 16-Lead SOIC ......................................................... Universal
Updated Outline Dimensions ......................................................... 9
Changes to Ordering Guide ...........................................................10
12/06—Revision 0: Initial Version
Pin Configuration and Function Descriptions ..............................5
Typical Performance Characteristics ..............................................6
Theory of Operation .........................................................................8
Circuit Description .......................................................................8
High Baud Rate ..............................................................................8
Outline Dimensions ..........................................................................9
Ordering Guide .......................................................................... 10
Rev. A | Page 2 of 12
ADM3232E
www.BDTIC.com/ADI
SPECIFICATIONS
VCC = 3.3 V ± 0.3 V, C1 to C4 = 0.1 µF; all specifications T
Table 1.
Parameter Min Typ Max Unit Test Conditions/Comments
DC CHARACTERISTICS
Operating Voltage Range 3.0 3.3 5.5 V
VCC Power Supply Current 1.3 3 mA No load
LOGIC
Input Logic Threshold Low, V
Input Logic Threshold High, V
TTL/CMOS Output Voltage Low, VOL 0.4 V I
TTLCMOS Output Voltage High, VOH VCC − 0.6 V
Logic Pull-Up Current 5 10 μA TIN = GND to VCC
Transmitter Input Hysteresis 0.5 V
RS-232 RECEIVER
Input Voltage Range −30 +30 V
Input Threshold Low 0.6 1.2 V
Input Threshold High 1.6 2.4 V
Input Hysteresis 0.4 V
Input Resistance 3 5 7 kΩ
RS-232 TRANSMITTER
Output Voltage Swing (RS-232) ±5.0 ±5.2 V VCC = 3.3 V, all transmitter outputs loaded with 3 kΩ to ground
Output Voltage Swing (RS-562) ±3.7 V VCC = 3.0 V
Transmitter Output Resistance 300 Ω VCC = 0 V, V
Output Short-Circuit Current (RS-232) ±15 mA
TIMING CHARACTERISTICS
Maximum Data Rate 460 kbps
Receiver Propagation Delay
t
0.4 1 μs
PHL
t
0.4 1 μs
PLH
Transmitter Propagation Delay 300 1.2 μs RL = 3 kΩ, CL = 1000 pF
Receiver Output Enable Time 200 ns
Receiver Output Disable Time 200 ns
Transmitter Skew 30 ns
Receiver Skew 300 ns
Transition Region Slew Rate 5.5 10 30 V/μs
ESD PROTECTION (RS-232 and TTL/
CMOS I/O PINS)
±15 kV Human body model
±15 kV IEC 1000-4-2 air discharge
±8 kV IEC 1000-4-2 contact discharge
0.8 V TIN
INL
2.0 V TIN
INH
MIN
to T
, unless otherwise noted.
MAX
= 1.6 mA
OUT
I
= −1 mA
OUT
= ±2 V
OUT
= 3.3 V, RL = 3 kΩ to 7 kΩ, CL = 50 pF to 1000 pF, one
V
CC
Tx switching
Measured from +3 V to −3 V or −3 V to +3 V, V
R
= 3 kΩ, CL = 1000 pF, TA = 25°C
L
= 3.3 V;
CC
Rev. A | Page 3 of 12
ADM3232E
www.BDTIC.com/ADI
ABSOLUTE MAXIMUM RATINGS
TA = 25°C, unless otherwise noted.
Table 2.
