Datasheet

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General Description

The MAX3222/MAX3232/MAX3237/MAX3241 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 devices require only

four small 0.1µF external charge-pump capacitors. The

MAX3222, MAX3232, and MAX3241 are guaranteed to

run at data rates of 120kbps while maintaining RS-232

output levels. The MAX3237 is guaranteed to run at data

rates of 250kbps in normal operating mode and 1Mbps in

the MegaBaud™ operating mode.

The MAX3222/MAX3232 have 2 receivers and 2 drivers.

The MAX3222 and MAX3232 are pin, package, and func-

tionally compatible with the industry-standard MAX242

and MAX232, respectively.

The MAX3241 has 5 receivers and 3 drivers, while the

MAX3237 has 3 receivers and 5 drivers. Receivers R1

(MAX3237/MAX3241) and R2 (MAX3241) have extra

outputs in addition to their standard outputs. These extra

outputs are always active, allowing external devices to be

monitored without forward biasing the protection diodes in

circuitry that may have V

completely removed.

The MAX3222, MAX3232, and MAX3241 are available in

space-saving TSSOP and SSOP packages with operating

temperatures of either -40°C to +85°C or 0°C to 70°C.

Applications

● Battery-Powered Equipment

● Hand-Held Equipment

● Peripherals

● Datacom Equipment

Benefits and Features

● Integrated Features Saves Board Space and

Simplifies Design

• Charge Pump Circuitry Eliminates the Need for a

Bipolar ±12V Supply

• Wide Single-Supply Operation From +3V to +5.5V

Supply

• Always-On Extra Outputs Enable Monitoring of

External Devices

● Power Saving Extends Battery Life

• 1µA Supply Current in Shutdown Mode While

Receiver is Active (MAX3222, MAX3237, MAX3241)

Ordering Information continued at end of data sheet.

Typical Operating Circuits appear at end of data sheet.

Pin Configurations continued at end of data sheet.

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; and other patents

pending.

19-0273; Rev 10; 5/19

+Denotes lead-free package.

PART TEMP RANGE

PIN-

PACKAGE

PKG

CODE

MAX3222CUP+ 0°C to +70°C 20 TSSOP U20+2

MAX3222CAP+ 0°C to +70°C 20 SSOP A20+1

MAX3222CWN+ 0°C to +70°C 18 SO W18+1

MAX3222CPN+ 0°C to +70°C 18 Plastic Dip P18+5

Ordering Information

Pin Congurations

SHDN

GND

T1OUT

C1-

V+

C1+

TOP VIEW

R1IN

R1OUT

T1IN

T2IN

T2OUT

V-

C2-

C2+

R2OUTR2IN

DIP/SO

MAX3222

Click here for production status of specic part numbers.

MAX3222/MAX3232/

MAX3237/MAX3241*

3.0V to 5.5V, Low-Power, Up to 1Mbps,

True RS-232 Transceivers

Summary of content (17 pages)

