MAXIM MAX3224E, MAX3227E, MAX3244E, MAX3245E User Manual

________________General Description

The MAX3224E/MAX3225E/MAX3226E/MAX3227E/
MAX3244E/MAX3245E are 3V-powered EIA/TIA-232
and V.28/V.24 communications interfaces with automat­ic shutdown/wakeup features, high data-rate capabili­ties, and enhanced electrostatic discharge (ESD)
protection. All transmitter outputs and receiver inputs
are protected to ±15kV using IEC 1000-4-2 Air-Gap
Discharge, ±8kV using IEC 1000-4-2 Contact Discharge,
and ±15kV using the Human Body Model.

All devices achieve a 1µA supply current using Maxim’s
revolutionary AutoShutdown Plus™ feature. These
devices automatically enter a low-power shutdown
mode when the RS-232 cable is disconnected or the
transmitters of the connected peripherals are inactive,
and the UART driving the transmitter inputs is inactive
for more than 30 seconds. They turn on again when
they sense a valid transition at any transmitter or receiv­er input. AutoShutdown Plus saves power without
changes to the existing BIOS or operating system.

The MAX3225E/MAX3227E/MAX3245E also feature
MegaBaud™ operation, guaranteeing 1Mbps for high­speed applications such as communicating with ISDN
modems. The MAX3224E/MAX3226E/MAX3244E guar­antee 250kbps operation. The transceivers have a pro­prietary low-dropout transmitter output stage enabling
true RS-232 performance from a +3.0V to +5.5V supply
with a dual charge pump. The charge pump requires
only four small 0.1µF capacitors for operation from a

3.3V supply. The MAX3224E–MAX3227E feature a logic­level output (READY) that asserts when the charge
pump is regulating and the device is ready to begin
transmitting.

All devices are available in a space-saving TQFN,
SSOP, and TSSOP (MAX3224E/MAX3225E/MAX3244E/
MAX3245E) packages.

________________________Applications

Notebook, Subnotebook, and Palmtop Computers

Cellular Phones

Battery-Powered Equipment

Hand-Held Equipment

Peripherals

Printers

__Next Generation Device Features

♦ For Space-Constrained Applications:

MAX3228E/MAX3229E: ±15kV ESD-Protected,
+2.5V to +5.5V, RS-232 Transceivers in UCSP

MAX3222E/MAX3232E/MAX3241E

†

/MAX3246E:
±15kV ESD-Protected, Down to 10nA, +3.0V to
+5.5V, Up to 1Mbps, True RS-232 Transceivers
(MAX3246E Available in UCSP™)

♦ For Low-Voltage or Data Cable Applications:

MAX3380E/MAX3381E: +2.35V to +5.5V, 1µA,
2Tx/2Rx RS-232 Transceivers with ±15kV
ESD-Protected I/O and Logic Pins

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,

RS-232 Transceivers with AutoShutdown Plus

________________________________________________________________ Maxim Integrated Products 1

19-1339; Rev 9; 2/07

PART

MAX3224E

MAX3225E

MAX3226E

1/1

2/2

2/2

NO. OF

DRIVERS/

RECEIVERS

READY

OUTPUT

✔

✔

✔

Auto-

Shutdown

Plus

✔

✔

✔

250k

1M

250k

GUARANTEED

DATA RATE

(bps)

MAX3227E

MAX3244E

MAX3245E

3/5

3/5

1/1

✔

—

—

✔

✔

✔

1M

250k

1M

Ordering Information continued at end of data sheet.

*EP = Exposed paddle.

†

Covered by U.S. Patent numbers 4,636,930; 4,679,134; 4,777,577;
4,797,899; 4,809,152; 4,897,774; 4,999,761; 5,649,210; and other
patents pending.

AutoShutdown Plus, MegaBaud, and UCSP are trademarks of
Maxim Integrated Products, Inc.

_____________________ Selector Guide

Ordering Information

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

PART

MAX3224ECTP

MAX3224ECUP

MAX3224ECAP

MAX3224ECPP

MAX3224EETP

MAX3224EEUP

MAX3224EEAP

MAX3224EEPP

MAX3224EAAP

TEMP

RANGE

0°C to +70°C

0°C to +70°C
0°C to +70°C

0°C to +70°C

-40°C to +85°C

-40°C to +85°C

-40°C to +85°C

-40°C to +85°C

-40°C to +125°C

PIN

PKG

20 TQFN-

EP*

20 TSSOP —

20 SSOP —

20 Plastic

DIP

20 TQFN-

EP*

20 TSSOP —

20 SSOP —

20 Plastic

DIP

20 SSOP —

PKG
CODE

T2055-5

—

T2055-5

—

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC= +3V to +5.5V, C1–C4 = 0.1µF, tested at 3.3V ±10%; C1= 0.047µF, C2–C4 = 0.33µF, tested at 5.0V ±10%; TA= T

MIN

to T

MAX

,

unless otherwise noted. Typical values are at T

A

= +25°C.)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

VCCto GND..............................................................-0.3V to +6V

V+ to GND (Note 1) ..................................................-0.3V to +7V

V- to GND (Note 1) ...................................................+0.3V to -7V

V+ +⏐V-⏐(Note 1) ................................................................+13V

Input Voltages

T_IN, FORCEON, FORCEOFF to GND ................ -0.3V to +6V

R_IN to GND ....................................................................±25V

Output Voltages

T_OUT to GND.............................................................±13.2V

R_OUT, INVALID, READY to GND .........-0.3V to (V

CC

+ 0.3V)

Short-Circuit Duration

T_OUT to GND .......................................................Continuous

Continuous Power Dissipation (T

A

= +70°C)

16-Pin SSOP (derate 7.14mW/°C above +70°C) .........571mW

16-Pin TSSOP (derate 9.4mW/°C above +70°C) ......754.7mW

16-Pin TQFN (derate 20.8mW/°C above +70°C) ....1666.7mW

20-Pin TQFN (derate 21.3mW/°C above +70°C) ....1702.1mW

20-Pin Plastic DIP (derate 11.11mW/°C above +70°C) ...889mW

20-Pin SSOP (derate 8.00mW/°C above +70°C) .........640mW

20-Pin TSSOP (derate 10.9mW/°C above +70°C) .......879mW

28-Pin Wide SO (derate 12.5mW/°C above +70°C)............1W

28-Pin SSOP (derate 9.52mW/°C above +70°C) .........762mW

28-Pin TSSOP (derate 12.8mW/°C above +70°C) .......1026mW

36-Pin TQFN (derate 26.3mW/°C above +70°C)...........2105mW

Operating Temperature Ranges

MAX32_ _EC_ _ .................................................0°C to +70°C

MAX32_ _EE_ _................................................-40°C to +85°C

MAX32_ _EAA_..............................................-40°C to +125°C

Storage Temperature Range .............................-65°C to +160°C

Lead Temperature (soldering, 10s) .................................+300°C

Note 1: V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V.

