ANALOG DEVICES ADM3232E Service Manual

±15 kV ESD Protected, 3.3 V, RS-232

T

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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: [phone] www.analog.com
Fax: [phone] ©2006–2008 Analog Devices, Inc. All rights reserved.

ADM3232E

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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

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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

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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

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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

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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

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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

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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

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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

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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

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NOTES

Rev. A | Page 11 of 12

ADM3232E

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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