a
FEATURES
Green Idle Power Saving Mode
Full RS-232 Compliance
Operates with 3 V Logic
Low EMI
Ultralow Power CMOS: 450 A Operation
Low Power Shutdown: 20 nA
460 kbits/s Data Rate
0.1 F to 1 F Charge Pump Capacitors
Single +2.7 V to +3.6 V Power Supply
One Receiver Active in Shutdown
ESD >15 kV
Pin Compatible with DS14C335
APPLICATIONS
Laptop Computers
Notebook Computers
Printers
Peripherals
Modems
15 kV ESD Protected, +2.7 V to +3.6 V
Serial Port Transceiver with Green Idle
™
ADM3311E*
FUNCTIONAL BLOCK DIAGRAM
C1
0.1 F
C4
0.1 F
1
V+
C2+
C3+
28
C3
0.1 F
0.1 F
CERAMIC
V
CC
1 F
ENABLE
INPUT
C2
0.1 F
GND
27
VOLTAGE
TRIPLER/
C3–
26
3
V
CC
INVERTER
+3V TO 9V
4
C2–
V–
25
2
5
6
C5
0.1 F
EN
C1+
T1
T2
T3
R1
R2
R3
R4
C1–
24
SD
23
22
21
20
19
18
SHUTDOWN
INPUT
T1
OUT
T2
OUT
T3
OUT
R1
IN
R2
IN
R3
IN
R4
IN
R5
IN
EIA/TIA-232
INPUTS
**
EIA/TIA-232
OUTPUTS
T1
IN
CMOS
INPUTS*
T2
IN
T3
IN
R1
OUT
R2
OUT
CMOS
OUTPUTS
R3
OUT
R4
OUT
R5
OUT
7
8
9
10
11
12
13
14
17
16
GENERAL DESCRIPTION
The ADM3311E is a three driver/five receiver product designed
to fully meet the EIA-232 standard while operating with a single
+2.7 V to +3.6 V power supply. The device features an on-board,
charge pump, dc-to-dc converter, eliminating the need for dual
power supplies. This dc-to-dc converter contains a voltage tri-
pler and voltage inverter, which internally generates positive and
negative supplies from the input +3 V power supply. The dc-
to-dc converter operates in Green Idle Mode, whereby the
charge pump oscillator is gated on and off to maintain the out-
put voltage at
±
7.25 V under varying load conditions. This
minimizes the power consumption and makes these products
ideal for battery powered portable devices.
The ADM3311E is suitable for operation in harsh electrical
environments and contains ESD protection up to
±
15 kV on all
I-O lines.
The ADM3311E contains three drivers and five receivers and
is intended for serial port applications on notebook/laptop
computers.
R5
15
ADM3311E
NOTES:
*
INTERNAL 400k PULL-UP RESISTOR ON EACH CMOS INPUT
**
INTERNAL 5k PULL-DOWN RESISTOR ON EACH RS-232 INPUT
A shutdown facility is also provided that reduces the power
consumption to 3
µW.
While in shutdown, one receiver remains
active, thereby allowing monitoring of peripheral devices. This
feature allows the device to be shut down until a peripheral device
begins communication. The active receiver can alert the processor,
which can then take the ADM3311E out of the shutdown
mode.
The ADM3311E is fabricated using CMOS technology for
minimal power consumption. It features a high level of over-
voltage protection and latch-up immunity.
The ADM3311E is packaged in a 28-lead SSOP/TSSOP
package.
*Protected by Patent No. 5,606,491.
Green Idle is a trademark of Analog Devices, Inc.
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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 2000
ADM3311E–SPECIFICATIONS
Parameter
Operating Voltage Range
V
CC
Power Supply Current
Min
+2.7
(V
CC
= +2.7 V to +3.6 V, C1–C5 = 0.1 F. All specifications T
MIN
to T
MAX
unless
otherwise noted.)
Max
+3.6
1
4.5
35
1
25
±
1
0.8
0.4
0.4
Units
V
mA
mA
mA
µA
µA
µA
V
V
V
V
V
µA
V
V
V
V
V
V
kΩ
V
V
Ω
mA
kbps
µs
ns
ns
ns
V/µs
kV
kV
kV
kV
V/m
Test Conditions/Comments
V
CC
= 3.0 V to 3.6 V, T
A
= 0°C to +85°C,
No Load
V
CC
= 2.7 V to 3.6 V, T
A
= –40°C to +85°C,
No Load
R
L
= 3 kΩ to GND on all T
OUTS
T
IN
= GND
T
IN
,
EN,
SD
T
IN
,
EN,
SD, V
CC
= 2.7 V
T
IN
,
EN,
SD
I
OUT
= 1.6 mA
I
OUT
= –200
µA
EN
= V
CC
, 0 V < R
OUT
< V
CC
No Load
No Load
Typ
+3.3
0.45
0.45
Shutdown Supply Current
Input Pull-Up Current
Input Leakage Current, SD,
EN
Input Logic Threshold Low, V
INL
Input Logic Threshold High, V
INH
CMOS Output Voltage Low, V
OL
CMOS Output Voltage High, V
OH
CMOS Output Leakage Current
Charge Pump Output Voltage, V+
Charge Pump Output Voltage, V–
EIA-232 Input Voltage Range
EIA-232 Input Threshold Low
EIA-232 Input Threshold High
EIA-232 Input Hysteresis
EIA-232 Input Resistance
Output Voltage Swing (V
CC
= 3.0 V)
Output Voltage Swing (V
CC
= 2.7 V)
Transmitter Output Resistance
RS-232 Output Short Circuit Current
Maximum Data Rate
Receiver Propagation Delay, T
PHL
, T
PLH
Receiver Output Enable Time, t
ER
Receiver Output Disable Time, t
DR
Transmitter Propagation Delay, T
PHL
, T
PLH
Transition Region Slew Rate
ESD Protection (I-O Pins)
ESD Protection (All Other Pins)
EFT Protection (I-O Pins)
EMI Immunity
Specifications subject to change without notice.
