_______________General Description
The MAX214 +5V RS-232 transceiver provides a com-
plete, 8-line, software-configurable, DTE or DCE port
RS-232 interface. Tx, Rx, RTS, CTS, DTR, DSR, DCD,
and RI circuits can be configured as either Data
Terminal Equipment (DTE) or Data Circuit-Terminating
Equipment (DCE) using the DTE/DCE control pin. The
MAX214 eliminates the need to swap cables when
switching between DTE and DCE configurations.
________________________Applications
AT-Compatible Laptop Computers
AT-Compatible Desktop Computers
Modems, Printers, and Other Peripherals
____________________________Features
♦Eliminates Null Modem Cables
♦Programmable DTE or DCE Serial Port
♦1µF Charge-Pump Capacitors
♦116kbps Data Rate—Guaranteed
♦20µA Shutdown Mode
♦Receivers Active in Shutdown
______________Ordering Information
* Dice are specified at T
A
= +25°C.
MAX214
Programmable DTE/DCE,
+5V RS-232 Transceiver
________________________________________________________________
Maxim Integrated Products
1
28
27
26
25
24
23
22
21
20
19
18
17
16
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
TOP VIEW
MAX214
C1-
C1+
SHDN
TB
TC
RB
RC
DTE/DCE
TRB
RTB
TRC
RTC
VCC
V+
C2+
C2-
HI-Z
N.C.
TA
RA
RDC
RE
TRA
RTA
RDTC
RRE
GND
V-
DIP/SO
__________________Pin Configuration
RTA
VCC
TRA
TRB
RTB
TRC
RTC
RDTC
RRE
RE
RC
TC
RB
TB
RA
TA
C1+
C1-
C2+
C2-
V+
V-
15
14
9
10
20
19
18
17
11
12
5
6
25
23
24
22
7
8
27
28
1
2
16
GND
13
1µF
1µF
1µF
1µF
+5V
DTE
DTE
DCE
DTE
DTE
DCE
DTE
DTE
DCE
DTEDTE
DCE
DTE/DCE
SHDN
HI-Z
21
26
3
RDC DCE
MAX214
1µF
__________Typical Operating Circuit
Call toll free 1-800-998-8800 for free samples or literature.
PART TEMP. RANGE PIN-PACKAGE
MAX214CPI 0°C to +70°C 28 Plastic DIP
MAX214CWI 0°C to +70°C 28 Wide SO
MAX214C/D 0°C to +70°C Dice*
MAX214EPI -40°C to +85°C 28 Plastic DIP
MAX214EWI -40°C to +85°C 28 Wide SO
19-0199; Rev 1; 8/95
MAX214
Programmable DTE/DCE,
+5V RS-232 Transceiver
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
VCC...........................................................................-0.3V to +6V
Input Voltages
TIN, DTE/DCE, SHDN HI-Z......................-0.3V to (VCC + 0.3V)
RIN ....................................................................................±15V
Output Voltages:
TOUT..................................................................................±15V
ROUT........................................................-0.3V to (VCC + 0.3V)
Short-Circuit (one output at a time)
TOUT to GND...........................................................Continuous
ROUT to GND...........................................................Continuous
Continuous Power Dissipation (TA= +70°C)
Plastic DIP (derate 9.09mW/°C above +70°C) .............727mW
Wide SO (derate 12.50mW/°C above +70°C) ............1000mW
Operating Temperature Ranges:
MAX214C–I ..............................................0°C to +70°C
MAX214E–I ..........................................-40°C to +85°C
Storage Temperature Range......................-65°C to +150°C
Lead Temperature (soldering, 10sec) .......................+300°C
ELECTRICAL CHARACTERISTICS
(VCC = 4.5V to 5.5V, C1 to C4 = 1µF, TA= TMIN to TMAX, unless otherwise noted.)
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.
