MAXIM MAX3224, MAX3227, MAX3244, MAX3245 User Manual

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

†

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.

19-1289; Rev 3; 9/05

________________General Description

The MAX3224–MAX3227/MAX3244/MAX3245 are 3V­powered EIA/TIA-232 and V.28/V.24 communications
interfaces with automatic shutdown/wakeup features
and high data-rate capabilities.

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 MAX3225/MAX3227/MAX3245 also feature
MegaBaud™ operation, guaranteeing 1Mbps for high­speed applications such as communicating with ISDN
modems. The MAX3224/MAX3226/MAX3244 guarantee
250kbps operation. The transceivers have a proprietary
low-dropout transmitter output stage enabling true RS­232 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 MAX3224–MAX3227 feature a logic-level 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,
TSSOP, and SSOP packages.

________________________Applications

Notebook, Subnotebook, and Palmtop Computers

Cellular Phones

Battery-Powered Equipment

Hand-Held Equipment

Peripherals

Printers

_Next Generation Device Features

♦ For Smaller Packaging:

MAX3228/MAX3229: +2.5V to +5.5V RS-232
Transceivers in UCSP™

♦ For Low-Voltage or Data Cable Applications:

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

♦ For Integrated ESD Protection:

MAX3222E/MAX3232E/MAX3237E/MAX3241E

†

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

MAX3224–MAX3227/MAX3244/MAX3245

†

1µA Supply Current, 1Mbps, 3.0V to 5.5V,

RS-232 Transceivers with AutoShutdown Plus

________________________________________________________________ Maxim Integrated Products 1

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

MAX3224

MAX3225

MAX3226

1/1

2/2

2/2

NO. OF

DRIVERS/

RECEIVERS

READY

OUTPUT

✔

✔

✔

AUTO-

SHUTDOWN

PLUS

✔

✔

✔

250k

1M

250k

GUARANTEED

DATA RATE

(bps)

MAX3227

MAX3244

MAX3245

3/5

3/5

1/1

✔

—

—

✔

✔

✔

1M

250k

1M

Ordering Information continued at end of data sheet.

_____________________ Selector Guide

_______________Ordering Information

PART

TEMP RANGE

PIN-PACKAGE

PKG

CODE

M A X3 2 2 4C P P

20 Plastic DIP —

M AX3224C AP

20 S S OP

T4477- 3

M AX3224C TP

20 Thin QFN-EP*

T2055-5

M AX3224C U P

20 TS S OP —

M AX3224E P P

20 Plastic DIP —

M AX3224E AP

20 S S OP —

M AX3224E TP

20 Thin QFN-EP*
5mm x 5mm

T2055-5

M AX3224E U P

20 TS S OP —

*EP = Exposed paddle.

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

MAX3224–MAX3227/MAX3244/MAX3245

†

1µA Supply Current, 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 TQFN (derate 21.3mW/°C above +70°C)........1702.1mW

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

20-Pin TSSOP (derate 7.00mW/°C above +70°C) .......559mW

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

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

Operating Temperature Ranges

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

MAX32_ _E_ _..................................................-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 (MAX3244/MAX3245), 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

MAX3224–MAX3227/MAX3244/MAX3245

†

1µA Supply Current, 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
(MAX3224–MAX3227)
Output Voltage High

V0.4

INVALID, READY
(MAX3224–MAX3227)
Output Voltage Low

V-0.3 0.3

Receiver Input Threshold to
INVALID Output Low

-2.7

V

2.7

Receiver Input Threshold to
INVALID Output High

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

VCC= 0 or 3V to 5.5V, V

OUT

= ±12V,

Transmitters disabled

TRANSMITTER OUTPUTS

MOUSE DRIVEABILITY (MAX3244/MAX3245)

AUTOSHUTDOWN PLUS (FORCEON = GND, FORCEOFF = VCC)

MAX3224–MAX3227/MAX3244/MAX3245

†

1µA Supply Current, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus

4 _______________________________________________________________________________________