VCC= 5.0V

FORCEON = GND, FORCEOFF = VCC,
all R_IN idle, all T_IN idle

TA= +25°C

VCC= 3.3V

T_IN, FORCEON,

FORCEOFF

CONDITIONS

kΩ357Input Resistance

V0.5Input Hysteresis

1.8 2.4

V

1.5 2.4

Input Threshold High

0.8 1.5

V

0.6 1.2

Input Threshold Low

V-25 +25Input Voltage Range

V

VCC- 0.6 VCC- 0.1

Output Voltage High

V0.4Output Voltage Low

µA110Supply Current, Shutdown

µA110

Supply Current,
AutoShutDown Plus

µA±0.05 ±10Output Leakage Current

µA±0.01 ±1

Transmitter Input Hysteresis V0.5

V

2.4

Input Logic Threshold High

mA0.3 1

Supply Current,
AutoShutDown Plus Disabled

V0.8Input Logic Threshold Low

2

UNITSMIN TYP MAXSYMBOLPARAMETER

FORCEOFF = GND

TA= +25°C

VCC= 5.0V

VCC= 3.3V

TA= +25°C

R_OUT (MAX3244E/MAX3245E), receivers
disabled

T_IN, FORCEON, FORCEOFF

VCC= 5.0V

FORCEON = FORCEOFF = VCC, no load

T_IN, FORCEON, FORCEOFF

I

OUT

= -1.0mA

VCC= 3.3V

I

OUT

= 1.6mA

DC CHARACTERISTICS (VCC= 3.3V or 5.0V, TA= +25°C)

LOGIC INPUTS AND RECEIVER OUTPUTS

RECEIVER INPUTS

Input Leakage Current

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,

RS-232 Transceivers with AutoShutdown Plus

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VCC= +3V to +5.5V, C1–C4 = 0.1µF, tested at 3.3V ±10%; C1= 0.047µF, C2–C4 = 0.33µF, tested at 5.0V ±10%; TA= T

MIN

to T

MAX

,

unless otherwise noted. Typical values are at T

A

= +25°C.)

CONDITIONS

Ω300 10MOutput Resistance

V±5 ±5.4Output Voltage Swing

UNITSMIN TYP MAXSYMBOLPARAMETER

Figure 4a

T1IN = T2IN = GND, T3IN = VCC,
T3OUT loaded with 3kΩ to GND,
T1OUT and T2OUT loaded with

2.5mA each

s15 30 60t

AUTOSHDN

Receiver or Transmitter Edge to
Transmitters Shutdown

µs100t

WU

Receiver or Transmitter Edge to
Transmitters Enabled

µs30t

INVL

Receiver Positive or Negative
Threshold to INVALID Low

µs1t

INVH

Receiver Positive or Negative
Threshold to INVALID High

V

V

CC

- 0.6

INVALID, READY
Output Voltage High
(MAX3224E–MAX3227E)

V0.4

INVALID, READY
Output Voltage Low
(MAX3224E–MAX3227E)

V-0.3 +0.3

Receiver Input Threshold to
INVALID Output Low

-2.7

V

2.7

Receiver Input Threshold to
INVALID Output High

±15

±8R_IN, T_OUT kV

±15

V±5Transmitter Output Voltage

µA±25Output Leakage Current

±60 mAOutput Short-Circuit Current

VCC= V+ = V- = 0, transmitter outputs = ±2V

All transmitter outputs loaded with 3kΩ to
ground

VCC= 5V, Figure 5b (Note 2)

VCC= 5V, Figure 5b (Note 2)

VCC= 5V, Figure 4b

VCC= 5V, Figure 4b

I

OUT

= -1.0mA

I

OUT

= -1.6mA

Figure 4a

Negative threshold

Positive threshold

Human Body Model

VCC= 0 or 3V to 5.5V, V

OUT

= ±12V,

Transmitters disabled

IEC1000-4-2 Contact Discharge

IEC1000-4-2 Air Discharge

TRANSMITTER OUTPUTS

MOUSE DRIVEABILITY (MAX3244E/MAX3245E)

ESD PROTECTION

AutoShutdown Plus (FORCEON = GND, FORCEOFF = VCC)

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus

4 _______________________________________________________________________________________

TIMING CHARACTERISTICS—MAX3224E/MAX3226E/MAX3244E

(VCC= +3V to +5.5V, C1–C4 = 0.1µF, tested at 3.3V ±10%; C1= 0.047µF, C2–C4 = 0.33µF, tested at 5.0V ±10%; TA= T

MIN

to T

MAX

,

unless otherwise noted. Typical values are at T

A

= +25°C.)

TIMING CHARACTERISTICS—MAX3225E/MAX3227E/MAX3245E

(VCC= +3V to +5.5V, C1–C4 = 0.1µF, tested at 3.3V ±10%; C1= 0.047µF, C2–C4 = 0.33µF, tested at 5.0V ±10%; TA= T

MIN

to T

MAX

,

unless otherwise noted. Typical values are at T

A

= +25°C.)

Note 2: A transmitter/receiver edge is defined as a transition through the transmitter/receiver input logic thresholds.
Note 3: Transmitter skew is measured at the transmitter zero cross points.

CL= 150pF
to 1000pF

R_IN to R_OUT, CL= 150pF

RL= 3kΩ, CL= 1000pF,
one transmitter switching

VCC= 3.3V, TA= +25°C,
RL= 3kΩ to 7kΩ,
measured from +3V to -3V
or -3V to +3V, one trans­mitter switching

Normal operation (MAX3244E only)

Normal operation (MAX3244E only)

(Note 3)

CONDITIONS

0.15t

PLH

µs

0.15t

PHL

kbps250Maximum Data Rate

Receiver Propagation Delay

V/µs630Transition-Region Slew Rate

ns200Receiver Output Enable Time

ns200Receiver Output Disable Time

ns100

⏐

t

PHL

- t

PLH

⏐

Transmitter Skew

ns50

⏐

t

PHL

- t

PLH ⏐

Receiver Skew

UNITSMIN TYP MAXSYMBOLPARAMETER

VCC= 4.5V to 5.5V, RL= 3kΩ,
C

L

= 1000pF, one transmitter switching

VCC= 3.0V to 4.5V, RL= 3kΩ,
CL= 250pF, one transmitter switching

RL= 3kΩ, CL= 1000pF,
one transmitter switching

VCC= 3.3V, TA= +25°C,
RL= 3kΩ to 7kΩ, CL= 150pF to 1000pF,
measured from +3V to -3V or -3V to +3V,
one transmitter switching

(Note 3)

R_IN to R_OUT, CL= 150pF

Normal operation (MAX3245E only)

Normal operation (MAX3245E only)

CONDITIONS

1000

1000

kbps

250

Maximum Data Rate

V/µs24 150Transition-Region Slew Rate

ns50

⏐

t

PHL

- t

PLH

⏐

Receiver Skew

ns25

⏐

t

PHL

- t

PLH

⏐

Transmitter Skew

µs

0.15t

PHL

Receiver Propagation Delay

0.15t

PLH

ns200Receiver Output Enable Time

ns200Receiver Output Disable Time

UNITSMIN TYP MAXSYMBOLPARAMETER

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,

RS-232 Transceivers with AutoShutdown Plus

_______________________________________________________________________________________ 5

__________________________________________Typical Operating Characteristics

(VCC= +3.3V, 250kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ and CL, TA= +25°C, unless otherwise noted.)

