Analog Devices ADM3311E Datasheet

a

15 kV ESD Protected, +2.7 V to +3.6 V

™

Serial Port Transceiver with Green Idle

ADM3311E*

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

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 tri­pler and voltage inverter, which internally generates positive and
negative supplies from the input +3 V power supply. The dc­to-dc converter operates in Green Idle Mode, whereby the
charge pump oscillator is gated on and off to maintain the out­put 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.

FUNCTIONAL BLOCK DIAGRAM

C1

0.1␮F

C4

V

CC

ENABLE

INPUT

0.1␮F

1

V+

0.1␮F

CERAMIC

1␮F

CMOS

INPUTS*

R1

R2

CMOS

OUTPUTS

R3

R4

R5

NOTES:

* INTERNAL 400k⍀ PULL-UP RESISTOR ON EACH CMOS INPUT
** INTERNAL 5k⍀ PULL-DOWN RESISTOR ON EACH RS-232 INPUT

0.1␮F

T1

T2

T3

OUT

OUT

OUT

OUT

OUT

2

C2+

VOLTAGE

TRIPLER/

3

V

CC

INVERTER

4

C2–

5

EN

6

C1+

7

8

9

10

11

12

13

14

+3V TO ⴞ9V

T1

R1

R2

ADM3311E

C2

IN

IN

IN

C3+

GND

C3–

C1–

SD

T2

T3

R3

R4

R5

C3

28

0.1␮F

27

26

C5

25

V–

24

23

22

21

20

19

18

17

16

15

0.1␮F

SHUTDOWN
INPUT

T1

OUT

T2

OUT

T3

OUT

R1

IN

R2

IN

EIA/TIA-232

R3

IN

INPUTS

R4

IN

R5

IN

EIA/TIA-232
OUTPUTS

**

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 over­voltage 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: [phone] World Wide Web Site: http://www.analog.com
Fax: [phone] © Analog Devices, Inc., 2000

ADM3311E–SPECIFICATIONS

(VCC = +2.7 V to +3.6 V, C1–C5 = 0.1 ␮F. All specifications T
otherwise noted.)

MIN

to T

MAX

unless

Parameter Min Typ Max Units Test Conditions/Comments

Operating Voltage Range +2.7 +3.3 +3.6 V
V

Power Supply Current 0.45 1 mA VCC = 3.0 V to 3.6 V, TA = 0°C to +85°C,

CC

No Load

0.45 4.5 mA VCC = 2.7 V to 3.6 V, TA = –40°C to +85°C,
No Load

35 mA RL = 3 kΩ to GND on all T

OUTS

Shutdown Supply Current 0.02 1 µA
Input Pull-Up Current 10 25 µAT

= GND

IN

Input Leakage Current, SD, EN ± 1 µA
Input Logic Threshold Low, V

Input Logic Threshold High, V
CMOS Output Voltage Low, V
CMOS Output Voltage High, V

INL

INH

OL

OH

2.0 V TIN, EN, SD

VCC – 0.6 V I

CMOS Output Leakage Current 0.05 ± 5 µA EN = V

0.8 V TIN, EN, SD

0.4 V T

0.4 V I

EN, SD, VCC = 2.7 V

IN,

= 1.6 mA

OUT

= –200 µA

OUT

, 0 V < R

CC

OUT

< V

CC

Charge Pump Output Voltage, V+ 7.25 V No Load
Charge Pump Output Voltage, V– –7.25 V No Load
EIA-232 Input Voltage Range –25 +25 V
EIA-232 Input Threshold Low 0.4 1.3 V
EIA-232 Input Threshold High 2.0 2.4 V
EIA-232 Input Hysteresis 0.14 V
EIA-232 Input Resistance 357kΩ
Output Voltage Swing (V
Output Voltage Swing (V
Transmitter Output Resistance 300 Ω V

= 3.0 V) ± 5.0 ± 6.4 V All Transmitter Outputs

CC

= 2.7 V) ± 5.5 V Loaded with 3 kΩ to Ground

CC

= 0 V, V

CC

OUT

= ± 2 V
RS-232 Output Short Circuit Current ± 15 ± 60 mA
Maximum Data Rate 460 kbps RL = 3 kΩ to 7 kΩ, CL = 50 pF to 1000 pF
Receiver Propagation Delay, T
Receiver Output Enable Time, t
Receiver Output Disable Time, t
Transmitter Propagation Delay, T

PHL

ER

DR

, T

PHL

PLH

, T

PLH

Transition Region Slew Rate 6 18 V/µsR

0.3 µsC

= 150 pF

L

100 ns
300 ns
500 ns RL = 3 kΩ, CL = 1000 pF

= 3 kΩ, CL = 50 pF to 1000 pF,

L

Measured from +3 V to –3 V or –3 V to +3 V

ESD Protection (I-O Pins) ± 8 kV IEC1000-4-2 Contact Discharge

± 15 kV IEC1000-4-2 Air Discharge
ESD Protection (All Other Pins) ± 3.0 kV Human Body Model, MIL-STD-883B
EFT Protection (I-O Pins) ± 4 kV IEC1000-4-4
EMI Immunity 10 V/m IEC1000-4-3

Specifications subject to change without notice.

