MAX3225ECPP ,【15kV ESD-Protected, 1レA, 1Mbps, 3.0V to 5.5V, RS-232 Transceivers with AutoShutdown Plusfeatures, high data-rate capabili-±15kV—IEC1000-4-2, Air-Gap Dischargeties, and enhanced electrosta ..
MAX3225ECUP ,±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V, RS-232 Transceivers with AutoShutdown PlusGeneral Description ________
MAX3225ECUP+ ,±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V, RS-232 Transceivers with AutoShutdown PlusELECTRICAL CHARACTERISTICS(V = +3V to +5.5V, C1–C4 = 0.1µF, tested at 3.3V ±10%; C = 0.047µF, C2–C4 ..
MAX3225ECUP+ ,±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V, RS-232 Transceivers with AutoShutdown PlusApplicationsOrdering Information continued at end of data sheet.Notebook, Subnotebook, and Palmtop ..
MAX3225EEAP ,【15kV ESD-Protected, 1レA, 1Mbps, 3.0V to 5.5V, RS-232 Transceivers with AutoShutdown PlusApplicationsOrdering Information continued at end of data sheet.Notebook, Subnotebook, and Palmtop ..
MAX3225EEAP ,【15kV ESD-Protected, 1レA, 1Mbps, 3.0V to 5.5V, RS-232 Transceivers with AutoShutdown PlusGeneral Description ________
MAX664ESA+ ,Dual Mode™ 5V Programmable Micropower Voltage Regulators19-0921;Rev1;7/96 IVI/JXI/VI
Dual Mode"' SWProgrammahte
Micropower Voltage Regulators
E
MAX6650EUB ,Fan-Speed Regulators and Monitors with SMBus/I2C-Compatible InterfaceApplicationsI C is a trademark of Philips Corp.RAID Desktop ComputersPin Configurations appear at e ..
MAX6650EUB+ ,Fan-Speed Regulators and Monitors with SMBus/I²C-Compatible InterfaceFeatures♦ Closed/Open-Loop Fan-Speed Control for The MAX6650/MAX6651 fan controllers use an25V/12V ..
MAX6650EUB+T ,Fan-Speed Regulators and Monitors with SMBus/I²C-Compatible InterfaceFeatures♦ Closed/Open-Loop Fan-Speed Control for The MAX6650/MAX6651 fan controllers use an25V/12V ..
MAX6650EUB+T ,Fan-Speed Regulators and Monitors with SMBus/I²C-Compatible InterfaceEVALUATION KIT AVAILABLE MAX6650/MAX6651Fan-Speed Regulators and Monitors 2with SMBus/I C-Compatib ..
MAX6651EEE ,Fan-Speed Regulators and Monitors with SMBus/I2C-Compatible InterfaceFeaturesThe MAX6650/MAX6651 fan controllers use an Closed/Open-Loop Fan-Speed Control for 2SMBus™ ..
MAX3224ECAP-MAX3224EEAP-MAX3225ECAP-MAX3225ECPP-MAX3225EEAP
【15kV ESD-Protected, 1レA, 1Mbps, 3.0V to 5.5V, RS-232 Transceivers with AutoShutdown Plus
________________General DescriptionThe MAX3224E/MAX3225E/MAX3226E/MAX3227E/
MAX3244E/MAX3245E are 3V-powered EIA/TIA-232
and V.28/V.24 communications interfaces with automat-
ic shutdown/wakeup features, high data-rate capabili-
ties, 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 receiv-
er 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 high-
speed applications such as communicating with ISDN
modems. The MAX3224E/MAX3226E/MAX3244E guar-
antee 250kbps operation. The transceivers have a pro-
prietary 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 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 SSOP pack-
age.