TIMING CHARACTERISTICS—MAX3224/MAX3226/MAX3244

(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—MAX3225/MAX3227/MAX3245

(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 2500pF

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

Normal operation (MAX3244 only)

Normal operation (MAX3244 only)

(Note 3)

CONDITIONS

0.15t

PLH

µs

0.15t

PHL

kbps250Maximum Data Rate

Receiver Propagation Delay

V/µs

430

630

Transition-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

(Note 3)

R_IN to R_OUT, CL= 150pF

Normal operation (MAX3245 only)

Normal operation (MAX3245 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

MAX3224–MAX3227/MAX3244/MAX3245

†

1µA Supply Current, 1Mbps, 3.0V to 5.5V,

RS-232 Transceivers with AutoShutdown Plus

_______________________________________________________________________________________ 5

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

0 1000 2000 3000 4000 5000

MAX3224/MAX3226

TRANSMITTER OUTPUT VOLTAGE

vs. LOAD CAPACITANCE

MAX3224-01

LOAD CAPACITANCE (pF)

TRANSMITTER OUTPUT VOLTAGE (V)

T1 TRANSMITTING AT 250kbps
T2 (MAX3224) TRANSMITTING AT 15.6kbps

V

OUT+

V

OUT-

0

2

4

6

8

10

12

14

16

0 1000 2000 3000 4000 5000

MAX3224/MAX3226

SLEW RATE vs. LOAD CAPACITANCE

MAX3224-02

LOAD CAPACITANCE (pF)

SLEW RATE (V/µs)

-SLEW

+SLEW

FOR DATA RATES UP TO 250kbps

0

5

10

15

20

25

30

35

40

45

020001000 3000 4000 5000

MAX3224/MAX3226

OPERATING SUPPLY CURRENT

vs. LOAD CAPACITANCE

MAX3224-03

LOAD CAPACITANCE (pF)

SUPPLY CURRENT (mA)

250kbps

120kbps

20kbps

T1 TRANSMITTING AT 250kbps
T2 (MAX3224) TRANSMITTING AT 15.6kbps

-7.5

0

-2.5

-5.0

2.5

5.0

7.5

01000500 1500 2000 2500

MAX3225/MAX3227

TRANSMITTER OUTPUT VOLTAGE

vs. LOAD CAPACITANCE

MAX3224-04

LOAD CAPACITANCE (pF)

TRANSMITTER OUTPUT VOLTAGE (V)

2Mbps

2Mbps

1.5Mbps

1.5Mbps

1Mbps

1Mbps

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

(MAX3225)
LOAD = 3kΩ + C

L

0

15

10

5

20

25

30

35

40

45

50

01000500 1500 2000 2500 3000

MAX3225/MAX3227

TRANSMITTER SKEW vs.

LOAD CAPACITANCE

MAX3224-07

LOAD CAPACITANCE (pF)

TRANSMITTER SKEW (ns)

AVERAGE; 10 PARTS

1 TRANSMITTER AT 512kbps
1 TRANSMITTER AT 30kbps

(MAX3225)
LOAD = 3kΩ + C

L

0

80

70

60

50

40

30

20

10

0 500 1000 1500 2000 2500

MAX3225/MAX3227

SLEW RATE vs. LOAD CAPACITANCE

MAX3224-05

LOAD CAPACITANCE (pF)

SLEW RATE (V/µs)

1 TRANSMITTER AT 1Mbps
1 TRANSMITTER AT 62.5kbps (MAX3225)

-SLEW

+SLEW

0

20

10

40

30

60

50

70

90

80

100

05001000 1500 2000 2500

MAX3225/MAX3227

OPERATING SUPPLY CURRENT

vs. LOAD CAPACITANCE

MAX3224-06

LOAD CAPACITANCE (pF)

SUPPLY CURRENT (mA)

2Mbps

1.5Mbps

1Mbps

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

(MAX3225)
LOAD = 3kΩ + C

L

20

24

22

30

28

26

36

34

32

38

-40 0 20-20 40 60 80 100

MAX3224–MAX3227

READY TURN-ON TIME

vs. TEMPERATURE

MAX3224-08

TEMPERATURE (°C)

