MAXIM MAX3224E, MAX3225E, MAX3226E, MAX3227E, MAX3244E 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 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 6; 10/04

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.

†

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 TEMP RANGE PIN-PACKAGE

MAX3224ECUP

MAX3224ECAP

MAX3224ECPP

MAX3224EEUP

MAX3224EEAP

MAX3224EEPP

MAX3225ECUP

MAX3225ECAP

MAX3225ECPP

MAX3225EEUP

MAX3225EEAP

MAX3225EEPP

MAX3226ECAE

MAX3226EEAE

MAX3227ECAE

MAX3227EEAE

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
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
0°C to +70°C

-40°C to +85°C
0°C to +70°C

-40°C to +85°C

20 TSSOP

20 SSOP

20 Plastic DIP

20 TSSOP

20 SSOP

20 Plastic DIP

20 TSSOP

20 SSOP

20 Plastic DIP

20 TSSOP

20 SSOP

20 Plastic DIP

16 SSOP

16 SSOP

16 SSOP

16 SSOP

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%; CL= 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

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 Thin QFN (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

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%; CL= 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%; CL= 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%; CL= 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.)

MAX3224E/MAX3226E

TRANSMITTER OUTPUT VOLTAGE

vs. LOAD CAPACITANCE

6
5
4
3

T1 TRANSMITTING AT 250kbps

2

T2 (MAX3224E) TRANSMITTING AT 15.6kbps

1
0

-1

-2

-3

-4

TRANSMITTER OUTPUT VOLTAGE (V)

-5

-6
0 10002000300040005000

LOAD CAPACITANCE (pF)

MAX3225E/MAX3227E

TRANSMITTER OUTPUT VOLTAGE

vs. LOAD CAPACITANCE

7.5

5.0

2.5
1 TRANSMITTER AT FULL DATA RATE
1 TRANSMITTER AT 1/16 DATA RATE

0

(MAX3225E)
LOAD = 3kΩ + C

-2.5

-5.0

TRANSMITTER OUTPUT VOLTAGE (V)

-7.5
01000500 1500 2000 2500

2Mbps

LOAD CAPACITANCE (pF)

L

2Mbps

1.5Mbps

1.5Mbps

MAX3225E/MAX3227E

TRANSMITTER SKEW

vs. LOAD CAPACITANCE

50

1 TRANSMITTER AT 512kbps

45

1 TRANSMITTER AT 30kbps

40

(MAX3225E)
LOAD = 3kΩ + C

35

30

25

20

15

TRANSMITTER SKEW (ns)

10

5

0

0 1000500 1500 2000 2500 3000

L

AVERAGE: 10 PARTS

LOAD CAPACITANCE (pF)

MAX3224E/MAX3226E

SLEW RATE vs. LOAD CAPACITANCE

16

V

OUT+

V

OUT-

14

12

MAX3224-7/44/45E-01

10

8

6

SLEW RATE (V/µs)

4

2

0

-SLEW

+SLEW

FOR DATA RATES UP TO 250kbps

0 1000 2000 3000 4000 5000

LOAD CAPACITANCE (pF)

45

40

35

MAX3224-7/44/45E-02

30

25

20

15

SUPPLY CURRENT (mA)

10

5

0

MAX3225E/MAX3227E

SLEW RATE vs. LOAD CAPACITANCE

100

90

80

MAX3224-7/44/45E-05

70

60

50

40

30

SUPPLY CURRENT (mA)

20

10

0

1Mbps

1Mbps

80

70

60

MAX3224-7/44/45E-04

50

40

30

SLEW RATE (V/µs)

20

10

-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

200

180

160

MAX3224-7/44/45E-08

140

120

100

80

60

READY TURN-OFF TIME (ns)

40

20

0

MAX3224-7/44/45E-07

READY TURN-ON TIME (µs)

38

36

34

32

30

28

26

24

22

20

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

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)

MAX3224E–MAX3227E

READY TURN-OFF TIME

vs. TEMPERATURE

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

MAX3224-7/44/45E-03

MAX3224-7/44/45E-06

MAX3224-7/44/45E-09

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 10002000300040005000

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/µs)

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

0800400 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/µs)

1 TRANSMITTER AT 1Mbps
2 TRANSMITTERS AT 62.5kbps

0

15

10

5

20

25

30

35

40

45

50

0 100020003000

MAX3245E

TRANSMITT SKEW

vs. LOAD CAPACITANCE

MAX3224-7/44/45E-16

LOAD CAPACITANCE (pF)

TRANSMITTER SKEW (ns)

_______________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.

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

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

RS-232 Transceivers with AutoShutdown Plus

_______________________________________________________________________________________ 7

PIN

MAX3245E

(TQFN)