0

200

180

160

140

120

100

80

60

40

20

-40 0 20-20 406080100

MAX3224E–MAX3227E

READY TURN-OFF TIME

vs. TEMPERATURE

MAX3224-7/44/45E-09

TEMPERATURE (°C)

READY TURN-OFF TIME (ns)

MAX3224E/MAX3226E

TRANSMITTER OUTPUT VOLTAGE

6
5
4
3
2
1
0

-1

-2

-3

-4

TRANSMITTER OUTPUT VOLTAGE (V)

-5

-6

7.5

5.0

2.5

0

-2.5

-5.0

TRANSMITTER OUTPUT VOLTAGE (V)

-7.5

50

45

40

35

30

25

20

15

TRANSMITTER SKEW (ns)

10

5

0

vs. LOAD CAPACITANCE

T1 TRANSMITTING AT 250kbps
T2 (MAX3224E) TRANSMITTING AT 15.6kbps

0 10002000300040005000

LOAD CAPACITANCE (pF)

MAX3225E/MAX3227E

TRANSMITTER OUTPUT VOLTAGE

vs. LOAD CAPACITANCE

2Mbps

1 TRANSMITTER AT FULL DATA RATE
1 TRANSMITTER AT 1/16 DATA RATE

(MAX3225E)
LOAD = 3kΩ + C

01000500 1500 2000 2500

L

LOAD CAPACITANCE (pF)

MAX3225E/MAX3227E

TRANSMITTER SKEW

vs. LOAD CAPACITANCE

1 TRANSMITTER AT 512kbps
1 TRANSMITTER AT 30kbps

(MAX3225E)
LOAD = 3kΩ + C

0 1000500 1500 2000 2500 3000

L

AVERAGE: 10 PARTS

LOAD CAPACITANCE (pF)

2Mbps

V

V

1.5Mbps

1.5Mbps

OUT+

OUT-

1Mbps

1Mbps

16

14

12

MAX3224-7/44/45E-01

10

SLEW RATE (V/μs)

80

70

60

MAX3224-7/44/45E-04

50

40

30

SLEW RATE (V/μs)

20

10

MAX3224-7/44/45E-07

READY TURN-ON TIME (μs)

MAX3224E/MAX3226E

SLEW RATE vs. LOAD CAPACITANCE

-SLEW

8

6

4

2

0

0 1000 2000 3000 4000 5000

+SLEW

FOR DATA RATES UP TO 250kbps

LOAD CAPACITANCE (pF)

MAX3225E/MAX3227E

SLEW RATE vs. LOAD CAPACITANCE

-SLEW

+SLEW

1 TRANSMITTER AT 1Mbps
1 TRANSMITTER AT 62.5kbps (MAX3225E)

0

0 500 1000 1500 2000 2500

LOAD CAPACITANCE (pF)

MAX3224E–MAX3227E
READY TURN-ON TIME

vs. TEMPERATURE

38

36

34

32

30

28

26

24

22

20

-40 0 20-20 40 60 80 100
TEMPERATURE (°C)

45

40

35

MAX3224-7/44/45E-02

30

25

20

15

SUPPLY CURRENT (mA)

10

5

0

100

90

80

MAX3224-7/44/45E-05

70

60

50

40

30

SUPPLY CURRENT (mA)

20

10

0

MAX3224-7/44/45E-08

MAX3224E/MAX3226E

OPERATING SUPPLY CURRENT

vs. LOAD CAPACITANCE

250kbps

120kbps

20kbps

T1 TRANSMITTING AT 250kbps
T2 (MAX3224E) TRANSMITTING AT 15.6kbps

020001000 3000 4000 5000

LOAD CAPACITANCE (pF)

MAX3225E/MAX3227E

OPERATING SUPPLY CURRENT

vs. LOAD CAPACITANCE

1 TRANSMITTER AT FULL DATA RATE
1 TRANSMITTER AT 1/16 DATA RATE

(MAX3225E)
LOAD = 3kΩ + C

2Mbps

0 500 1000 1500 2000 2500

L

1.5Mbps

1Mbps

LOAD CAPACITANCE (pF)

MAX3224-7/44/45E-03

MAX3224-7/44/45E-06

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus

6 _______________________________________________________________________________________

_____________________________Typical Operating Characteristics (continued)

(V

CC

= +3.3V, 250kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩ and CL, TA= +25°C, unless otherwise noted.)

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

0 1000 2000 3000 4000 5000

MAX3244E

TRANSMITTER OUTPUT VOLTAGE

vs. LOAD CAPACITANCE

MAX3224-7/44/45E-10

LOAD CAPACITANCE (pF)

TRANSMITTER OUTPUT VOLTAGE (V)

1 TRANSMITTER AT 250kbps
2 TRANSMITTERS AT 15.6kbps

V

OUT+

V

OUT-

0

4

2

8

6

12

10

14

0 1000 2000 3000 4000 5000

MAX3244E

SLEW RATE vs. LOAD CAPACITANCE

MAX3224-7/44/45E-11

LOAD CAPACITANCE (pF)

SLEW RATE (V/

μ

s)

0

30

20

10

40

50

60

0 20001000 3000 4000 5000

MAX3244E

OPERATING SUPPLY CURRENT

vs. LOAD CAPACITANCE

MAX3224-7/44/45E-12

LOAD CAPACITANCE (pF)

SUPPLY CURRENT (mA)

250kbps

120kbps

20kbps

1 TRANSMITTER AT 250kbps
2 TRANSMITTERS AT 15.6kbps

-7.5

0

-2.5

-5.0

2.5

5.0

7.5

0 800400 1200 1600 2000

MAX3245E

TRANSMITTER OUTPUT VOLTAGE

vs. LOAD CAPACITANCE

MAX3224-7/44/45E-13

LOAD CAPACITANCE (pF)

TRANSMITTER OUTPUT VOLTAGE (V)

2Mbps

2Mbps

1.5Mbps

1.5Mbps

1Mbps

1Mbps

1 TRANSMITTER AT FULL DATA RATE
2 TRANSMITTERS AT 1/16 DATA RATE

0

20

10

40

30

60

50

70

90

80

100

0 400 800 1200 1600 2000

MAX3245E

OPERATING SUPPLY CURRENT

vs. LOAD CAPACITANCE

MAX3224-7/44/45E-15

LOAD CAPACITANCE (pF)

SUPPLY CURRENT (mA)

2Mbps

1.5Mbps

1Mbps

1 TRANSMITTER AT FULL DATA RATE
2 TRANSMITTERS AT 1/16 DATA RATE

0

20

10

40

30

60

50

70

0 400 800 1200 1600 2000

MAX3245E

SLEW RATE vs. LOAD CAPACITANCE

MAX3224-7/44/45E-14

LOAD CAPACITANCE (pF)

SLEW RATE (V/

μ

s)

1 TRANSMITTER AT 1Mbps
2 TRANSMITTERS AT 62.5kbps

0

15

10

5

20

25

30

35

40

45

50

0 1000 2000 3000

MAX3245E

TRANSMITT SKEW

vs. LOAD CAPACITANCE

MAX3224-7/44/45E-16

LOAD CAPACITANCE (pF)

TRANSMITTER SKEW (ns)

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,

RS-232 Transceivers with AutoShutdown Plus

_______________________________________________________________________________________ 7

______________________________________________________________ Pin Description

PIN

MAX3224E
MAX3225E

TQFN

19 1 14 1 — — READY

1 2 16 2 28 31 C1+

20 3 15 3 27 30

2 4 1 4 24 26 C1-

3 5 2 5 1 33 C2+

DIP/

SSOP/

TSSOP

MAX3226E
MAX3227E

TQFN

SSOP/

TSSOP

MAX3244E
MAX3245E

SO/ SSOP/ TSSOP

MAX3245E

(TQFN)

NAME FUNCTION

Ready to Transmit Output,
active-high. READY is
enabled high when V- goes
below -4V and the device is
ready to transmit.

Positive Terminal of Voltage­Doubler Charge-Pump
Capacitor

V+

+5.5V generated by the
charge pump

Negative Terminal of
Voltage-Doubler Charge­Pump Capacitor

Positive Terminal of
Inverting Charge-Pump
Capacitor

4 6 3 6 2 34 C2-

5747 3 35 V-

6, 15 8, 17 10 13 9, 10, 11 7, 8, 9 T_OUT

7, 14 9, 16 5 8 4-8 1-5 R_IN

8, 13 10, 15 6 9

911710

15-19

21 23 INVALID

15, 16, 17,

19, 20

R_OUT

Negative Terminal of
Inverting Charge-Pump
Capacitor

-5.5V Generated by the
Charge Pump

RS-232 Transmitter Outputs

RS-232 Receiver Inputs

TTL/CMOS Receiver
Outputs

Valid Signal Detector
Output, active low. A logic
high indicates that a valid
RS-232 level is present on a
receiver input.