READY TURN-ON TIME (µs)

0

200

180

160

140

120

100

80

60

40

20

-40 0 20-20 40 6080100

MAX3224–MAX3227

READY TURN-OFF TIME

vs. TEMPERATURE

MAX3224-09

TEMPERATURE (°C)

READY TURN-OFF TIME (ns)

__________________________________________Typical Operating Characteristics

(VCC= +3.3V, 250kbps data rate, C1–C4 = 0.1µF, all transmitters loaded with 3kΩ and CL, TA= +25°C, unless otherwise noted.)

MAX3224–MAX3227/MAX3244/MAX3245

†

1µA Supply Current, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus

6 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

(VCC= +3.3V, 250kbps data rate, C1–C4 = 0.1µF, 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

MAX3244

TRANSMITTER OUTPUT VOLTAGE

vs. LOAD CAPACITANCE

MAX3224-10

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

MAX3244

SLEW RATE vs. LOAD CAPACITANCE

MAX3224-11

LOAD CAPACITANCE (pF)

SLEW RATE (V/

µ

s)

0

30

20

10

40

50

60

0 20001000 3000 4000 5000

MAX3244

OPERATING SUPPLY CURRENT

vs. LOAD CAPACITANCE

MAX3224-12

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

MAX3245

TRANSMITTER OUTPUT VOLTAGE

vs. LOAD CAPACITANCE

MAX3224-13

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

MAX3245

OPERATING SUPPLY CURRENT

vs. LOAD CAPACITANCE

MAX3224-15

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

0400 800 1200 1600 2000

MAX3245

SLEW RATE vs. LOAD CAPACITANCE

MAX3224-14

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

01000 2000 3000

MAX3245

TRANSMITTER SKEW vs.

LOAD CAPACITANCE

MAX3224-16

LOAD CAPACITANCE (pF)

TRANSMITTER SKEW (ns)

_______________Detailed Description

Dual Charge-Pump Voltage Converter

The MAX3224–MAX3227/MAX3244/MAX3245’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 (MAX3224–MAX3227) is low when
the charge pumps are disabled in shutdown mode. The
READY signal asserts high when V- goes below -4V.

MAX3224–MAX3227/MAX3244/MAX3245

†

1µA Supply Current, 1Mbps, 3.0V to 5.5V,

RS-232 Transceivers with AutoShutdown Plus

_______________________________________________________________________________________ 7

Pin Description

LapLink is a trademark of Traveling Software.

PIN

MAX3224
MAX3225

DIP/

SSIP/

TSSOP

NAME FUNCTION

1191 —READY

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

21 228C1+ Positive Terminal of Voltage-Doubler Charge-Pump Capacitor

3203 27 V+ +5.5V Generated By the Charge Pump

42 424C1- Negative Terminal of Voltage-Doubler Charge-Pump Capacitor

53 51C2+ Positive Terminal of Inverting Charge-Pump Capacitor

64 62C2- Negative Terminal of Inverting Charge-Pump Capacitor

75 73V--5.5V Generated By the Charge Pump

8, 17

13

T_OUT RS-232 Transmitter Outputs

9, 16

8 4–8 R_IN RS-232 Receiver Inputs

10, 15

9 15–19 R_OUT TTL/CMOS Transmitter Outputs

11 9 10 21

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

T_IN TTL/CMOS Transmitter Inputs

14 12 12 23

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

18 16 14 25 GND Ground

19 17 15 26 V

CC

+3.0V to +5.5V Single Supply Voltage

20 18 16 22

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

TTL/CMOS Noninverting Complementary Receiver Outputs. Always
active.

—EP — — EP

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

TQFN

6, 15

7, 14

8, 13

10, 11

MAX3226
MAX3227

MAX3244
MAX3245

9, 10, 11

INVALID

12, 13, 14

FORCEON

FORCEOFF

R2OUTB