________________________ApplicationsNotebook, Subnotebook, and Palmtop Computers
Cellular Phones
Battery-Powered Equipment
Hand-Held Equipment
Peripherals
Printers
____________________________FeaturesESD Protection for RS-232 I/O Pins:
±15kV—Human Body Model
±8kV—IEC1000-4-2, Contact Discharge
±15kV—IEC1000-4-2, Air-Gap DischargeLatchup Free1µA Supply Current AutoShutdown Plus—EDN Innovation of the YearGuaranteed Data Rate:
250kbps (MAX3224E/3226E/3244E)
1Mbps (MAX3225E/3227E/3245E)Guaranteed Slew Rate:
6V/µs (MAX3224E/3226E/3244E)
24V/µs (MAX3225E/3227E/3245E)Meets EIA/TIA-232 Specifications Down to 3.0VGuaranteed Mouse Driveability
(MAX3244E/3245E)Ready-to-Transmit Logic-Level Output
MAX3224E–MAX3227E/MAX3244E/MAX3245E
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus19-1339; Rev 0; 1/98
MAX3224E–MAX3227E/MAX3244E/MAX3245
±15kV ESD-Protected, 1µA, 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_ _EC_ _.................................................0°C to +70°C
MAX32_ _EE_ _................................................-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.
MAX3224E–MAX3227E/MAX3244E/MAX3245
±15kV ESD-Protected, 1µA, 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.)
MAX3224E–MAX3227E/MAX3244E/MAX3245
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
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= TMINto TMAX,
unless otherwise noted. Typical values are at TA= +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= 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.
MAX3224E–MAX3227E/MAX3244E/MAX3245
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
__________________________________________Typical Operating Characteristics(VCC= +3.3V, 250kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩand CL, TA= +25°C, unless otherwise noted.)
MAX3224E–MAX3227E/MAX3244E/MAX3245
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
_____________________________Typical Operating Characteristics (continued)(VCC= +3.3V, 250kbps data rate, 0.1µF capacitors, all transmitters loaded with 3kΩand CL, TA= +25°C, unless otherwise noted.)
_______________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.
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 3kΩin parallel with
1000pF, providing compatibility with PC-to-PC com-
MAX3224E–MAX3227E/MAX3244E/MAX3245
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown Plus
______________________________________________________________Pin Description
MAX3224E–MAX3227E/MAX3244E/MAX3245munication software (such as LapLink™). Transmitters
can be paralleled to drive multiple receivers. Figure 1
shows a complete system connection.
When 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 MAX3224E–MAX3227E feature
inverting outputs that always remain active (Table 1).
The MAX3244E/MAX3245E have inverting three-state
±15kV ESD-Protected, 1µA, 1Mbps, 3.0V to 5.5V,
RS-232 Transceivers with AutoShutdown PlusFigure 1. Interface Under Control of PMU
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 sys-
tems where VCCis set to ground in shutdown to
accommodate peripherals such as UARTs (Figure 2).
The MAX3224E–MAX3227E/MAX3244E/MAX3245E fea-
ture 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 MAX3224E–MAX3227E/MAX3244E/MAX3245E
achieve a1µAsupplycurrentwith Maxim’s AutoShutdown
Plus feature, 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-
MAX3224E–MAX3227E/MAX3244E/MAX3245
±15kV ESD-Protected, 1µA, 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
MAX3224E–MAX3227E/MAX3244E/MAX3245tem saves power without changes to the existing BIOS
or operating system.
Figures 3a and 3b depict valid and invalid RS-232
receiver voltage levels. INVALIDindicates the receiver
input’s condition, and is independent of FORCEON andFORCEOFFstates. Figure 3 and Tables 1 and 2 sum-
marize the operating modes of the MAX3224E–
MAX3227E/MAX3244E/MAX3245E. FORCEON and
FORCEOFFoverride 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
(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 30sec, and wake up when a valid receiver
level or receiver or transmitter edge is detected.
By connecting FORCEON and FORCEOFFto INVALID,
the MAX3224E–MAX3227E/MAX3244E/MAX3245Eshut
down when no valid receiver level is detected and
±15kV ESD-Protected, 1µA, 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
