MAX3226CAE ,1microA supply current, 1Mbps, 3.0V to 5.5V, RS-232 transceiver with autoshutdown plusfeaturesand high data-rate capabilities.' Guaranteed Data Rate:All devices achieve a 1µA supply cur ..
MAX3226CAE+ ,1µA Supply Current, 1Mbps, 3.0V to 5.5V, RS-232 Transceivers with AutoShutdown PlusMAX3224–MAX3227/ MAX3244/MAX32451µA Supply Current, 1Mbps, 3.0V to 5.5V, RS-232 Transceivers with A ..
MAX3226EAAE+ ,±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V, RS-232 Transceivers with AutoShutdown PlusFeaturesThe MAX3224E/MAX3225E/MAX3226E/MAX3227E/ ESD Protection for RS-232 I/O Pins:MAX3244E/MAX3 ..
MAX3226EAE ,1microA supply current, 1Mbps, 3.0V to 5.5V, RS-232 transceiver with autoshutdown plusApplicationsMAX3225EAP -40°C to +85°C 20 SSOPOrdering Information continued at end of data sheet.No ..
MAX3226EAE+ ,±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V, RS-232 Transceivers with AutoShutdown PlusFeaturesThe MAX3224E/MAX3225E/MAX3226E/MAX3227E/ ESD Protection for RS-232 I/O Pins:MAX3244E/MAX3 ..
MAX3226ECAE ,+-15kV ESD-protected, 1microA, 1Mbps, 3.0V to 5.5V, RS-232 transceiver with autoshutdown plus.FeaturesThe MAX3224E/MAX3225E/MAX3226E/MAX3227E/' ESD Protection for RS-232 I/O Pins:MAX3244E/MAX32 ..
MAX6652AUB ,Temperature Sensor and System Monitor in a 10-Pin UMAXApplicationsoutput can also be masked by writing to the appropriateWorkstations Networkingbits in t ..
MAX6652AUB+ ,Temperature Sensor and System Monitor in a 10-Pin µMAXfeatures 60Hz or 50Hz line-frequencyrejection for optimal performance. The device operatesfrom +2.7 ..
MAX6652AUB+T ,Temperature Sensor and System Monitor in a 10-Pin µMAXApplicationsoutput can also be masked by writing to the appropriateWorkstations Networkingbits in t ..
MAX6653AEE ,Temperature Monitors and PWM Fan ControllersFeaturesThe MAX6653/MAX6663/MAX6664 are ACPI-compliant Remote-Junction Temperature Sensor Withinlo ..
MAX6653AEE+ ,Temperature Monitors and PWM Fan ControllersFeaturesThe MAX6653/MAX6663/MAX6664 are ACPI-compliant♦ Remote-Junction Temperature Sensor Withinlo ..
MAX6653AEE+ ,Temperature Monitors and PWM Fan ControllersELECTRICAL CHARACTERISTICS(V = +3.0V to +5.5V, T = 0°C to +125°C, unless otherwise noted. Typical v ..
MAX3226CAE-MAX3226EAE-MAX3227CAE-MAX3227EAE-MAX3244CAI-MAX3244EAI-MAX3244EWI-MAX3245CAI-MAX3245EAI-MAX3245EWI
1microA supply current, 1Mbps, 3.0V to 5.5V, RS-232 transceiver with autoshutdown plus
________________General DescriptionThe MAX3224–MAX3227/MAX3244/MAX3245 are 3V-
powered 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 receiv-
er 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 high-
speed 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 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 MAX3224–MAX3227 feature a logic-level output
(READY) that asserts when the charge pump is regulat-
ing and the device is ready to begin transmitting.
All devices are available in a space-saving SSOP pack-
age.
________________________ApplicationsNotebook, Subnotebook, and Palmtop Computers
Cellular Phones
Battery-Powered Equipment
Hand-Held Equipment
Peripherals
Printers
____________________________Features1µA Supply Current AutoShutdown Plus—EDN Innovation of the YearGuaranteed Data Rate:
250kbps (MAX3224/3226/3244)
1Mbps (MAX3225/3227/3245)Guaranteed Slew Rate:
6V/µs (MAX3224/3226/3244)
24V/µs (MAX3225/3227/3245)Meets EIA/TIA-232 Specifications Down to 3.0VGuaranteed Mouse Driveability (MAX3244/3245)Ready-to-Transmit Logic-Level Output
MAX3224–MAX3227/MAX3244/MAX3245
1µA Supply Current, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus19-1289; Rev 1; 3/98
MAX3224–MAX3227/MAX3244/MAX3245
1µA Supply Current, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
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= TMINto TMAX,
unless otherwise noted. Typical values are at TA= +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, FORCEOFFto 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 (VCC+ 0.3V)
Short-Circuit Duration
T_OUT to GND.......................................................Continuous
Continuous Power Dissipation (TA= +70°C)
16-Pin SSOP (derate 7.14mW/°C above +70°C).........571mW
20-PinPlastic DIP (derate 11.11mW/°C above +70°C)...889mW
20-Pin SSOP (derate 8.00mW/°C above +70°C).........640mW
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, 10sec).............................+300°C
Note 1:V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V.