MAX3244E
MAX3245E

(SO, SSOP,

TSSOP)

MAX3224E
MAX3225E

MAX3226E
MAX3227E

2 2 28 31 Positive Terminal of Voltage-Doubler Charge-Pump Capacitor

3 3 27 30 +5.5V generated by the charge pump

4 4 24 26

Negative Terminal of Voltage-Doubler Charge-Pump
Capacitor

5 5 1 33 Positive Terminal of Inverting Charge-Pump Capacitor

6 6 2 34 Negative Terminal of Inverting Charge-Pump Capacitor

7 7 3 35 -5.5V generated by the charge pump

8, 17 13 9, 10, 11 7, 8, 9 RS-232 Transmitter Outputs

9, 16 8 4–8 1–5 RS-232 Receiver Inputs

10, 15 9 15–19 15, 16, 17, 19, 20 TTL/CMOS Receiver Outputs

11 10 21 23

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

12, 13 11 12–14 11, 12, 13 TTL/CMOS Transmitter Inputs

14 12 23 25

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

18 14 25 27 Ground

19 15 26 29 +3.0V to +5.5V Single Supply Voltage

20 16 22 24

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).

— — 20 21

TTL/CMOS Noninverting Complementary Receiver Outputs.
Always active.

FUNCTION

______________________________________________________________ Pin Description

NAME

C1+

V+

C1-

C2+

C2-

V-

T_OUT

R_IN

R_OUT

INVALID

T_IN

FORCEON

GND

V

CC

FORCEOFF

R2OUTB

— — —

6, 10, 14, 18,

22, 28, 32, 36

No Connection. Not internally connected.N.C.

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

READY1 1 — —

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

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

.

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

8 _______________________________________________________________________________________

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.

POWER­MANAGEMENT
UNIT OR
KEYBOARD
CONTROLLER

CPU

FORCEOFF

FORCEON

INVALID

I/O

CHIP
WITH
UART

MAX3244E
MAX3245E

RS-232

V

CC

PROTECTION
DIODE

V

CC

Rx

UART

Tx

GND

I

SHDN = GND

PREVIOUS

RS-232

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

R2OUTB

MAX3244E
MAX3245E

Rx

UART

R2OUT

THREE-STATED

Tx

T1IN

GND

FORCEOFF = GND

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

5kΩ

T1OUT

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 VCCis 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

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

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

RS-232 Transceivers with AutoShutdown Plus

_______________________________________________________________________________________ 9

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

†

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.

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

10 ______________________________________________________________________________________

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

+2.7V

+0.3V

0

-0.3V

RECEIVER INPUT LEVELS

-2.7V

INVALID HIGH

INDETERMINATE

INVALID LOW

INDETERMINATE

INVALID HIGH

AUTOSHDN

POWERDOWN*

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
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

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

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

RS-232 Transceivers with AutoShutdown Plus

______________________________________________________________________________________ 11

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

INVALID

}

REGION

INVALID
OUTPUT

OUTPUT

*MAX3224E–MAX3227E

V

CC

t

INVL

0

*V

CC

0

V+

V

CC

0

V-

t

INVH

t

AUTOSHDN

t

t

WU

AUTOSHDN

t

WU

POWER-

MANAGEMENT

UNIT

MASTER SHDN LINE

FORCEOFF

0.1µF1MΩ

FORCEON

MAX3224E
MAX3225E
MAX3226E
MAX3227E
MAX3244E
MAX3245E

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

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.

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

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

12 ______________________________________________________________________________________

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

HIGH-

VOLTAGE

DC

SOURCE

Ω

1M

R

C

CHARGE-CURRENT

LIMIT RESISTOR

C

100pF

Ω

RD 1500

DISCHARGE

RESISTANCE

STORAGE

s

CAPACITOR

DEVICE
UNDER

TEST

HIGH-

VOLTAGE

DC

SOURCE

50MΩ to 100MΩRD 330

R

C

CHARGE CURRENT

LIMIT RESISTOR

C

s

150pF

I

PEAK

I

100%

90%

10%

AMPERES

IP 100%

90%

36.8%

10%

PEAK-TO-PEAK RINGING

I

r

(NOT DRAWN TO SCALE)

0

0

t

RL

TIME

t

DL

CURRENT WAVEFORM

DISCHARGE

RESISTANCE

STORAGE
CAPACITOR

Ω

DEVICE
UNDER

TEST

tr = 0.7ns to 1ns

30ns

60ns

t

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 lev-

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

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

RS-232 Transceivers with AutoShutdown Plus

______________________________________________________________________________________ 13

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

VCC = 3.3V

5V/div

C1–C4 = 0.1µF

0

5µs/div

FORCEON = FORCEOFF

T1OUT

T2OUT

READY

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

els (one transmitter input is high, the other is low). Each
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.