PARAMETER MIN TYP MAX UNITS
Output Short-Circuit Current ±7 ±25 mA
Transmitter Output Resistance 300 300k Ω
Output Voltage Swing ±5.0 ±7.5 V
Logic Input Pull-Up Current 11050
µA
Input Voltage Operating Range ±15 V
Positive Threshold Input Low 0.8 1.3 V
Positive Threshold Input High 1.8 2.4 V
Logic Input Threshold Low 0.8 1.4 V
Logic Input Threshold High 1.4 2.0 V
0.2 0.5 1.0 V
Negative Threshold Input Low 0.8 1.3 V
Negative Threshold Input High 1.3 2.4 V
Negative Threshold Input
Hysteresis 0.2 0.4 1.0 V
Input Resistance 100 300 kΩ
TTL/CMOS Output Voltage Low 0.2 0.4 V
TTL/CMOS Output Voltage High 3.5 VCC - 0.2 V
CONDITIONS
VCC = 5V, normal operation, SHDN = 0V (no hysteresis
in shutdown)
VOUT = 0V
TA= +25°C, VCC = 5V
VCC = V+ = V- = 0V, VOUT = ±2V (Note 1)
All transmitter outputs loaded with 3kΩto ground
Normal operation
TA= +25°C, VCC = 5V
VCC = 5V, normal operation, SHDN = 0V (no hysteresis
in shutdown)
TA= +25°C, VCC = 5V, normal operation, SHDN = 0V
TA= +25°C, VCC = 5V, normal operation, SHDN = 0V
HI-Z = 5V or SHDN = 5V
IOUT = 3.2mA
IOUT = -1.0mA
Shutdown, SHDN = 5V
Shutdown, SHDN = 5V
Shutdown ±0.01 ±1
Normal operation, SHDN = 0V -2.6 -1.9
-1.5 -0.2Normal operation, SHDN = 0V
HI-Z = 0V and SHDN = 0V 357
Positive Threshold Input
Hysteresis
RS-232 TRANSMITTERS
RS-232 RECEIVERS
MAX214
Programmable DTE/DCE,
+5V RS-232 Transceiver
_______________________________________________________________________________________ 3
PARAMETER
Transmitter + to - Propagation-Delay
Difference (Normal Operation)
MIN TYP MAX
100
UNITS
Input Leakage Current
ns
±1
Receiver Propagation Delay,
RS-232 to TTL (Normal Operation)
µA
Logic Input Threshold High 1.3 2.0 V
Logic Input Threshold Low 0.8 1.3
µs
V
Receiver Propagation Delay,
RS-232 to TTL (Shutdown Mode)
Data Rate 20 kbps
1.5 10 µs
Receiver Propagation-Delay Difference
(Normal Operation)
Transition-Region Slew Rate 61230
100
V/µs
Transmitter Propagation Delay,
TTL to RS-232 (Normal Operation)
ns
1.4 3.5 µs
Transmitter Enable Time
VCC Supply Current
250 µs
Transmitter Disable Time 600 ns
Transmitter DTE/DCE Switch Time 600 ns
Receiver DTE/DCE Switch Time
920mA
300 ns
Receiver Termination-Resistor
Connect/Disconnect Time
Shutdown Supply Current
300 ns
420µA
Receiver Termination-Resistor Connect
Entering SHDN Time 250 µs
Receiver Termination-Resistor
Disconnect Exiting SHDN Time 300 ns
CONDITIONS
tPHLT - tPLHT
Receivers in shutdown mode
tPLHR
tPHLT- tPLHT
TA = +25°C, V CC = 5V, R L= 3kΩto 7k Ω,
CL= to 2500pF,
measured from 3V to -3V or -3V to 3V
tPLHT
tTEN (includes charge-pump start-up time)
tTTR
tTSW
No load, TA= +25°C
tRSW
(SHDN = 0V)
DTE/DCE = 0V, SHDN =
HI-Z = VCC, Figure 1
ELECTRICAL CHARACTERISTICS (continued)
(VCC = 4.5V to 5.5V, C1 to C4 = 1µF, TA= TMIN to TMAX, unless otherwise noted.)
TA= TMIN to TMAX
TA= +25°C
Normal operation, transmitters and receivers
tPHLT
200 116
1.3 3.5
tPHLR, tPLHR 0.4 1.5
tPHLR 0.4 10
Note 1: The 300Ωminimum is the EIA/TIA-232E specification, but the actual resistance when in shutdown mode or when VCC = 0V
is typically 300kΩ.