MAX3224–MAX3227/MAX3244/MAX3245
1µA Supply Current, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
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= TMINto TMAX,
unless otherwise noted. Typical values are at TA= +25°C.)
MAX3224–MAX3227/MAX3244/MAX3245
1µA Supply Current, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
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= TMINto TMAX,
unless otherwise noted. Typical values are at TA= +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= TMINto TMAX,
unless otherwise noted. Typical values are at TA= +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.
MAX3224–MAX3227/MAX3244/MAX3245
1µA Supply Current, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
__________________________________________Typical Operating Characteristics(VCC= +3.3V, 250kbps data rate, C1–C4 = 0.1µF, all transmitters loaded with 3kΩand 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
Typical Operating Characteristics (continued)(VCC= +3.3V, 250kbps data rate, C1–C4 = 0.1µF, all transmitters loaded with 3kΩand CL, TA= +25°C, unless otherwise noted.)
_______________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.
RS-232 Transmitters The transmitters are inverting level translators that
convert CMOS-logic levels to 5.0V EIA/TIA-232 levels.
The MAX3224/MAX3226/MAX3244 guarantee a
250kbps data rate (1Mbps for the MAX3225/MAX3227/
MAX3245) with worst-case loads of 3kΩin parallel with
1000pF, providing compatibility with PC-to-PC com-
munication software (such as LapLink™). Transmitters
can be paralleled to drive multiple receivers. Figure 1
shows a complete system connection.
MAX3224–MAX3227/MAX3244/MAX3245
1µA Supply Current, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
Pin DescriptionLapLink is a trademark of Traveling Software.
MAX3224–MAX3227/MAX3244/MAX3245When FORCEOFFis driven to ground or when the Auto-
Shutdown Plus circuitry senses that all receiver and
transmitter inputs are inactive for more than 30sec, the
transmitters are disabled and the outputs go into a high-
impedance state. When powered off or shut down, the
outputs can be driven to ±12V. The transmitter inputs
do not have pull-up resistors. Connect unused inputs to
GND or VCC.
RS-232 Receivers The receivers convert RS-232 signals to CMOS-logic
output levels. The MAX3224–MAX3227 feature inverting
outputs that always remain active (Table 1). The
MAX3244/MAX3245 have inverting three-state outputs
that are high impedance when shut down (FORCEOFF
= GND) (Table 1).
1µA Supply Current, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown PlusFigure 1. Interface Under Control of PMU
The MAX3244/MAX3245 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 sys-
tems where VCCis set to ground in shutdown to
accommodate peripherals such as UARTs (Figure 2).
The MAX3224–MAX3227/MAX3244/MAX3245 feature
an INVALIDoutput that is enabled low when no valid
RS-232 voltage levels have been detected on all
receiver inputs. Because INVALIDindicates the receiv-
er input’s condition, it is independent of FORCEON and
FORCEOFFstates (Figures 3 and 4).
AutoShutdown Plus ModeThe MAX3224–MAX3227/MAX3244/MAX3245 achieve a
1µAsupplycurrentwith Maxim’s AutoShutdown
Plusfeature, which operates when FORCEOFFis high
and a FORCEON is low. When these devices do not
sense a valid signal transition on any receiver and trans-
mitter input for 30sec, 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
peripheral transmitters are turned off, and the UART dri-
ving 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 sys-
tem saves power without changes to the existing BIOS
or operating system.
MAX3224–MAX3227/MAX3244/MAX3245
1µA Supply Current, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
Table 1. Output Control Truth TableX = Don’t careINVALIDconnected to FORCEONINVALIDconnected to FORCEON and FORCEOFF
MAX3224–MAX3227/MAX3244/MAX3245Figures 3a and 3b depict valid and invalid RS-232
receiver voltage levels. INVALIDindicates the receiver
input’s condition, and is independent of FORCEON and
FORCEOFFstates. Figure 3 and Tables 1 and 2 sum-
marize the operating modes of the MAX3224–
MAX3227/MAX3244/MAX3245 devices. FORCEON andFORCEOFFoverride 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 transmit-
ter outputs are high impedance, and READY
(MAX3224–MAX3227) is driven low. The time required
to exit shutdown is typically 100µs (Figure 8).
By connecting FORCEON to INVALID, the MAX3224–
MAX3227/MAX3244/MAX3245 shut down when no valid
receiver level and no receiver or transmitter edge is
detected for 30sec, and wake up when a valid receiver
level or receiver or transmitter edge is detected.
By connecting FORCEON and FORCEOFFto INVALID,
the MAX3224–MAX3227/MAX3244/MAX3245shutdown
when no valid receiver level is detected and wake up
1µA Supply Current, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown PlusFigure 3a. INVALIDFunctional Diagram, INVALIDLow
Figure 3b. INVALIDFunctional Diagram, INVALIDHigh
Figure 3c. AutoShutdown Plus Logic
Figure 3d. Power-Down Logic