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

14 ______________________________________________________________________________________

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

T1IN

T1OUT

5V/div

5V/div

5V/div

5V/div

5V/div

V

CC

C

BYPASS

V

C1+

C1

C2

V

CC

*C3 CAN BE RETURNED TO VCC OR GND.

C1-

C2+

C2-

T_ IN

R_ OUT

FORCEON

FORCEOFF

CC

MAX3224E
MAX3225E
MAX3226E
MAX3227E
MAX3244E
MAX3245E

GND

T_ OUT

R_ IN

Ω

5k

V+

C3*

V-

C4

1000pF

R1OUT

VCC = 3.3V

2µs/div

T1IN

T1OUT

R1OUT

VCC = 3.3V

200ns/div

5V/div

5V/div

5V/div

5V/div

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

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

RS-232 Transceivers with AutoShutdown Plus

______________________________________________________________________________________ 15

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

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

TO POWER-

MANAGEMENT

UNIT

CC

22

21

FORCEOFF

INVALID

GND

5kΩ

R2IN 5

5kΩ

6

5kΩ

5kΩ

R3IN

R4IN

7

RS-232
INPUTS

SERIAL

R5IN 8

5kΩ

25

MOUSE

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

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.

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

16 ______________________________________________________________________________________

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+

V

MAX2343E-FIG15

OUT-

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

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

RS-232 Transceivers with AutoShutdown Plus

______________________________________________________________________________________ 17

___________________________________________________Typical Operating Circuits

+3.3V

26

V

CC

MAX3244E
MAX3245E

AUTOSHUTDOWN

PLUS

V+

V-

T1OUT 9

T2OUT 10

T3OUT

INVALID

R1IN

R2IN 5

R3IN

R4IN

R5IN 8

27

C3

0.1µF

3

C4

0.1µF

11

21

4

6

7

C

BYPASS

C1

0.1µF

C2

0.1µF

C

BYPASS

C1

0.1µF

C2

0.1µF

TTL/CMOS

INPUTS

+3.3V

+3.3V

0.1µF

0.1µF

12

11

13

12

2

4

5

6

1

2

4

5

6

C1+

C1-

C2+

C2-

T1IN

R1OUT9

READY

FORCEON

C1+

C1-

C2+

C2-

T1IN

T2IN

15

V

CC

MAX3226E
MAX3227E

AUTOSHUTDOWN

PLUS

GND

14

19

V

CC

MAX3224E
MAX3225E

T1OUT 13

R1IN 8

5kΩ

INVALID 10

FORCEOFF

T1OUT 17

T2OUT

C

BYPASS

3

V+

V-

V+

V-

7

16

3

7

8

C3

0.1µF

C4

0.1µF

TO POWER­MANAGEMENT
UNIT

V

CC

C3

0.1µF

C4

0.1µF

RS-232
OUTPUTS

0.1µF

C1

0.1µF

C2

0.1µF

28

24

1

2

14

13

12

22

23

20

19

18

17

16

15

C1+

C1-

C2+

C2-

T1IN

T2IN

T3IN

FORCEOFF

FORCEON

R2OUTB

R1OUT

R2OUT

R3OUT

R4OUT

R5OUT

TTL/CMOS

OUTPUTS

GND

25

14

1

R1OUT15

R2OUT10

READY

FORCEON

AUTOSHUTDOWN

PLUS

GND

18

R1IN

5kΩ

R2IN

5kΩ

INVALID 11

FORCEOFF

16

9

20

RS-232
INPUTS

TO POWER­MANAGEMENT
UNIT

V

CC

MAX3224E–MAX3227E/MAX3244E/MAX3245E

†

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

18 ______________________________________________________________________________________