50
MODE-CHANGE TIMING (DTE/DCE)
AC CHARACTERISTICS
POWER SUPPLY
CONTROL LOGIC (DTE/DCE, SHDN, HI-Z)
TRANSMITTER OUTPUT VOLTAGE (VOH)
vs. VCC POSITIVE SUPPLY VOLTAGE
VOH (V)
6.5
7.0
7.5
8.0
8.5
9.0
4.5 VCC (V)
MAX214-03
4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4 5.5
1 TRANSMITTER LOADED
2 TRANSMITTERS LOADED
3 TRANSMITTERS LOADED
DATA RATE = 0kbps
TRANSMITTER OUTPUT VOLTAGE (VOH)
vs. LOAD CAPACITANCE
AT DIFFERENT DATA RATES
VOH (V)
6.0 0LOAD CAPACITANCE (pF)
MAX214-02
6.2
6.4
6.6
6.8
7.0
7.2
7.4
7.6
1000 2000 3000 4000 5000 6000 7000
20kbps
64kbps
120kbps
TRANSMITTER OUTPUT VOLTAGE (VOL)
vs. LOAD CAPACITANCE
AT DIFFERENT DATA RATES
VOL (V)
-8.5
-8.0
-7.5
-7.0
-6.5
-6.0
0 1000 2000 3000 4000 5000 6000 7000
LOAD CAPACITANCE (pF)
-5.5
MAX214-01
120kbps
64kbps
20kbps
MAX214
Programmable DTE/DCE,
+5V RS-232 Transceiver
4 _______________________________________________________________________________________
__________________________________________Typical Operating Characteristics
(VCC = 5V, C1 to C4 = 1µF, all transmitters loaded with 3kΩin parallel with 2.5nF, TA = +25°C, unless otherwise noted.)
TRANSMITTER OUTPUT VOLTAGE (VOL)
vs. POSITIVE SUPPLY VOLTAGE
VOL (V)
-9.5
-9.0
-8.5
-8.0
-7.5
-7.0
4.5 VCC (V)
MAX214-04
4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4 5.5
3 TRANSMITTERS LOADED
2 TRANSMITTERS LOADED
1 TRANSMITTER LOADED
DATA RATE = 0kbps
TRANSMITTER OUTPUT VOLTAGES
vs. V+, V- LOAD CURRENT
TOUT +, T OUT- (V)
-10 0LOAD CURRENT (mA)
MAX214-05
20 40 60 80
-8
-6
-4
-2
0
2
4
6
8
10
V+ AND V-
EQUALLY
LOADED
V+ LOADED,
NO L OAD
ON V-
V- LOADED,
NO L OAD
ON V+
ALL TRANSMITTERS UNLOADED, 0kbps
SLEW RATE vs. LOAD CAPACITANCE
SLEW RATE (V/µs)
40LOAD CAPACITANCE (pF)
MAX214-06
2000 4000 6000
6
8
10
12
14
16
18
20 SLEW+
3 TRANSMITTERS LOADED
SLEW-
3 TRANSMITTERS LOADED
SLEW+
1 TRANSMITTER LOADED
SLEW-
1 TRANSMITTER LOADED
_______________Detailed Description
The MAX214 RS-232 transceiver provides a complete,
8-line, software-configurable, DTE or DCE port RS-232
interface. Tx, Rx, RTS, CTS, DTR, DSR, DCD, and RI
circuits can be configured as either Data Terminal
Equipment (DTE) or Data Circuit-Terminating
Equipment (DCE) using the DTE/DCE control pin. The
MAX214 eliminates the need to swap cables when
switching between DTE and DCE configurations. This
is useful when, for example, a portable computer is
required to communicate with printers, modems, and
other computers without carrying multiple cables.
The MAX214 runs from a single +5V supply and incor-
porates a dual charge-pump voltage converter to gener-
ate the necessary voltages for the RS-232 transmitters.
A shutdown mode is provided to save power when
transmission is not required, but the receivers always
stay active for simple detection of ring indicator signals.
DTE/DCE Operation
The DTE/DCE pin allows circuit configuration under
software control. Tables 1a and 1b show the pin defini-
tions of the MAX214 in both DTE and DCE modes. The
Function columns show the direction of data flow from
the input pin to the output pin of the MAX214, and onto
the corresponding DB-25 connector’s pin.
