MAX221EEAE+ ,±15kV ESD-Protected, +5V, 1µA, Single RS-232 Transceiver with AutoShutdownELECTRICAL CHARACTERISTICS(V = +5V ±10%, C1–C4 = 0.1µF, T = T to T , unless otherwise noted. Typica ..
MAX221EEAE+ ,±15kV ESD-Protected, +5V, 1µA, Single RS-232 Transceiver with AutoShutdownFeaturesThe MAX221E is a +5V powered, single transmit/♦ Single RS-232 Transceiver in a Small 16-Pin ..
MAX221EEAE+ ,±15kV ESD-Protected, +5V, 1µA, Single RS-232 Transceiver with AutoShutdownApplicationsTypical Operating CircuitMaintenance/Diagnostic PortsIndustrial Systems+5V 15Telecommun ..
MAX221EEAE-T ,±15kV ESD-Protected, +5V, 1µA, Single RS-232 Transceiver with AutoShutdownfeatures enhanced electrostatic discharge±15kV—IEC 1000-4-2, Air-Gap Discharge(ESD) protection. Bot ..
MAX221EEUE ,【15kV ESD-Protected, +5V, 1レA, Single RS-232 Transceiver with AutoShutdownApplicationsTypical Operating CircuitMaintenance/Diagnostic PortsIndustrial Systems+5V 15Telecommun ..
MAX221EEUE+ ,±15kV ESD-Protected, +5V, 1µA, Single RS-232 Transceiver with AutoShutdownELECTRICAL CHARACTERISTICS(V = +5V ±10%, C1–C4 = 0.1µF, T = T to T , unless otherwise noted. Typica ..
MAX530AEAG+ ,+5V, Low-Power, Parallel-Input, Voltage-Output, 12-Bit DACapplications. In40μA Shutdown-Mode Currentaddition, the SSOP (Shrink-Small-Outline-Package) mea-sur ..
MAX530AENG+ ,+5V, Low-Power, Parallel-Input, Voltage-Output, 12-Bit DACFeatures♦ Buffered Voltage OutputThe MAX530 is a low-power, 12-bit, voltage-output digi-tal-to-anal ..
MAX530AEWG ,+5V, Low-Power, Parallel-Input, Voltage-Output, 12-Bit DACApplications /MAX530ACNG 0°C to +70°C 24 Narrow Plastic DIP ±2Battery-Powered Data-Conversion Produ ..
MAX530BCAG ,+5V, Low-Power, Parallel-Input, Voltage-Output, 12-Bit DACGeneral Description ________
MAX530BCAG+ ,+5V, Low-Power, Parallel-Input, Voltage-Output, 12-Bit DACfeatures but with a serial data interface, referto the MAX531/MAX538/MAX539 data sheet.ERRORPART TE ..
MAX530BCNG ,+5V, Low-Power, Parallel-Input, Voltage-Output, 12-Bit DACFeatures' Buffered Voltage OutputThe MAX530 is a low-power, 12-bit, voltage-output digi-tal-to-anal ..
MAX221EAE+-MAX221ECAE+-MAX221ECUE+-MAX221EEAE+-MAX221EEAE-T-MAX221EEUE+-MAX221EUE+
±15kV ESD-Protected, +5V, 1µA, Single RS-232 Transceiver with AutoShutdown
General DescriptionThe MAX221E is a +5V powered, single transmit/
receive RS-232 and V.28 communications interface with
automatic shutdown/wake-up features and high data
rate capabilities.
The MAX221E features enhanced electrostatic discharge
(ESD) protection. Both the transmitter output and receiver
input are protected to ±15kV using the IEC 1000-4-2 Air-
Gap Discharge Method, to ±8kV using the IEC 1000-4-2
Contact Discharge Method, and to ±15kV using the
Human Body Model.
The MAX221E achieves a low 1µA supply current with
Maxim’s revolutionary AutoShutdown™ feature.
AutoShutdown saves power without changes to the
existing BIOS or operating system by entering low-
power shutdown mode when the RS-232 cable is dis-
connected or when the transmitter of the connected
peripheral is off. The MAX221E wakes up and drives the
INVALIDpin high when an active RS-232 cable is con-
nected, signaling the host that a peripheral is connected
to the communications port.
The MAX221E is available in a 16-pin SSOP package as
well as a 16-pin TSSOP that uses 50% less board space
than a 16-pin SO.
