ANALOG DEVICES ADM1385 Service Manual
Low Power, 3.3 V, RS-232
FEATURES
460 kbps data rate
Specified at 3.3 V
Meets EIA-232E specifications
0.1 μF charge pump capacitors
Low power shutdown (ADM3222 and ADM1385)
PDIP, SOIC_N, SOIC_W, SSOP, and TSSOP options
Upgrade for MAX3222/MAX3232 and LTC1385
ESD protection to IEC 1000-4-2 (801.2)
on RS-232 pins (ADM3202 only)
±8 kV: contact discharge
±15 kV: air gap discharge
APPLICATIONS
General-purpose RS-232 data link
Portable instruments
Printers, palmtop computers, PDAs
GENERAL DESCRIPTION
The ADM3202/ADM3222/ADM1385 transceivers are high
speed, 2-channel RS-232/V.28 interface devices that operate
from a single 3.3 V power supply. Low power consumption and
a shutdown facility (ADM3222/ADM1385) make them ideal for
battery-powered portable instruments.
The ADM3202/ADM3222/ADM1385 parts conform to the
EIA-232E and CCITT V.28 specifications and operate at data
rates up to 460 kbps.
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 ADM3222 contains additional enable and shutdown
circuitry. The
outputs. The
and transmitter outputs, reducing the quiescent current to less
than 0.5 μA. The receivers remain enabled during shutdown
unless disabled using
The ADM1385 contains a driver disable mode and a complete
shutdown mode.
The ADM3202 is available in a 16-lead PDIP, SOIC_W, and
SOIC_N, as well as a space-saving 16-lead TSSOP. The ADM3222
is available in 18-lead PDIP and SOIC_W and in 20-lead SSOP
and TSSOP. The ADM1385 is available in a 20-lead SSOP,
which is pin-compatible with the LTC1385 CG.
EN
input can be used to three-state the receiver
SD
input is used to power down the charge pump
EN
.
Line Drivers/Receivers
ADM3202/ADM3222/ADM1385
FUNCTIONAL BLOCK DIAGRAMS
+3.3VINPUT
CMOS
INPUTS
CMOS
OUTPUTS
CMOS
INPUTS
CMOS
OUTPUTS
CMOS
INPUTS
CMOS
OUTPUTS
0.1µF
0.1µF
R1
R2
0.1µF
0.1µF
R1
R2
0.1µF
10V
0.1µF
10V
R1
R2
10V
10V
10V
10V
T1
T2
OUT
OUT
T1
T2
T1
T2
OUT
OUT
OUT
OUT
IN
IN
+3.3V TO +6.6V
C1+
+
+
IN
IN
C1–
+6.6V TO –6.6V
C2+
C2–
T1
ADM3202
GND
VOLTAGE
DOUBLER
VOLTAGE
INVERTER
T2
V
CC
+
V+
V–
+
T1
T2
R1
R2
*INTERNAL 5kΩ PULL-DOWN RESISTOR
ON EACH RS-232 INPUT
R1
R2
Figure 1.
+3.3VINPUT
+3.3V TO +6.6V
C1+
+
+
IN
IN
EN
C1–
+6.6V TO –6.6V
C2+
C2–
T1
GND
VOLTAGE
DOUBLER
VOLTAGE
INVERTER
T2
V
CC
+
V+
V–
+
T1
T2
R1
R2
R1
R2
SD
ADM3222
*INTERNAL 5kΩ PULL-DOWN RESISTOR
ON EACH RS-232 INPUT
Figure 2.
+3.3V INPUT
+3.3V TO +6.6V
C1+
+
+
DD
C1–
+6.6V TO –6.6V
C2+
C2–
T1
GND
VOLTAGE
DOUBLER
VOLTAGE
INVERTER
T2
V
CC
V+
V–
C4
+
0.1µF
10V
T1
T2
R1
R2
R1
R2
SD
ADM1385
*INTERNAL 5kΩ PULL-DOWN RESISTOR
ON EACH RS-232 INPUT
Figure 3.