Parameter Rating
VCC −0.3 V to +6 V
V+ (VCC − 0.3 V) to 14 V
V− +0.3 V to –14 V
Input Voltages
TxIN −0.3 V to (VCC + 0.3 V)
RxIN ±30 V
Output Voltages
Tx
±15 V
OUT
Rx
−0.3 V to (VCC + 0.3 V)
OUT
Short-Circuit Duration
Tx
Continuous
OUT
Power Dissipation R-16/RW-16 450 mW
(Derate 6 mW/°C Above 50°C)
θJA, Thermal Impedance
Power Dissipation RU-16 500 mW
(Derate 6 mW/°C Above 50°C)
θJA, Thermal Impedance
Operating Temperature Range
Industrial (A Version) −40°C to +85°C
Storage Temperature Range −65°C to +150°C
Lead Temperature
(Soldering, 10 sec)
158°C/W
158°C/W
JEDEC industry-standard
J-STD-020
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
ESD CAUTION
Rev. A | Page 4 of 12
ADM3232E
www.BDTIC.com/ADI
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
1
C1+
2
V+
ADM3232E
3
C1–
C2+
C2–
V–
T2
OUT
R2
IN
4
(Not to Scale)
5
6
7
8
TOP VIEW
16
V
CC
15
GND
14
T1
OUT
13
R1
IN
12
R1
OUT
11
T1
IN
10
T2
IN
9
R2
OUT
06410-002
Figure 2. Pin Configuration
Table 3. Pin Function Descriptions
Pin No. Mnemonic Description
1, 3 C1+, C1–
External Capacitor 1 is connected between these pins. A 0.1 μF capacitor is recommended, but larger capacitors
of up to 47 μF can be used.
2 V+ Internally Generated Positive Supply (6 V Nominal).
4, 5 C2+, C2–
External Capacitor 2 is connected between these pins. A 0.1 μF capacitor is recommended, but larger capacitors
of up to 47 μF can be used.
6 V– Internally Generated Negative Supply (−6 V Nominal).
7, 14 T2
8, 13 R2IN, R1IN
OUT
, T1
Transmitter (Driver) Outputs. These are RS-232 signal levels (typically ±6 V).
OUT
Receiver Inputs. These inputs accept RS-232 signal levels. An internal 5 kΩ pull-down resistor to GND is connected
on each input.
9, 12 R2
OUT
, R1
Receiver Outputs. These are TTL/CMOS output logic levels.
OUT
10, 11 T2IN, T1IN Transmitter (Driver) Inputs. These inputs accept TTL/CMOS levels.
15 GND Ground Pin. Must be connected to 0 V.
16 VCC Power Supply Input (3.3 V ± 0.3 V).
Rev. A | Page 5 of 12
ADM3232E
www.BDTIC.com/ADI
TYPICAL PERFORMANCE CHARACTERISTICS
8
Tx
(HIGH)
6
4
OUT
8
6
V+
4
2
(V)
0
OUT
Tx
–2
–4
Tx
(LOW)
–6
–8
0 1200200 400 600 800
OUT
LOAD CAPACITANCE ( pF)
Figure 3. Transmitter Output Voltage High/Low vs.
Load Capacitance @ 460 kbps
8
Tx
HIGH
6
4
2
0
(V)
OUT
–2
Tx
–4
–6
OUT
Tx
LOW
OUT
1000
2
0
V+, V– (V)
–2
–4
–6
–8
6410-003
02468
LOAD CURRENT (mA)
V–
10 12
06410-006
Figure 6. Charge Pump V+, V− vs. Load Current
350
300
250
200
150
IMPEDANCE (Ω)
100
50
V+ (IMPEDANCE)
V– (IMPEDANCE)
–8
2.7 2.9 3.1 3.3 3.5
Figure 4. Transmitter Output Voltage vs. V
8
6
4
2
(V)
0
OUT
Tx
–2
–4
–6
–8
02468
VCC (V)
Tx
OUT
Tx
OUT
LOAD CURRENT (mA)
HIGH
LOW
CC
10 12
Figure 5. Transmitter Output Voltage High/Low vs. Load Current
0
2.7 2.9 3.1 3.3 3.5
06410-004
Figure 7. Charge Pump Impedance vs. V
20
18
16
14
12
10
(mA)
CC
I
8
6
4
2
0
06410-005
0 1000 2000 3000
LOAD CAPACITANCE ( pF)
VCC (V)
@ 460kbps
I
CC
I
@ 230kbps
CC
06410-007
CC
06410-008
Figure 8. Power Supply Current vs. Load Capacitance
Rev. A | Page 6 of 12
ADM3232E
www.BDTIC.com/ADI
1
2
CH 1 5.00V CH 2 5.00V M1.00µs CH1
Figure 9. 460 kbps Data Transmission
T
T
0V
06410-009
Rev. A | Page 7 of 12
ADM3232E
T
www.BDTIC.com/ADI
THEORY OF OPERATION
The ADM3232E is a single-channel RS-232 line driver/receiver.