ApplicationsMaintenance/Diagnostic Ports
Industrial Systems
Telecommunications
Set-Top Boxes
FeaturesSingle RS-232 Transceiver in a Small 16-Pin TSSOPESD Protection for RS-232 I/O Pins
±15kV—Human Body Model
±8kV—IEC 1000-4-2, Contact Discharge
±15kV—IEC 1000-4-2, Air-Gap DischargeLatchup Free1μA Supply CurrentAutoShutdown Saves Power without Changes
to BIOSGuaranteed 250kbps Data Rate
MAX221E
±15kV ESD-Protected, +5V, 1µA, Single RS-232
Transceiver with AutoShutdown FORCEOFF
VCC
GND
TOUT
FORCEON
TIN
INVALID
ROUT
TOP VIEW
MAX221E
TSSOP/SSOPC1+
C2-
C1-
C2+
RIN
MAX221E
FORCEON
ROUT9
FORCEOFF16
INVALID10
GND
TIN11
C2-6
C2+5
C1-4
C1+2
RIN8
TOUT137VCC
VCC
0.1μF
0.1μF
15
C1
0.1μF
C2
0.1μF
CBYPASS
0.1μF
+5V
TO POWER-
MANAGEMENT
UNIT
CAPACITORS MAY BE
POLARIZED OR UNPOLARIZED.
ypical Operating Circuit19-1527; Rev 0; 8/99
PARTMAX221ECUE
MAX221ECAE
MAX221EEUE40°C to +85°C
0°C to +70°C
0°C to +70°C
TEMP. RANGEPIN-PACKAGE16 TSSOP
16 SSOP
16 TSSOP
Pin Configuration
Ordering InformationAutoShutdown is a trademark of Maxim Integrated Products.
MAX221EEAE40°C to +85°C16 SSOP
MAX221E
±15kV ESD-Protected, +5V, 1µA, Single RS-232
Transceiver with AutoShutdown
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(VCC = +5V ±10%, C1–C4 = 0.1µF, 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.
VCC..........................................................................-0.3V to +6V
V+ ...............................................................(VCC- 0.3V) to +14V
V- ...........................................................................-14V to +0.3V
Input Voltages
TIN............................................................-0.3V to (V+ + 0.3V)
RIN...................................................................................±30V
FORCEON, FORCEOFF, EN..................-0.3V to (VCC+ 0.3V)
Output Voltages
TOUT................................................(V- - 0.3V) to (V+ + 0.3V)
ROUT, INVALID......................................-0.3V to (VCC+ 0.3V)
Short-Circuit Duration, TOUT.....................................Continuous
Continuous Power Dissipation (TA= +70°C)
16-Pin TSSOP (derated 6.7mW/°C above +70°C).......533mW
16-Pin SSOP (derated 7.1mW/°C above +70°C).........571mW
Operating Temperature Range
MAX221EC_ _.....................................................0°C to +70°C
MAX221EE_ _..................................................-40°C to +85°C
Maximum Junction Temperature....................................+150°C
Storage Temperature Range ...........................-65°C to +150°C
Lead Temperature (soldering, 10sec)............................+300°C
Figure 3
Figure 3
No load, TA= +25°C
Figure 3
ISOURCE= 1.0mA
ISINK= 1.6mA
CONDITIONSICC= 1µA, Figure 3
ROUT; ISINK= 3.2mA
Figure 3
TIN, EN, FORCEOFF, FORCEON= +25°C, Figure 1= VCC, 0 ≤ROUT ≤VCC
TIN = 0 to VCC
ROUT; ISOURCE= 1.0mA30tINVLReceiver Positive or Negative
Threshold to INVALIDLow1tINVHReceiver Positive or Negative
Threshold to INVALIDHigh250tWUReceiver Threshold to
Transmitter Enabled VCC- 0.6INVALIDOutput Voltage High0.4INVALIDOutput Voltage Low-0.30.3Receiver Input Threshold,
Transmitter Disabled
Positive thresholdV2.7Receiver Input Threshold,
Transmitter Enabled±0.05±10
Negative threshold
Output Leakage Current3.5VOHOutput Voltage High510ICCVCCSupply Current
UNITSMINTYPMAXSYMBOLPARAMETER0.4VOLOutput Voltage Low0.8VILInput Threshold Low110ISHDNShutdown Supply Current110IASAutoShutdown Supply Current±1Input Leakage Current
EN, FORCEOFF, TINV2.4VIHInput Threshold High
DC CHARACTERISTICS
LOGIC INPUTS
AUTOSHUTDOWN
MAX221E
±15kV ESD-Protected, +5V, 1µA, Single RS-232
Transceiver with AutoShutdown
TIMING CHARACTERISTICS(VCC= +5V ±10%, C1–C4 = 0.1µF, TA = TMINto TMAX, unless otherwise noted. Typical values are at TA= +25°C.)
ELECTRICAL CHARACTERISTICS (continued)(VCC = +5V ±10%, C1–C4 = 0.1µF, TA= TMINto TMAX, unless otherwise noted. Typical values are at TA= +25°C.)