ABSOLUTE MAXIMUM RATINGS*

(TA = +25°C unless otherwise noted)

VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +4 V

V+ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (V

–0.3 V) to +8 V

CC

V– . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +0.3 V to –8 V

Input Voltages

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +6 V

T

IN

R

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 30 V

IN

Output Voltages

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±15 V

T

OUT

R

. . . . . . . . . . . . . . . . . . . . . . . –0.3 V to (VCC +0.3 V)

OUT

Short Circuit Duration

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Continuous

T

OUT

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 specifica­tion 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 Function

V

CC

V+ Internally generated positive supply (+7.25 V nominal) Capacitor C4 is connected between VCC and V+.
V– Internally generated negative supply (–7.25 V nominal) Capacitor C5 is connected between V– and GND.
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

C2+, C2– External capacitor 2 is connected between these pins. A 0.1 µF capacitor is recommended, but larger capacitors

C3+, C3– External capacitor 3 is connected between these pins. A 0.1 µF capacitor is recommended, but larger capacitors

T

IN

T

OUT

R

IN

R

OUT

EN Receiver Enable. A high level three-states all the receiver outputs.
SD Shutdown Control. A high level will disable the charge pump and reduce the quiescent current to 20 nA.

Power Supply Input +2.7 V to +3.6 V. Requires capacitor of 1 µF or greater to GND.

up to 1 µF may be used.

up to 1 µF may be used.

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

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.

All transmitters and receivers R1–R4 are disabled. Receiver R5 remains active in shutdown.

CC

Table I. Truth Table

SD EN Status T

OUT

1–3 R

OUT

1–4 R

OUT

5

0 0 Normal Enabled Enabled Enabled

Operation

0 1 Receivers Enabled Disabled Disabled

Disabled
1 0 Shutdown Disabled Disabled Enabled
1 1 Shutdown Disabled Disabled Disabled

PIN CONFIGURATION

1

V+

2

C2+

3

V

CC

4

C2–

5

EN

6

C1+

ADM3311E

7

T1

T2

T3

R1

OUT

R2

OUT

R3

OUT

R4

OUT

R5

OUT

IN

8

IN

9

IN

10

11

12

13

14

TOP VIEW

(Not to Scale)

28

C3+

27

GND

26

C3–

25

V–

24

C1–

23

SD

22

T1

21

T2

T3

20

19

R1

18

R2

17

R3

16

R4

15

R5

OUT

OUT

OUT

IN

IN

IN

IN

IN

ORDERING GUIDE

Temperature Package Package

Model Range Descriptions Option

ADM3311EARS-Reel 2.5 –40°C to +85°C 28-Lead Shrink Small Outline (SSOP) RS-28
ADM3311EARU-Reel 2.5 –40°C to +85°C 28-Lead Thin Shrink Small Outline (TSSOP) RU-28

–3–REV. A

ADM3311E

–Typical Performance Characteristics

90

80

EN 55022 CLASS B

CONDUCTED QUASI-PEAK dB␮V

70

60

50

40

LEVEL – dB␮V

30

20

10

100k 10M

1M

FREQUENCY – Hz

Figure 1. EMC Conducted Emissions

70

60

50

RADIATED EMISSIONS dB␮V/m (EUT at 3m)

40

30

LEVEL – dB␮V/m

20

EN 55022 CLASS B

10

8

T

HIGH

6

4

2

0

Tx O/P – Volts

–2

–4

–6

–8

OUT

T

OUT

0 2500500

LOW

1000

LOAD CAPACITANCE – pF

1500 2000

Figure 4. Transmitter Output High/Low vs. Load
Capacitance

0.57

0.56

0.55

0.54

– mA

CC

0.53

I

0.52

10

0

20 200

FREQUENCY – MHz

180160140120100806040

Figure 2. EMC Radiated Emissions

8
7

6

5
4
3
2

1
0

–1

VOLTAGE – V

–2

–3

–4

–5

–6

–7

–8

V–

V+

I

LOAD

– mA

12108642

14

16 18 200

Figure 3. Charge Pump V+, V– vs. Load Current

0.51

0.50

2.7

2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6
VCC – Volts

Figure 5. Power Supply Current vs. Power Supply Voltage
(Unloaded)

25

20

15

– mA

CC

I

10

5

0

2.7

2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6
VCC – Volts

Figure 6. Power Supply Current vs. Power Supply Voltage

= 3 kΩ)

(R

L

–4–

REV. A