C3
0.1µF
6.3V
C4
0.1µF
10V
OUT
OUT
IN
IN
C3
0.1µF
6.3V
C4
0.1µF
10V
OUT
OUT
IN
IN
OUT
OUT
IN
IN
+
C5
0.1µF
EIA/TIA-232
OUTPUTS
EIA/TIA-232
INPUTS*
+
C5
0.1µF
EIA/TIA-232
OUTPUTS
EIA/TIA-232
INPUTS*
+
C3
0.1µF
10V
EIA/TIA-232
OUTPUTS
EIA/TIA-232
INPUTS*
+
C5
0.1µF
00071-001
00071-002
00071-003
Rev. E
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Anal og Devices for its use, nor for any infringements of patents or ot her
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 ©1998–2011 Analog Devices, Inc. All rights reserved.
ADM3202/ADM3222/ADM1385
TABLE OF CONTENTS
Features.............................................................................................. 1
Pin Configurations (N, RN, RU, and RW Packages)................5
Applications....................................................................................... 1
General Description ......................................................................... 1
Functional Block Diagrams............................................................. 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Absolute Maximum Ratings............................................................ 4
ESD Caution.................................................................................. 4
Pin Configurations and Function Descriptions ........................... 5
REVISION HISTORY
7/11—Rev. D to Rev. E
Changes to Figure 3.......................................................................... 1
Changes to Table 2............................................................................ 4
Changes to Figure 17........................................................................ 8
Updated Outline Dimensions....................................................... 10
Changes to Ordering Guide.......................................................... 14
8/06—Rev. C to Rev. D
Changes to Table 1............................................................................ 3
Updated Outline Dimensions....................................................... 10
Changes to Ordering Guide.......................................................... 12
9/05—Rev. B to Rev. C
Updated Outline Dimensions....................................................... 10
Changes to Ordering Guide.......................................................... 12
12/01—Rev. A to Rev. B
Changes to Specifications Page....................................................... 2
Pin Configurations (RS and RU Packages)................................5
Typical Performance Characteristics..............................................6
General Description..........................................................................8
Circuit Description .......................................................................8
High Baud Rate..............................................................................9
Outline Dimensions....................................................................... 10
Ordering Guide .......................................................................... 14
Rev. E | Page 2 of 16
ADM3202/ADM3222/ADM1385
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
8 12 mA RL = 3 kΩ to GND
Shutdown Supply Current 0.01 0.5 μA
LOGIC
Input Logic Threshold Low, V
Input Logic Threshold High, V
0.8 V TIN
INL
2.0 V TIN
INH
CMOS Output Voltage Low, VOL 0.4 V I
CMOS Output Voltage High, VOH VCC − 0.6 V I
Logic Pull-Up Current 5 10 μA TIN = GND to V
Output Leakage Current ±10 μA Receivers disabled
RS-232 RECEIVER
EIA-232 Input Voltage Range −30 +30 V
EIA-232 Input Threshold Low 0.6 1.2 V
EIA-232 Input Threshold High 1.6 2.4 V
EIA-232 Input Hysteresis 0.4 V
EIA-232 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
RS-232 Output Short-Circuit Current ±15 mA
Output Leakage Current ±25 μA
TIMING CHARACTERISTICS
Maximum Data Rate 460 kbps
Receiver Propagation Delay
TPHL 0.4 1 μs
TPLH 0.4 1 μs
Transmitter Propagation Delay 0.3 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
1
ADM1385: Input leakage current typically −10 μA when TIN = GND.
MIN
to T
, unless otherwise noted.