+5V to ±10V Dual Charge-Pump
Voltage Converter
The +5V to ±10V conversion is performed by two
charge-pump voltage converters (Figure 2). The first
uses capacitor C1 to double the +5V to +10V, storing
the +10V on the output filter capacitor, C3. The second
charge-pump voltage converter uses C2 to invert the
+10V to -10V, storing the -10V on the V- output filter
capacitor, C4.
In shutdown mode, V+ is pulled to VCC by an internal
resistor, and V- falls to GND.
MAX214
Programmable DTE/DCE,
+5V RS-232 Transceiver
_______________________________________________________________________________________ 5
PIN
14
NAME
V-
9, 18, 20 TRA, TRC, TRB
15 V+
7 RDC
6, 8, 22, 23 RA, RE, RC, RB
5, 24, 25 TA, TC, TB
16
10, 17, 19 RTA, RTC, RTB
11 RDTC
VCC
21
12
DTE/DCE
RRE
13 GND
26 SHDN
27, 28
3
C1+, C1-
1, 2 C2+, C2-
HI-Z
4 N.C.
FUNCTION
-2VCC voltage generated by the charge pump
+2VCC voltage generated by the charge pump
TTL/CMOS receiver A, E, C, B outputs
TTL/CMOS driver A, C, B inputs
+4.5V to +5.5V supply voltage
RS-232 receiver input
Ground
Shutdown control; shutdown high, normal operation low
Terminals for positive charge-pump capacitor
Terminals for negative charge-pump capacitor
No connect—not internally connected
______________________________________________________________Pin Description
RS-232 receiver impedance control. Take high to disconnect the termination resistor.
TTL/CMOS DTE receiver output D for DTE/DCE = 0V, or TTL/CMOS DCE receiver output C for
DTE/DCE = +5V
RS-232 DTE receiver input for DT E/DCE = 0V, or RS-232 DCE driver output for D T E/DCE = +5V
RS-232 DTE receiver input D for DTE/DCE = 0V, or RS-232 DCE driver output C for
DTE/DCE = +5V
Data terminal equipment (DTE) and data circuit-terminating equipment (DCE) control pin.
DCE active high and DTE active low.
RS-232 DTE driver output for DT E/DCE = 0V, or RS-232 DCE receiver input for DT E/D C E = +5V
MAX214
Programmable DTE/DCE,
+5V RS-232 Transceiver
6 _______________________________________________________________________________________
Table 1a. DTE-Operation Pin Configurations
TTL/CMOS
I/O LABEL MAX214
PIN
Detector Carrier Data (DCD) 7
Data Set Ready (DSR) 22
Data Terminal Ready (DTR) 24
Clear to Send (CTS) 23
Ring Indicator (RI) 8
Receiver (RxD)
Transmitter (TxD)
6
Request to Send (RTS) 25
FUNCTION
5
11
17
18
19
12
9
10
20
RS-232
I/O LABEL
DCD
DSR
DTR
CTS
RI
TxD
RxD
RTS
INPUT
THRESHOLD
+
-
-
+
+
MAX214
PIN DB-25
PIN
8
6
20
5
22
2
3
4
MAX214
Table 1b. DCE-Operation Pin Configurations
MAX214
PIN
MAX214
PIN
12
18
17
20
8
11
10
9
19
RS-232
I/O LABEL
22
RI
DTR
24 DSR
RTS23
DCD
RxD
TxD
CTS
INPUT
THRESHOLD
8
7
+
-
-
+
DB-25
PIN
22
20
6
4
3
2
5
5
6
25
FUNCTION
MAX214
Programmable DTE/DCE,
+5V RS-232 Transceiver
_______________________________________________________________________________________ 7
RS-232 Drivers
With VCC = 5V, the typical driver output voltage swing
is ±8V when loaded with a nominal 5kΩRS-232
receiver. Under worst-case operating conditions
(including 116kbps data rate, 3kΩ2500pF load,
VCC = 4.5V, maximum rated temperature) the output
swing is guaranteed to meet the ±5V minimum speci-
fied by EIA/TIA-232 and V.28. The open-circuit output
voltage swing ranges from (V+ - 0.6V) to V-.