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus

8 _______________________________________________________________________________________

______________________________________________________________ Pin Description

_______________Detailed Description

Dual Charge-Pump Voltage Converter

The MAX3224E–MAX3227E/MAX3244E/MAX3245E’s
internal power supply consists of a regulated dual
charge pump that provides output voltages of +5.5V
(doubling charge pump) and -5.5V (inverting charge
pump), over the +3.0V to +5.5V range. The charge
pump operates in discontinuous mode: if the output
voltages are less than 5.5V, the charge pump is

enabled; if the output voltages exceed 5.5V, the
charge-pump is disabled. Each charge pump requires
a flying capacitor (C1, C2) and a reservoir capacitor
(C3, C4) to generate the V+ and V- supplies.

The READY output (MAX3224E–MAX3227E) is low
when the charge pumps are disabled in shutdown
mode. The READY signal asserts high when V- goes
below -4V.

PIN

MAX3224E
MAX3225E

TQFN

10, 11 12, 13 8 11 12-14 11, 12, 13 T_IN

12 14 9 12 23 25 FORCEON

16 18 11 14 25 27

17 19 12 15 26 29

18 20 13 16 22 24

— — — — 20 21 R2OUTB

DIP/

SSOP/

TSSOP

MAX3226E
MAX3227E

TQFN

SSOP/

TSSOP

MAX3244E
MAX3245E

DIP/ SSOP/ TSSOP

MAX3245E

TQFN

NAME

GND

V

CC

FORCEOFF

FUNCTION

TTL/CMOS Transmitter
Inputs

Force-On Input, Active High.
Drive high to override
AutoShutdown Plus, keeping
transmitters and receivers
on (FORCEOFF must be
high) (Table 1).

Ground

+3.0V to +5.5V Single
Supply Voltage

Force-Off Input, Active Low.
Drive low to shut down
transmitters, receivers
(except R2OUTB), and
charge pump. This
overrides AutoShutdown
Plus and FORCEON (Table

1).

TTL/CMOS Noninverting
Complementary Receiver
Outputs. Always active.

———— —

EP — EP — — EP EP

6, 10, 14,

18, 22, 28,

32, 36

N.C.

No Connection. Not
internally connected.

Exposed Paddle. Solder the
exposed paddle to the
ground plane or leave
unconnected.

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,

RS-232 Transceivers with AutoShutdown Plus

_______________________________________________________________________________________ 9

RS-232 Transmitters

The transmitters are inverting level translators that
convert CMOS-logic levels to 5.0V EIA/TIA-232 levels.
The MAX3224E/MAX3226E/MAX3244E guarantee a
250kbps data rate (1Mbps, for the MAX3225E/MAX3227E/
MAX3245E) with worst-case loads of 3kΩ in parallel with
1000pF, providing compatibility with PC-to-PC com­munication software (such as LapLink™). Transmitters
can be paralleled to drive multiple receivers. Figure 1
shows a complete system connection.

When FORCEOFF is driven to ground or when the Auto­Shutdown Plus circuitry senses that all receiver and
transmitter inputs are inactive for more than 30s, the
transmitters are disabled and the outputs go into a high­impedance state. When powered off or shut down, the
outputs can be driven to ±12V. The transmitter inputs
do not have pullup resistors. Connect unused inputs to
GND or V

CC

.

Figure 1. Interface Under Control of PMU

Figure 2. The MAX3244E/MAX3245E detect RS-232 activity
when the UART and interface are shut down.

LapLink is a trademark of Traveling Software.

V

POWER­MANAGEMENT
UNIT OR
KEYBOARD
CONTROLLER

FORCEOFF

FORCEON

INVALID

MAX3244E
MAX3245E

V

PROTECTION
DIODE

CC

Rx

CC

PREVIOUS

RS-232

I

I/O

CPU

CHIP
WITH
UART

RS-232

UART

GND

Tx

SHDN = GND

5kΩ

a) OLDER RS-232: POWERED-DOWN UART DRAWS CURRENT FROM ACTIVE

RECEIVER OUTPUT IN SHUTDOWN.

V

CC

TO

LOGIC

μP

TRANSITION

DETECTOR

I

PROTECTION
DIODE

V

CC

Rx

UART

Tx

GND

R2OUTB

R2OUT

THREE-STATED

T1IN

FORCEOFF = GND

MAX3244E
MAX3245E

5kΩ

b) NEW MAX3244E/MAX3245E: IN SHUTDOWN, R2OUTB IS USED TO MONITOR

EXTERNAL DEVICES AND R2OUT IS THREE STATED, ELIMINATING A CURRENT
PATH THROUGH THE UART'S PROTECTION DIODE.

R2IN

T1OUT

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus

10 ______________________________________________________________________________________

RS-232 Receivers

The receivers convert RS-232 signals to CMOS-logic
output levels. The MAX3224E–MAX3227E feature
inverting outputs that always remain active (Table 1).
The MAX3244E/MAX3245E have inverting three-state
outputs that are high impedance when shut down
(FORCEOFF = GND) (Table 1).

The MAX3244E/MAX3245E feature an extra, always
active, noninverting output, R2OUTB. R2OUTB output
monitors receiver activity while the other receivers are
high impedance, allowing ring indicator applications to
be monitored without forward biasing other devices
connected to the receiver outputs. This is ideal for sys­tems where V

CC

is set to ground in shutdown to

accommodate peripherals such as UARTs (Figure 2).

The MAX3224E–MAX3227E/MAX3244E/MAX3245E fea­ture an INVALID output that is enabled low when no
valid RS-232 voltage levels have been detected on all
receiver inputs. Because INVALID indicates the receiv­er input’s condition, it is independent of FORCEON and
FORCEOFF states (Figures 3 and 4).

AutoShutdown Plus Mode

The MAX3224E–MAX3227E/MAX3244E/MAX3245E
achieve a 1µA supplycurrent with Maxim’s AutoShutdown
Plus feature, which operates when FORCEOFF is high
and a FORCEON is low. When these devices do not
sense a valid signal transition on any receiver and trans­mitter input for 30s, the on-board charge pumps are
shut down, reducing supply current to 1µA. This occurs
if the RS-232 cable is disconnected or if the connected

Table 1. Output Control Truth Table

OPERATION

STATUS

FORCEON

FORCEOFF

VALID

RECEIVER

LEVEL

RECEIVER OR

TRANSMITTER

EDGE WITHIN

30s

T_OUT

R_OUT

(MAX3224E/

MAX3225E/
MAX3226E/
MAX3227E)

R_OUT

(MAX3244E/

MAX3245E)

R2OUTB

(MAX3244E/

MAX3245E)

Shutdown
(Forced Off)

X 0 X X High-Z Active High-Z Active

Normal
Operation
(Forced On)

1 1 X X Active Active Active Active

Normal
Operation
(AutoShutdown
Plus)

0 1 X Yes Active Active Active Active

Shutdown (Auto­Shutdown Plus)

0 1 X No High-Z Active Active Active

Normal
Operation

INVALID*

1 Yes X Active Active Active Active

Normal
Operation

INVALID*

1 X Yes Active Active Active Active

Shutdown

INVALID*

1 No No High-Z Active Active Active

Normal
Operation
(AutoShutdown)

INVALID* INVALID**

Yes X Active Active Active Active

Shutdown
(AutoShutdown)

INVALID* INVALID**

No X High-Z Active High-Z Active

X = Don’t care

*

INVALID

connected to FORCEON

**

INVALID

connected to FORCEON and

FORCEOFF

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,

RS-232 Transceivers with AutoShutdown Plus

______________________________________________________________________________________ 11

peripheral transmitters are turned off, and the UART dri­ving the transmitter inputs is inactive. The system turns
on again when a valid transition is applied to any
RS-232 receiver or transmitter input. As a result, the sys­tem saves power without changes to the existing BIOS
or operating system.