MAX
= 1.6 mA
OUT
= −1 mA
OUT
= low, V
SD
= 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
= 3 kΩ, CL = 1000 pF, TA = 25°C
R
L
= ±2 V
OUT
= 12 V
OUT
1
CC
= +3.3 V;
CC
Rev. E | Page 3 of 16
ADM3202/ADM3222/ADM1385
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
TIN −0.3 V to (V+, +0.3 V)
RIN ±30 V
Output Voltages
T
±15 V
OUT
R
−0.3 V to (VCC + 0.3 V)
OUT
Short-Circuit Duration
T
Continuous
OUT
Power Dissipation (Derates 6 mW/°C
above 50°C)
Thermal Impedance, θJA
N-16/N-18 (2-Layer Test Board) 117°C/W
RW-16/RW-18 (4-Layer Test Board) 56°C/W
R-16 (4-Layer Test Board) 81°C/W
RU-16 (4-Layer Test Board) 113°C/W
RU-20 (4-Layer Test Board) 110°C/W
RS-20 (4-Layer Test Board) 83°C/W
Operating Temperature Range
Industrial (A Version) −40°C to +85°C
Storage Temperature Range −65°C to +150°C
Lead Temperature
(Soldering, 10 sec)
450 mW
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. E | Page 4 of 16
ADM3202/ADM3222/ADM1385
T
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
PIN CONFIGURATIONS (N, R, RU, AND RW PACKAGES)
1
C1+
2
V+
ADM3202
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
00071-004
Figure 4. N, R, RU, and RW Packages Pin Configuration
PIN CONFIGURATIONS (RS AND RU PACKAGES)
1
EN
2
C1+
3
V+
ADM3222
4
C1–
(SSOP/TSSOP)
TOP VIEW
5
C2+
(Not to Scale)
6
C2–
7
V–
8
T2
OUT
9
R2
IN
10
R2
OUT
NC = NO CONNECT
Figure 6. RS and RU Packages Pin Configuration
20
SD
19
V
CC
18
GND
17
T1
OUT
16
R1
IN
15
R1
OUT
14
NC
13
T1
IN
12
T2
IN
11
NC
00071-006
1
EN
2
C1+
3
V+
ADM3222
4
C1–
C2+
C2–
V–
T2
OUT
R2
IN
TOP VIEW
(Not to Scale)
5
6
7
8
9
Figure 5. N and RW Packages Pin Configuration
1
DD
2
C1+
3
V+
4
5
6
V–
7
8
9
IN
10
NC = NO CONNECT
ADM1385
(SSOP)
TOP VIEW
(Not to Scale)
C1–
C2+
C2–
2
OUT
R2
NC
Figure 7. RS Package Pin Configuration
18
SD
17
V
CC
16
GND
15
T1
OUT
14
R1
IN
13
R1
OUT
12
T1
IN
11
T2
IN
10
R2
OUT
00071-005
SD
20
V
19
CC
GND
18
T1
17
OUT
R1
16
IN
R1
15
OUT
T1
14
IN
13
T2
IN
R2
12
OUT
NC
11
00071-007
Table 3. Pin Function Descriptions
Mnemonic Description
VCC Power Supply Input (3.3 V ± 0.3 V).
V+ Internally Generated Positive Supply (+6 V nominal).
V– Internally Generated Negative Supply (−6 V nominal).
GND Ground Pin. Must be connected to 0 V.
C1+, C1–
External Capacitor 1 is connected between these pins. A 0.1 μF capacitor is recommended but larger capacitors up to 47 μF
can be used.
C2+, C2–
External Capacitor 2 is connected between these pins. A 0.1 μF capacitor is recommended but larger capacitors up to 47 μF
can be used.
TxIN Transmitter (Driver) Inputs. These inputs accept TTL/CMOS levels.
Tx
Transmitter (Driver) Outputs. These are RS-232 signal levels (typically ±9 V).
OUT
RxIN Receiver Inputs. These inputs accept RS-232 signal levels. An internal 5 kΩ pull-down resistor to GND is connected on each input.
Rx
Receiver Outputs. These are CMOS output logic levels.
OUT
EN
(ADM3222 only) Shutdown Control. Active low. When low, the charge pump is shut down and the transmitter outputs
SD
(ADM3222 only) Receiver Enable. Active low. When low, the receiver outputs are enabled. When high, they are three-stated.
are disabled.
SD
DD
(ADM1385 only) Shutdown Control. When low, the charge pump is shut down and all transmitters and receivers are disabled.
(ADM1385 only) Driver Disable. When low, the charge pump is turned off and the transmitters are disabled. The receivers
remain active.
NC No Connect.
Rev. E | Page 5 of 16
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