PAGE 1
Click here for production status of specific part numbers. MAX3222/MAX3232/ MAX3237/MAX3241* General Description The MAX3222/MAX3232/MAX3237/MAX3241 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 devices require only four small 0.1µF external charge-pump capacitors. The MAX3222, MAX3232, and MAX3241 are guaranteed to run at data rates of 120kbps while maintaining RS-232 output levels.
PAGE 2
MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Absolute Maximum Ratings VCC...........................................................................-0.3V to +6V V+ (Note 1)...............................................................-0.3V to +7V V- (Note 1)................................................................+0.3V to -7V V+ + V- (Note 1)...................................................................+13V Input Voltages T_IN, SHDN, EN......
PAGE 3
MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Electrical Characteristics (continued) (VCC = +3.0V to +5.5V, C1–C4 = 0.1μF (Note 2), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER CONDITIONS MIN Input Hysteresis Input Resistance TYP MAX 0.3 TA = +25°C 3 5 UNITS V 7 kΩ TRANSMITTER OUTPUTS Output Voltage Swing All transmitter outputs loaded with 3kΩ to ground ±5.0 ±5.
PAGE 4
MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Timing Characteristics—MAX3237 (VCC = +3.0V to +5.5V, C1–C4 = 0.1μF (Note 2), TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER CONDITIONS Maximum Data Rate MIN RL = 3kΩ, CL = 1000pF, one transmitter switching, MBAUD = GND 250 VCC = 3.0V to 4.5V, RL = 3kΩ, CL = 250pF, one transmitter switching, MBAUD = VCC 1000 VCC = 4.5V to 5.
PAGE 5
MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Typical Operating Characteristics (continued) (VCC = +3.3V, 235kbps data rate, 0.1μF capacitors, all transmitters loaded with 3kΩ, TA = +25°C, unless otherwise noted.) MAX3241 SLEW RATE vs. LOAD CAPACITANCE 5.0 24 22 1 TRANSMITTER AT 235kbps 2 TRANSMITTERS AT 30kbps 0 -2.5 VOUT- -5.
PAGE 6
MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Pin Description PIN MAX3222 MAX3232 MAX3237 MAX3241 NAME FUNCTION DIP/SO SSOP 1 1 — 13 23 EN Receiver Enable. Active low. 2 2 1 28 28 C1+ Positive Terminal of Voltage-Doubler Charge-Pump Capacitor 3 3 2 27 27 V+ +5.
PAGE 7
MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Detailed Description The MAX3222/MAX3237/MAX3241’s output stage is turned off (high impedance) when the device is in shutdown mode. When the power is off, the MAX3222/ MAX3232/MAX3237/MAX3241 permit the outputs to be driven up to ±12V. Dual Charge-Pump Voltage Converter The MAX3222/MAX3232/MAX3237/MAX3241’s internal power supply consists of a regulated dual charge pump that provides output voltages of +5.
PAGE 8
MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers RS-232 Receivers The receivers convert RS-232 signals to CMOS-logic output levels. The MAX3222/MAX3237/MAX3241 receivers have inverting three-state outputs. In shutdown, the receivers can be active or inactive (Table 1). The complementary outputs on the MAX3237 (R1OUTB) and the MAX3241 (R1OUTB, R2OUTB) are always active, regardless of the state of EN or SHDN.
PAGE 9
MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Table 1. MAX3222/MAX3237/MAX3241 Shutdown and Enable Control Truth Table Power-Supply Decoupling SHDN EN T_OUT R_OUT R_OUTB (MAX3237/ MAX3241) 0 0 High-Z Active Active 0 1 High-Z High-Z Active 1 0 Active Active Active 1 1 Active High-Z Active Table 2. Required Minimum Capacitor Values V CC (V) C1 (µF) C2, C3, C4 (µF) MAX3222/MAX3232/MAX3241 3.0 to 3.6 0.1 0.1 4.5 to 5.5 0.
PAGE 10
3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers 6 5 4 3 VOUT+ VCC = 3.0V 2 1 T1 0 -1 T2 MAX3222-04 TRANSMITTER OUTPUT VOLTAGE (V) MAX3222/MAX3232/ MAX3237/MAX3241 VOUT+ -2 -3 VCC VOUT- T3 VOUT- -4 -5 -6 0 1 2 3 4 5 6 7 LOAD CURRENT PER TRANSMITTER (mA) Figure 4a. MAX3241 Transmitter Output Voltage vs. Load Current per Transmitter VCC = 3V to 5.5V 28 C1 C2 C1+ 0.
PAGE 11
MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers VCC 0.1µF V+ C3 C1C2+ C2 C2- 5V/div T1OUT 5V/div R1OUT 5V/div VCC C1+ C1 T1IN MAX3222 MAX3232 MAX3237 MAX3241 VC4 5µs/div VCC = 3.3V T_ OUT T_ IN Figure 6. MAX3241 Loopback Test Result at 120kbps R_ IN R_ OUT 0V VCC EN* SHDN* 5kΩ 1000pF T1IN 5V/div T1OUT 5V/div R1OUT 5V/div GND * MAX3222/MAX3241 ONLY Figure 5.
PAGE 12
MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Interconnection with 3V and 5V Logic Table 3. Logic-Family Compatibility with Various Supply Voltages The MAX3222/MAX3232/MAX3237/MAX3241 can directly interface with various 5V logic families, including ACT and HCT CMOS. See Table 3 for more information on possible combinations of interconnections. SYSTEM POWERSUPPLY VOLTAGE (V) MAX32_ _ V CC SUPPLY VOLTAGE (V) 3.3 3.3 5 5 5 3.
PAGE 13
MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Typical Operating Circuits (continued) 0.1µF +3.3V 26 0.1µF 28 C1+ 3 C2+ 27 0.1µF MAX3237 V- 4 23 T2IN 22 T3IN 19 T4IN T1 T2 T3 0.
PAGE 14
MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Pin Configurations (continued) TOP VIEW EN 1 20 SHDN C1+ 2 19 VCC C1+ 1 V+ 3 18 GND V+ 2 15 GND C1- 4 17 T1OUT C1- 3 14 T1OUT C2+ 5 16 R1IN C2+ 4 C2- 6 15 R1OUT C2- 5 V- 7 14 N.C. V- 6 11 T1IN T2OUT 8 13 T1IN T2OUT 7 10 T2IN R2IN 9 12 T2IN R2IN 8 R2OUT 10 11 N.C.
PAGE 15
MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.
PAGE 16
MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.5V, Low-Power, Up to 1Mbps, True RS-232 Transceivers Package Information For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status.
PAGE 17
MAX3222/MAX3232/ MAX3237/MAX3241 3.0V to 5.