Figures 3a and 3b depict valid and invalid RS-232
receiver voltage levels. INVALID indicates the receiver
input’s condition, and is independent of FORCEON and
FORCEOFF states. Figure 3 and Tables 1 and 2 sum­marize the operating modes of the MAX3224E–
MAX3227E/MAX3244E/MAX3245E. FORCEON and
FORCEOFF override AutoShutdown Plus circuitry.
When neither control is asserted, the IC selects
between these states automatically based on the last
receiver or transmitter input edge received.

When shut down, the device’s charge pumps turn off,
V+ is pulled to VCC, V- is pulled to ground, the transmit­ter outputs are high impedance, and READY
(MAX3224E–MAX3227E) is driven low. The time
required to exit shutdown is typically 100µs (Figure 8).

By connecting FORCEON to INVALID, the MAX3224E–
MAX3227E/MAX3244E/MAX3245E shut down when no
valid receiver level and no receiver or transmitter edge is
detected for 30s, and wake up when a valid receiver
level or receiver or transmitter edge is detected.

Figure 3a.

INVALID

Functional Diagram,

INVALID

Low

Figure 3b.

INVALID

Functional Diagram,

INVALID

High

Figure 3c. AutoShutdown Plus Logic

Figure 3d. Power-Down Logic

Figure 4a. Receiver Positive/Negative Thresholds for

INVALID

RS-232 SIGNAL

PRESENT AT ANY

RECEIVER INPUT

INVALID OUTPUT

Yes High

No Low

Table 2. INVALID Truth Table

+0.3V

R_IN

-0.3V

INVALID ASSERTED IF ALL RECEIVER INPUTS ARE BETWEEN +0.3V AND -0.3V FOR
AT LEAST 30μs.

+2.7V

R_IN

-2.7V

INVALID DEASSERTED IF ANY RECEIVER INPUT HAS BEEN BETWEEN +2.7V AND -2.7V
FOR LESS THAN 30μs.

30µs

TIMER

R

30µs

TIMER

R

INVALID

INVALID

EDGE

T_IN

DETECT

EDGE

R_IN

DETECT

FORCEON

FORCEOFF

FORCEON

AUTOSHDN

* POWERDOWN IS ONLY AN INTERNAL SIGNAL.
IT CONTROLS THE OPERATIONAL STATUS OF
THE TRANSMITTERS AND THE POWER SUPPLIES.

FORCEOFF

S

30s

TIMER

R

AUTOSHDN

POWERDOWN*

INVALID HIGH

+2.7V

INDETERMINATE

+0.3V

0

-0.3V

RECEIVER INPUT LEVELS

-2.7V

INVALID LOW

INDETERMINATE

INVALID HIGH

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus

12 ______________________________________________________________________________________

By connecting FORCEON and FORCEOFF to INVALID,
the MAX3224E–MAX3227E/MAX3244E/MAX3245E shut
down when no valid receiver level is detected and
wake up when a valid receiver level is detected (same
functionality as AutoShutdown feature on MAX3221E/
MAX3223E/MAX3243E).

A mouse or other system with AutoShutdown Plus may
need time to wake up. Figure 5 shows a circuit that
forces the transmitters on for 100ms, allowing enough
time for the other system to realize that the MAX3244E/
MAX3245E is awake. If the other system outputs valid
RS-232 signal transitions within that time, the RS-232
ports on both systems remain enabled.

Software-Controlled Shutdown

If direct software control is desired, use INVALID to
indicate DTR or ring indicator signal. Tie FORCEOFF
and FORCEON together to bypass the AutoShutdown
Plus so the line acts like a SHDN input.

±15kV ESD Protection

As with all Maxim devices, ESD-protection structures are
incorporated on all pins to protect against electrostatic

discharges encountered during handling and assembly.
The driver outputs and receiver inputs of the
MAX3224E–MAX3227E/MAX3244E/MAX3245E have extra
protection against static electricity. Maxim’s engineers
have developed state-of-the-art structures to protect

Figure 4b. AutoShutdown Plus,

INVALID,

and READY Timing Diagram

Figure 5. AutoShutdown Plus Initial Turn-On to Wake Up a
Mouse or Another System

RECEIVER

INPUTS

TRANSMITTER

INPUTS

TRANSMITTER

OUTPUTS

V

INVALID
OUTPUT

READY

*MAX3224E–MAX3227E

CC

t

INVL

0

*V

CC

0

V+

V

CC

0

V-

t

INVH

t

AUTOSHDN

INVALID

}

REGION

t

t

WU

AUTOSHDN

t

WU

POWER-

MANAGEMENT

UNIT

MASTER SHDN LINE

0.1μF1MΩ

FORCEOFF

FORCEON

MAX3224E
MAX3225E
MAX3226E
MAX3227E
MAX3244E
MAX3245E

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,

RS-232 Transceivers with AutoShutdown Plus

______________________________________________________________________________________ 13

these pins against ESD of ±15kV without damage. The
ESD structures withstand high ESD in all states: normal
operation, shutdown, and powered down. After an ESD
event, Maxim’s E versions keep working without
latchup, whereas competing RS-232 products can
latch and must be powered down to remove latchup.

ESD protection can be tested in various ways; the
transmitter outputs and receiver inputs of this product
family are characterized for protection to the following
limits:

1) ±15kV using the Human Body Model

2) ±8kV using the Contact-Discharge Method specified
in IEC1000-4-2

3) ±15kV using IEC1000-4-2’s Air-Gap Method.

ESD Test Conditions

ESD performance depends on a variety of conditions.
Contact Maxim for a reliability report that documents
test setup, test methodology, and test results.

Human Body Model

Figure 6a shows the Human Body Model and Figure 6b
shows the current waveform it generates when dis­charged into a low impedance. This model consists of
a 100pF capacitor charged to the ESD voltage of inter­est, which is then discharged into the test device
through a 1.5kΩ resistor.

Figure 6b. Human Body Current Waveform

Figure 7b. IEC1000-4-2 ESD Generator Current Waveform

Figure 6a. Human Body ESD Test Model Figure 7a. IEC1000-4-2 ESD Test Model

50MΩ to 100MΩ RD 330Ω

R

1MΩ RD 1500Ω

R

C

CHARGE-CURRENT

LIMIT RESISTOR

DISCHARGE

RESISTANCE

C

CHARGE CURRENT

LIMIT RESISTOR

DISCHARGE

RESISTANCE

HIGH-

VOLTAGE

DC

SOURCE

100pF

STORAGE

C

s

CAPACITOR

DEVICE
UNDER

TEST

HIGH-

VOLTAGE

DC

SOURCE

150pF

STORAGE

C

s

CAPACITOR

I

PEAK

I

100%

90%

10%

30ns

60ns

AMPERES

IP 100%

90%

36.8%

10%

0

0

t

RL

I

r

TIME

t

DL

CURRENT WAVEFORM

PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)

tr = 0.7ns to 1ns

DEVICE
UNDER

TEST

t

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus

14 ______________________________________________________________________________________

IEC1000-4-2

The IEC1000-4-2 standard covers ESD testing and per­formance of finished equipment; it does not specifically
refer to integrated circuits. The MAX3224E–MAX3227E,
MAX3244E/MAX3245E help you design equipment that
meets Level 4 (the highest level) of IEC1000-4-2, with­out the need for additional ESD-protection components.