0.02
10
2.0
V
CC
– 0.6
0.05
7.25
–7.25
–25
0.4
1.3
2.0
0.14
5
±
6.4
±
5.5
±
15
460
0.3
100
300
500
18
±
8
±
15
±
3.0
±
4
10
±
5
+25
2.4
7
3
±
5.0
300
±
60
All Transmitter Outputs
Loaded with 3 kΩ to Ground
V
CC
= 0 V, V
OUT
=
±
2 V
R
L
= 3 kΩ to 7 kΩ, C
L
= 50 pF to 1000 pF
C
L
= 150 pF
6
R
L
= 3 kΩ, C
L
= 1000 pF
R
L
= 3 kΩ, C
L
= 50 pF to 1000 pF,
Measured from +3 V to –3 V or –3 V to +3 V
IEC1000-4-2 Contact Discharge
IEC1000-4-2 Air Discharge
Human Body Model, MIL-STD-883B
IEC1000-4-4
IEC1000-4-3
ABSOLUTE MAXIMUM RATINGS*
(T
A
= +25°C unless otherwise noted)
V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +4 V
V+ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (V
CC
–0.3 V) to +8 V
V– . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +0.3 V to –8 V
Input Voltages
T
IN
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +6 V
R
IN
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
±
30 V
Output Voltages
T
OUT
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
±
15 V
R
OUT
. . . . . . . . . . . . . . . . . . . . . . . –0.3 V to (V
CC
+0.3 V)
Short Circuit Duration
T
OUT
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Continuous
Power Dissipation
RU-28 TSSOP (Derate 12 mW/°C Above +70°C) . . 900 mW
RS-28 SSOP (Derate 10 mW/°C Above +70°C) . . . . 900 mW
Operating Temperature Range
Industrial (A Version) . . . . . . . . . . . . . . . . –40°C to +85°C
Storage Temperature Range . . . . . . . . . . . . –65°C to +150°C
Lead Temperature (Soldering, 10 sec) . . . . . . . . . . . . +300°C
ESD Rating (MIL-STD-883B) (I-O Pins) . . . . . . . . . .
±
15 kV
ESD Rating (MIL-STD-883B) (Except I-O) . . . . . . .
±
3.0 kV
ESD Rating (IEC1000-4-2 Contact) (I-O Pins) . . . . . .
±
8 kV
ESD Rating (IEC1000-4-2 Air) (I-O Pins) . . . . . . . . .
±
15 kV
EFT Rating (IEC1000-4-4) (I-O Pins) . . . . . . . . . . . . .
±
4 kV
*This is a stress rating only and functional operation of the device at these or any
other conditions above those indicated in the operation sections of this specifica-
tion is not implied. Exposure to absolute maximum rating conditions for extended
periods of time may affect reliability.
–2–
REV. A
ADM3311E
PIN FUNCTION DESCRIPTIONS
Mnemonic
V
CC
V+
V–
GND
C1+, C1–
C2+, C2–
C3+, C3–
T
IN
T
OUT
R
IN
R
OUT
EN
SD
Function
Power Supply Input +2.7 V to +3.6 V. Requires capacitor of 1
µF
or greater to GND.
Internally generated positive supply (+7.25 V nominal) Capacitor C4 is connected between V
CC
and V+.
Internally generated negative supply (–7.25 V nominal) Capacitor C5 is connected between V– and GND.
Ground Pin. Must be connected to 0 V.
External capacitor 1 is connected between these pins. A 0.1
µF
capacitor is recommended, but larger capacitors
up to 1
µF
may be used.
External capacitor 2 is connected between these pins. A 0.1
µF
capacitor is recommended, but larger capacitors
up to 1
µF
may be used.
External capacitor 3 is connected between these pins. A 0.1
µF
capacitor is recommended, but larger capacitors
up to 1
µF
may be used.
Transmitter (Driver) Inputs. These inputs accept TTL/CMOS levels. An internal 400 kΩ pull-up resistor to V
CC
is connected on each input.
Transmitter (Driver) Outputs, (typically
±
6.4 V).
Receiver Inputs. These inputs accept RS-232 signal levels. An internal 5 kΩ pull-down resistor to GND is
connected on each of these inputs.