Input thresholds are both CMOS and TTL compatible.
The inputs of unused drivers can be left unconnected
because 400kΩpull-up resistors to VCC are included
on-chip. Since all drivers invert, the pull-up resistors
force the outputs of unused drivers low. The input
pull-up resistors typically source 10µA; in shutdown
mode, they are disconnected to reduce supply current.
When in low-power shutdown mode, the driver outputs
are turned off and their leakage current is less than
1µA, even if the transmitter output is back-driven with
voltages up to ±15V.
RS-232 Receivers
The receivers convert the RS-232 signals to
CMOS-logic levels. They invert, to match the inversion
of RS-232 drivers. The guaranteed receiver input
thresholds are significantly tighter than the ±3V
thresholds required by the EIA/TIA-232E specification,
V+
GND
MAX214
1µF
VCC
1µF
Rx
Tx
1µF
C1+
C1-
C2+
C2-
+5V
+5.5V TOUT
ROUT
400k
5k
ISHDN
0V OR +5.5V
DRIVE
1µF
1µF
3k
+5.5V
RIN
TIN
CAPACITORS MAY BE
POLARIZED OR UNPOLARIZED
DTE/DCE
+5.5V
V-
+5.5V
+5.5V
SHDN
HI-Z
Figure 1. MAX214 Shutdown-Current Test Circuit
C1-
IL - RL -
V+
S1
V -
S2 S5 S6
C1 C3 C2
IL + RL +
S3 S4 S7 S8
C4
C1+
GND
GND
VCC
VCC
C2-
C2+
120kHz
Figure 2. Charge-Pump Diagram
MAX214
Programmable DTE/DCE,
+5V RS-232 Transceiver
8 _______________________________________________________________________________________
which improves noise margins. The polarity of each
receiver’s input threshold is shown in Tables 1a and 1b.
In normal operating mode, receiver inputs are internally
connected to ground with 5kΩresistors. So uncon-
nected receivers with positive input thresholds have
high outputs, and those with negative input thresholds
have low outputs.
When shut down, all receivers have positive thresholds.
This allows the receiver inputs to respond to
TTL-/CMOS-logic levels, as well as RS-232 levels. The
guaranteed 0.8V input threshold ensures that receivers
shorted to ground will have a logic 1 output. Also, the
300kΩinput resistance to ground ensures that a receiv-
er with its input left open will also have a logic 1 output.
The receiver’s 0.5V of hysteresis provides clean output
transitions, even with slow rise-time and fall-time sig-
nals with moderate amounts of noise and ringing. The
receivers have no hysteresis in shutdown mode.
HI-Z Control
The receiver inputs are terminated with 5kΩresistors, to
comply with the requirements of EIA/TIA-232E.
However, these internal resistors can be disconnected
by taking the HI-Z control pin to a logic high. This
makes all of the MAX214’s receiver inputs high imped-
ance, and facilitates the transmission of RS-232 data
from a single transmitter to multiple receivers. In this
case, all but one of the receiving ICs should be put into
the high input-impedance state.
Shutdown Control
In shutdown mode, the charge pumps are turned off,
V+ is pulled down to VCC, V- is pulled to ground, and
the transmitter outputs are disabled. This reduces sup-
ply current typically to 4µA. The time required to exit
shutdown is about 250µs, as shown in Figure 3.
Receivers
Receiver outputs never go into a high-impedance state;
they are always active, even in shutdown mode (see
Table 2). These awake-in-shutdown receivers are use-
ful for monitoring external activity (for example, on RI),
while maintaining minimal power consumption.
Receivers in shutdown mode are slower (20kbps) than
when not shut down (116kbps), and lack the hysteresis
present in normal operation.
Drivers
The driver outputs are high impedance in shutdown
mode, even when back-driven with voltages up
to ±15V.
__________Applications Information
Capacitor Selection
The type of capacitor (C1 to C4) used is not critical for
proper operation. The MAX214 requires 1µF capaci-
tors, although in all cases capacitors of up to 10µF
can be used without harm. Ceramic dielectrics are
suggested for the 1µF capacitors.