The major difference between tests done using the
Human Body Model and IEC1000-4-2 is higher peak
current in IEC1000-4-2, because series resistance is
lower in the IEC1000-4-2 model. Hence, the ESD with­stand voltage measured to IEC1000-4-2 is generally
lower than that measured using the Human Body
Model. Figure 7a shows the IEC1000-4-2 model and
Figure 7b shows the current waveform for the 8kV,
IEC1000-4-2, Level 4, ESD Contact-Discharge Method.

The Air-Gap Method involves approaching the device
with a charged probe. The Contact-Discharge Method
connects the probe to the device before the probe is
energized.

Machine Model

The Machine Model for ESD tests all pins using a
200pF storage capacitor and zero discharge resis­tance. Its objective is to emulate the stress caused by
contact that occurs with handling and assembly during
manufacturing. Of course, all pins require this protec­tion during manufacturing, not just RS-232 inputs and
outputs. Therefore, after PC board assembly, the
Machine Model is less relevant to I/O ports.

__________Applications Information

Capacitor Selection

The capacitor type used for C1–C4 is not critical for
proper operation; polarized or nonpolarized capacitors

can be used. The charge pump requires 0.1µF capaci­tors for 3.3V operation. For other supply voltages, see
Table 3 for required capacitor values. Do not use val­ues smaller than those listed in Table 3. Increasing the
capacitor values (e.g., by a factor of 2) reduces ripple
on the transmitter outputs and slightly reduces power
consumption. C2, C3, and C4 can be increased without
changing C1’s value. However, do not increase C1

without also increasing the values of C2, C3, C4,
and C

BYPASS

, to maintain the proper ratios (C1 to

the other capacitors).

When using the minimum required capacitor values,
make sure the capacitor value does not degrade
excessively with temperature. If in doubt, use capaci­tors with a larger nominal value. The capacitor’s equiv­alent series resistance (ESR), which usually rises at low
temperatures, influences the amount of ripple on V+
and V-.

Power-Supply Decoupling

In most circumstances, a 0.1µF VCCbypass capacitor
is adequate. In applications that are sensitive to power­supply noise, use a capacitor of the same value as
charge-pump capacitor C1. Connect bypass capaci­tors as close to the IC as possible.

Transmitter Outputs

when Exiting Shutdown

Figure 8 shows two transmitter outputs when exiting
shutdown mode. As they become active, the two trans­mitter outputs are shown going to opposite RS-232 lev­els (one transmitter input is high, the other is low). Each

V

CC

(V)

C2, C3, C4

(

µF)

3.0 to 3.6 0.22

3.15 to 3.6 0.1

C1, C

BYPASS

(µF)

0.22

0.1

4.5 to 5.5 0.33

3.0 to 5.5 1

0.047

0.22

Table 3. Required Minimum Capacitance
Values

Figure 8. Transmitter Outputs when Exiting Shutdown or
Powering Up

5V/div

0

2V/div

0

5V/div

0

VCC = 3.3V
C1–C4 = 0.1μF

5μs/div

FORCEON = FORCEOFF

T1OUT

T2OUT

READY

transmitter is loaded with 3kΩ in parallel with 1000pF.
The transmitter outputs display no ringing or undesir­able transients as they come out of shutdown. Note that
the transmitters are enabled only when the magnitude
of V- exceeds approximately -3V.

High Data Rates

The MAX3224E/MAX3226E/MAX3244E maintain the
RS-232 ±5.0V minimum transmitter output voltage even
at high data rates. Figure 9 shows a transmitter loop­back test circuit. Figure 10 shows a loopback test result
at 120kbps, and Figure 11 shows the same test at
250kbps. For Figure 10, all transmitters were driven
simultaneously at 120kbps into RS-232 loads in parallel
with 1000pF. For Figure 11, a single transmitter was dri­ven at 250kbps, and all transmitters were loaded with
an RS-232 receiver in parallel with 250pF.

The MAX3225E/MAX3227E/MAX3245E maintain the
RS-232 ±5.0V minimum transmitter output voltage at
data rates up to 1Mbps (MegaBaud). Figure 12 shows
a loopback test result with a single transmitter driven at
1Mbps and all transmitters loaded with an RS-232
receiver in parallel with 250pF.

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,

RS-232 Transceivers with AutoShutdown Plus

______________________________________________________________________________________ 15

Figure 9. Loopback Test Circuit

Figure 10. MAX3224E/MAX3226E/MAX3244E Loopback Test
Result at 120kbps

Figure 11. MAX3224E/MAX3226E/MAX3244E Loopback Test
Result at 250kbps

Figure 12. MAX3225E/MAX3227E/MAX3245E Loopback Test
Result at 1Mbps

T1IN

T1OUT

R1OUT

VCC = 3.3V

2μs/div

5V/div

5V/div

5V/div

T1IN

T1OUT

5V/div

5V/div

V

CC

C

BYPASS

C1+

C1

C2

V

CC

*C3 CAN BE RETURNED TO VCC OR GND.

C1-

C2+

C2-

T_ IN

R_ OUT

FORCEON

FORCEOFF

MAX3224E
MAX3225E
MAX3226E
MAX3227E
MAX3244E
MAX3245E

GND

R1OUT

VCC = 3.3V

V

CC

V+

C3*

2μs/div

5V/div

T1IN

T1OUT

R1OUT

VCC = 3.3V

5V/div

5V/div

5V/div

200ns/div

T_ OUT

R_ IN

5kΩ

V-

C4

1000pF

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus

16 ______________________________________________________________________________________

Figure 13a. Mouse Driver Test Circuit

C1

0.1μF

C2

0.1μF

LOGIC

INPUTS

+3.3V

0.1μF

26

V

28

C1+

24

C1-

1

C2+

2

C2-

T1IN

14

T2IN

13

T3IN

12

R2OUTB

20

R1OUT

19

CC

MAX3244E
MAX3245E

5kΩ

V+

V-

T1OUT 9

T2OUT 10

T3OUT

R1IN

27

C3

0.1μF

3

C4

0.1μF

11

4

COMPUTER SERIAL PORT

+V

+V

-V

GND

Tx

R2OUT

18

LOGIC

OUTPUTS

R3OUT

17

R4OUT

16

R5OUT

15

23

FORCEON

V

CC

TO POWER-

MANAGEMENT

UNIT

22

21

FORCEOFF

INVALID

GND

25

5kΩ

5kΩ

5kΩ

5kΩ

R2IN 5

R3IN

R4IN

R5IN 8

6

7

RS-232
INPUTS

SERIAL

MOUSE

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,

RS-232 Transceivers with AutoShutdown Plus

______________________________________________________________________________________ 17

Mouse Driveability

The MAX3244E/MAX3245E are specifically designed to
power serial mice while operating from low-voltage
power supplies. They have been tested with leading
mouse brands from manufacturers such as Microsoft
and Logitech. The MAX3244E/MAX3245E successfully
drove all serial mice tested and met their respective
current and voltage requirements. The MAX3244E/
MAX3245E dual charge pump ensures the transmitters
supply at least ±5V during worst-case conditions.
Figure 13b shows the transmitter output voltages under
increasing load current. Figure 13a shows a typical
mouse connection.

Interconnection with 3V and 5V Logic

The MAX3224E–MAX3227E/MAX3244E/MAX3245E can
directly interface with various 5V logic families, includ­ing ACT and HCT CMOS. See Table 4 for more informa­tion on possible combinations of interconnections.