___________________________________________________________ Pin Configurations

___________________ Chip Information

MAX3224E TRANSISTOR COUNT: 1129
MAX3225E TRANSISTOR COUNT: 1129
MAX3226E TRANSISTOR COUNT: 1129
MAX3227E

TRANSISTOR COUNT: 1129

MAX3244E/MAX3245E TRANSISTOR COUNT: 1335

__Ordering Information (continued)

PART TEMP RANGE PIN-PACKAGE

MAX3244ECWI

0°C to +70°C 28 Wide SO

MAX3244ECAI

MAX3244EEWI

MAX3244EEAI -40°C to +85°C

-40°C to +85°C

0°C to +70°C 28 SSOP

28 Wide SO

28 SSOP

MAX3245ECWI

0°C to +70°C 28 Wide SO

MAX3245ECAI

MAX3245EEAI 0°C to +70°C

0°C to +70°C 28 SSOP

28 SSOP

MAX3244EEUI -40°C to +85°C 28 TSSOP

MAX3245ECTX 0°C to +70°C 36 TQFN

MAX3245EEUI -40°C to +85°C 28 TSSOP

MAX3244ECUI 0°C to +70°C 28 TSSOP

MAX3245EETX -40°C to +85°C 36 TQFN

MAX3245EEWI -40°C to +85°C 28 Wide SO

READY

C1+

C1-

C2+

C2-

R1IN

16

15

14

13

12

11

10

9

FORCEOFF

V

CC

GND

T1OUT

FORCEON

T1IN

INVALID

R1OUT

1

2

3

V+

4

MAX3226E
MAX3227E

5

6

7

V-

8

SSOP

READY

C1+

C1-

C2+

C2-

T2OUT

R2IN

1

2

V+

3

4

MAX3224E

5

MAX3225E

6

V-

7

8

9

10

DIP/SSOP/TSSOP

TOP VIEW

R1IN
R2IN
R3IN
R4IN
R5IN

N.C.

T1OUT
T2OUT
T3OUT

N.C.

V-

C2-

C2+

36 35 34 33 32 31 30 29 28

1

2

3

4

5

6

7

8

9

MAX3245E

EXPOSED PADDLE

10 11 12 13 14 15 16 17 18

N.C.

20

19

18

17

16

15

14

13

12

11

C1+V+V

FORCEOFF

V

CC

GND

T1OUT

R1IN

R1OUT

FORCEON

T1IN

T2IN

INVALIDR2OUT

CC

N.C.

27

26

25

24

23

22

21

20

19

R1IN

R2IN

R3IN

R4IN

R5IN

T1OUT

T2OUT

T3OUT

T3IN

T2IN

T1IN

GND
C1­FORCEON
FORCEOFF
INVALID
N.C.
R2OUTB
R1OUT

R2OUT

C2+

1

C2-

2

V-

3

4

5

MAX3244E

6

MAX3245E

7

8

9

10

11

12

13

14

SO/SSOP/TSSOP

28

27

26

25

24

23

22

21

20

19

18

17

16

15

C1+

V+

V

CC

GND

C1-

FORCEON

FORCEOFF

INVALID

R2OUTB

R1OUT

R2OUT

R3OUT

R4OUT

R5OUT

N.C.

T3IN

T2IN

T1IN

N.C.

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

______________________________________________________________________________________ 19

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

20 ______________________________________________________________________________________

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

TSSOP4.40mm.EPS

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.

Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 21

© 2004 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

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

.)

D

D/2

E/2

(NE-1) X e

L

L1

e

A1 A2

E

A

D2

C

L

k

(ND-1) X e

C

L

e e

PACKAGE OUTLINE
36, 40, 48L THIN QFN, 6x6x0.8mm

b

D2/2

e

21-0141

E2/2

C

E2

L

k

L

C

L

QFN THIN 6x6x0.8.EPS

LL

1

E

2

NOTES:

1. DIMENSIONING & TOLERANCING CONFORM TO ASME Y14.5M-1994.

2. ALL DIMENSIONS ARE IN MILLIMETERS. ANGLES ARE IN DEGREES.

3. N IS THE TOTAL NUMBER OF TERMINALS.

4. THE TERMINAL #1 IDENTIFIER AND TERMINAL NUMBERING CONVENTION SHALL CONFORM TO JESD 95-1
SPP-012. DETAILS OF TERMINAL #1 IDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED WITHIN THE
ZONE INDICATED. THE TERMINAL #1 IDENTIFIER MAY BE EITHER A MOLD OR MARKED FEATURE.

5. DIMENSION b APPLIES TO METALLIZED TERMINAL AND IS MEASURED BETWEEN 0.25 mm AND 0.30 mm
FROM TERMINAL TIP.

6. ND AND NE REFER TO THE NUMBER OF TERMINALS ON EACH D AND E SIDE RESPECTIVELY.

7. DEPOPULATION IS POSSIBLE IN A SYMMETRICAL FASHION.

8. COPLANARITY APPLIES TO THE EXPOSED HEAT SINK SLUG AS WELL AS THE TERMINALS.

9. DRAWING CONFORMS TO JEDEC MO220, EXCEPT FOR 0.4mm LEAD PITCH PACKAGE T4866-1.

10. WARPAGE SHALL NOT EXCEED 0.10 mm.

PACKAGE OUTLINE
36, 40, 48L THIN QFN, 6x6x0.8mm

21-0141

2

E

2