Step-up voltage converters, coupled with level-shifting transmitters
and receivers, allow RS-232 levels to be developed while operating
from a single 3.3 V supply.
CMOS technology is used to keep the power dissipation to an
absolute minimum, allowing maximum battery life in portable
applications.
CIRCUIT DESCRIPTION
The internal circuitry consists of the following main sections:
• A charge pump voltage converter
• A 3.3 V logic to RS-232 transmitter
• An RS-232 to 3.3 V logic receiver
Charge Pump Voltage Converter
The charge pump voltage converter consists of a 200 kHz
oscillator and a switching matrix. The converter generates a
±6.6 V supply from the input 3.3 V level. This is accomplished
in two stages by using a switched capacitor technique as shown
in Figure 10. First, the 3.3 V input supply is doubled to 6.6 V by
using Capacitor C1 as the charge storage element. The +6.6 V
level is then inverted to generate −6.6 V, using C2 as the storage
element.
Capacitor C3 and Capacitor C4 are used to reduce the output
ripple. Their values are not critical and can be increased, if desired.
Capacitor C3 is shown connected between V+ and V
acceptable to connect this capacitor between V+ and GND.
If desired, larger capacitors (up to 10 µF) can be used for
Capacitor C1 to Capacitor C4.
+3.3V INPU
ADM3232E
+3.3V TO +6.6V
C1+
C1–
+6.6V TO –6.6V
C2+
C2–
GND
V
VOLTAGE
DOUBLER
VOLTAGE
INVERTER
T1
T2
R1
R2
*INTERNAL 5kΩ PULL-DOWN RESISTOR
ON EACH RS-232 INPUT.
CC
V+
V–
5kΩ
5kΩ
T1
T2
R1
R2
C3
+
0.1µF
6.3V
C4
+
0.1µF
10V
OUT
OUT
IN
IN
TTL/CMOS
INPUTS
TTL/CMOS
OUTPUTS
0.1µF
10V
0.1µF
10V
R1
R2
C1
C2
T1
T2
+
+
IN
IN
OUT
OUT
Figure 10. Typical Operating Circuit
. It is also
CC
+
C5
0.1µF
RS-232
OUTPUTS
RS-232
INPUTS*
V
CC
GND
INTERNAL
OSCILLATOR
S1
C1
S2
S3
+
C3
S4
V+ = 2V
+
CC
V
CC
06410-011
Figure 11. Charge Pump Voltage Doubler
S3
+
C2
C4
S4
+
GND
V– = –(V+)
06410-012
FROM
VOLTAGE
DOUBLER
V+
GND
INTERNAL
OSCILLAT OR
S1
S2
Figure 12. Charge Pump Voltage Inverter
3.3 V Logic to RS-232 Transmitter
The drivers convert 3.3 V logic input levels into RS-232 output
levels. With V
= 3.3 V and driving an RS-232 load, the output
CC
voltage swing is typically ±6 V.
RS-232 to 3.3 V Logic Receiver
The receivers are inverting level shifters that accept RS-232 input
levels and translate them into 3 V logic output levels. The inputs
have internal 5 kΩ pull-down resistors to ground and are also
protected against overvoltages up to ±30 V. Unconnected inputs
are pulled to 0 V by the internal 5 k pull-down resistor. This
results in a Logic 1 output level for unconnected inputs or for
inputs connected to GND.
The receivers have Schmitt trigger inputs with a hysteresis level
of 0.4 V. This ensures error-free reception for both noisy inputs
and for inputs with slow transition times.
ESD Protection on RS-232 and TTL/CMOS I/O Pins
All RS-232 (Tx
and RxIN) and TTL/CMOS (TxIN and Rx
OUT
OUT
)
inputs and outputs are protected against electrostatic discharges
(up to ±15 kV). This ensures compliance with IEC 1000-4-2
requirements.
HIGH BAUD RATE
The ADM3232E features high slew rates, permitting data transmission at rates well in excess of the EIA-232E specifications.
RS-232 voltage levels are maintained at data rates up to 460 kbps,
even under worst-case loading conditions. The slew rate is
internally controlled to less than 30 V/µs to minimize EMI
06410-010
interference.