Table 5 lists other Maxim ESD-powered transceivers.

SYSTEM

POWER-SUPPLY

VOLTAGE (V)

COMPATIBILITY

3.3 Compatible with all CMOS families

5 Compatible with all TTL and CMOS families

VCCSUPPLY

VOLTAGE

(V)

3.3

5

5 Compatible with ACT and HCT CMOS, and with AC, HC, or CD4000 CMOS3.3

PART

SUPPLY

VOLTAGE

RANGE

(V)

NO.

OF

Tx/Rx

GUARANTEED

DATA RATE

(kbps)

MAX3241E +3.0 to +5.5 3/5 250

MAX3243E +3.0 to +5.5 3/5 250

MAX3244E +3.0 to +5.5 3/5 250

MAX3245E +3.0 to +5.5 3/5 1Mbps

MAX3232E +3.0 to +5.5 2/2 250

MAX3222E +3.0 to +5.5 2/2 250

MAX3223E +3.0 to +5.5 2/2 250

MAX3224E +3.0 to +5.5 2/2 250

MAX3225E +3.0 to +5.5 2/2 1Mbps

MAX3221E +3.0 to +5.5 1/1 250

MAX3227E +3.0 to +5.5 1/1 1Mbps

MAX3226E +3.0 to +5.5 1/1 250

SUPPLY

CURRENT

(

µA)

300

1

1

1

300

300

1

1

1

1

1

1

Auto-

Shutdown

Plus

—

—

Yes

Yes

—

—

—

Yes

Yes

—

Yes

Yes

Auto-

Shutdown

—

Yes

—

—

—

—

Yes

—

—

Yes

—

—

Human

Body

Model

(kV)

±15

±15

±15

±15

±15

±15

±15

±15

±15

±15

±15

±15

IEC 1000-4-2

Contact

Discharge

(kV)

±8

±8

±8

±8

±8

±8

±8

±8

±8

±8

±8

±8

IEC 1000-4-2

Air-Gap

Discharge

(kV)

±15

±15

±15

±15

±15

±15

±15

±15

±15

±15

±15

±15

Figure 13b. MAX324_E Transmitter Output Voltage vs. Load
Current per Transmitter

Table 5. ±15kV ESD-Protected, 3.0V to 5.5V Powered RS-232 Transceivers from Maxim

Table 4. Logic Family Compatibility with Various Supply Voltages

6
5
4

VCC = 3.0V

3
2
1
0

-1

-2
V

CC

-3

-4

TRANSMITTER OUTPUT VOLTAGE (V)

-5

-6

012345678910

LOAD CURRENT PER TRANSMITTER (mA)

V

V

OUT+

OUT-

V

OUT+

MAX2343E-FIG15

V

OUT-

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus

18 ______________________________________________________________________________________

___________________________________________________Typical Operating Circuits

+3.3V

26

V

CC

MAX3244E***

MAX3245E

V+

V-

T1OUT 9

27

3

C

BYPASS

C1

0.1μF

C2

0.1μF

+3.3V

0.1μF

15

V

2

C1+

4

C1-

5

C2+

6

C2-

11

T1IN

CC

MAX3226E*

MAX3227E

V+

V-

T1OUT 13

3

C3

0.1μF

7

C4

0.1μF

C

BYPASS

0.1μF

0.1μF

0.1μF

C2

28

C1

C1+

24

C1-

1

C2+

2

C2-

T1IN

14

C3

0.1μF

C4

0.1μF

C

BYPASS

C1

0.1μF

C2

0.1μF

TTL/CMOS

INPUTS

TTL/CMOS

OUTPUTS

+3.3V

0.1μF

12

13

12

1

2

4

5

6

R1OUT9

READY

FORCEON

C1+

C1-

C2+

C2-

T1IN

T2IN

R1OUT15

R2OUT10

AUTOSHUTDOWN

PLUS

GND

14

19

V

CC

MAX3224E**

MAX3225E

R1IN 8

5kΩ

INVALID 10

FORCEOFF

T1OUT 17

T2OUT

R1IN

5kΩ

R2IN

T2IN

13

T3IN

12

FORCEOFF

TO POWER­MANAGEMENT
UNIT

16

V

CC

3

V+

V-

C3

0.1μF

7

C4

0.1μF

RS-232
OUTPUTS

8

16

RS-232
INPUTS

9

22

23

20

19

18

17

16

15

FORCEON

R2OUTB

R1OUT

R2OUT

R3OUT

R4OUT

R5OUT

AUTOSHUTDOWN

PLUS

GND

25

T2OUT 10

T3OUT

INVALID

R1IN

R2IN 5

R3IN

R4IN

R5IN 8

11

21

4

6

7

AUTOSHUTDOWN

PLUS

GND

18

14

1

READY

FORCEON

5kΩ

INVALID 11

FORCEOFF

20

TO POWER­MANAGEMENT
UNIT

V

CC

*MAX3226E/MAX3227E PIN OUT REFERS TO SSOP/TSSOP PACKAGES.

**MAX3224E/MAX3225E PIN OUT REFERS TO DIP/ SSOP/TSSOP PACKAGES.

***MAX3244E/MAX3245E PIN OUT REFERS TO SO/SSOP/TSSOP PACKAGES.

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,

RS-232 Transceivers with AutoShutdown Plus

______________________________________________________________________________________ 19

___________________________________________________________ Pin Configurations

READY

C1+

V+

C1-

C2+

C2-

V-

R1IN

TOP VIEW

FORCEOFF

TOP VIEW

1

2

3

4

MAX3226E
MAX3227E

5

6

7

8

SSOP/TSSOP

GND

16

V

17

CC

18

READY

19

20

V+

16

FORCEOFF

15

V

CC

14

GND

T1OUT

13

FORCEON

12

T1IN

11

INVALID

10

9

R1OUT

R1IN

T1OUT

15 14 12 11

13

R1OUT

FORCEON

MAX3224E
MAX3225E

EXPOSED PADDLE

12

C1+

C1-

3

C2+

45

C2-

TQFN

CC

GND

V

12 11 9

10

READY

C1+

C1-

C2+

C2-

T2OUT

R2IN

T1IN

V-

FORCEON

1

2

V+

3

4

MAX3224E

5

MAX3225E

6

V-

7

8

9

10

DIP/SSOP/TSSOP

T2IN

10

INVALID

9

8

R2OUT

R2IN

7

T2OUT

6

20

19

18

17

16

15

14

13

12

11

TOP VIEW

R1IN
R2IN
R3IN
R4IN
R5IN

N.C.

T1OUT
T2OUT
T3OUT

FORCEOFF

V

CC

GND

T1OUT

R1IN

R1OUT

FORCEON

T1IN

T2IN

INVALIDR2OUT

1

2

3

4

5

6

7

8

9

T1OUT

T2OUT

T3OUT

V-

N.C.

36 35 34 33 32 31 30 29 28

EXPOSED PADDLE

10 11 12 13 14 15 16 17 18

C2+

1

C2-

2

V-

3

R1IN

4

R2IN

5

R3IN

6

R4IN

7

R5IN

8

9

10

11

T3IN

12

T2IN

13

T1IN

14

SO/SSOP/TSSOP

C2-

C2+

N.C.

C1+V+V

MAX3245E

MAX3244E
MAX3245E

CC

N.C.