Note 1:Transmitter skew is measured at the transmitter zero crosspoints.= 3kΩto 7kΩ, CL= 50pF to 1000pF,
VCC= 4.5V
CONDITIONSkbps250Maximum Data Rate
UNITSMINTYPMAXSYMBOLPARAMETER= +25°C, VCC= 5V, RL= 3kΩto 7kΩ, = 500pF to 1000pF, measured from
-3V to +3V or +3V to -3V
(Note 1)
Normal operation
Normal operation= 150pF
V/µs3630Transition-Region Slew Rate50|tPHL tPLH|Receiver Skew200|tPHL tPLH|Transmitter Skew200Receiver Output Disable Time300Receiver Output Enable Time0.15tPHL,tPLHReceiver Propagation Delay
CONDITIONSUNITSMINTYPMAXSYMBOLPARAMETERVCC = V+ = V- = 0, VOUT= ±2V
Driver loaded with 3kΩto ground = +25°C, VCC = 5V
VCC= 5V, no hysteresis in shutdown= +25°C, VCC= 5V= +25°C, VCC= 5V±10±60Output Short-Circuit Current300Output Resistance±5±9Output Voltage Swing357Input Resistance 0.5Input Hysteresis1.72.4Input Threshold High0.81.2Input Threshold Low-2525Input Voltage Range
IEC 1000-4-2 Air-Gap Discharge
±15
RIN, TOUTIEC 1000-4-2 Contact Discharge±8
Human Body Model±15
RECEIVER INPUT
TRANSMITTER OUTPUT
ESD PROTECTION
MAX221E
±15kV ESD-Protected, +5V, 1µA, Single RS-232
Transceiver with AutoShutdown10002000300040005000
SLEW RATE vs.
LOAD CAPACITANCEMAX221Etoc02
LOAD CAPACITANCE (pF)
SLEW RATE (V/+SLEW
-SLEW
NAMEFUNCTIONENReceiver Enable Control. Drive low for normal operation. Drive high to force the receiver output
(ROUT) into a high-impedance state.C1+Positive Terminal of the Voltage Doubler Charge-Pump Capacitor
PINV+Positive Voltage Generated by the Charge PumpC1-Negative Terminal of the Voltage Doubler Charge-Pump CapacitorRINRS-232 Receiver Input, ±15kV ESD protectedV-Negative Voltage Generated by the Charge PumpC2-Negative Terminal of the Inverting Charge-Pump CapacitorC2+Positive Terminal of the Inverting Charge-Pump CapacitorTOUTRS-232 Transmitter Output, ±15kV ESD ProtectedFORCEONDrive high to override automatic circuitry, keeping transmitter and charge pump on. FORCEOFF
must be high (Table 1).TINTTL/CMOS Transmitter InputINVALIDOutput of the Invalid Signal Detector. INVALIDis pulled low if no valid RS-232 level is present on
the receiver input.ROUTTTL/CMOS Receiver Output
Pin DescriptionGNDGroundVCC+4.5V to +5.5V Supply VoltageFORCEOFFForce-Off Input, active low. Drive low to shut down transmitter, receiver, and on-board charge
pump. This overrides all automatic circuitry and FORCEON (Table 1).
TRANSMITTER OUTPUT
VOLTAGE vs. LOAD CAPACITANCE
MAX221Etoc01
LOAD CAPACITANCE (pF)
TRANSMITTER OUTPUT VOLTAGE (V)
250kbps
250kbps
120kbps20kbps
20kbps120kbps10002000300040005000
OPERATING SUPPLY
CURRENT vs. LOAD CAPACITANCE MAX221Etoc03
LOAD CAPACITANCE (pF)
SUPPLY CURRENT (mA)
250kbps
20kbps120kbps
Typical Operating Characteristics(VCC= +5V, 250kbps data rate, 0.1µF capacitors, transmitter loaded with 3kΩand CL, TA= +25°C, unless otherwise noted.)
MAX221E
±15kV ESD-Protected, +5V, 1µA, Single RS-232
Transceiver with AutoShutdown
_______________Detailed Description
Dual Charge-Pump Voltage ConverterThe MAX221E’s internal power supply consists of a
dual charge pump that provides a positive output volt-
age (doubling charge pump) and negative output volt-
age (inverting charge pump) from a single +5V supply.
The charge pumps operate in continuous mode. Each
charge pump requires a flying capacitor (C1, C2) and a
reservoir capacitor (C3, C4) to generate the V+ and V-
supplies.
RS-232 TransmitterThe transmitter is an inverting level translator that con-
verts CMOS-logic levels to 5.0V EIA/TIA-232 levels. It
guarantees a 250kbps data rate with worst-case loads
of 3kΩin parallel with 1000pF.
When FORCEOFFis driven to ground, or when the
AutoShutdown circuitry senses invalid voltage levels on
the receiver input, the transmitter is disabled and the
output is forced into a high-impedance state. The trans-
mitter input does not have a pull-up resistor.