Receiver Outputs. These are TTL/CMOS levels.
Receiver Enable. A high level three-states all the receiver outputs.
Shutdown Control. A high level will disable the charge pump and reduce the quiescent current to 20 nA.
All transmitters and receivers R1–R4 are disabled. Receiver R5 remains active in shutdown.
Table I. Truth Table
PIN CONFIGURATION
SD
0
0
1
1
EN
0
1
0
1
Status
Normal
Operation
Receivers
Disabled
Shutdown
Shutdown
T
OUT
1–3
Enabled
Enabled
Disabled
Disabled
R
OUT
1–4
Enabled
Disabled
Disabled
Disabled
R
OUT
5
Enabled
Disabled
Enabled
Disabled
V+
1
C2+
2
V
CC 3
C2–
4
EN
5
28
27
26
25
24
C3+
GND
C3–
V–
C1–
SD
T1
OUT
T2
OUT
T3
OUT
R1
IN
R2
IN
R3
IN
R4
IN
C1+
6
T1
IN 7
T2
IN 8
T3
IN 9
R1
OUT 10
R2
OUT 11
R3
OUT 12
R4
OUT 13
R5
OUT 14
ADM3311E
TOP VIEW
(Not to Scale)
23
22
21
20
19
18
17
16
15
R5
IN
ORDERING GUIDE
Model
ADM3311EARS-Reel 2.5
ADM3311EARU-Reel 2.5
Temperature
Range
–40°C to +85°C
–40°C to +85°C
Package
Descriptions
28-Lead Shrink Small Outline (SSOP)
28-Lead Thin Shrink Small Outline (TSSOP)
Package
Option
RS-28
RU-28
REV. A
–3–
ADM3311E –Typical Performance Characteristics
90
80
70
EN 55022 CLASS B
CONDUCTED QUASI-PEAK dB V
Tx O/P – Volts
10
8
6
4
2
0
–2
–4
T
OUT
LOW
–6
–8
1M
FREQUENCY – Hz
10M
T
OUT
HIGH
LEVEL – dB V
60
50
40
30
20
10
100k
0
500
1500
1000
LOAD CAPACITANCE – pF
2000
2500
Figure 1. EMC Conducted Emissions
Figure 4. Transmitter Output High/Low vs. Load
Capacitance
70
0.57
0.56
0.55
EN 55022 CLASS B
RADIATED EMISSIONS dB V/m (EUT at 3m)
I
CC
– mA
60
50
LEVEL – dB V/m
40
0.54
0.53
0.52
0.51
0.50
2.7
30
20
10
0
20
40
60
80
100
120
140
FREQUENCY – MHz
160
180
200
2.8
2.9
3.0
3.1
3.2
V
CC
– Volts
3.3
3.4
3.5
3.6
Figure 2. EMC Radiated Emissions
Figure 5. Power Supply Current vs. Power Supply Voltage
(Unloaded)
8
7
6
5
4
3
2
1
0
–1
–2
–3
–4
–5
–6
–7
–8
0
2
4
6
8
10
12
I
LOAD
– mA
14
16
18
20
V+
25
20
VOLTAGE – V
I
CC
– mA
15
10
5
V–
0
2.7
2.8
2.9
3.0
3.1
3.2
V
CC
– Volts
3.3
3.4
3.5
3.6
Figure 3. Charge Pump V+, V– vs. Load Current
Figure 6. Power Supply Current vs. Power Supply Voltage
(R
L
= 3 k
Ω
)
–4–
REV. A
ADM3311E
40
35
12
10
LOAD CURRENT – mA
30
SLEW RATE – V/ s
8
25
20
15
10
6
4
2
5
0
0
150
470
1000
1500
LOAD CAPACITANCE – pF
2000
2500
0
0
50
100
150
200
OSCILLATOR FREQUENCY – kHz
250
300
Figure 7. Slew Rate vs. Load Capacitance
Figure 10. Load Current vs. Oscillator Frequency
40
35
30
Tek Stop 500kS/s
[
429 Acqs
T
]
T
25
1
SD
I
CC
– mA
20
15
10
5
Tx O/P HIGH
2
T
Ch1 5.00V
0
0
500
1000
1500
LOAD CAPACITANCE – pF
2000
2500
Ch2
5.00V
M 100 s
Ch1
0V
Figure 8. Supply Current vs. Load Capacitance (R
L
= 3 k
Ω
)
Figure 11. Transmitter Output (High) Exiting Shutdown
30
Tek Stop 500kS/s
[
247 Acqs
T
]
25
T
SD
20
I
CC
– mA
1
15
2
T
Tx O/P LOW
10
5
Ch1 5.00V
Ch2
5.00V
M 100 s
Ch1
0V
0
0
500
1000
1500
LOAD CAPACITANCE – pF
2000
2500
Figure 9. Supply Current vs. Load Capacitance (R
L
=
∞
)
Figure 12. Transmitter Output (Low) Exiting Shutdown
REV. A
–5–
Talking
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