27

26

25

24

23

22

21

20

19

28

27

26

25

24

23

22

21

20

19

18

17

16

15

GND
C1­FORCEON
FORCEOFF
INVALID
N.C.
R2OUTB
R1OUT

R2OUT

C1+

V+

V

CC

GND

C1-

FORCEON

FORCEOFF

INVALID

R2OUTB

R1OUT

R2OUT

R3OUT

R4OUT

R5OUT

T1IN

FORCEOFF

READY

C1+

13

14

V+

15

16

MAX3226E
MAX3227E

EXPOSED PADDLE

12

C1-

C2+

3

C2- T1OUT

8

7

INVALID

R1OUT

6

R1IN

5

4

V-

N.C.

T3IN

T2IN

N.C.

T1IN

TQFN

R5OUT

R4OUT

R3OUT

N.C.

TQFN

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus

20 ______________________________________________________________________________________

___________________________________________Ordering Information (continued)

___________________ Chip Information

MAX3224E TRANSISTOR COUNT: 1129
MAX3225E TRANSISTOR COUNT: 1129
MAX3226E TRANSISTOR COUNT: 1129
MAX3227E TRANSISTOR COUNT: 1129
MAX3244E/MAX3245E TRANSISTOR COUNT: 1335

PROCESS: BICMOS

*EP = Exposed paddle.

PART

MAX3225ECUP

MAX3225ECTP

MAX3225ECAP

MAX3225ECPP

MAX3225EETP

MAX3225EEUP

MAX3225EEAP

MAX3225EEPP

MAX3225EAAP

MAX3226ECTE

MAX3226ECUE

MAX3226ECAE

MAX3226EEAE

MAX3226EETE -40°C to +85°C

MAX3226EEUE

MAX3226EAAE

MAX3227ECAE

MAX3227ECTE 0°C to +70°C

MAX3227ECUE 0°C to +70°C

MAX3227EEAE

TEMP

RANGE

0°C to +70°C

0°C to +70°C

0°C to +70°C

0°C to +70°C

-40°C to +85°C

-40°C to +85°C

-40°C to +85°C

-40°C to +85°C

-40°C to +125°C

0°C to +70°C

0°C to +70°C
0°C to +70°C

-40°C to +85°C

-40°C to +85°C

-40°C to +125°C
0°C to +70°C

-40°C to +85°C

PIN

PKG

20 TSSOP —

20 TQFN-

EP*

20 SSOP —

20 Plastic

DIP

20 TQFN -

EP*

20 TSSOP —

20 SSOP —

20 Plastic

DIP

20 SSOP —

16 TQFN-

EP*

16 TSSOP —

16 SSOP —

16 SSOP —

16 TQFN-

EP*

16 TSSOP —

16 SSOP —

16 SSOP —

16 TQFN-

EP*

16

TSSOP

16 SSOP —

PKG
CODE

T2055-5

—

T2055-5

—

T1655-2

T1655-2

T1655-2

—

PART

MAX3227EETE -40°C to +85°C

MAX3227EEUE -40°C to +85°C

MAX3227EAAE -40°C to +125°C 16 SSOP —

MAX3244ECWI 0°C to +70°C

MAX3244ECAI 0°C to +70°C 28 SSOP

MAX3244ECUI 0°C to +70°C

MAX3244EEWI -40°C to +85°C

MAX3244EEAI -40°C to +85°C 28 SSOP —

MAX3244EEUI -40°C to +85°C

MAX3245ECWI 0°C to +70°C

MAX3245ECAI 0°C to +70°C 28 SSOP —

MAX3245ECTX 0°C to +70°C

MAX3245EEAI -40°C to +85°C 28 SSOP —

MAX3245EEWI -40°C to +85°C

MAX3245EEUI -40°C to +85°C

MAX3245EETX -40°C to +85°C

TEMP

RANGE

PIN

PKG

16 TQFN-

EP*

16

TSSOP

28 Wide

SO

28

TSSOP

28 Wide

SO

28

TSSOP

28 Wide

SO

36 TQ FN -

E P *

28 WIDE

SO

28

TSSOP

36 TQ FN -

E P *

PKG
CODE

T1655-2

—

—

—

—

—

—

T3666-3

—

—

T3666-3

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,

RS-232 Transceivers with AutoShutdown Plus

______________________________________________________________________________________ 21

Package Information

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages

.)

QFN THIN.EPS

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus

22 ______________________________________________________________________________________

Package Information

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages

.)

TSSOP4.40mm.EPS

PACKAGE OUTLINE, TSSOP 4.40mm BODY

21-0066

1

I

1

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,

RS-232 Transceivers with AutoShutdown Plus

______________________________________________________________________________________ 23

Package Information

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages

.)

NOTES:

1. D&E DO NOT INCLUDE MOLD FLASH.

2. MOLD FLASH OR PROTRUSIONS NOT TO EXCEED .15 MM (.006").

3. CONTROLLING DIMENSION: MILLIMETERS.

4. MEETS JEDEC MO150.

5. LEADS TO BE COPLANAR WITHIN 0.10 MM.

12

INCHES

DIM

MIN

A

0.068

A1

0.002

B

0.010

C

HE

N

A

e

B

D

A1

D

E

e

H

L

0.004

0.205

0.0256 BSC

0.301

0.025

0∞

MILLIMETERS

MAX

MIN

0.078

1.73 1.99

0.008

0.05

0.25

0.015

0.09

0.008

SEE VARIATIONS

0.212

5.20

0.311

7.65

0.037

0.63

8∞

L

0.65 BSC

0∞

MAX

0.21

0.38

0.20

5.38

7.90

0.95

8∞

INCHES

MAX

MIN

D

0.239

0.249

D

0.239

0.249

D

0.278

0.289

D

0.317

0.328

0.397

0.407

D

PROPRIETARY INFORMATION

TITLE:

PACKAGE OUTLINE, SSOP, 5.3 MM

MILLIMETERS

MAX

MIN

6.07

6.33

6.07

6.33

7.33

7.07

8.33

8.07

10.33

10.07

21-0056

SSOP.EPS

N

14L
16L

20L

24L

28L

C

REV.DOCUMENT CONTROL NO.APPROVAL

1

C

1

N

1

e

TOP VIEW

D

FRONT VIEW

INCHES

MIN

DIM

0.093A

0.004

A1

0.014

B

0.009

C

H

E

A

B

A1

C

L

e 0.050 1.27

0.291

E
H 0.4190.394 10.00 10.65

0.016L

VARIATIONS:

INCHES

MINDIM

D

0.398 0.413 AA10.5010.10 16

D

0.447 0.463 AB11.7511.35 18

D 0.6140.598 15.20 2415.60 AD
D 0.7130.697 17.70 2818.10 AE

0∞-8∞

SIDE VIEW

PROPRIETARY INFORMATION

TITLE:

PACKAGE OUTLINE, .300" SOIC

MAX

0.104

0.012

0.019

0.013

0.299

0.050

MAX

0.5120.496D

MILLIMETERS

MAX

MIN

2.35

2.65

0.10

0.30

0.35

0.49

0.23

0.32

7.40 7.60

0.40 1.27

MILLIMETERS

MAX

MIN

12.60 13.00

21-0042

N MS013

20 AC

REV.DOCUMENT CONTROL NO.APPROVAL

B

1

SOICW.EPS

1

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus

24 ______________________________________________________________________________________

Package Information (continued)

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages

.)

PDIPN.EPS

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,

RS-232 Transceivers with AutoShutdown Plus

______________________________________________________________________________________ 25

Package Information (continued)

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages

.)

QFN THIN.EPS

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

±15kV ESD-Protected, 1µA, 1Mbps 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

26 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

© 2007 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.

Package Information (continued)

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages

.)

Revision History

Pages changed at Rev 4: 1, 12, 20, 25, 26