Table 2. Control Pin Configurations
CONTROL INPUTS
SHUTDOWN HI-Z DTE/DCE RTA, RTB, RTC, RDTC RRE
0 0 0 Receive Mode/5kΩReceive Mode/5kΩ
0 0 1 Transmit Mode Receive Mode/5kΩ
0 1 0 Receive Mode/HI-Z Receive Mode/HI-Z
0 1 1 Transmit Mode Receive Mode/HI-Z
1 0 0 Slow Receive/HI-Z Slow Receive/HI-Z
1 0 1 Disabled/HI-Z Slow Receive/HI-Z
1 1 0 Slow Receive/HI-Z Slow Receive/HI-Z
1 1 1 Disabled/HI-Z Slow Receive/HI-Z
RS-232 PINS
TRA, TRB, TRC
Transmit Mode
Receive Mode/5kΩ
Transmit Mode
Receive Mode/HI-Z
Disabled/HI-Z
Slow Receive/HI-Z
Disabled/HI-Z
Slow Receive/HI-Z
When using the minimum recommended capacitor
values, make sure the capacitance value does not
degrade excessively as the operating temperature
varies. If in doubt, use capacitors with a
larger nominal value (for example, 2 times larger).
The effective series resistance (ESR) of the capaci-
tors may vary over temperature and increase
when below 0°C. ESR influences the amount of rip-
ple on V+ and V-, so if low ripple is required over
wide temperature ranges, use larger capacitors or
low-ESR types.
To reduce the output impedance at V+ and V-, use
larger capacitors (up to 10µF). This can be useful
when “stealing” power from V+ or from V-.
Driver Outputs when Exiting Shutdown
Figure 3 shows the MAX214 driver outputs when exiting
shutdown. As they become active, the two driver out-
puts are shown going to opposite RS-232 levels (one
driver input is high, the other is low). Each driver is
loaded with 3kΩin parallel with 2.5nF.
Power-Supply Bypassing
Decouple VCC to ground with a capacitor of the same
value as the charge-pump capacitors.
V+ and V- as Power Supplies
A small amount of power can be drawn from V+ and V-,
although this will reduce noise margins. See the
Output Voltage vs. Load Current graph in the
Typical
Operating Characteristics
. Increasing the charge-
pump capacitor sizes up to 10µF reduces the imped-
ance of the V+ and V- outputs.
High Data Rates
The MAX214 maintains the RS-232 ±5.0V minimum
driver output voltage even at high data rates. The
Typical Operating Characteristics
show transmitter out-
put voltage levels driving 3kΩin parallel with various
capacitive loads at data rates up to 120kbps.
MAX214
Programmable DTE/DCE,
+5V RS-232 Transceiver
_______________________________________________________________________________________
9
+5V
A
B
C
+10V
+5V
0V
-10V
0V
A = TRANSMITTER OUTPUT HIGH, +5V/div
B = TRANSMITTER OUTPUT LOW, +5V/div
C = SHDN INPUT, +5V/div
HORIZONTAL = 200µs
-5V
Figure 3. Transmitter Outputs When Exiting Shutdown
MAX214
Programmable DTE/DCE,
+5V RS-232 Transceiver
10 ______________________________________________________________________________________
TRA
RTA
TRB
RTB
TRC
RTC
RDTC
RRE
3
2
7
8
4
6
1
9
TxD
RxD
RTS
CTS
DTR
DSR
DCD
RI
5
6
25
23
24
22
7
8
MAX214
HI-Z SHDN DTE/DCE
MAX214
HI-Z SHDN DTE/DCE
TA
RA
TB
RB
TC
RC
RDC
RE
9
10
20
19
18
17
11
12
HIGH HIGH
5
6
25
23
24
22
7
8
TA
RA
TB
RB
TC
RC
RDC
RE
TRA
RTA
TRB
RTB
TRC
RTC
RDTC
RRE
PC1
(DTE MODE)
STANDARD
RS-232
CABLE
PC2
(DCE MODE)
DB-9 CONNECTORS
21263 21263 VCC
9
10
20
19
18
17
11
12
3
2
7
8
4
6
1
9
POWER CONNECTIONS OMITTED FOR CLARITY.