RS-232 ReceiverThe MAX221E’s receiver converts RS-232 signals to
CMOS-logic output levels. The receiver has an inverting
three-state output and can be active or inactive. In
shutdown (FORCEOFF= low) or in AutoShutdown, the
receiver is active (Table 1). Drive ENhigh to place the
receiver in a high-impedance state. The receiver is
high-impedance when the MAX221E is in shutdown
(FORCEOFF= low).
The MAX221E’s INVALIDoutput is pulled low when
there is no valid RS-232 signal level detected on the
receiver input. INVALIDis functional in any mode
(Figures 2 and 3).
AutoShutdownThe MAX221E achieves 1µA supply current with
Maxim’s AutoShutdown feature, which operates when
FORCEON is low and FORCEOFFis high. When the
device senses no valid signal levels on the receiver
input for 30µs, the on-board charge pump and driver
are shut off, reducing supply current to 1µA. This
occurs if the RS-232 cable is disconnected or the con-
nected peripheral transmitter is turned off. The
MAX221E turns on again when a valid level is applied
to the RS-232 receiver input. As a result, the system
saves power without changes to the existing BIOS or
operating system.
Table 1 and Figure 2c summarize the MAX221E operat-
ing modes. FORCEON and FORCEOFFoverride
AutoShutdown. When neither control is asserted, the
device selects between these states automatically,
based on the receiver input level. Figures 2a, 2b, and
3a depict valid and invalid RS-232 receiver levels.
Figure 3 shows the input levels and timing diagram for
AutoShutdown operation.
A device or another system with AutoShutdown con-
nected to the MAX221E may need time to wake up.
Figure 4 shows a circuit that forces the transmitter on
for 100ms, allowing enough time for the other system to
realize that the MAX221E is awake. If the other system
transmits valid RS-232 signals within that time, the
RS-232 ports on both systems remain enabled.
When shut down, the device’s charge pumps turn off,
V+ is pulled to VCC, V- is pulled to ground, and the
transmitter output is high impedance. The time required
to exit shutdown is typically 100µs (Figure 3b).
MAX221E
FORCEON
ROUT
ISHDN
FORCEOFF16
INVALID10
GND
TIN11
C2-6
C2+5
C1-4
C1+2
RIN8
TOUT137VCC
0.1μF 15
C1
0.1μF
C2
0.1μF
CBYPASS
0.1μF
+5V
TO POWER-
MANAGEMENT
UNIT
0.1μF
Figure 1. Shutdown Current Test Circuit
MAX221E
±15kV ESD-Protected, +5V, 1µA, Single RS-232
Transceiver with AutoShutdownNo
Shutdown
(AutoShutdown)High-Z1High-Z0
OPERATION
STATUS0
VALID
RECEIVEREN
Shutdown
(Forced Off)
Normal Operation
(Forced On)0
Yes
Normal Operation
(AutoShutdown)
Yes0
High-Z
Active
Active
High-Z
TOUTActive
High-Z
Active
FORCEOFF
High-Z
High-Z
Active
Active
ROUTHigh-Z
Active
Active
FORCEON
RS-232 SIGNAL PRESENT
AT RECEIVER INPUTINVALID
OUTPUTYesHighLow
Table 1. Output Control Truth Table
Table 2. INVALIDTruth TableFigure 2c. AutoShutdown Logic
+0.3V
-0.3V
INVALID
TO MAX221E
POWER SUPPLY
AND TRANSMITTERRIN
* TRANSMITTER IS DISABLED, REDUCING SUPPLY CURRENT TO 1μA IF
RECEIVER INPUT IS BETWEEN +0.3V AND -0.3V FOR AT LEAST 30μs.
30µs
COUNTER
+2.7V
-2.7V
INVALID
TO MAX221E
POWER SUPPLYRIN
* TRANSMITTER IS ENABLED IF:
RECEIVER INPUT IS GREATER THAN +2.7V OR LESS THAN -2.7V.
RECEIVER INPUT HAS BEEN BETWEEN +0.3V AND -0.3V FOR LESS THAN 30μs.
30µs
COUNTER
FORCEOFFPOWER DOWN
INVALID
FORCEON
INVALID IS AN INTERNALLY GENERATED SIGNAL USED BY
AUTOSHUTDOWN LOGIC AND APPEARS AS AN OUTPUT.
POWER DOWN IS ONLY AN INTERNAL SIGNAL. IT CONTROLS THE
OPERATIONAL STATUS OF THE TRANSMITTER AND POWER SUPPLIES.
Figure 2b. Transmitter Enabled Using AutoShutdown
Figure 2a. Entering 1µA Supply Mode via AutoShutdown
x = Don’t care