Rev. A | Page 8 of 12
ADM3232E
www.BDTIC.com/ADI
OUTLINE DIMENSIONS
10.00 (0.3937)
9.80 (0.3858)
4.00 (0.1575)
3.80 (0.1496)
0.25 (0.0098)
0.10 (0.0039)
COPLANARITY
0.10
CONTROLL ING DIMENSIONS ARE IN MILLIMETERS; INCH DI MENSIONS
(IN PARENTHESES) ARE ROUNDED-O FF MIL LIMETER EQUIVALENTS FOR
REFERENCE ON LY AND ARE NOT APPROPRI ATE FOR USE IN DES IGN.
16
1
1.27 (0.0500)
BSC
0.51 (0.0201)
0.31 (0.0122)
COMPLIANT TO JEDEC STANDARDS MS-012-AC
9
6.20 (0.2441)
5.80 (0.2283)
8
1.75 (0.0689)
1.35 (0.0531)
SEATING
PLANE
8°
0°
0.25 (0.0098)
0.17 (0.0067)
0.50 (0.0197)
0.25 (0.0098)
1.27 (0.0500)
0.40 (0.0157)
45°
060606-A
Figure 13. 16-Lead Standard Small Outline Package [SOIC_N]
Narrow Body
(R-16)
Dimensions shown in millimeters (and inches)
5.10
5.00
4.90
0.15
0.05
4.50
4.40
4.30
PIN 1
16
0.65
BSC
COPLANARITY
0.10
COMPLIANT TO JEDEC STANDARDS MO-153-AB
0.30
0.19
9
BSC
81
1.20
MAX
SEATING
PLANE
6.40
0.20
0.09
8°
0°
0.75
0.60
0.45
Figure 14. 16-Lead Thin Shrink Small Outline Package [TSSOP]
(RU-16)
Dimensions shown in millimeters
Rev. A | Page 9 of 12
ADM3232E
C
www.BDTIC.com/ADI
0.30 (0.0118)
0.10 (0.0039)
OPLANARITY
0.10
10.50 (0.4134)
10.10 (0.3976)
BSC
9
7.60 (0.2992)
7.40 (0.2913)
8
10.65 (0.4193)
10.00 (0.3937)
2.65 (0.1043)
2.35 (0.0925)
SEATING
PLANE
8°
0°
0.33 (0.0130)
0.20 (0.0079)
5
0
.
7
5
0
.
2
16
1
1.27 (0.0500)
0.51 (0.0201)
0.31 (0.0122)
CONTROLLI NG DIMENSI ONS ARE IN MILLIME TERS; INCH DIMENSIONS
(IN PARENTHESES) ARE ROUNDED-OF F MILL IMETER EQ UIVALENTS FOR
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE I N DESIGN.
COMPLIANT TO JEDEC STANDARDS MS-013- AA
(
0
.
0
2
9
(
0
.
0
0
9
1.27 (0.0500)
0.40 (0.0157)
5
)
45°
8
)
032707-B
Figure 15. 16-Lead Standard Small Outline Package [SOIC_W]
Wide Body
(RW-16)
Dimensions shown in millimeters (and inches)
ORDERING GUIDE
Model Temperature Range Package Description Package Option
ADM3232EARNZ
ADM3232EARNZ-REEL7
ADM3232EARUZ
ADM3232EARUZ-REEL7
ADM3232EARWZ
ADM3232EARWZ-REEL
1
Z = RoHS Compliant Part.
1
–40°C to +85°C 16-Lead SOIC_N R-16
1
–40°C to +85°C 16-Lead SOIC_N R-16
1
–40°C to +85°C 16-Lead TSSOP RU-16
1
–40°C to +85°C 16-Lead TSSOP RU-16
1
–40°C to +85°C 16-Lead SOIC_W RW-16
1
–40°C to +85°C 16-Lead SOIC_W RW-16
Rev. A | Page 10 of 12
ADM3232E
www.BDTIC.com/ADI
NOTES
Rev. A | Page 11 of 12
ADM3232E
www.BDTIC.com/ADI
NOTES
©2006–2008 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D06410-0-7/08(A)
Rev. A | Page 12 of 12
Loading...