Figure 4. Typical Application Circuit Showing 2 PCs with Both DTE and DCE Operation
MAX214
Programmable DTE/DCE,
+5V RS-232 Transceiver
______________________________________________________________________________________ 11
PARAMETER CONDITIONS
Driver Output
Resistance -2V < VOUT < +2V
Transition Rate on
Driver Output
V.28
Instantaneous
Slew Rate, Max
3kΩ to 7kΩ load
300Ω
100mA
30V/µs
+5.0V to +15V
-5.0V to -15V
3kΩ to 7kΩ load
3kΩ≤RL≤7kΩ,
CL≤2500pF
EIA/TIA-232E 4% of the period
EIA/TIA-232E, V.28
SPECIFICATIONS
Driver Output
Voltage
0 Level
1 Level
Output Level, Max
Driver Output
Short-Circuit
Current, Max 1ms or 3% of the
period
DB9 PIN DB25 PIN NAME SYMBOL FUNCTION
1 8 DCD Handshake from DCE
2 3 Receive Data RxD Data from DCE
3 2 Transmit Data Data from DTE
4 20 Data Terminal Ready DTR Handshake from DTE
5 7 Signal Ground GND
6 6 Data Set Ready DSR Handshake from DCE
7 4 Request to Send RTS Handshake from DTE
8 5 Clear to Send CTS Handshake from DCE
9 22 Ring Indicator RI Handshake from DCE
Reference point for signals
Received Line Signal Detector, sometimes
called Data Carrier Detect
TxD
Table 3. Summary of EIA/TIA-232E, V.28
Specifications
Table 4. DB9/DB25 Cable Connections Commonly Used for EIA/TIA-232 and V.24
Asynchronous Interfaces
Data Rate 3kΩ≤RL≤7kΩ,
CL≤2500pF Up to 20kbits/sec
No load ±25V
-3.0V to -15V
±25V
+3.0V to +15V
Receiver Input
Voltage
0 Level
1 Level
Input Level, Max
___________________Chip Topography
TRANSISTOR COUNT: 694;
SUBSTRATE CONNECTED TO V+.
TC
0.178"
4.52mm
0.156"
3.96mm
RB
RC
DTE/DCE
TRB
RTB
HI-Z C2+ C1+ SHDN
TB
RTA
TRA
RE
RDC
RA
TA
C2- C1-
RDTC
RRE GND V- V+VCC RTC
TRC
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
12
__________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600
© 1995 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
MAX214
Programmable DTE/DCE,
+5V RS-232 Transceiver
________________________________________________________Package Information
C
A
A2 E1
D
E
eA
eB
A3
B1
B
DIM
A
A1
A2
A3
B
B1
C
D
D1
E
E1
e
eA
eB
L
α
MIN
–
0.015
0.125
0.055
0.016
0.045
0.008
1.430
0.050
0.600
0.525
–
0.125
0˚
MAX
0.200
–
0.175
0.080
0.020
0.065
0.012
1.470
0.090
0.625
0.575
0.700
0.150
15˚
MIN
–
0.38
3.18
1.40
0.41
1.14
0.20
36.32
1.27
15.24
13.34
–
3.18
0˚
MAX
5.08
–
4.45
2.03
0.51
1.65
0.30
37.34
2.29
15.88
14.61
17.78
3.81
15˚
INCHES MILLIMETERS
2.54 BSC
15.24 BSC
0.100 BSC
0.600 BSC
A1
L
D1
e21-342A
28-PIN PLASTIC
DUAL-IN-LINE
PACKAGE
α
L
DIM
A
A1
B
C
D
E
e
H
h
L
α
MIN
0.093
0.004
0.014
0.009
0.697
0.291
0.394
0.010
0.016
0˚
MAX
0.104
0.012
0.019
0.013
0.713
0.299
0.419
0.030
0.050
8˚
MIN
2.35
0.10
0.35
0.23
17.70
7.40
10.00
0.25
0.40
0˚
MAX
2.65
0.30
0.49
0.32
18.10
7.60
10.65
0.75
1.27
8˚
INCHES MILLIMETERS
α28-PIN PLASTIC
SMALL-OUTLINE
PACKAGE
HE
D
e
A
A1 C
h x 45˚
0.127mm
0.004in.
B
1.27 BSC0.050 BSC
21-343A
